Merge pull request #1166 from trapexit/docs

Remove duplicate entries in docs
2026-10-19 16:16:48 +00:00 · 2023-04-01 14:41:33 -04:00 · 2023-04-01 14:40:49 -04:00 · 2023-03-31 13:38:08 -04:00 · 2023-03-31 12:54:57 -04:00 · 2023-03-28 21:57:51 -04:00
125 changed files with 47024 additions and 9512 deletions
@@ -51,8 +51,8 @@ linux_task:
  container:
    image: alpine:3.11
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make STATIC=1 LTO=1
@@ -62,8 +62,8 @@ linux_task:
  container:
    image: alpine:3.12
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make STATIC=1 LTO=1
@@ -73,8 +73,8 @@ linux_task:
  container:
    image: alpine:3.13
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make STATIC=1 LTO=1
@@ -84,8 +84,41 @@ linux_task:
  container:
    image: alpine:3.14
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
+  script:
+    - tools/install-build-pkgs
+    - make STATIC=1 LTO=1
+
+linux_task:
+  name: "alpine:3.15"
+  container:
+    image: alpine:3.15
+    cpu: 4
+    memory: 4G
+  timeout_in: 15m
+  script:
+    - tools/install-build-pkgs
+    - make STATIC=1 LTO=1
+
+linux_task:
+  name: "alpine:3.16"
+  container:
+    image: alpine:3.16
+    cpu: 4
+    memory: 4G
+  timeout_in: 15m
+  script:
+    - tools/install-build-pkgs
+    - make STATIC=1 LTO=1
+
+linux_task:
+  name: "alpine:3.17"
+  container:
+    image: alpine:3.17
+    cpu: 4
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make STATIC=1 LTO=1
@@ -95,8 +128,8 @@ linux_task:
  container:
    image: alpine:latest
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make STATIC=1 LTO=1
@@ -106,8 +139,8 @@ linux_task:
  arm_container:
    image: alpine:latest
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make STATIC=1 LTO=1
@@ -117,20 +150,20 @@ linux_task:
  container:
    image: centos:7
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make
    - make rpm

 linux_task:
-  name: "centos:8"
+  name: "rocky:8"
  container:
-    image: centos:8
+    image: rocky:8
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make
@@ -141,8 +174,8 @@ linux_task:
  container:
    image: fedora:30
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make
@@ -153,8 +186,8 @@ linux_task:
  container:
    image: fedora:31
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make
@@ -165,8 +198,8 @@ linux_task:
  container:
    image: fedora:32
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make
@@ -177,8 +210,8 @@ linux_task:
  container:
    image: fedora:33
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make
@@ -189,8 +222,56 @@ linux_task:
  container:
    image: fedora:34
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
+  script:
+    - tools/install-build-pkgs
+    - make
+    - make rpm
+
+linux_task:
+  name: "fedora:35"
+  container:
+    image: fedora:35
+    cpu: 4
+    memory: 4G
+  timeout_in: 15m
+  script:
+    - tools/install-build-pkgs
+    - make
+    - make rpm
+
+linux_task:
+  name: "fedora:36"
+  container:
+    image: fedora:36
+    cpu: 4
+    memory: 4G
+  timeout_in: 15m
+  script:
+    - tools/install-build-pkgs
+    - make
+    - make rpm
+
+linux_task:
+  name: "fedora:37"
+  container:
+    image: fedora:37
+    cpu: 4
+    memory: 4G
+  timeout_in: 15m
+  script:
+    - tools/install-build-pkgs
+    - make
+    - make rpm
+
+linux_task:
+  name: "fedora:38"
+  container:
+    image: fedora:38
+    cpu: 4
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make
@@ -201,8 +282,8 @@ linux_task:
  container:
    image: fedora:latest
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make
@@ -213,8 +294,8 @@ linux_task:
  arm_container:
    image: fedora:latest
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - make
@@ -225,8 +306,8 @@ linux_task:
  container:
    image: ubuntu:14.04
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - git fetch
@@ -240,8 +321,8 @@ linux_task:
  container:
    image: ubuntu:16.04
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - git fetch
@@ -255,8 +336,8 @@ linux_task:
  container:
    image: ubuntu:18.04
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - git fetch
@@ -270,8 +351,23 @@ linux_task:
  container:
    image: ubuntu:20.04
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
+  script:
+    - tools/install-build-pkgs
+    - git fetch
+    - make deb
+    - apt-get -y install fuse
+    - dpkg -i ../*.deb
+    - mergerfs -v || true
+
+linux_task:
+  name: "ubuntu:22.04"
+  container:
+    image: ubuntu:22.04
+    cpu: 4
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - git fetch
@@ -285,8 +381,8 @@ linux_task:
  container:
    image: ubuntu:latest
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - git fetch
@@ -300,8 +396,8 @@ linux_task:
  arm_container:
    image: ubuntu:latest
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - git fetch
@@ -315,8 +411,8 @@ linux_task:
  container:
    image: debian:8
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - git fetch
@@ -330,8 +426,8 @@ linux_task:
  container:
    image: debian:8
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - git fetch
@@ -345,8 +441,8 @@ linux_task:
  container:
    image: debian:9
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - git fetch
@@ -360,8 +456,8 @@ linux_task:
  container:
    image: debian:10
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - git fetch
@@ -375,8 +471,8 @@ linux_task:
  container:
    image: debian:11
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - git fetch
@@ -390,8 +486,8 @@ linux_task:
  container:
    image: debian:latest
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - git fetch
@@ -405,8 +501,8 @@ linux_task:
  arm_container:
    image: debian:latest
    cpu: 4
-    memory: 2G
-  timeout_in: 10m
+    memory: 4G
+  timeout_in: 15m
  script:
    - tools/install-build-pkgs
    - git fetch
@@ -9,7 +9,9 @@ assignees: ''

 **Describe the bug**

-A clear and concise description of the unexpected behavior. Please be sure to use latest release of mergerfs to ensure the issue still exists.
+A clear and concise description of the unexpected behavior.
+
+**Please be sure to use latest release of mergerfs to ensure the issue still exists. Not your distro's latest but the latest official release.**

 The master branch is **not** to be considered production ready. Feel free to file bug reports but do so indicating clearly that you are testing unreleased code.

@@ -18,9 +20,9 @@ The master branch is **not** to be considered production ready. Feel free to fil

 Steps to reproduce the behavior. List **all** steps to reproduce. **All** settings.

-Please simplify the reproduction as much as possible. 
+Please simplify the reproduction as much as possible.
 - Unless it is dependenat on multiple branches, use a single branch
- - Use standard tooling if possible (touch,truncate,rm,rmdir,ln,etc.)
+ - Reproduce with standard tooling if possible (touch,truncate,rm,rmdir,ln,etc.) Having to install 3rd party software will make debugging more difficult.


 **Expected behavior**
@@ -36,7 +38,7 @@ A clear and concise description of the expected behavior.
 - List of drives, filesystems, & sizes:
   - `df -h`
   - `lsblk -f`
- - A strace of the application having a problem: 
+ - A strace of the application having a problem:
   - `strace -fvTtt -s 256 -o /tmp/app.strace.txt <cmd>`
   - `strace -fvTtt -s 256 -o /tmp/app.strace.txt -p <appPID>`
 - strace of mergerfs while app tried to do it's thing:
@@ -1,10 +1,10 @@
 ---
 name: Question
-about: When you're looking for information
+about: When you're looking for information or general support
 title: ''
 labels: investigating, question
 assignees: ''

 ---

-You can also ask questions on Discord for realtime help: https://discord.gg/MpAr69V
+For general questions and support please use [GitHub Discussions](https://github.com/trapexit/mergerfs/discussions) or [Discord](https://discord.gg/MpAr69V).
@@ -0,0 +1,42 @@
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ "master" ]
+  pull_request:
+    branches: [ "master" ]
+  schedule:
+    - cron: "7 3 * * 6"
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ python, cpp ]
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v2
+        with:
+          languages: ${{ matrix.language }}
+          queries: +security-and-quality
+
+      - name: Autobuild
+        uses: github/codeql-action/autobuild@v2
+        if: ${{ matrix.language == 'python' || matrix.language == 'cpp' }}
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v2
+        with:
+          category: "/language:${{ matrix.language }}"
@@ -1,7 +1,7 @@
 /*
  ISC License

-  Copyright (c) 2021, Antonio SJ Musumeci <trapexit@spawn.link>
+  Copyright (c) 2023, Antonio SJ Musumeci <trapexit@spawn.link>

  Permission to use, copy, modify, and/or distribute this software for any
  purpose with or without fee is hereby granted, provided that the above
@@ -79,8 +79,7 @@ CXXFLAGS    := \
              -MMD
 FUSE_FLAGS = \
              -Ilibfuse/include \
-              -D_FILE_OFFSET_BITS=64 \
-              -DFUSE_USE_VERSION=29
+              -D_FILE_OFFSET_BITS=64
 MFS_FLAGS  = \
 	      -DUSE_XATTR=$(USE_XATTR) \
 	      -DUGID_USE_RWLOCK=$(UGID_USE_RWLOCK)
@@ -31,14 +31,12 @@ INSTALLMAN1DIR = $(DESTDIR)$(MAN1DIR)

 AR ?= ar

-SRC   = \
+SRC_C = \
 	lib/buffer.c \
 	lib/crc32b.c \
 	lib/debug.c \
 	lib/fuse.c \
 	lib/fuse_dirents.c \
-	lib/fuse_kern_chan.c \
-	lib/fuse_loop_mt.c \
 	lib/fuse_lowlevel.c \
 	lib/fuse_mt.c \
 	lib/fuse_node.c \
@@ -47,8 +45,16 @@ SRC   = \
 	lib/fuse_signals.c \
 	lib/helper.c \
 	lib/mount.c
-OBJS = $(SRC:lib/%.c=build/%.o)
-DEPS = $(SRC:lib/%.c=build/%.d)
+SRC_CPP = \
+	lib/format.cpp \
+	lib/os.cpp \
+	lib/cpu.cpp \
+	lib/fuse_loop_mt.cpp \
+	lib/fuse_msgbuf.cpp
+OBJS_C   = $(SRC_C:lib/%.c=build/%.o)
+OBJS_CPP = $(SRC_CPP:lib/%.cpp=build/%.o)
+DEPS_C   = $(SRC_C:lib/%.c=build/%.d)
+DEPS_CPP = $(SRC_CPP:lib/%.cpp=build/%.d)
 CFLAGS ?= \
 	$(OPT_FLAGS)
 CFLAGS := \
@@ -57,13 +63,18 @@ CFLAGS := \
 	-Wall \
 	-pipe \
 	-MMD
+CXXFLAGS := \
+	${CXXFLAGS} \
+	-std=c++11 \
+	-Wall \
+	-pipe \
+	-MMD
 FUSERMOUNT_DIR = $(BINDIR)
 FUSE_FLAGS = \
 	-Iinclude \
 	-Ibuild \
 	-D_REENTRANT \
 	-D_FILE_OFFSET_BITS=64 \
-	-DFUSE_USE_VERSION=29 \
 	-DPACKAGE_VERSION=\"$(VERSION)\" \
 	-DFUSERMOUNT_DIR=\"$(FUSERMOUNT_DIR)\"
 LDFLAGS := \
@@ -81,10 +92,10 @@ build/stamp:
 	touch $@

 objects: build/config.h
-	$(MAKE) $(OBJS)
+	$(MAKE) $(OBJS_C) $(OBJS_CPP)

 build/libfuse.a: objects
-	${AR} rcs build/libfuse.a $(OBJS)
+	${AR} rcs build/libfuse.a $(OBJS_C) $(OBJS_CPP)

 utils: mergerfs-fusermount mount.mergerfs

@@ -101,6 +112,9 @@ mount.mergerfs: build/mount.mergerfs
 build/%.o: lib/%.c
 	$(CC) $(CFLAGS) $(FUSE_FLAGS) -c $< -o $@

+build/%.o: lib/%.cpp
+	$(CXX) $(CXXFLAGS) $(FUSE_FLAGS) -c $< -o $@
+
 clean:
 	rm -rf build

@@ -120,4 +134,4 @@ install: $(INSTALLUTILS)

 .PHONY: objects strip utils install install-utils

-include $(DEPS)
+-include $(DEPS_C) $(DEPS_CPP)
@@ -1,11 +0,0 @@
-#define _GNU_SOURCE
-#include <fcntl.h>
-
-int
-main(int   argc,
-     char *argv[])
-{
-  (void)splice;
-
-  return 0;
-}
@@ -1,12 +0,0 @@
-#define _GNU_SOURCE
-#include <fcntl.h>
-#include <sys/uio.h>
-
-int
-main(int   argc,
-     char *argv[])
-{
-  (void)vmsplice;
-
-  return 0;
-}
@@ -9,20 +9,6 @@
 #ifndef _FUSE_H_
 #define _FUSE_H_

-/** @file
- *
- * This file defines the library interface of FUSE
- *
- * IMPORTANT: you should define FUSE_USE_VERSION before including this
- * header.  To use the newest API define it to 26 (recommended for any
- * new application), to use the old API define it to 21 (default) 22
- * or 25, to use the even older 1.X API define it to 11.
- */
-
-#ifndef FUSE_USE_VERSION
-#define FUSE_USE_VERSION 21
-#endif
-
 #include "extern_c.h"
 #include "fuse_common.h"

@@ -475,9 +461,10 @@ struct fuse_operations
   *
   * Introduced in version 2.9
   */
-  int (*write_buf) (const fuse_file_info_t *ffi,
-                    struct fuse_bufvec     *buf,
-                    off_t                   off);
+  int (*write) (const fuse_file_info_t *ffi,
+                const char             *data,
+                size_t                  size,
+                off_t                   off);

  /** Store data from an open file in a buffer
   *
@@ -495,10 +482,10 @@ struct fuse_operations
   *
   * Introduced in version 2.9
   */
-  int (*read_buf) (const fuse_file_info_t  *ffi,
-                   struct fuse_bufvec     **bufp,
-                   size_t                   size,
-                   off_t                    off);
+  int (*read)(const fuse_file_info_t *ffi,
+              char                   *buf,
+              size_t                  size,
+              off_t                   off);
  /**
   * Perform BSD file locking operation
   *
@@ -640,7 +627,9 @@ void fuse_destroy(struct fuse *f);
 */
 void fuse_exit(struct fuse *f);

-int fuse_config_num_threads(const struct fuse *fuse_);
+int fuse_config_read_thread_count(const struct fuse *f);
+int fuse_config_process_thread_count(const struct fuse *f);
+const char* fuse_config_pin_threads(const struct fuse *f);

 /**
 * FUSE event loop with multiple threads
@@ -729,101 +718,6 @@ struct fuse_fs;
 * fuse_fs_releasedir and fuse_fs_statfs, which return 0.
 */

-int fuse_fs_getattr(struct fuse_fs  *fs,
-                    const char      *path,
-                    struct stat     *buf,
-                    fuse_timeouts_t *timeout);
-
-int fuse_fs_fgetattr(struct fuse_fs   *fs,
-                     struct stat      *buf,
-                     fuse_file_info_t *fi,
-                     fuse_timeouts_t  *timeout);
-
-int fuse_fs_rename(struct fuse_fs *fs, const char *oldpath,
-                   const char *newpath);
-int fuse_fs_unlink(struct fuse_fs *fs, const char *path);
-int fuse_fs_rmdir(struct fuse_fs *fs, const char *path);
-int fuse_fs_symlink(struct fuse_fs *fs,
-                    const char *linkname,
-		    const char *path,
-                    struct stat *st,
-                    fuse_timeouts_t *timeouts);
-int fuse_fs_link(struct fuse_fs *fs,
-                 const char *oldpath,
-                 const char *newpath,
-                 struct stat *st,
-                 fuse_timeouts_t *timeouts);
-int fuse_fs_release(struct fuse_fs *fs,
-                    fuse_file_info_t *fi);
-int fuse_fs_open(struct fuse_fs *fs, const char *path,
-                 fuse_file_info_t *fi);
-int fuse_fs_read_buf(struct fuse_fs *fs,
-                     struct fuse_bufvec **bufp, size_t size, off_t off,
-                     fuse_file_info_t *fi);
-int fuse_fs_write_buf(struct fuse_fs *fs,
-                      struct fuse_bufvec *buf, off_t off,
-                      fuse_file_info_t *fi);
-int fuse_fs_fsync(struct fuse_fs *fs, int datasync,
-                  fuse_file_info_t *fi);
-int fuse_fs_flush(struct fuse_fs *fs,
-                  fuse_file_info_t *fi);
-int fuse_fs_statfs(struct fuse_fs *fs, const char *path, struct statvfs *buf);
-int fuse_fs_opendir(struct fuse_fs *fs, const char *path,
-                    fuse_file_info_t *fi);
-int fuse_fs_readdir(struct fuse_fs        *fs,
-                    fuse_file_info_t *fi,
-                    fuse_dirents_t        *buf);
-int fuse_fs_fsyncdir(struct fuse_fs *fs, int datasync,
-                     fuse_file_info_t *fi);
-int fuse_fs_releasedir(struct fuse_fs *fs,
-                       fuse_file_info_t *fi);
-int fuse_fs_create(struct fuse_fs *fs, const char *path, mode_t mode,
-                   fuse_file_info_t *fi);
-int fuse_fs_lock(struct fuse_fs *fs,
-                 fuse_file_info_t *fi, int cmd, struct flock *lock);
-int fuse_fs_flock(struct fuse_fs *fs,
-                  fuse_file_info_t *fi, int op);
-int fuse_fs_chmod(struct fuse_fs *fs, const char *path, mode_t mode);
-int fuse_fs_chown(struct fuse_fs *fs, const char *path, uid_t uid, gid_t gid);
-int fuse_fs_truncate(struct fuse_fs *fs, const char *path, off_t size);
-int fuse_fs_ftruncate(struct fuse_fs *fs, off_t size,
-                      fuse_file_info_t *fi);
-int fuse_fs_utimens(struct fuse_fs *fs, const char *path,
-                    const struct timespec tv[2]);
-int fuse_fs_access(struct fuse_fs *fs, const char *path, int mask);
-int fuse_fs_readlink(struct fuse_fs *fs, const char *path, char *buf,
-                     size_t len);
-int fuse_fs_mknod(struct fuse_fs *fs, const char *path, mode_t mode,
-                  dev_t rdev);
-int fuse_fs_mkdir(struct fuse_fs *fs, const char *path, mode_t mode);
-int fuse_fs_setxattr(struct fuse_fs *fs, const char *path, const char *name,
-                     const char *value, size_t size, int flags);
-int fuse_fs_getxattr(struct fuse_fs *fs, const char *path, const char *name,
-                     char *value, size_t size);
-int fuse_fs_listxattr(struct fuse_fs *fs, const char *path, char *list,
-                      size_t size);
-int fuse_fs_removexattr(struct fuse_fs *fs, const char *path,
-                        const char *name);
-int fuse_fs_bmap(struct fuse_fs *fs, const char *path, size_t blocksize,
-                 uint64_t *idx);
-int fuse_fs_ioctl(struct fuse_fs *fs, unsigned long cmd, void *arg,
-                  fuse_file_info_t *fi, unsigned int flags,
-                  void *data, uint32_t *out_bufsz);
-int fuse_fs_poll(struct fuse_fs *fs,
-                 fuse_file_info_t *fi, fuse_pollhandle_t *ph,
-                 unsigned *reventsp);
-int fuse_fs_fallocate(struct fuse_fs *fs, int mode,
-                      off_t offset, off_t length, fuse_file_info_t *fi);
-void fuse_fs_init(struct fuse_fs *fs, struct fuse_conn_info *conn);
-void fuse_fs_destroy(struct fuse_fs *fs);
-
-int fuse_fs_prepare_hide(struct fuse_fs *fs, const char *path, uint64_t *fh);
-int fuse_fs_free_hide(struct fuse_fs *fs, uint64_t fh);
-ssize_t fuse_fs_copy_file_range(struct fuse_fs *fs,
-                                fuse_file_info_t *fi_in, off_t off_in,
-                                fuse_file_info_t *fi_out, off_t off_out,
-                                size_t len, int flags);
-
 int fuse_notify_poll(fuse_pollhandle_t *ph);

 /**
@@ -856,12 +750,6 @@ struct fuse *fuse_setup(int argc, char *argv[],
 /** This is the part of fuse_main() after the event loop */
 void fuse_teardown(struct fuse *fuse, char *mountpoint);

-/** Read a single command.  If none are read, return NULL */
-struct fuse_cmd *fuse_read_cmd(struct fuse *f);
-
-/** Process a single command */
-void fuse_process_cmd(struct fuse *f, struct fuse_cmd *cmd);
-
 /** Multi threaded event loop, which calls the custom command
    processor function */
 int fuse_loop_mt_proc(struct fuse *f, fuse_processor_t proc, void *data);
@@ -101,9 +101,6 @@ struct fuse_file_info_t
 * FUSE_CAP_EXPORT_SUPPORT: filesystem handles lookups of "." and ".."
 * FUSE_CAP_BIG_WRITES: filesystem can handle write size larger than 4kB
 * FUSE_CAP_DONT_MASK: don't apply umask to file mode on create operations
- * FUSE_CAP_SPLICE_WRITE: ability to use splice() to write to the fuse device
- * FUSE_CAP_SPLICE_MOVE: ability to move data to the fuse device with splice()
- * FUSE_CAP_SPLICE_READ: ability to use splice() to read from the fuse device
 * FUSE_CAP_IOCTL_DIR: ioctl support on directories
 * FUSE_CAP_CACHE_SYMLINKS: cache READLINK responses
 */
@@ -113,9 +110,6 @@ struct fuse_file_info_t
 #define FUSE_CAP_EXPORT_SUPPORT    (1 << 4)
 #define FUSE_CAP_BIG_WRITES        (1 << 5)
 #define FUSE_CAP_DONT_MASK         (1 << 6)
-#define FUSE_CAP_SPLICE_WRITE      (1 << 7)
-#define FUSE_CAP_SPLICE_MOVE       (1 << 8)
-#define FUSE_CAP_SPLICE_READ       (1 << 9)
 #define FUSE_CAP_FLOCK_LOCKS       (1 << 10)
 #define FUSE_CAP_IOCTL_DIR         (1 << 11)
 #define FUSE_CAP_READDIR_PLUS      (1 << 13)
@@ -126,6 +120,7 @@ struct fuse_file_info_t
 #define FUSE_CAP_POSIX_ACL         (1 << 19)
 #define FUSE_CAP_CACHE_SYMLINKS    (1 << 20)
 #define FUSE_CAP_MAX_PAGES         (1 << 21)
+#define FUSE_CAP_SETXATTR_EXT      (1 << 22)

 /**
 * Ioctl flags
@@ -172,6 +172,31 @@
 *  - add FUSE_WRITE_KILL_PRIV flag
 *  - add FUSE_SETUPMAPPING and FUSE_REMOVEMAPPING
 *  - add map_alignment to fuse_init_out, add FUSE_MAP_ALIGNMENT flag
+ *
+ *  7.32
+ *  - add flags to fuse_attr, add FUSE_ATTR_SUBMOUNT, add FUSE_SUBMOUNTS
+ *
+ *  7.33
+ *  - add FUSE_HANDLE_KILLPRIV_V2, FUSE_WRITE_KILL_SUIDGID, FATTR_KILL_SUIDGID
+ *  - add FUSE_OPEN_KILL_SUIDGID
+ *  - extend fuse_setxattr_in, add FUSE_SETXATTR_EXT
+ *  - add FUSE_SETXATTR_ACL_KILL_SGID
+ *
+ *  7.34
+ *  - add FUSE_SYNCFS
+ *
+ *  7.35
+ *  - add FOPEN_NOFLUSH
+ *
+ *  7.36
+ *  - extend fuse_init_in with reserved fields, add FUSE_INIT_EXT init flag
+ *  - add flags2 to fuse_init_in and fuse_init_out
+ *  - add FUSE_SECURITY_CTX init flag
+ *  - add security context to create, mkdir, symlink, and mknod requests
+ *  - add FUSE_HAS_INODE_DAX, FUSE_ATTR_DAX
+ *
+ *  7.37
+ *  - add FUSE_TMPFILE
 */

 #ifndef _LINUX_FUSE_H
@@ -207,7 +232,7 @@
 #define FUSE_KERNEL_VERSION 7

 /** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 31
+#define FUSE_KERNEL_MINOR_VERSION 37

 /** The node ID of the root inode */
 #define FUSE_ROOT_ID 1
@@ -231,7 +256,7 @@ struct fuse_attr {
 	uint32_t	gid;
 	uint32_t	rdev;
 	uint32_t	blksize;
-	uint32_t	padding;
+	uint32_t	flags;
 };

 struct fuse_kstatfs {
@@ -257,17 +282,18 @@ struct fuse_file_lock {
 /**
 * Bitmasks for fuse_setattr_in.valid
 */
-#define FATTR_MODE	(1 << 0)
-#define FATTR_UID	(1 << 1)
-#define FATTR_GID	(1 << 2)
-#define FATTR_SIZE	(1 << 3)
-#define FATTR_ATIME	(1 << 4)
-#define FATTR_MTIME	(1 << 5)
-#define FATTR_FH	(1 << 6)
-#define FATTR_ATIME_NOW	(1 << 7)
-#define FATTR_MTIME_NOW	(1 << 8)
-#define FATTR_LOCKOWNER	(1 << 9)
-#define FATTR_CTIME	(1 << 10)
+#define FATTR_MODE         (1 << 0)
+#define FATTR_UID          (1 << 1)
+#define FATTR_GID          (1 << 2)
+#define FATTR_SIZE         (1 << 3)
+#define FATTR_ATIME        (1 << 4)
+#define FATTR_MTIME        (1 << 5)
+#define FATTR_FH           (1 << 6)
+#define FATTR_ATIME_NOW    (1 << 7)
+#define FATTR_MTIME_NOW    (1 << 8)
+#define FATTR_LOCKOWNER    (1 << 9)
+#define FATTR_CTIME        (1 << 10)
+#define FATTR_KILL_SUIDGID (1 << 11)

 /**
 * Flags returned by the OPEN request
@@ -277,12 +303,14 @@ struct fuse_file_lock {
 * FOPEN_NONSEEKABLE: the file is not seekable
 * FOPEN_CACHE_DIR: allow caching this directory
 * FOPEN_STREAM: the file is stream-like (no file position at all)
+ * FOPEN_NOFLUSH: don't flush data cache on close (unless FUSE_WRITEBACK_CACHE)
 */
 #define FOPEN_DIRECT_IO		(1 << 0)
 #define FOPEN_KEEP_CACHE	(1 << 1)
 #define FOPEN_NONSEEKABLE	(1 << 2)
 #define FOPEN_CACHE_DIR		(1 << 3)
 #define FOPEN_STREAM		(1 << 4)
+#define FOPEN_NOFLUSH		(1 << 5)

 /**
 * INIT request/reply flags
@@ -313,7 +341,21 @@ struct fuse_file_lock {
 * FUSE_CACHE_SYMLINKS: cache READLINK responses
 * FUSE_NO_OPENDIR_SUPPORT: kernel supports zero-message opendir
 * FUSE_EXPLICIT_INVAL_DATA: only invalidate cached pages on explicit request
- * FUSE_MAP_ALIGNMENT: map_alignment field is valid
+ * FUSE_MAP_ALIGNMENT: init_out.map_alignment contains log2(byte alignment) for
+ *		       foffset and moffset fields in struct
+ *		       fuse_setupmapping_out and fuse_removemapping_one.
+ * FUSE_SUBMOUNTS: kernel supports auto-mounting directory submounts
+ * FUSE_HANDLE_KILLPRIV_V2: fs kills suid/sgid/cap on write/chown/trunc.
+ *			Upon write/truncate suid/sgid is only killed if caller
+ *			does not have CAP_FSETID. Additionally upon
+ *			write/truncate sgid is killed only if file has group
+ *			execute permission. (Same as Linux VFS behavior).
+ * FUSE_SETXATTR_EXT:	Server supports extended struct fuse_setxattr_in
+ * FUSE_INIT_EXT: extended fuse_init_in request
+ * FUSE_INIT_RESERVED: reserved, do not use
+ * FUSE_SECURITY_CTX:	add security context to create, mkdir, symlink, and
+ *			mknod
+ * FUSE_HAS_INODE_DAX:  use per inode DAX
 */
 #define FUSE_ASYNC_READ		(1 << 0)
 #define FUSE_POSIX_LOCKS	(1 << 1)
@@ -342,6 +384,14 @@ struct fuse_file_lock {
 #define FUSE_NO_OPENDIR_SUPPORT (1 << 24)
 #define FUSE_EXPLICIT_INVAL_DATA (1 << 25)
 #define FUSE_MAP_ALIGNMENT	(1 << 26)
+#define FUSE_SUBMOUNTS		(1 << 27)
+#define FUSE_HANDLE_KILLPRIV_V2	(1 << 28)
+#define FUSE_SETXATTR_EXT	(1 << 29)
+#define FUSE_INIT_EXT		(1 << 30)
+#define FUSE_INIT_RESERVED	(1 << 31)
+/* bits 32..63 get shifted down 32 bits into the flags2 field */
+#define FUSE_SECURITY_CTX	(1ULL << 32)
+#define FUSE_HAS_INODE_DAX	(1ULL << 33)

 /**
 * CUSE INIT request/reply flags
@@ -371,11 +421,14 @@ struct fuse_file_lock {
 *
 * FUSE_WRITE_CACHE: delayed write from page cache, file handle is guessed
 * FUSE_WRITE_LOCKOWNER: lock_owner field is valid
- * FUSE_WRITE_KILL_PRIV: kill suid and sgid bits
+ * FUSE_WRITE_KILL_SUIDGID: kill suid and sgid bits
 */
 #define FUSE_WRITE_CACHE	(1 << 0)
 #define FUSE_WRITE_LOCKOWNER	(1 << 1)
-#define FUSE_WRITE_KILL_PRIV	(1 << 2)
+#define FUSE_WRITE_KILL_SUIDGID (1 << 2)
+
+/* Obsolete alias; this flag implies killing suid/sgid only. */
+#define FUSE_WRITE_KILL_PRIV	FUSE_WRITE_KILL_SUIDGID

 /**
 * Read flags
@@ -417,6 +470,27 @@ struct fuse_file_lock {
 */
 #define FUSE_FSYNC_FDATASYNC	(1 << 0)

+/**
+ * fuse_attr flags
+ *
+ * FUSE_ATTR_SUBMOUNT: Object is a submount root
+ * FUSE_ATTR_DAX: Enable DAX for this file in per inode DAX mode
+ */
+#define FUSE_ATTR_SUBMOUNT      (1 << 0)
+#define FUSE_ATTR_DAX		(1 << 1)
+
+/**
+ * Open flags
+ * FUSE_OPEN_KILL_SUIDGID: Kill suid and sgid if executable
+ */
+#define FUSE_OPEN_KILL_SUIDGID	(1 << 0)
+
+/**
+ * setxattr flags
+ * FUSE_SETXATTR_ACL_KILL_SGID: Clear SGID when system.posix_acl_access is set
+ */
+#define FUSE_SETXATTR_ACL_KILL_SGID	(1 << 0)
+
 enum fuse_opcode {
 	FUSE_LOOKUP		= 1,
 	FUSE_FORGET		= 2,  /* no reply */
@@ -465,6 +539,8 @@ enum fuse_opcode {
 	FUSE_COPY_FILE_RANGE	= 47,
 	FUSE_SETUPMAPPING	= 48,
 	FUSE_REMOVEMAPPING	= 49,
+	FUSE_SYNCFS		= 50,
+	FUSE_TMPFILE		= 51,

 	/* CUSE specific operations */
 	CUSE_INIT		= 4096,
@@ -578,14 +654,14 @@ struct fuse_setattr_in {

 struct fuse_open_in {
 	uint32_t	flags;
-	uint32_t	unused;
+	uint32_t	open_flags;	/* FUSE_OPEN_... */
 };

 struct fuse_create_in {
 	uint32_t	flags;
 	uint32_t	mode;
 	uint32_t	umask;
-	uint32_t	padding;
+	uint32_t	open_flags;	/* FUSE_OPEN_... */
 };

 struct fuse_open_out {
@@ -647,9 +723,13 @@ struct fuse_fsync_in {
 	uint32_t	padding;
 };

+#define FUSE_COMPAT_SETXATTR_IN_SIZE 8
+
 struct fuse_setxattr_in {
 	uint32_t	size;
 	uint32_t	flags;
+	uint32_t	setxattr_flags;
+	uint32_t	padding;
 };

 struct fuse_getxattr_in {
@@ -684,6 +764,8 @@ struct fuse_init_in {
 	uint32_t	minor;
 	uint32_t	max_readahead;
 	uint32_t	flags;
+	uint32_t	flags2;
+	uint32_t	unused[11];
 };

 #define FUSE_COMPAT_INIT_OUT_SIZE 8
@@ -700,7 +782,8 @@ struct fuse_init_out {
 	uint32_t	time_gran;
 	uint16_t	max_pages;
 	uint16_t	map_alignment;
-	uint32_t	unused[8];
+	uint32_t	flags2;
+	uint32_t	unused[7];
 };

 #define CUSE_INIT_INFO_MAX 4096
@@ -808,9 +891,12 @@ struct fuse_dirent {
 	char name[];
 };

-#define FUSE_NAME_OFFSET offsetof(struct fuse_dirent, name)
-#define FUSE_DIRENT_ALIGN(x) \
+/* Align variable length records to 64bit boundary */
+#define FUSE_REC_ALIGN(x) \
 	(((x) + sizeof(uint64_t) - 1) & ~(sizeof(uint64_t) - 1))
+
+#define FUSE_NAME_OFFSET offsetof(struct fuse_dirent, name)
+#define FUSE_DIRENT_ALIGN(x) FUSE_REC_ALIGN(x)
 #define FUSE_DIRENT_SIZE(d) \
 	FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + (d)->namelen)

@@ -869,7 +955,8 @@ struct fuse_notify_retrieve_in {
 };

 /* Device ioctls: */
-#define FUSE_DEV_IOC_CLONE	_IOR(229, 0, uint32_t)
+#define FUSE_DEV_IOC_MAGIC		229
+#define FUSE_DEV_IOC_CLONE		_IOR(FUSE_DEV_IOC_MAGIC, 0, uint32_t)

 struct fuse_lseek_in {
 	uint64_t	fh;
@@ -892,4 +979,60 @@ struct fuse_copy_file_range_in {
 	uint64_t	flags;
 };

+#define FUSE_SETUPMAPPING_FLAG_WRITE (1ull << 0)
+#define FUSE_SETUPMAPPING_FLAG_READ (1ull << 1)
+struct fuse_setupmapping_in {
+	/* An already open handle */
+	uint64_t	fh;
+	/* Offset into the file to start the mapping */
+	uint64_t	foffset;
+	/* Length of mapping required */
+	uint64_t	len;
+	/* Flags, FUSE_SETUPMAPPING_FLAG_* */
+	uint64_t	flags;
+	/* Offset in Memory Window */
+	uint64_t	moffset;
+};
+
+struct fuse_removemapping_in {
+	/* number of fuse_removemapping_one follows */
+	uint32_t        count;
+};
+
+struct fuse_removemapping_one {
+	/* Offset into the dax window start the unmapping */
+	uint64_t        moffset;
+	/* Length of mapping required */
+	uint64_t	len;
+};
+
+#define FUSE_REMOVEMAPPING_MAX_ENTRY   \
+		(PAGE_SIZE / sizeof(struct fuse_removemapping_one))
+
+struct fuse_syncfs_in {
+	uint64_t	padding;
+};
+
+/*
+ * For each security context, send fuse_secctx with size of security context
+ * fuse_secctx will be followed by security context name and this in turn
+ * will be followed by actual context label.
+ * fuse_secctx, name, context
+ */
+struct fuse_secctx {
+	uint32_t	size;
+	uint32_t	padding;
+};
+
+/*
+ * Contains the information about how many fuse_secctx structures are being
+ * sent and what's the total size of all security contexts (including
+ * size of fuse_secctx_header).
+ *
+ */
+struct fuse_secctx_header {
+	uint32_t	size;
+	uint32_t	nr_secctx;
+};
+
 #endif /* _LINUX_FUSE_H */
@@ -9,22 +9,9 @@
 #ifndef _FUSE_LOWLEVEL_H_
 #define _FUSE_LOWLEVEL_H_

-/** @file
- *
- * Low level API
- *
- * IMPORTANT: you should define FUSE_USE_VERSION before including this
- * header.  To use the newest API define it to 26 (recommended for any
- * new application), to use the old API define it to 24 (default) or
- * 25
- */
-
-#ifndef FUSE_USE_VERSION
-#define FUSE_USE_VERSION 24
-#endif
-
 #include "extern_c.h"
 #include "fuse_common.h"
+#include "fuse_kernel.h"

 #include <fcntl.h>
 #include <stdint.h>
@@ -117,12 +104,6 @@ struct fuse_ctx
  mode_t umask;
 };

-struct fuse_forget_data
-{
-  uint64_t ino;
-  uint64_t nlookup;
-};
-
 /* ----------------------------------------------------------- *
 * Request methods and replies				       *
 * ----------------------------------------------------------- */
@@ -183,7 +164,8 @@ struct fuse_lowlevel_ops
   * @param parent inode number of the parent directory
   * @param name the name to look up
   */
-  void (*lookup)(fuse_req_t req, uint64_t parent, const char *name);
+  void (*lookup)(fuse_req_t             req,
+                 struct fuse_in_header *hdr);

  /**
   * Forget about an inode
@@ -221,7 +203,8 @@ struct fuse_lowlevel_ops
   * @param ino the inode number
   * @param nlookup the number of lookups to forget
   */
-  void (*forget)(fuse_req_t req, uint64_t ino, uint64_t nlookup);
+  void (*forget)(fuse_req_t             req,
+                 struct fuse_in_header *hdr);

  /**
   * Get file attributes
@@ -229,13 +212,9 @@ struct fuse_lowlevel_ops
   * Valid replies:
   *   fuse_reply_attr
   *   fuse_reply_err
-   *
-   * @param req request handle
-   * @param ino the inode number
-   * @param fi for future use, currently always NULL
   */
-  void (*getattr)(fuse_req_t req, uint64_t ino,
-                  fuse_file_info_t *fi);
+  void (*getattr)(fuse_req_t              req,
+                  struct fuse_in_header  *hdr);

  /**
   * Set file attributes
@@ -264,8 +243,8 @@ struct fuse_lowlevel_ops
   * Changed in version 2.5:
   *     file information filled in for ftruncate
   */
-  void (*setattr)(fuse_req_t req, uint64_t ino, struct stat *attr,
-                  int to_set, fuse_file_info_t *fi);
+  void (*setattr)(fuse_req_t             req,
+                  struct fuse_in_header *hdr);

  /**
   * Read symbolic link
@@ -277,7 +256,8 @@ struct fuse_lowlevel_ops
   * @param req request handle
   * @param ino the inode number
   */
-  void (*readlink)(fuse_req_t req, uint64_t ino);
+  void (*readlink)(fuse_req_t             req,
+                   struct fuse_in_header *hdr);

  /**
   * Create file node
@@ -295,8 +275,8 @@ struct fuse_lowlevel_ops
   * @param mode file type and mode with which to create the new file
   * @param rdev the device number (only valid if created file is a device)
   */
-  void (*mknod)(fuse_req_t req, uint64_t parent, const char *name,
-                mode_t mode, dev_t rdev);
+  void (*mknod)(fuse_req_t             req,
+                struct fuse_in_header *hdr);

  /**
   * Create a directory
@@ -310,8 +290,8 @@ struct fuse_lowlevel_ops
   * @param name to create
   * @param mode with which to create the new file
   */
-  void (*mkdir)(fuse_req_t req, uint64_t parent, const char *name,
-                mode_t mode);
+  void (*mkdir)(fuse_req_t             req,
+                struct fuse_in_header *hdr);

  /**
   * Remove a file
@@ -328,7 +308,8 @@ struct fuse_lowlevel_ops
   * @param parent inode number of the parent directory
   * @param name to remove
   */
-  void (*unlink)(fuse_req_t req, uint64_t parent, const char *name);
+  void (*unlink)(fuse_req_t             req,
+                 struct fuse_in_header *hdr);

  /**
   * Remove a directory
@@ -345,7 +326,8 @@ struct fuse_lowlevel_ops
   * @param parent inode number of the parent directory
   * @param name to remove
   */
-  void (*rmdir)(fuse_req_t req, uint64_t parent, const char *name);
+  void (*rmdir)(fuse_req_t             req,
+                struct fuse_in_header *hdr);

  /**
   * Create a symbolic link
@@ -359,8 +341,8 @@ struct fuse_lowlevel_ops
   * @param parent inode number of the parent directory
   * @param name to create
   */
-  void (*symlink)(fuse_req_t req, const char *link, uint64_t parent,
-                  const char *name);
+  void (*symlink)(fuse_req_t             req,
+                  struct fuse_in_header *hdr);

  /** Rename a file
   *
@@ -379,8 +361,8 @@ struct fuse_lowlevel_ops
   * @param newparent inode number of the new parent directory
   * @param newname new name
   */
-  void (*rename)(fuse_req_t req, uint64_t parent, const char *name,
-                 uint64_t newparent, const char *newname);
+  void (*rename)(fuse_req_t             req,
+                 struct fuse_in_header *hdr);

  /**
   * Create a hard link
@@ -394,8 +376,8 @@ struct fuse_lowlevel_ops
   * @param newparent inode number of the new parent directory
   * @param newname new name to create
   */
-  void (*link)(fuse_req_t req, uint64_t ino, uint64_t newparent,
-               const char *newname);
+  void (*link)(fuse_req_t             req,
+               struct fuse_in_header *hdr);

  /**
   * Open a file
@@ -422,8 +404,8 @@ struct fuse_lowlevel_ops
   * @param ino the inode number
   * @param fi file information
   */
-  void (*open)(fuse_req_t req, uint64_t ino,
-               fuse_file_info_t *fi);
+  void (*open)(fuse_req_t             req,
+               struct fuse_in_header *hdr);

  /**
   * Read data
@@ -450,8 +432,8 @@ struct fuse_lowlevel_ops
   * @param off offset to read from
   * @param fi file information
   */
-  void (*read)(fuse_req_t req, uint64_t ino, size_t size, off_t off,
-               fuse_file_info_t *fi);
+  void (*read)(fuse_req_t             req,
+               struct fuse_in_header *hdr);

  /**
   * Write data
@@ -476,8 +458,8 @@ struct fuse_lowlevel_ops
   * @param off offset to write to
   * @param fi file information
   */
-  void (*write)(fuse_req_t req, uint64_t ino, const char *buf,
-                size_t size, off_t off, fuse_file_info_t *fi);
+  void (*write)(fuse_req_t             req,
+                struct fuse_in_header *hdr);

  /**
   * Flush method
@@ -508,8 +490,8 @@ struct fuse_lowlevel_ops
   * @param ino the inode number
   * @param fi file information
   */
-  void (*flush)(fuse_req_t req, uint64_t ino,
-                fuse_file_info_t *fi);
+  void (*flush)(fuse_req_t             req,
+                struct fuse_in_header *hdr);

  /**
   * Release an open file
@@ -535,8 +517,8 @@ struct fuse_lowlevel_ops
   * @param ino the inode number
   * @param fi file information
   */
-  void (*release)(fuse_req_t req, uint64_t ino,
-                  fuse_file_info_t *fi);
+  void (*release)(fuse_req_t             req,
+                  struct fuse_in_header *hdr);

  /**
   * Synchronize file contents
@@ -552,8 +534,8 @@ struct fuse_lowlevel_ops
   * @param datasync flag indicating if only data should be flushed
   * @param fi file information
   */
-  void (*fsync)(fuse_req_t req, uint64_t ino, int datasync,
-                fuse_file_info_t *fi);
+  void (*fsync)(fuse_req_t             req,
+                struct fuse_in_header *hdr);

  /**
   * Open a directory
@@ -576,8 +558,8 @@ struct fuse_lowlevel_ops
   * @param ino the inode number
   * @param fi file information
   */
-  void (*opendir)(fuse_req_t req, uint64_t ino,
-                  fuse_file_info_t *fi);
+  void (*opendir)(fuse_req_t req,
+                  struct fuse_in_header *hdr);

  /**
   * Read directory
@@ -600,12 +582,11 @@ struct fuse_lowlevel_ops
   * @param off offset to continue reading the directory stream
   * @param fi file information
   */
-  void (*readdir)(fuse_req_t req, uint64_t ino, size_t size, off_t off,
-                  fuse_file_info_t *llffi);
+  void (*readdir)(fuse_req_t             req,
+                  struct fuse_in_header *hdr);

-  void (*readdir_plus)(fuse_req_t req, uint64_t ino,
-                       size_t size, off_t off,
-                       fuse_file_info_t *ffi);
+  void (*readdir_plus)(fuse_req_t             req,
+                       struct fuse_in_header *hdr);

  /**
   * Release an open directory
@@ -623,8 +604,8 @@ struct fuse_lowlevel_ops
   * @param ino the inode number
   * @param fi file information
   */
-  void (*releasedir)(fuse_req_t req, uint64_t ino,
-                     fuse_file_info_t *fi);
+  void (*releasedir)(fuse_req_t             req,
+                     struct fuse_in_header *hdr);

  /**
   * Synchronize directory contents
@@ -643,8 +624,8 @@ struct fuse_lowlevel_ops
   * @param datasync flag indicating if only data should be flushed
   * @param fi file information
   */
-  void (*fsyncdir)(fuse_req_t req, uint64_t ino, int datasync,
-                   fuse_file_info_t *fi);
+  void (*fsyncdir)(fuse_req_t             req,
+                   struct fuse_in_header *hdr);

  /**
   * Get file system statistics
@@ -656,7 +637,8 @@ struct fuse_lowlevel_ops
   * @param req request handle
   * @param ino the inode number, zero means "undefined"
   */
-  void (*statfs)(fuse_req_t req, uint64_t ino);
+  void (*statfs)(fuse_req_t             req,
+                 struct fuse_in_header *hdr);

  /**
   * Set an extended attribute
@@ -664,8 +646,8 @@ struct fuse_lowlevel_ops
   * Valid replies:
   *   fuse_reply_err
   */
-  void (*setxattr)(fuse_req_t req, uint64_t ino, const char *name,
-                   const char *value, size_t size, int flags);
+  void (*setxattr)(fuse_req_t             req,
+                   struct fuse_in_header *hdr);

  /**
   * Get an extended attribute
@@ -690,8 +672,8 @@ struct fuse_lowlevel_ops
   * @param name of the extended attribute
   * @param size maximum size of the value to send
   */
-  void (*getxattr)(fuse_req_t req, uint64_t ino, const char *name,
-                   size_t size);
+  void (*getxattr)(fuse_req_t             req,
+                   struct fuse_in_header *hdr);

  /**
   * List extended attribute names
@@ -716,7 +698,8 @@ struct fuse_lowlevel_ops
   * @param ino the inode number
   * @param size maximum size of the list to send
   */
-  void (*listxattr)(fuse_req_t req, uint64_t ino, size_t size);
+  void (*listxattr)(fuse_req_t             req,
+                    struct fuse_in_header *hdr);

  /**
   * Remove an extended attribute
@@ -728,7 +711,8 @@ struct fuse_lowlevel_ops
   * @param ino the inode number
   * @param name of the extended attribute
   */
-  void (*removexattr)(fuse_req_t req, uint64_t ino, const char *name);
+  void (*removexattr)(fuse_req_t                   req,
+                      const struct fuse_in_header *hdr);

  /**
   * Check file access permissions
@@ -748,7 +732,8 @@ struct fuse_lowlevel_ops
   * @param ino the inode number
   * @param mask requested access mode
   */
-  void (*access)(fuse_req_t req, uint64_t ino, int mask);
+  void (*access)(fuse_req_t             req,
+                 struct fuse_in_header *hdr);

  /**
   * Create and open a file
@@ -783,8 +768,8 @@ struct fuse_lowlevel_ops
   * @param mode file type and mode with which to create the new file
   * @param fi file information
   */
-  void (*create)(fuse_req_t req, uint64_t parent, const char *name,
-                 mode_t mode, fuse_file_info_t *fi);
+  void (*create)(fuse_req_t             req,
+                 struct fuse_in_header *hdr);

  /**
   * Test for a POSIX file lock
@@ -800,9 +785,8 @@ struct fuse_lowlevel_ops
   * @param fi file information
   * @param lock the region/type to test
   */
-  void (*getlk)(fuse_req_t req, uint64_t ino,
-                fuse_file_info_t *fi, struct flock *lock);
-
+  void (*getlk)(fuse_req_t                   req,
+                const struct fuse_in_header *hdr);
  /**
   * Acquire, modify or release a POSIX file lock
   *
@@ -848,8 +832,8 @@ struct fuse_lowlevel_ops
   * @param blocksize unit of block index
   * @param idx block index within file
   */
-  void (*bmap)(fuse_req_t req, uint64_t ino, size_t blocksize,
-               uint64_t idx);
+  void (*bmap)(fuse_req_t                   req,
+               const struct fuse_in_header *hdr);

  /**
   * Ioctl
@@ -878,9 +862,8 @@ struct fuse_lowlevel_ops
   * @param in_bufsz number of fetched bytes
   * @param out_bufsz maximum size of output data
   */
-  void (*ioctl)(fuse_req_t req, uint64_t ino, unsigned long cmd, void *arg,
-                fuse_file_info_t *fi, unsigned flags,
-                const void *in_buf, uint32_t in_bufsz, uint32_t out_bufsz);
+  void (*ioctl)(fuse_req_t                   req,
+                const struct fuse_in_header *hdr);

  /**
   * Poll for IO readiness
@@ -908,40 +891,8 @@ struct fuse_lowlevel_ops
   * @param fi file information
   * @param ph poll handle to be used for notification
   */
-  void (*poll)(fuse_req_t req,
-               uint64_t ino,
-               fuse_file_info_t *fi,
-               fuse_pollhandle_t *ph);
-
-  /**
-   * Write data made available in a buffer
-   *
-   * This is a more generic version of the ->write() method.  If
-   * FUSE_CAP_SPLICE_READ is set in fuse_conn_info.want and the
-   * kernel supports splicing from the fuse device, then the
-   * data will be made available in pipe for supporting zero
-   * copy data transfer.
-   *
-   * buf->count is guaranteed to be one (and thus buf->idx is
-   * always zero). The write_buf handler must ensure that
-   * bufv->off is correctly updated (reflecting the number of
-   * bytes read from bufv->buf[0]).
-   *
-   * Introduced in version 2.9
-   *
-   * Valid replies:
-   *   fuse_reply_write
-   *   fuse_reply_err
-   *
-   * @param req request handle
-   * @param ino the inode number
-   * @param bufv buffer containing the data
-   * @param off offset to write to
-   * @param fi file information
-   */
-  void (*write_buf)(fuse_req_t req, uint64_t ino,
-                    struct fuse_bufvec *bufv, off_t off,
-                    fuse_file_info_t *fi);
+  void (*poll)(fuse_req_t                   req,
+               const struct fuse_in_header *hdr);

  /**
   * Callback function for the retrieve request
@@ -957,8 +908,10 @@ struct fuse_lowlevel_ops
   * @param offset the offset supplied to fuse_lowlevel_notify_retrieve()
   * @param bufv the buffer containing the returned data
   */
-  void (*retrieve_reply)(fuse_req_t req, void *cookie, uint64_t ino,
-                         off_t offset, struct fuse_bufvec *bufv);
+  void (*retrieve_reply)(fuse_req_t req,
+                         void *cookie,
+                         uint64_t ino,
+                         off_t offset);

  /**
   * Forget about multiple inodes
@@ -973,8 +926,8 @@ struct fuse_lowlevel_ops
   *
   * @param req request handle
   */
-  void (*forget_multi)(fuse_req_t req, size_t count,
-                       struct fuse_forget_data *forgets);
+  void (*forget_multi)(fuse_req_t             req,
+                       struct fuse_in_header *hdr);

  /**
   * Acquire, modify or release a BSD file lock
@@ -1013,8 +966,8 @@ struct fuse_lowlevel_ops
   * @param mode determines the operation to be performed on the given range,
   *             see fallocate(2)
   */
-  void (*fallocate)(fuse_req_t req, uint64_t ino, int mode,
-                    off_t offset, off_t length, fuse_file_info_t *fi);
+  void (*fallocate)(fuse_req_t                   req,
+                    const struct fuse_in_header *hdr);

  /**
   * Copy a range of data from one file to another
@@ -1052,15 +1005,8 @@ struct fuse_lowlevel_ops
   * @param len maximum size of the data to copy
   * @param flags passed along with the copy_file_range() syscall
   */
-  void (*copy_file_range)(fuse_req_t        req,
-                          uint64_t        ino_in,
-                          off_t             off_in,
-                          fuse_file_info_t *fi_in,
-                          uint64_t        ino_out,
-                          off_t             off_out,
-                          fuse_file_info_t *fi_out,
-                          size_t            len,
-                          int               flags);
+  void (*copy_file_range)(fuse_req_t                   req,
+                          const struct fuse_in_header *hdr);
 };

 /**
@@ -1163,7 +1109,8 @@ int fuse_reply_readlink(fuse_req_t req, const char *link);
 * @param fi file information
 * @return zero for success, -errno for failure to send reply
 */
-int fuse_reply_open(fuse_req_t req, const fuse_file_info_t *fi);
+int fuse_reply_open(fuse_req_t req,
+                    const fuse_file_info_t *fi);

 /**
 * Reply with number of bytes written
@@ -1190,19 +1137,9 @@ int fuse_reply_write(fuse_req_t req, size_t count);
 */
 int fuse_reply_buf(fuse_req_t req, const char *buf, size_t size);

-/**
- * Reply with data copied/moved from buffer(s)
- *
- * Possible requests:
- *   read, readdir, getxattr, listxattr
- *
- * @param req request handle
- * @param bufv buffer vector
- * @param flags flags controlling the copy
- * @return zero for success, -errno for failure to send reply
- */
-int fuse_reply_data(fuse_req_t req, struct fuse_bufvec *bufv,
-                    enum fuse_buf_copy_flags flags);
+int fuse_reply_data(fuse_req_t  req,
+                    char       *buf,
+                    size_t      bufsize);

 /**
 * Reply with data vector
@@ -1503,231 +1440,33 @@ struct fuse_session *fuse_lowlevel_new(struct fuse_args *args,
 * Session interface					       *
 * ----------------------------------------------------------- */

-/**
- * Session operations
- *
- * This is used in session creation
- */
-struct fuse_session_ops
-{
-  /**
-   * Hook to process a request (mandatory)
-   *
-   * @param data user data passed to fuse_session_new()
-   * @param buf buffer containing the raw request
-   * @param len request length
-   * @param ch channel on which the request was received
-   */
-  void (*process)(void *data, const char *buf, size_t len,
-                  struct fuse_chan *ch);
-
-  /**
-   * Hook for session exit and reset (optional)
-   *
-   * @param data user data passed to fuse_session_new()
-   * @param val exited status (1 - exited, 0 - not exited)
-   */
-  void (*exit)(void *data, int val);
-
-  /**
-   * Hook for querying the current exited status (optional)
-   *
-   * @param data user data passed to fuse_session_new()
-   * @return 1 if exited, 0 if not exited
-   */
-  int (*exited)(void *data);
-
-  /**
-   * Hook for cleaning up the channel on destroy (optional)
-   *
-   * @param data user data passed to fuse_session_new()
-   */
-  void (*destroy)(void *data);
-};
-
-/**
- * Create a new session
- *
- * @param op session operations
- * @param data user data
- * @return new session object, or NULL on failure
- */
-struct fuse_session *fuse_session_new(struct fuse_session_ops *op, void *data);
-
-/**
- * Assign a channel to a session
- *
- * Note: currently only a single channel may be assigned.  This may
- * change in the future
- *
- * If a session is destroyed, the assigned channel is also destroyed
- *
- * @param se the session
- * @param ch the channel
- */
+struct fuse_session *fuse_session_new(void *data,
+                                      void *receive_buf,
+                                      void *process_buf,
+                                      void *destroy);
 void fuse_session_add_chan(struct fuse_session *se, struct fuse_chan *ch);
-
-/**
- * Remove a channel from a session
- *
- * If the channel is not assigned to a session, then this is a no-op
- *
- * @param ch the channel to remove
- */
 void fuse_session_remove_chan(struct fuse_chan *ch);
-
-/**
- * Iterate over the channels assigned to a session
- *
- * The iterating function needs to start with a NULL channel, and
- * after that needs to pass the previously returned channel to the
- * function.
- *
- * @param se the session
- * @param ch the previous channel, or NULL
- * @return the next channel, or NULL if no more channels exist
- */
-struct fuse_chan *fuse_session_next_chan(struct fuse_session *se,
-                                         struct fuse_chan *ch);
-
-/**
- * Process a raw request
- *
- * @param se the session
- * @param buf buffer containing the raw request
- * @param len request length
- * @param ch channel on which the request was received
- */
-void fuse_session_process(struct fuse_session *se, const char *buf, size_t len,
-                          struct fuse_chan *ch);
-
-/**
- * Process a raw request supplied in a generic buffer
- *
- * This is a more generic version of fuse_session_process().  The
- * fuse_buf may contain a memory buffer or a pipe file descriptor.
- *
- * @param se the session
- * @param buf the fuse_buf containing the request
- * @param ch channel on which the request was received
- */
-void fuse_session_process_buf(struct fuse_session *se,
-                              const struct fuse_buf *buf, struct fuse_chan *ch);
-
-/**
- * Receive a raw request supplied in a generic buffer
- *
- * This is a more generic version of fuse_chan_recv().  The fuse_buf
- * supplied to this function contains a suitably allocated memory
- * buffer.  This may be overwritten with a file descriptor buffer.
- *
- * @param se the session
- * @param buf the fuse_buf to store the request in
- * @param chp pointer to the channel
- * @return the actual size of the raw request, or -errno on error
- */
-int fuse_session_receive_buf(struct fuse_session *se, struct fuse_buf *buf,
-                             struct fuse_chan **chp);
-
-/**
- * Destroy a session
- *
- * @param se the session
- */
 void fuse_session_destroy(struct fuse_session *se);
-
-/**
- * Exit a session
- *
- * @param se the session
- */
 void fuse_session_exit(struct fuse_session *se);
-
-/**
- * Reset the exited status of a session
- *
- * @param se the session
- */
-void fuse_session_reset(struct fuse_session *se);
-
-/**
- * Query the exited status of a session
- *
- * @param se the session
- * @return 1 if exited, 0 if not exited
- */
 int fuse_session_exited(struct fuse_session *se);
-
-/**
- * Get the user data provided to the session
- *
- * @param se the session
- * @return the user data
- */
+void fuse_session_reset(struct fuse_session *se);
 void *fuse_session_data(struct fuse_session *se);
+int fuse_session_receive(struct fuse_session *se,
+                         struct fuse_buf *buf);
+void fuse_session_process(struct fuse_session *se,
+                          const void          *buf,
+                          const size_t         bufsize);

-/**
- * Enter a multi-threaded event loop
- *
- * @param se the session
- * @return 0 on success, -1 on error
- */
-int fuse_session_loop_mt(struct fuse_session *se, const int threads);
+int fuse_session_loop_mt(struct fuse_session *se,
+                         const int            read_thread_count,
+                         const int            process_thread_count,
+                         const char          *pin_threads_type);

 /* ----------------------------------------------------------- *
 * Channel interface					       *
 * ----------------------------------------------------------- */

-/**
- * Channel operations
- *
- * This is used in channel creation
- */
-struct fuse_chan_ops
-{
-  /**
-   * Hook for receiving a raw request
-   *
-   * @param ch pointer to the channel
-   * @param buf the buffer to store the request in
-   * @param size the size of the buffer
-   * @return the actual size of the raw request, or -1 on error
-   */
-  int (*receive)(struct fuse_chan **chp, char *buf, size_t size);
-
-  /**
-   * Hook for sending a raw reply
-   *
-   * A return value of -ENOENT means, that the request was
-   * interrupted, and the reply was discarded
-   *
-   * @param ch the channel
-   * @param iov vector of blocks
-   * @param count the number of blocks in vector
-   * @return zero on success, -errno on failure
-   */
-  int (*send)(struct fuse_chan *ch, const struct iovec iov[],
-              size_t count);
-
-  /**
-   * Destroy the channel
-   *
-   * @param ch the channel
-   */
-  void (*destroy)(struct fuse_chan *ch);
-};
-
-/**
- * Create a new channel
- *
- * @param op channel operations
- * @param fd file descriptor of the channel
- * @param bufsize the minimal receive buffer size
- * @param data user data
- * @return the new channel object, or NULL on failure
- */
-struct fuse_chan *fuse_chan_new(struct fuse_chan_ops *op, int fd,
-                                size_t bufsize, void *data);
+struct fuse_chan *fuse_chan_new(int fd, size_t bufsize);

 /**
 * Query the file descriptor of the channel
@@ -1761,37 +1500,6 @@ void *fuse_chan_data(struct fuse_chan *ch);
 */
 struct fuse_session *fuse_chan_session(struct fuse_chan *ch);

-/**
- * Receive a raw request
- *
- * A return value of -ENODEV means, that the filesystem was unmounted
- *
- * @param ch pointer to the channel
- * @param buf the buffer to store the request in
- * @param size the size of the buffer
- * @return the actual size of the raw request, or -errno on error
- */
-int fuse_chan_recv(struct fuse_chan **ch, char *buf, size_t size);
-
-/**
- * Send a raw reply
- *
- * A return value of -ENOENT means, that the request was
- * interrupted, and the reply was discarded
- *
- * @param ch the channel
- * @param iov vector of blocks
- * @param count the number of blocks in vector
- * @return zero on success, -errno on failure
- */
-int fuse_chan_send(struct fuse_chan *ch, const struct iovec iov[],
-                   size_t count);
-
-/**
- * Destroy a channel
- *
- * @param ch the channel
- */
 void fuse_chan_destroy(struct fuse_chan *ch);

 EXTERN_C_END
@@ -0,0 +1,11 @@
+#pragma once
+
+#include <stdint.h>
+
+typedef struct fuse_msgbuf_t fuse_msgbuf_t;
+struct fuse_msgbuf_t
+{
+  char     *mem;
+  uint32_t  size;
+  uint32_t  used;
+};
@@ -0,0 +1,14 @@
+#pragma once
+
+#include <stdint.h>
+
+struct fuse_chan;
+struct fuse_ll;
+
+typedef struct fuse_pollhandle_t fuse_pollhandle_t;
+struct fuse_pollhandle_t
+{
+  uint64_t kh;
+  struct fuse_chan *ch;
+  struct fuse_ll *f;
+};
@@ -0,0 +1,165 @@
+#pragma once
+
+#include <condition_variable>
+#include <mutex>
+#include <queue>
+#include <utility>
+
+
+template<typename T>
+class BoundedQueue
+{
+public:
+  explicit
+  BoundedQueue(std::size_t max_size_,
+               bool        block_ = true)
+    : _block(block),
+      _max_size(max_size_)
+  {
+    if(_max_size == 0)
+      _max_size = 1;
+  }
+
+  bool
+  push(const T& item_)
+  {
+    {
+      std::unique_lock guard(_queue_lock);
+
+      _condition_push.wait(guard, [&]() { return _queue.size() < _max_size || !_block; });
+
+      if(_queue.size() == _max_size)
+        return false;
+
+      _queue.push(item);
+    }
+
+    _condition_pop.notify_one();
+
+    return true;
+  }
+
+  bool
+  push(T&& item_)
+  {
+    {
+      std::unique_lock guard(_queue_lock);
+
+      _condition_push.wait(guard, [&]() { return _queue.size() < _max_size || !_block; });
+
+      if(_queue.size() == _max_size)
+        return false;
+
+      _queue.push(std::move(item_));
+    }
+    _condition_pop.notify_one();
+    return true;
+  }
+
+  template<typename... Args>
+  bool
+  emplace(Args&&... args_)
+  {
+    {
+      std::unique_lock guard(_queue_lock);
+
+      _condition_push.wait(guard, [&]() { return _queue.size() < _max_size || !_block; });
+
+      if(_queue.size() == _max_size)
+        return false;
+
+      _queue.emplace(std::forward<Args>(args_)...);
+    }
+
+    _condition_pop.notify_one();
+
+    return true;
+  }
+
+  bool
+  pop(T& item_)
+  {
+    {
+      std::unique_lock guard(_queue_lock);
+
+      _condition_pop.wait(guard, [&]() { return !_queue.empty() || !_block; });
+      if(_queue.empty())
+        return false;
+
+      item_ = std::move(_queue.front());
+
+      _queue.pop();
+    }
+
+    _condition_push.notify_one();
+
+    return true;
+  }
+
+  std::size_t
+  size() const
+  {
+    std::lock_guard guard(_queue_lock);
+
+    return _queue.size();
+  }
+
+  std::size_t
+  capacity() const
+  {
+    return _max_size;
+  }
+
+  bool
+  empty() const
+  {
+    std::lock_guard guard(_queue_lock);
+
+    return _queue.empty();
+  }
+
+  bool
+  full() const
+  {
+    std::lock_guard lock(_queue_lock);
+
+    return (_queue.size() == capacity());
+  }
+
+  void
+  block()
+  {
+    std::lock_guard guard(_queue_lock);
+    _block = true;
+  }
+
+  void
+  unblock()
+  {
+    {
+      std::lock_guard guard(_queue_lock);
+      _block = false;
+    }
+
+    _condition_push.notify_all();
+    _condition_pop.notify_all();
+  }
+
+  bool
+  blocking() const
+  {
+    std::lock_guard guard(_queue_lock);
+
+    return _block;
+  }
+
+private:
+  mutable std::mutex _queue_lock;
+
+private:
+  bool _block;
+  std::queue<T> _queue;
+  const std::size_t _max_size;
+  std::condition_variable _condition_push;
+  std::condition_variable _condition_pop;
+};
@@ -182,8 +182,7 @@ static ssize_t fuse_buf_splice(const struct fuse_buf *dst, size_t dst_off,
  }

  while (len) {
-    res = splice(src->fd, srcpos, dst->fd, dstpos, len,
-                 splice_flags);
+    res = splice(src->fd, srcpos, dst->fd, dstpos, len, splice_flags);
    if (res == -1) {
      if (copied)
        break;
@@ -0,0 +1,163 @@
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include "cpu.hpp"
+#include "ghc/filesystem.hpp"
+#include "fmt/core.h"
+
+#include <sched.h>
+
+#include <fstream>
+
+
+int
+CPU::getaffinity(const pthread_t  thread_id_,
+                 cpu_set_t       *cpuset_)
+{
+  CPU_ZERO(cpuset_);
+  return sched_getaffinity(thread_id_,
+                           sizeof(cpu_set_t),
+                           cpuset_);
+}
+
+int
+CPU::setaffinity(const pthread_t  thread_id_,
+                 cpu_set_t       *cpuset_)
+{
+  return pthread_setaffinity_np(thread_id_,
+                                sizeof(cpu_set_t),
+                                cpuset_);
+}
+
+int
+CPU::setaffinity(const pthread_t thread_id_,
+                 const int       cpu_)
+{
+  cpu_set_t cpuset;
+
+  CPU_ZERO(&cpuset);
+  CPU_SET(cpu_,&cpuset);
+
+  return CPU::setaffinity(thread_id_,&cpuset);
+}
+
+int
+CPU::setaffinity(const pthread_t     thread_id_,
+                 const std::set<int> cpus_)
+{
+  cpu_set_t cpuset;
+
+  CPU_ZERO(&cpuset);
+  for(auto const cpu : cpus_)
+    CPU_SET(cpu,&cpuset);
+
+  return CPU::setaffinity(thread_id_,&cpuset);
+}
+
+static
+ghc::filesystem::path
+generate_cpu_core_id_path(const int cpu_id_)
+{
+  const ghc::filesystem::path basepath{"/sys/devices/system/cpu"};
+
+  return basepath / fmt::format("cpu{}",cpu_id_) / "topology" / "core_id";
+}
+
+int
+CPU::count()
+{
+  int rv;
+  cpu_set_t cpuset;
+
+  rv = CPU::getaffinity(0,&cpuset);
+  if(rv < 0)
+    return rv;
+
+  return CPU_COUNT(&cpuset);
+}
+
+CPU::CPUVec
+CPU::cpus()
+{
+  cpu_set_t cpuset;
+  CPU::CPUVec cpuvec;
+
+  CPU::getaffinity(0,&cpuset);
+
+  for(int i = 0; i < CPU_SETSIZE; i++)
+    {
+      if(!CPU_ISSET(i,&cpuset))
+        continue;
+
+      cpuvec.push_back(i);
+    }
+
+  return cpuvec;
+}
+
+CPU::CPU2CoreMap
+CPU::cpu2core()
+{
+  cpu_set_t cpuset;
+  CPU::CPU2CoreMap c2c;
+
+  CPU::getaffinity(0,&cpuset);
+
+  for(int i = 0; i < CPU_SETSIZE; i++)
+    {
+      int core_id;
+      std::ifstream ifs;
+      ghc::filesystem::path path;
+
+      if(!CPU_ISSET(i,&cpuset))
+        continue;
+
+      path = ::generate_cpu_core_id_path(i);
+
+      ifs.open(path);
+      if(!ifs)
+        break;
+
+      ifs >> core_id;
+
+      c2c[i] = core_id;
+
+      ifs.close();
+    }
+
+  return c2c;
+}
+
+CPU::Core2CPUsMap
+CPU::core2cpus()
+{
+  cpu_set_t cpuset;
+  CPU::Core2CPUsMap c2c;
+
+  CPU::getaffinity(0,&cpuset);
+
+  for(int i = 0; i < CPU_SETSIZE; i++)
+    {
+      int core_id;
+      std::ifstream ifs;
+      ghc::filesystem::path path;
+
+      if(!CPU_ISSET(i,&cpuset))
+        continue;
+
+      path = ::generate_cpu_core_id_path(i);
+
+      ifs.open(path);
+      if(!ifs)
+        break;
+
+      ifs >> core_id;
+
+      c2c[core_id].insert(i);
+
+      ifs.close();
+    }
+
+  return c2c;
+}
@@ -0,0 +1,33 @@
+#pragma once
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <pthread.h>
+#include <sched.h>
+
+#include <set>
+#include <unordered_map>
+#include <vector>
+
+
+class CPU
+{
+public:
+  typedef std::vector<pthread_t> ThreadIdVec;
+  typedef std::vector<int> CPUVec;
+  typedef std::unordered_map<int,int> CPU2CoreMap;
+  typedef std::unordered_map<int,std::set<int>> Core2CPUsMap;
+
+public:
+  static int count();
+  static int getaffinity(const pthread_t thread_id, cpu_set_t *cpuset);
+  static int setaffinity(const pthread_t thread_id, cpu_set_t *cpuset);
+  static int setaffinity(const pthread_t thread_id, const int cpu);
+  static int setaffinity(const pthread_t thread_id, const std::set<int> cpus);
+
+  static CPU::CPUVec cpus();
+  static CPU::CPU2CoreMap cpu2core();
+  static CPU::Core2CPUsMap core2cpus();
+};
@@ -0,0 +1,234 @@
+// Formatting library for C++ - dynamic format arguments
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_ARGS_H_
+#define FMT_ARGS_H_
+
+#include <functional>  // std::reference_wrapper
+#include <memory>      // std::unique_ptr
+#include <vector>
+
+#include "core.h"
+
+FMT_BEGIN_NAMESPACE
+
+namespace detail {
+
+template <typename T> struct is_reference_wrapper : std::false_type {};
+template <typename T>
+struct is_reference_wrapper<std::reference_wrapper<T>> : std::true_type {};
+
+template <typename T> const T& unwrap(const T& v) { return v; }
+template <typename T> const T& unwrap(const std::reference_wrapper<T>& v) {
+  return static_cast<const T&>(v);
+}
+
+class dynamic_arg_list {
+  // Workaround for clang's -Wweak-vtables. Unlike for regular classes, for
+  // templates it doesn't complain about inability to deduce single translation
+  // unit for placing vtable. So storage_node_base is made a fake template.
+  template <typename = void> struct node {
+    virtual ~node() = default;
+    std::unique_ptr<node<>> next;
+  };
+
+  template <typename T> struct typed_node : node<> {
+    T value;
+
+    template <typename Arg>
+    FMT_CONSTEXPR typed_node(const Arg& arg) : value(arg) {}
+
+    template <typename Char>
+    FMT_CONSTEXPR typed_node(const basic_string_view<Char>& arg)
+        : value(arg.data(), arg.size()) {}
+  };
+
+  std::unique_ptr<node<>> head_;
+
+ public:
+  template <typename T, typename Arg> const T& push(const Arg& arg) {
+    auto new_node = std::unique_ptr<typed_node<T>>(new typed_node<T>(arg));
+    auto& value = new_node->value;
+    new_node->next = std::move(head_);
+    head_ = std::move(new_node);
+    return value;
+  }
+};
+}  // namespace detail
+
+/**
+  \rst
+  A dynamic version of `fmt::format_arg_store`.
+  It's equipped with a storage to potentially temporary objects which lifetimes
+  could be shorter than the format arguments object.
+
+  It can be implicitly converted into `~fmt::basic_format_args` for passing
+  into type-erased formatting functions such as `~fmt::vformat`.
+  \endrst
+ */
+template <typename Context>
+class dynamic_format_arg_store
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+    // Workaround a GCC template argument substitution bug.
+    : public basic_format_args<Context>
+#endif
+{
+ private:
+  using char_type = typename Context::char_type;
+
+  template <typename T> struct need_copy {
+    static constexpr detail::type mapped_type =
+        detail::mapped_type_constant<T, Context>::value;
+
+    enum {
+      value = !(detail::is_reference_wrapper<T>::value ||
+                std::is_same<T, basic_string_view<char_type>>::value ||
+                std::is_same<T, detail::std_string_view<char_type>>::value ||
+                (mapped_type != detail::type::cstring_type &&
+                 mapped_type != detail::type::string_type &&
+                 mapped_type != detail::type::custom_type))
+    };
+  };
+
+  template <typename T>
+  using stored_type = conditional_t<
+      std::is_convertible<T, std::basic_string<char_type>>::value &&
+          !detail::is_reference_wrapper<T>::value,
+      std::basic_string<char_type>, T>;
+
+  // Storage of basic_format_arg must be contiguous.
+  std::vector<basic_format_arg<Context>> data_;
+  std::vector<detail::named_arg_info<char_type>> named_info_;
+
+  // Storage of arguments not fitting into basic_format_arg must grow
+  // without relocation because items in data_ refer to it.
+  detail::dynamic_arg_list dynamic_args_;
+
+  friend class basic_format_args<Context>;
+
+  unsigned long long get_types() const {
+    return detail::is_unpacked_bit | data_.size() |
+           (named_info_.empty()
+                ? 0ULL
+                : static_cast<unsigned long long>(detail::has_named_args_bit));
+  }
+
+  const basic_format_arg<Context>* data() const {
+    return named_info_.empty() ? data_.data() : data_.data() + 1;
+  }
+
+  template <typename T> void emplace_arg(const T& arg) {
+    data_.emplace_back(detail::make_arg<Context>(arg));
+  }
+
+  template <typename T>
+  void emplace_arg(const detail::named_arg<char_type, T>& arg) {
+    if (named_info_.empty()) {
+      constexpr const detail::named_arg_info<char_type>* zero_ptr{nullptr};
+      data_.insert(data_.begin(), {zero_ptr, 0});
+    }
+    data_.emplace_back(detail::make_arg<Context>(detail::unwrap(arg.value)));
+    auto pop_one = [](std::vector<basic_format_arg<Context>>* data) {
+      data->pop_back();
+    };
+    std::unique_ptr<std::vector<basic_format_arg<Context>>, decltype(pop_one)>
+        guard{&data_, pop_one};
+    named_info_.push_back({arg.name, static_cast<int>(data_.size() - 2u)});
+    data_[0].value_.named_args = {named_info_.data(), named_info_.size()};
+    guard.release();
+  }
+
+ public:
+  constexpr dynamic_format_arg_store() = default;
+
+  /**
+    \rst
+    Adds an argument into the dynamic store for later passing to a formatting
+    function.
+
+    Note that custom types and string types (but not string views) are copied
+    into the store dynamically allocating memory if necessary.
+
+    **Example**::
+
+      fmt::dynamic_format_arg_store<fmt::format_context> store;
+      store.push_back(42);
+      store.push_back("abc");
+      store.push_back(1.5f);
+      std::string result = fmt::vformat("{} and {} and {}", store);
+    \endrst
+  */
+  template <typename T> void push_back(const T& arg) {
+    if (detail::const_check(need_copy<T>::value))
+      emplace_arg(dynamic_args_.push<stored_type<T>>(arg));
+    else
+      emplace_arg(detail::unwrap(arg));
+  }
+
+  /**
+    \rst
+    Adds a reference to the argument into the dynamic store for later passing to
+    a formatting function.
+
+    **Example**::
+
+      fmt::dynamic_format_arg_store<fmt::format_context> store;
+      char band[] = "Rolling Stones";
+      store.push_back(std::cref(band));
+      band[9] = 'c'; // Changing str affects the output.
+      std::string result = fmt::vformat("{}", store);
+      // result == "Rolling Scones"
+    \endrst
+  */
+  template <typename T> void push_back(std::reference_wrapper<T> arg) {
+    static_assert(
+        need_copy<T>::value,
+        "objects of built-in types and string views are always copied");
+    emplace_arg(arg.get());
+  }
+
+  /**
+    Adds named argument into the dynamic store for later passing to a formatting
+    function. ``std::reference_wrapper`` is supported to avoid copying of the
+    argument. The name is always copied into the store.
+  */
+  template <typename T>
+  void push_back(const detail::named_arg<char_type, T>& arg) {
+    const char_type* arg_name =
+        dynamic_args_.push<std::basic_string<char_type>>(arg.name).c_str();
+    if (detail::const_check(need_copy<T>::value)) {
+      emplace_arg(
+          fmt::arg(arg_name, dynamic_args_.push<stored_type<T>>(arg.value)));
+    } else {
+      emplace_arg(fmt::arg(arg_name, arg.value));
+    }
+  }
+
+  /** Erase all elements from the store */
+  void clear() {
+    data_.clear();
+    named_info_.clear();
+    dynamic_args_ = detail::dynamic_arg_list();
+  }
+
+  /**
+    \rst
+    Reserves space to store at least *new_cap* arguments including
+    *new_cap_named* named arguments.
+    \endrst
+  */
+  void reserve(size_t new_cap, size_t new_cap_named) {
+    FMT_ASSERT(new_cap >= new_cap_named,
+               "Set of arguments includes set of named arguments");
+    data_.reserve(new_cap);
+    named_info_.reserve(new_cap_named);
+  }
+};
+
+FMT_END_NAMESPACE
+
+#endif  // FMT_ARGS_H_
@@ -0,0 +1,651 @@
+// Formatting library for C++ - color support
+//
+// Copyright (c) 2018 - present, Victor Zverovich and fmt contributors
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_COLOR_H_
+#define FMT_COLOR_H_
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
+
+enum class color : uint32_t {
+  alice_blue = 0xF0F8FF,               // rgb(240,248,255)
+  antique_white = 0xFAEBD7,            // rgb(250,235,215)
+  aqua = 0x00FFFF,                     // rgb(0,255,255)
+  aquamarine = 0x7FFFD4,               // rgb(127,255,212)
+  azure = 0xF0FFFF,                    // rgb(240,255,255)
+  beige = 0xF5F5DC,                    // rgb(245,245,220)
+  bisque = 0xFFE4C4,                   // rgb(255,228,196)
+  black = 0x000000,                    // rgb(0,0,0)
+  blanched_almond = 0xFFEBCD,          // rgb(255,235,205)
+  blue = 0x0000FF,                     // rgb(0,0,255)
+  blue_violet = 0x8A2BE2,              // rgb(138,43,226)
+  brown = 0xA52A2A,                    // rgb(165,42,42)
+  burly_wood = 0xDEB887,               // rgb(222,184,135)
+  cadet_blue = 0x5F9EA0,               // rgb(95,158,160)
+  chartreuse = 0x7FFF00,               // rgb(127,255,0)
+  chocolate = 0xD2691E,                // rgb(210,105,30)
+  coral = 0xFF7F50,                    // rgb(255,127,80)
+  cornflower_blue = 0x6495ED,          // rgb(100,149,237)
+  cornsilk = 0xFFF8DC,                 // rgb(255,248,220)
+  crimson = 0xDC143C,                  // rgb(220,20,60)
+  cyan = 0x00FFFF,                     // rgb(0,255,255)
+  dark_blue = 0x00008B,                // rgb(0,0,139)
+  dark_cyan = 0x008B8B,                // rgb(0,139,139)
+  dark_golden_rod = 0xB8860B,          // rgb(184,134,11)
+  dark_gray = 0xA9A9A9,                // rgb(169,169,169)
+  dark_green = 0x006400,               // rgb(0,100,0)
+  dark_khaki = 0xBDB76B,               // rgb(189,183,107)
+  dark_magenta = 0x8B008B,             // rgb(139,0,139)
+  dark_olive_green = 0x556B2F,         // rgb(85,107,47)
+  dark_orange = 0xFF8C00,              // rgb(255,140,0)
+  dark_orchid = 0x9932CC,              // rgb(153,50,204)
+  dark_red = 0x8B0000,                 // rgb(139,0,0)
+  dark_salmon = 0xE9967A,              // rgb(233,150,122)
+  dark_sea_green = 0x8FBC8F,           // rgb(143,188,143)
+  dark_slate_blue = 0x483D8B,          // rgb(72,61,139)
+  dark_slate_gray = 0x2F4F4F,          // rgb(47,79,79)
+  dark_turquoise = 0x00CED1,           // rgb(0,206,209)
+  dark_violet = 0x9400D3,              // rgb(148,0,211)
+  deep_pink = 0xFF1493,                // rgb(255,20,147)
+  deep_sky_blue = 0x00BFFF,            // rgb(0,191,255)
+  dim_gray = 0x696969,                 // rgb(105,105,105)
+  dodger_blue = 0x1E90FF,              // rgb(30,144,255)
+  fire_brick = 0xB22222,               // rgb(178,34,34)
+  floral_white = 0xFFFAF0,             // rgb(255,250,240)
+  forest_green = 0x228B22,             // rgb(34,139,34)
+  fuchsia = 0xFF00FF,                  // rgb(255,0,255)
+  gainsboro = 0xDCDCDC,                // rgb(220,220,220)
+  ghost_white = 0xF8F8FF,              // rgb(248,248,255)
+  gold = 0xFFD700,                     // rgb(255,215,0)
+  golden_rod = 0xDAA520,               // rgb(218,165,32)
+  gray = 0x808080,                     // rgb(128,128,128)
+  green = 0x008000,                    // rgb(0,128,0)
+  green_yellow = 0xADFF2F,             // rgb(173,255,47)
+  honey_dew = 0xF0FFF0,                // rgb(240,255,240)
+  hot_pink = 0xFF69B4,                 // rgb(255,105,180)
+  indian_red = 0xCD5C5C,               // rgb(205,92,92)
+  indigo = 0x4B0082,                   // rgb(75,0,130)
+  ivory = 0xFFFFF0,                    // rgb(255,255,240)
+  khaki = 0xF0E68C,                    // rgb(240,230,140)
+  lavender = 0xE6E6FA,                 // rgb(230,230,250)
+  lavender_blush = 0xFFF0F5,           // rgb(255,240,245)
+  lawn_green = 0x7CFC00,               // rgb(124,252,0)
+  lemon_chiffon = 0xFFFACD,            // rgb(255,250,205)
+  light_blue = 0xADD8E6,               // rgb(173,216,230)
+  light_coral = 0xF08080,              // rgb(240,128,128)
+  light_cyan = 0xE0FFFF,               // rgb(224,255,255)
+  light_golden_rod_yellow = 0xFAFAD2,  // rgb(250,250,210)
+  light_gray = 0xD3D3D3,               // rgb(211,211,211)
+  light_green = 0x90EE90,              // rgb(144,238,144)
+  light_pink = 0xFFB6C1,               // rgb(255,182,193)
+  light_salmon = 0xFFA07A,             // rgb(255,160,122)
+  light_sea_green = 0x20B2AA,          // rgb(32,178,170)
+  light_sky_blue = 0x87CEFA,           // rgb(135,206,250)
+  light_slate_gray = 0x778899,         // rgb(119,136,153)
+  light_steel_blue = 0xB0C4DE,         // rgb(176,196,222)
+  light_yellow = 0xFFFFE0,             // rgb(255,255,224)
+  lime = 0x00FF00,                     // rgb(0,255,0)
+  lime_green = 0x32CD32,               // rgb(50,205,50)
+  linen = 0xFAF0E6,                    // rgb(250,240,230)
+  magenta = 0xFF00FF,                  // rgb(255,0,255)
+  maroon = 0x800000,                   // rgb(128,0,0)
+  medium_aquamarine = 0x66CDAA,        // rgb(102,205,170)
+  medium_blue = 0x0000CD,              // rgb(0,0,205)
+  medium_orchid = 0xBA55D3,            // rgb(186,85,211)
+  medium_purple = 0x9370DB,            // rgb(147,112,219)
+  medium_sea_green = 0x3CB371,         // rgb(60,179,113)
+  medium_slate_blue = 0x7B68EE,        // rgb(123,104,238)
+  medium_spring_green = 0x00FA9A,      // rgb(0,250,154)
+  medium_turquoise = 0x48D1CC,         // rgb(72,209,204)
+  medium_violet_red = 0xC71585,        // rgb(199,21,133)
+  midnight_blue = 0x191970,            // rgb(25,25,112)
+  mint_cream = 0xF5FFFA,               // rgb(245,255,250)
+  misty_rose = 0xFFE4E1,               // rgb(255,228,225)
+  moccasin = 0xFFE4B5,                 // rgb(255,228,181)
+  navajo_white = 0xFFDEAD,             // rgb(255,222,173)
+  navy = 0x000080,                     // rgb(0,0,128)
+  old_lace = 0xFDF5E6,                 // rgb(253,245,230)
+  olive = 0x808000,                    // rgb(128,128,0)
+  olive_drab = 0x6B8E23,               // rgb(107,142,35)
+  orange = 0xFFA500,                   // rgb(255,165,0)
+  orange_red = 0xFF4500,               // rgb(255,69,0)
+  orchid = 0xDA70D6,                   // rgb(218,112,214)
+  pale_golden_rod = 0xEEE8AA,          // rgb(238,232,170)
+  pale_green = 0x98FB98,               // rgb(152,251,152)
+  pale_turquoise = 0xAFEEEE,           // rgb(175,238,238)
+  pale_violet_red = 0xDB7093,          // rgb(219,112,147)
+  papaya_whip = 0xFFEFD5,              // rgb(255,239,213)
+  peach_puff = 0xFFDAB9,               // rgb(255,218,185)
+  peru = 0xCD853F,                     // rgb(205,133,63)
+  pink = 0xFFC0CB,                     // rgb(255,192,203)
+  plum = 0xDDA0DD,                     // rgb(221,160,221)
+  powder_blue = 0xB0E0E6,              // rgb(176,224,230)
+  purple = 0x800080,                   // rgb(128,0,128)
+  rebecca_purple = 0x663399,           // rgb(102,51,153)
+  red = 0xFF0000,                      // rgb(255,0,0)
+  rosy_brown = 0xBC8F8F,               // rgb(188,143,143)
+  royal_blue = 0x4169E1,               // rgb(65,105,225)
+  saddle_brown = 0x8B4513,             // rgb(139,69,19)
+  salmon = 0xFA8072,                   // rgb(250,128,114)
+  sandy_brown = 0xF4A460,              // rgb(244,164,96)
+  sea_green = 0x2E8B57,                // rgb(46,139,87)
+  sea_shell = 0xFFF5EE,                // rgb(255,245,238)
+  sienna = 0xA0522D,                   // rgb(160,82,45)
+  silver = 0xC0C0C0,                   // rgb(192,192,192)
+  sky_blue = 0x87CEEB,                 // rgb(135,206,235)
+  slate_blue = 0x6A5ACD,               // rgb(106,90,205)
+  slate_gray = 0x708090,               // rgb(112,128,144)
+  snow = 0xFFFAFA,                     // rgb(255,250,250)
+  spring_green = 0x00FF7F,             // rgb(0,255,127)
+  steel_blue = 0x4682B4,               // rgb(70,130,180)
+  tan = 0xD2B48C,                      // rgb(210,180,140)
+  teal = 0x008080,                     // rgb(0,128,128)
+  thistle = 0xD8BFD8,                  // rgb(216,191,216)
+  tomato = 0xFF6347,                   // rgb(255,99,71)
+  turquoise = 0x40E0D0,                // rgb(64,224,208)
+  violet = 0xEE82EE,                   // rgb(238,130,238)
+  wheat = 0xF5DEB3,                    // rgb(245,222,179)
+  white = 0xFFFFFF,                    // rgb(255,255,255)
+  white_smoke = 0xF5F5F5,              // rgb(245,245,245)
+  yellow = 0xFFFF00,                   // rgb(255,255,0)
+  yellow_green = 0x9ACD32              // rgb(154,205,50)
+};                                     // enum class color
+
+enum class terminal_color : uint8_t {
+  black = 30,
+  red,
+  green,
+  yellow,
+  blue,
+  magenta,
+  cyan,
+  white,
+  bright_black = 90,
+  bright_red,
+  bright_green,
+  bright_yellow,
+  bright_blue,
+  bright_magenta,
+  bright_cyan,
+  bright_white
+};
+
+enum class emphasis : uint8_t {
+  bold = 1,
+  faint = 1 << 1,
+  italic = 1 << 2,
+  underline = 1 << 3,
+  blink = 1 << 4,
+  reverse = 1 << 5,
+  conceal = 1 << 6,
+  strikethrough = 1 << 7,
+};
+
+// rgb is a struct for red, green and blue colors.
+// Using the name "rgb" makes some editors show the color in a tooltip.
+struct rgb {
+  FMT_CONSTEXPR rgb() : r(0), g(0), b(0) {}
+  FMT_CONSTEXPR rgb(uint8_t r_, uint8_t g_, uint8_t b_) : r(r_), g(g_), b(b_) {}
+  FMT_CONSTEXPR rgb(uint32_t hex)
+      : r((hex >> 16) & 0xFF), g((hex >> 8) & 0xFF), b(hex & 0xFF) {}
+  FMT_CONSTEXPR rgb(color hex)
+      : r((uint32_t(hex) >> 16) & 0xFF),
+        g((uint32_t(hex) >> 8) & 0xFF),
+        b(uint32_t(hex) & 0xFF) {}
+  uint8_t r;
+  uint8_t g;
+  uint8_t b;
+};
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+// color is a struct of either a rgb color or a terminal color.
+struct color_type {
+  FMT_CONSTEXPR color_type() noexcept : is_rgb(), value{} {}
+  FMT_CONSTEXPR color_type(color rgb_color) noexcept : is_rgb(true), value{} {
+    value.rgb_color = static_cast<uint32_t>(rgb_color);
+  }
+  FMT_CONSTEXPR color_type(rgb rgb_color) noexcept : is_rgb(true), value{} {
+    value.rgb_color = (static_cast<uint32_t>(rgb_color.r) << 16) |
+                      (static_cast<uint32_t>(rgb_color.g) << 8) | rgb_color.b;
+  }
+  FMT_CONSTEXPR color_type(terminal_color term_color) noexcept
+      : is_rgb(), value{} {
+    value.term_color = static_cast<uint8_t>(term_color);
+  }
+  bool is_rgb;
+  union color_union {
+    uint8_t term_color;
+    uint32_t rgb_color;
+  } value;
+};
+
+FMT_END_DETAIL_NAMESPACE
+
+/** A text style consisting of foreground and background colors and emphasis. */
+class text_style {
+ public:
+  FMT_CONSTEXPR text_style(emphasis em = emphasis()) noexcept
+      : set_foreground_color(), set_background_color(), ems(em) {}
+
+  FMT_CONSTEXPR text_style& operator|=(const text_style& rhs) {
+    if (!set_foreground_color) {
+      set_foreground_color = rhs.set_foreground_color;
+      foreground_color = rhs.foreground_color;
+    } else if (rhs.set_foreground_color) {
+      if (!foreground_color.is_rgb || !rhs.foreground_color.is_rgb)
+        FMT_THROW(format_error("can't OR a terminal color"));
+      foreground_color.value.rgb_color |= rhs.foreground_color.value.rgb_color;
+    }
+
+    if (!set_background_color) {
+      set_background_color = rhs.set_background_color;
+      background_color = rhs.background_color;
+    } else if (rhs.set_background_color) {
+      if (!background_color.is_rgb || !rhs.background_color.is_rgb)
+        FMT_THROW(format_error("can't OR a terminal color"));
+      background_color.value.rgb_color |= rhs.background_color.value.rgb_color;
+    }
+
+    ems = static_cast<emphasis>(static_cast<uint8_t>(ems) |
+                                static_cast<uint8_t>(rhs.ems));
+    return *this;
+  }
+
+  friend FMT_CONSTEXPR text_style operator|(text_style lhs,
+                                            const text_style& rhs) {
+    return lhs |= rhs;
+  }
+
+  FMT_CONSTEXPR bool has_foreground() const noexcept {
+    return set_foreground_color;
+  }
+  FMT_CONSTEXPR bool has_background() const noexcept {
+    return set_background_color;
+  }
+  FMT_CONSTEXPR bool has_emphasis() const noexcept {
+    return static_cast<uint8_t>(ems) != 0;
+  }
+  FMT_CONSTEXPR detail::color_type get_foreground() const noexcept {
+    FMT_ASSERT(has_foreground(), "no foreground specified for this style");
+    return foreground_color;
+  }
+  FMT_CONSTEXPR detail::color_type get_background() const noexcept {
+    FMT_ASSERT(has_background(), "no background specified for this style");
+    return background_color;
+  }
+  FMT_CONSTEXPR emphasis get_emphasis() const noexcept {
+    FMT_ASSERT(has_emphasis(), "no emphasis specified for this style");
+    return ems;
+  }
+
+ private:
+  FMT_CONSTEXPR text_style(bool is_foreground,
+                           detail::color_type text_color) noexcept
+      : set_foreground_color(), set_background_color(), ems() {
+    if (is_foreground) {
+      foreground_color = text_color;
+      set_foreground_color = true;
+    } else {
+      background_color = text_color;
+      set_background_color = true;
+    }
+  }
+
+  friend FMT_CONSTEXPR text_style fg(detail::color_type foreground) noexcept;
+
+  friend FMT_CONSTEXPR text_style bg(detail::color_type background) noexcept;
+
+  detail::color_type foreground_color;
+  detail::color_type background_color;
+  bool set_foreground_color;
+  bool set_background_color;
+  emphasis ems;
+};
+
+/** Creates a text style from the foreground (text) color. */
+FMT_CONSTEXPR inline text_style fg(detail::color_type foreground) noexcept {
+  return text_style(true, foreground);
+}
+
+/** Creates a text style from the background color. */
+FMT_CONSTEXPR inline text_style bg(detail::color_type background) noexcept {
+  return text_style(false, background);
+}
+
+FMT_CONSTEXPR inline text_style operator|(emphasis lhs, emphasis rhs) noexcept {
+  return text_style(lhs) | rhs;
+}
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+template <typename Char> struct ansi_color_escape {
+  FMT_CONSTEXPR ansi_color_escape(detail::color_type text_color,
+                                  const char* esc) noexcept {
+    // If we have a terminal color, we need to output another escape code
+    // sequence.
+    if (!text_color.is_rgb) {
+      bool is_background = esc == string_view("\x1b[48;2;");
+      uint32_t value = text_color.value.term_color;
+      // Background ASCII codes are the same as the foreground ones but with
+      // 10 more.
+      if (is_background) value += 10u;
+
+      size_t index = 0;
+      buffer[index++] = static_cast<Char>('\x1b');
+      buffer[index++] = static_cast<Char>('[');
+
+      if (value >= 100u) {
+        buffer[index++] = static_cast<Char>('1');
+        value %= 100u;
+      }
+      buffer[index++] = static_cast<Char>('0' + value / 10u);
+      buffer[index++] = static_cast<Char>('0' + value % 10u);
+
+      buffer[index++] = static_cast<Char>('m');
+      buffer[index++] = static_cast<Char>('\0');
+      return;
+    }
+
+    for (int i = 0; i < 7; i++) {
+      buffer[i] = static_cast<Char>(esc[i]);
+    }
+    rgb color(text_color.value.rgb_color);
+    to_esc(color.r, buffer + 7, ';');
+    to_esc(color.g, buffer + 11, ';');
+    to_esc(color.b, buffer + 15, 'm');
+    buffer[19] = static_cast<Char>(0);
+  }
+  FMT_CONSTEXPR ansi_color_escape(emphasis em) noexcept {
+    uint8_t em_codes[num_emphases] = {};
+    if (has_emphasis(em, emphasis::bold)) em_codes[0] = 1;
+    if (has_emphasis(em, emphasis::faint)) em_codes[1] = 2;
+    if (has_emphasis(em, emphasis::italic)) em_codes[2] = 3;
+    if (has_emphasis(em, emphasis::underline)) em_codes[3] = 4;
+    if (has_emphasis(em, emphasis::blink)) em_codes[4] = 5;
+    if (has_emphasis(em, emphasis::reverse)) em_codes[5] = 7;
+    if (has_emphasis(em, emphasis::conceal)) em_codes[6] = 8;
+    if (has_emphasis(em, emphasis::strikethrough)) em_codes[7] = 9;
+
+    size_t index = 0;
+    for (size_t i = 0; i < num_emphases; ++i) {
+      if (!em_codes[i]) continue;
+      buffer[index++] = static_cast<Char>('\x1b');
+      buffer[index++] = static_cast<Char>('[');
+      buffer[index++] = static_cast<Char>('0' + em_codes[i]);
+      buffer[index++] = static_cast<Char>('m');
+    }
+    buffer[index++] = static_cast<Char>(0);
+  }
+  FMT_CONSTEXPR operator const Char*() const noexcept { return buffer; }
+
+  FMT_CONSTEXPR const Char* begin() const noexcept { return buffer; }
+  FMT_CONSTEXPR_CHAR_TRAITS const Char* end() const noexcept {
+    return buffer + std::char_traits<Char>::length(buffer);
+  }
+
+ private:
+  static constexpr size_t num_emphases = 8;
+  Char buffer[7u + 3u * num_emphases + 1u];
+
+  static FMT_CONSTEXPR void to_esc(uint8_t c, Char* out,
+                                   char delimiter) noexcept {
+    out[0] = static_cast<Char>('0' + c / 100);
+    out[1] = static_cast<Char>('0' + c / 10 % 10);
+    out[2] = static_cast<Char>('0' + c % 10);
+    out[3] = static_cast<Char>(delimiter);
+  }
+  static FMT_CONSTEXPR bool has_emphasis(emphasis em, emphasis mask) noexcept {
+    return static_cast<uint8_t>(em) & static_cast<uint8_t>(mask);
+  }
+};
+
+template <typename Char>
+FMT_CONSTEXPR ansi_color_escape<Char> make_foreground_color(
+    detail::color_type foreground) noexcept {
+  return ansi_color_escape<Char>(foreground, "\x1b[38;2;");
+}
+
+template <typename Char>
+FMT_CONSTEXPR ansi_color_escape<Char> make_background_color(
+    detail::color_type background) noexcept {
+  return ansi_color_escape<Char>(background, "\x1b[48;2;");
+}
+
+template <typename Char>
+FMT_CONSTEXPR ansi_color_escape<Char> make_emphasis(emphasis em) noexcept {
+  return ansi_color_escape<Char>(em);
+}
+
+template <typename Char> inline void fputs(const Char* chars, FILE* stream) {
+  int result = std::fputs(chars, stream);
+  if (result < 0)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+template <> inline void fputs<wchar_t>(const wchar_t* chars, FILE* stream) {
+  int result = std::fputws(chars, stream);
+  if (result < 0)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+template <typename Char> inline void reset_color(FILE* stream) {
+  fputs("\x1b[0m", stream);
+}
+
+template <> inline void reset_color<wchar_t>(FILE* stream) {
+  fputs(L"\x1b[0m", stream);
+}
+
+template <typename Char> inline void reset_color(buffer<Char>& buffer) {
+  auto reset_color = string_view("\x1b[0m");
+  buffer.append(reset_color.begin(), reset_color.end());
+}
+
+template <typename T> struct styled_arg {
+  const T& value;
+  text_style style;
+};
+
+template <typename Char>
+void vformat_to(buffer<Char>& buf, const text_style& ts,
+                basic_string_view<Char> format_str,
+                basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  bool has_style = false;
+  if (ts.has_emphasis()) {
+    has_style = true;
+    auto emphasis = detail::make_emphasis<Char>(ts.get_emphasis());
+    buf.append(emphasis.begin(), emphasis.end());
+  }
+  if (ts.has_foreground()) {
+    has_style = true;
+    auto foreground = detail::make_foreground_color<Char>(ts.get_foreground());
+    buf.append(foreground.begin(), foreground.end());
+  }
+  if (ts.has_background()) {
+    has_style = true;
+    auto background = detail::make_background_color<Char>(ts.get_background());
+    buf.append(background.begin(), background.end());
+  }
+  detail::vformat_to(buf, format_str, args, {});
+  if (has_style) detail::reset_color<Char>(buf);
+}
+
+FMT_END_DETAIL_NAMESPACE
+
+template <typename S, typename Char = char_t<S>>
+void vprint(std::FILE* f, const text_style& ts, const S& format,
+            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  basic_memory_buffer<Char> buf;
+  detail::vformat_to(buf, ts, detail::to_string_view(format), args);
+  if (detail::is_utf8()) {
+    detail::print(f, basic_string_view<Char>(buf.begin(), buf.size()));
+  } else {
+    buf.push_back(Char(0));
+    detail::fputs(buf.data(), f);
+  }
+}
+
+/**
+  \rst
+  Formats a string and prints it to the specified file stream using ANSI
+  escape sequences to specify text formatting.
+
+  **Example**::
+
+    fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
+               "Elapsed time: {0:.2f} seconds", 1.23);
+  \endrst
+ */
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_string<S>::value)>
+void print(std::FILE* f, const text_style& ts, const S& format_str,
+           const Args&... args) {
+  vprint(f, ts, format_str,
+         fmt::make_format_args<buffer_context<char_t<S>>>(args...));
+}
+
+/**
+  \rst
+  Formats a string and prints it to stdout using ANSI escape sequences to
+  specify text formatting.
+
+  **Example**::
+
+    fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
+               "Elapsed time: {0:.2f} seconds", 1.23);
+  \endrst
+ */
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_string<S>::value)>
+void print(const text_style& ts, const S& format_str, const Args&... args) {
+  return print(stdout, ts, format_str, args...);
+}
+
+template <typename S, typename Char = char_t<S>>
+inline std::basic_string<Char> vformat(
+    const text_style& ts, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  basic_memory_buffer<Char> buf;
+  detail::vformat_to(buf, ts, detail::to_string_view(format_str), args);
+  return fmt::to_string(buf);
+}
+
+/**
+  \rst
+  Formats arguments and returns the result as a string using ANSI
+  escape sequences to specify text formatting.
+
+  **Example**::
+
+    #include <fmt/color.h>
+    std::string message = fmt::format(fmt::emphasis::bold | fg(fmt::color::red),
+                                      "The answer is {}", 42);
+  \endrst
+*/
+template <typename S, typename... Args, typename Char = char_t<S>>
+inline std::basic_string<Char> format(const text_style& ts, const S& format_str,
+                                      const Args&... args) {
+  return fmt::vformat(ts, detail::to_string_view(format_str),
+                      fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+/**
+  Formats a string with the given text_style and writes the output to ``out``.
+ */
+template <typename OutputIt, typename Char,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value)>
+OutputIt vformat_to(
+    OutputIt out, const text_style& ts, basic_string_view<Char> format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  auto&& buf = detail::get_buffer<Char>(out);
+  detail::vformat_to(buf, ts, format_str, args);
+  return detail::get_iterator(buf);
+}
+
+/**
+  \rst
+  Formats arguments with the given text_style, writes the result to the output
+  iterator ``out`` and returns the iterator past the end of the output range.
+
+  **Example**::
+
+    std::vector<char> out;
+    fmt::format_to(std::back_inserter(out),
+                   fmt::emphasis::bold | fg(fmt::color::red), "{}", 42);
+  \endrst
+*/
+template <typename OutputIt, typename S, typename... Args,
+          bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value&&
+              detail::is_string<S>::value>
+inline auto format_to(OutputIt out, const text_style& ts, const S& format_str,
+                      Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  return vformat_to(out, ts, detail::to_string_view(format_str),
+                    fmt::make_format_args<buffer_context<char_t<S>>>(args...));
+}
+
+template <typename T, typename Char>
+struct formatter<detail::styled_arg<T>, Char> : formatter<T, Char> {
+  template <typename FormatContext>
+  auto format(const detail::styled_arg<T>& arg, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    const auto& ts = arg.style;
+    const auto& value = arg.value;
+    auto out = ctx.out();
+
+    bool has_style = false;
+    if (ts.has_emphasis()) {
+      has_style = true;
+      auto emphasis = detail::make_emphasis<Char>(ts.get_emphasis());
+      out = std::copy(emphasis.begin(), emphasis.end(), out);
+    }
+    if (ts.has_foreground()) {
+      has_style = true;
+      auto foreground =
+          detail::make_foreground_color<Char>(ts.get_foreground());
+      out = std::copy(foreground.begin(), foreground.end(), out);
+    }
+    if (ts.has_background()) {
+      has_style = true;
+      auto background =
+          detail::make_background_color<Char>(ts.get_background());
+      out = std::copy(background.begin(), background.end(), out);
+    }
+    out = formatter<T, Char>::format(value, ctx);
+    if (has_style) {
+      auto reset_color = string_view("\x1b[0m");
+      out = std::copy(reset_color.begin(), reset_color.end(), out);
+    }
+    return out;
+  }
+};
+
+/**
+  \rst
+  Returns an argument that will be formatted using ANSI escape sequences,
+  to be used in a formatting function.
+
+  **Example**::
+
+    fmt::print("Elapsed time: {0:.2f} seconds",
+               fmt::styled(1.23, fmt::fg(fmt::color::green) |
+                                 fmt::bg(fmt::color::blue)));
+  \endrst
+ */
+template <typename T>
+FMT_CONSTEXPR auto styled(const T& value, text_style ts)
+    -> detail::styled_arg<remove_cvref_t<T>> {
+  return detail::styled_arg<remove_cvref_t<T>>{value, ts};
+}
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_COLOR_H_
@@ -0,0 +1,611 @@
+// Formatting library for C++ - experimental format string compilation
+//
+// Copyright (c) 2012 - present, Victor Zverovich and fmt contributors
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_COMPILE_H_
+#define FMT_COMPILE_H_
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+
+template <typename Char, typename InputIt>
+FMT_CONSTEXPR inline counting_iterator copy_str(InputIt begin, InputIt end,
+                                                counting_iterator it) {
+  return it + (end - begin);
+}
+
+template <typename OutputIt> class truncating_iterator_base {
+ protected:
+  OutputIt out_;
+  size_t limit_;
+  size_t count_ = 0;
+
+  truncating_iterator_base() : out_(), limit_(0) {}
+
+  truncating_iterator_base(OutputIt out, size_t limit)
+      : out_(out), limit_(limit) {}
+
+ public:
+  using iterator_category = std::output_iterator_tag;
+  using value_type = typename std::iterator_traits<OutputIt>::value_type;
+  using difference_type = std::ptrdiff_t;
+  using pointer = void;
+  using reference = void;
+  FMT_UNCHECKED_ITERATOR(truncating_iterator_base);
+
+  OutputIt base() const { return out_; }
+  size_t count() const { return count_; }
+};
+
+// An output iterator that truncates the output and counts the number of objects
+// written to it.
+template <typename OutputIt,
+          typename Enable = typename std::is_void<
+              typename std::iterator_traits<OutputIt>::value_type>::type>
+class truncating_iterator;
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::false_type>
+    : public truncating_iterator_base<OutputIt> {
+  mutable typename truncating_iterator_base<OutputIt>::value_type blackhole_;
+
+ public:
+  using value_type = typename truncating_iterator_base<OutputIt>::value_type;
+
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  truncating_iterator& operator++() {
+    if (this->count_++ < this->limit_) ++this->out_;
+    return *this;
+  }
+
+  truncating_iterator operator++(int) {
+    auto it = *this;
+    ++*this;
+    return it;
+  }
+
+  value_type& operator*() const {
+    return this->count_ < this->limit_ ? *this->out_ : blackhole_;
+  }
+};
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::true_type>
+    : public truncating_iterator_base<OutputIt> {
+ public:
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  template <typename T> truncating_iterator& operator=(T val) {
+    if (this->count_++ < this->limit_) *this->out_++ = val;
+    return *this;
+  }
+
+  truncating_iterator& operator++() { return *this; }
+  truncating_iterator& operator++(int) { return *this; }
+  truncating_iterator& operator*() { return *this; }
+};
+
+// A compile-time string which is compiled into fast formatting code.
+class compiled_string {};
+
+template <typename S>
+struct is_compiled_string : std::is_base_of<compiled_string, S> {};
+
+/**
+  \rst
+  Converts a string literal *s* into a format string that will be parsed at
+  compile time and converted into efficient formatting code. Requires C++17
+  ``constexpr if`` compiler support.
+
+  **Example**::
+
+    // Converts 42 into std::string using the most efficient method and no
+    // runtime format string processing.
+    std::string s = fmt::format(FMT_COMPILE("{}"), 42);
+  \endrst
+ */
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+#  define FMT_COMPILE(s) \
+    FMT_STRING_IMPL(s, fmt::detail::compiled_string, explicit)
+#else
+#  define FMT_COMPILE(s) FMT_STRING(s)
+#endif
+
+#if FMT_USE_NONTYPE_TEMPLATE_ARGS
+template <typename Char, size_t N,
+          fmt::detail_exported::fixed_string<Char, N> Str>
+struct udl_compiled_string : compiled_string {
+  using char_type = Char;
+  explicit constexpr operator basic_string_view<char_type>() const {
+    return {Str.data, N - 1};
+  }
+};
+#endif
+
+template <typename T, typename... Tail>
+const T& first(const T& value, const Tail&...) {
+  return value;
+}
+
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+template <typename... Args> struct type_list {};
+
+// Returns a reference to the argument at index N from [first, rest...].
+template <int N, typename T, typename... Args>
+constexpr const auto& get([[maybe_unused]] const T& first,
+                          [[maybe_unused]] const Args&... rest) {
+  static_assert(N < 1 + sizeof...(Args), "index is out of bounds");
+  if constexpr (N == 0)
+    return first;
+  else
+    return detail::get<N - 1>(rest...);
+}
+
+template <typename Char, typename... Args>
+constexpr int get_arg_index_by_name(basic_string_view<Char> name,
+                                    type_list<Args...>) {
+  return get_arg_index_by_name<Args...>(name);
+}
+
+template <int N, typename> struct get_type_impl;
+
+template <int N, typename... Args> struct get_type_impl<N, type_list<Args...>> {
+  using type =
+      remove_cvref_t<decltype(detail::get<N>(std::declval<Args>()...))>;
+};
+
+template <int N, typename T>
+using get_type = typename get_type_impl<N, T>::type;
+
+template <typename T> struct is_compiled_format : std::false_type {};
+
+template <typename Char> struct text {
+  basic_string_view<Char> data;
+  using char_type = Char;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&...) const {
+    return write<Char>(out, data);
+  }
+};
+
+template <typename Char>
+struct is_compiled_format<text<Char>> : std::true_type {};
+
+template <typename Char>
+constexpr text<Char> make_text(basic_string_view<Char> s, size_t pos,
+                               size_t size) {
+  return {{&s[pos], size}};
+}
+
+template <typename Char> struct code_unit {
+  Char value;
+  using char_type = Char;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&...) const {
+    return write<Char>(out, value);
+  }
+};
+
+// This ensures that the argument type is convertible to `const T&`.
+template <typename T, int N, typename... Args>
+constexpr const T& get_arg_checked(const Args&... args) {
+  const auto& arg = detail::get<N>(args...);
+  if constexpr (detail::is_named_arg<remove_cvref_t<decltype(arg)>>()) {
+    return arg.value;
+  } else {
+    return arg;
+  }
+}
+
+template <typename Char>
+struct is_compiled_format<code_unit<Char>> : std::true_type {};
+
+// A replacement field that refers to argument N.
+template <typename Char, typename T, int N> struct field {
+  using char_type = Char;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+    return write<Char>(out, get_arg_checked<T, N>(args...));
+  }
+};
+
+template <typename Char, typename T, int N>
+struct is_compiled_format<field<Char, T, N>> : std::true_type {};
+
+// A replacement field that refers to argument with name.
+template <typename Char> struct runtime_named_field {
+  using char_type = Char;
+  basic_string_view<Char> name;
+
+  template <typename OutputIt, typename T>
+  constexpr static bool try_format_argument(
+      OutputIt& out,
+      // [[maybe_unused]] due to unused-but-set-parameter warning in GCC 7,8,9
+      [[maybe_unused]] basic_string_view<Char> arg_name, const T& arg) {
+    if constexpr (is_named_arg<typename std::remove_cv<T>::type>::value) {
+      if (arg_name == arg.name) {
+        out = write<Char>(out, arg.value);
+        return true;
+      }
+    }
+    return false;
+  }
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+    bool found = (try_format_argument(out, name, args) || ...);
+    if (!found) {
+      FMT_THROW(format_error("argument with specified name is not found"));
+    }
+    return out;
+  }
+};
+
+template <typename Char>
+struct is_compiled_format<runtime_named_field<Char>> : std::true_type {};
+
+// A replacement field that refers to argument N and has format specifiers.
+template <typename Char, typename T, int N> struct spec_field {
+  using char_type = Char;
+  formatter<T, Char> fmt;
+
+  template <typename OutputIt, typename... Args>
+  constexpr FMT_INLINE OutputIt format(OutputIt out,
+                                       const Args&... args) const {
+    const auto& vargs =
+        fmt::make_format_args<basic_format_context<OutputIt, Char>>(args...);
+    basic_format_context<OutputIt, Char> ctx(out, vargs);
+    return fmt.format(get_arg_checked<T, N>(args...), ctx);
+  }
+};
+
+template <typename Char, typename T, int N>
+struct is_compiled_format<spec_field<Char, T, N>> : std::true_type {};
+
+template <typename L, typename R> struct concat {
+  L lhs;
+  R rhs;
+  using char_type = typename L::char_type;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+    out = lhs.format(out, args...);
+    return rhs.format(out, args...);
+  }
+};
+
+template <typename L, typename R>
+struct is_compiled_format<concat<L, R>> : std::true_type {};
+
+template <typename L, typename R>
+constexpr concat<L, R> make_concat(L lhs, R rhs) {
+  return {lhs, rhs};
+}
+
+struct unknown_format {};
+
+template <typename Char>
+constexpr size_t parse_text(basic_string_view<Char> str, size_t pos) {
+  for (size_t size = str.size(); pos != size; ++pos) {
+    if (str[pos] == '{' || str[pos] == '}') break;
+  }
+  return pos;
+}
+
+template <typename Args, size_t POS, int ID, typename S>
+constexpr auto compile_format_string(S format_str);
+
+template <typename Args, size_t POS, int ID, typename T, typename S>
+constexpr auto parse_tail(T head, S format_str) {
+  if constexpr (POS !=
+                basic_string_view<typename S::char_type>(format_str).size()) {
+    constexpr auto tail = compile_format_string<Args, POS, ID>(format_str);
+    if constexpr (std::is_same<remove_cvref_t<decltype(tail)>,
+                               unknown_format>())
+      return tail;
+    else
+      return make_concat(head, tail);
+  } else {
+    return head;
+  }
+}
+
+template <typename T, typename Char> struct parse_specs_result {
+  formatter<T, Char> fmt;
+  size_t end;
+  int next_arg_id;
+};
+
+constexpr int manual_indexing_id = -1;
+
+template <typename T, typename Char>
+constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,
+                                                  size_t pos, int next_arg_id) {
+  str.remove_prefix(pos);
+  auto ctx = compile_parse_context<Char>(str, max_value<int>(), nullptr, {},
+                                         next_arg_id);
+  auto f = formatter<T, Char>();
+  auto end = f.parse(ctx);
+  return {f, pos + fmt::detail::to_unsigned(end - str.data()),
+          next_arg_id == 0 ? manual_indexing_id : ctx.next_arg_id()};
+}
+
+template <typename Char> struct arg_id_handler {
+  arg_ref<Char> arg_id;
+
+  constexpr int operator()() {
+    FMT_ASSERT(false, "handler cannot be used with automatic indexing");
+    return 0;
+  }
+  constexpr int operator()(int id) {
+    arg_id = arg_ref<Char>(id);
+    return 0;
+  }
+  constexpr int operator()(basic_string_view<Char> id) {
+    arg_id = arg_ref<Char>(id);
+    return 0;
+  }
+
+  constexpr void on_error(const char* message) {
+    FMT_THROW(format_error(message));
+  }
+};
+
+template <typename Char> struct parse_arg_id_result {
+  arg_ref<Char> arg_id;
+  const Char* arg_id_end;
+};
+
+template <int ID, typename Char>
+constexpr auto parse_arg_id(const Char* begin, const Char* end) {
+  auto handler = arg_id_handler<Char>{arg_ref<Char>{}};
+  auto arg_id_end = parse_arg_id(begin, end, handler);
+  return parse_arg_id_result<Char>{handler.arg_id, arg_id_end};
+}
+
+template <typename T, typename Enable = void> struct field_type {
+  using type = remove_cvref_t<T>;
+};
+
+template <typename T>
+struct field_type<T, enable_if_t<detail::is_named_arg<T>::value>> {
+  using type = remove_cvref_t<decltype(T::value)>;
+};
+
+template <typename T, typename Args, size_t END_POS, int ARG_INDEX, int NEXT_ID,
+          typename S>
+constexpr auto parse_replacement_field_then_tail(S format_str) {
+  using char_type = typename S::char_type;
+  constexpr auto str = basic_string_view<char_type>(format_str);
+  constexpr char_type c = END_POS != str.size() ? str[END_POS] : char_type();
+  if constexpr (c == '}') {
+    return parse_tail<Args, END_POS + 1, NEXT_ID>(
+        field<char_type, typename field_type<T>::type, ARG_INDEX>(),
+        format_str);
+  } else if constexpr (c != ':') {
+    FMT_THROW(format_error("expected ':'"));
+  } else {
+    constexpr auto result = parse_specs<typename field_type<T>::type>(
+        str, END_POS + 1, NEXT_ID == manual_indexing_id ? 0 : NEXT_ID);
+    if constexpr (result.end >= str.size() || str[result.end] != '}') {
+      FMT_THROW(format_error("expected '}'"));
+      return 0;
+    } else {
+      return parse_tail<Args, result.end + 1, result.next_arg_id>(
+          spec_field<char_type, typename field_type<T>::type, ARG_INDEX>{
+              result.fmt},
+          format_str);
+    }
+  }
+}
+
+// Compiles a non-empty format string and returns the compiled representation
+// or unknown_format() on unrecognized input.
+template <typename Args, size_t POS, int ID, typename S>
+constexpr auto compile_format_string(S format_str) {
+  using char_type = typename S::char_type;
+  constexpr auto str = basic_string_view<char_type>(format_str);
+  if constexpr (str[POS] == '{') {
+    if constexpr (POS + 1 == str.size())
+      FMT_THROW(format_error("unmatched '{' in format string"));
+    if constexpr (str[POS + 1] == '{') {
+      return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+    } else if constexpr (str[POS + 1] == '}' || str[POS + 1] == ':') {
+      static_assert(ID != manual_indexing_id,
+                    "cannot switch from manual to automatic argument indexing");
+      constexpr auto next_id =
+          ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
+      return parse_replacement_field_then_tail<get_type<ID, Args>, Args,
+                                               POS + 1, ID, next_id>(
+          format_str);
+    } else {
+      constexpr auto arg_id_result =
+          parse_arg_id<ID>(str.data() + POS + 1, str.data() + str.size());
+      constexpr auto arg_id_end_pos = arg_id_result.arg_id_end - str.data();
+      constexpr char_type c =
+          arg_id_end_pos != str.size() ? str[arg_id_end_pos] : char_type();
+      static_assert(c == '}' || c == ':', "missing '}' in format string");
+      if constexpr (arg_id_result.arg_id.kind == arg_id_kind::index) {
+        static_assert(
+            ID == manual_indexing_id || ID == 0,
+            "cannot switch from automatic to manual argument indexing");
+        constexpr auto arg_index = arg_id_result.arg_id.val.index;
+        return parse_replacement_field_then_tail<get_type<arg_index, Args>,
+                                                 Args, arg_id_end_pos,
+                                                 arg_index, manual_indexing_id>(
+            format_str);
+      } else if constexpr (arg_id_result.arg_id.kind == arg_id_kind::name) {
+        constexpr auto arg_index =
+            get_arg_index_by_name(arg_id_result.arg_id.val.name, Args{});
+        if constexpr (arg_index != invalid_arg_index) {
+          constexpr auto next_id =
+              ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
+          return parse_replacement_field_then_tail<
+              decltype(get_type<arg_index, Args>::value), Args, arg_id_end_pos,
+              arg_index, next_id>(format_str);
+        } else {
+          if constexpr (c == '}') {
+            return parse_tail<Args, arg_id_end_pos + 1, ID>(
+                runtime_named_field<char_type>{arg_id_result.arg_id.val.name},
+                format_str);
+          } else if constexpr (c == ':') {
+            return unknown_format();  // no type info for specs parsing
+          }
+        }
+      }
+    }
+  } else if constexpr (str[POS] == '}') {
+    if constexpr (POS + 1 == str.size())
+      FMT_THROW(format_error("unmatched '}' in format string"));
+    return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+  } else {
+    constexpr auto end = parse_text(str, POS + 1);
+    if constexpr (end - POS > 1) {
+      return parse_tail<Args, end, ID>(make_text(str, POS, end - POS),
+                                       format_str);
+    } else {
+      return parse_tail<Args, end, ID>(code_unit<char_type>{str[POS]},
+                                       format_str);
+    }
+  }
+}
+
+template <typename... Args, typename S,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+constexpr auto compile(S format_str) {
+  constexpr auto str = basic_string_view<typename S::char_type>(format_str);
+  if constexpr (str.size() == 0) {
+    return detail::make_text(str, 0, 0);
+  } else {
+    constexpr auto result =
+        detail::compile_format_string<detail::type_list<Args...>, 0, 0>(
+            format_str);
+    return result;
+  }
+}
+#endif  // defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+}  // namespace detail
+
+FMT_MODULE_EXPORT_BEGIN
+
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+
+template <typename CompiledFormat, typename... Args,
+          typename Char = typename CompiledFormat::char_type,
+          FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
+FMT_INLINE std::basic_string<Char> format(const CompiledFormat& cf,
+                                          const Args&... args) {
+  auto s = std::basic_string<Char>();
+  cf.format(std::back_inserter(s), args...);
+  return s;
+}
+
+template <typename OutputIt, typename CompiledFormat, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
+constexpr FMT_INLINE OutputIt format_to(OutputIt out, const CompiledFormat& cf,
+                                        const Args&... args) {
+  return cf.format(out, args...);
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+FMT_INLINE std::basic_string<typename S::char_type> format(const S&,
+                                                           Args&&... args) {
+  if constexpr (std::is_same<typename S::char_type, char>::value) {
+    constexpr auto str = basic_string_view<typename S::char_type>(S());
+    if constexpr (str.size() == 2 && str[0] == '{' && str[1] == '}') {
+      const auto& first = detail::first(args...);
+      if constexpr (detail::is_named_arg<
+                        remove_cvref_t<decltype(first)>>::value) {
+        return fmt::to_string(first.value);
+      } else {
+        return fmt::to_string(first);
+      }
+    }
+  }
+  constexpr auto compiled = detail::compile<Args...>(S());
+  if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
+                             detail::unknown_format>()) {
+    return fmt::format(
+        static_cast<basic_string_view<typename S::char_type>>(S()),
+        std::forward<Args>(args)...);
+  } else {
+    return fmt::format(compiled, std::forward<Args>(args)...);
+  }
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+FMT_CONSTEXPR OutputIt format_to(OutputIt out, const S&, Args&&... args) {
+  constexpr auto compiled = detail::compile<Args...>(S());
+  if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
+                             detail::unknown_format>()) {
+    return fmt::format_to(
+        out, static_cast<basic_string_view<typename S::char_type>>(S()),
+        std::forward<Args>(args)...);
+  } else {
+    return fmt::format_to(out, compiled, std::forward<Args>(args)...);
+  }
+}
+#endif
+
+template <typename OutputIt, typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n,
+                                         const S& format_str, Args&&... args) {
+  auto it = fmt::format_to(detail::truncating_iterator<OutputIt>(out, n),
+                           format_str, std::forward<Args>(args)...);
+  return {it.base(), it.count()};
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+FMT_CONSTEXPR20 size_t formatted_size(const S& format_str,
+                                      const Args&... args) {
+  return fmt::format_to(detail::counting_iterator(), format_str, args...)
+      .count();
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(std::FILE* f, const S& format_str, const Args&... args) {
+  memory_buffer buffer;
+  fmt::format_to(std::back_inserter(buffer), format_str, args...);
+  detail::print(f, {buffer.data(), buffer.size()});
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(const S& format_str, const Args&... args) {
+  print(stdout, format_str, args...);
+}
+
+#if FMT_USE_NONTYPE_TEMPLATE_ARGS
+inline namespace literals {
+template <detail_exported::fixed_string Str> constexpr auto operator""_cf() {
+  using char_t = remove_cvref_t<decltype(Str.data[0])>;
+  return detail::udl_compiled_string<char_t, sizeof(Str.data) / sizeof(char_t),
+                                     Str>();
+}
+}  // namespace literals
+#endif
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_COMPILE_H_
@@ -0,0 +1,478 @@
+// Formatting library for C++ - optional OS-specific functionality
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_OS_H_
+#define FMT_OS_H_
+
+#include <cerrno>
+#include <cstddef>
+#include <cstdio>
+#include <system_error>  // std::system_error
+
+#if defined __APPLE__ || defined(__FreeBSD__)
+#  include <xlocale.h>  // for LC_NUMERIC_MASK on OS X
+#endif
+
+#include "format.h"
+
+#ifndef FMT_USE_FCNTL
+// UWP doesn't provide _pipe.
+#  if FMT_HAS_INCLUDE("winapifamily.h")
+#    include <winapifamily.h>
+#  endif
+#  if (FMT_HAS_INCLUDE(<fcntl.h>) || defined(__APPLE__) || \
+       defined(__linux__)) &&                              \
+      (!defined(WINAPI_FAMILY) ||                          \
+       (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
+#    include <fcntl.h>  // for O_RDONLY
+#    define FMT_USE_FCNTL 1
+#  else
+#    define FMT_USE_FCNTL 0
+#  endif
+#endif
+
+#ifndef FMT_POSIX
+#  if defined(_WIN32) && !defined(__MINGW32__)
+// Fix warnings about deprecated symbols.
+#    define FMT_POSIX(call) _##call
+#  else
+#    define FMT_POSIX(call) call
+#  endif
+#endif
+
+// Calls to system functions are wrapped in FMT_SYSTEM for testability.
+#ifdef FMT_SYSTEM
+#  define FMT_POSIX_CALL(call) FMT_SYSTEM(call)
+#else
+#  define FMT_SYSTEM(call) ::call
+#  ifdef _WIN32
+// Fix warnings about deprecated symbols.
+#    define FMT_POSIX_CALL(call) ::_##call
+#  else
+#    define FMT_POSIX_CALL(call) ::call
+#  endif
+#endif
+
+// Retries the expression while it evaluates to error_result and errno
+// equals to EINTR.
+#ifndef _WIN32
+#  define FMT_RETRY_VAL(result, expression, error_result) \
+    do {                                                  \
+      (result) = (expression);                            \
+    } while ((result) == (error_result) && errno == EINTR)
+#else
+#  define FMT_RETRY_VAL(result, expression, error_result) result = (expression)
+#endif
+
+#define FMT_RETRY(result, expression) FMT_RETRY_VAL(result, expression, -1)
+
+FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
+
+/**
+  \rst
+  A reference to a null-terminated string. It can be constructed from a C
+  string or ``std::string``.
+
+  You can use one of the following type aliases for common character types:
+
+  +---------------+-----------------------------+
+  | Type          | Definition                  |
+  +===============+=============================+
+  | cstring_view  | basic_cstring_view<char>    |
+  +---------------+-----------------------------+
+  | wcstring_view | basic_cstring_view<wchar_t> |
+  +---------------+-----------------------------+
+
+  This class is most useful as a parameter type to allow passing
+  different types of strings to a function, for example::
+
+    template <typename... Args>
+    std::string format(cstring_view format_str, const Args & ... args);
+
+    format("{}", 42);
+    format(std::string("{}"), 42);
+  \endrst
+ */
+template <typename Char> class basic_cstring_view {
+ private:
+  const Char* data_;
+
+ public:
+  /** Constructs a string reference object from a C string. */
+  basic_cstring_view(const Char* s) : data_(s) {}
+
+  /**
+    \rst
+    Constructs a string reference from an ``std::string`` object.
+    \endrst
+   */
+  basic_cstring_view(const std::basic_string<Char>& s) : data_(s.c_str()) {}
+
+  /** Returns the pointer to a C string. */
+  const Char* c_str() const { return data_; }
+};
+
+using cstring_view = basic_cstring_view<char>;
+using wcstring_view = basic_cstring_view<wchar_t>;
+
+template <typename Char> struct formatter<std::error_code, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  FMT_CONSTEXPR auto format(const std::error_code& ec, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    out = detail::write_bytes(out, ec.category().name(),
+                              basic_format_specs<Char>());
+    out = detail::write<Char>(out, Char(':'));
+    out = detail::write<Char>(out, ec.value());
+    return out;
+  }
+};
+
+#ifdef _WIN32
+FMT_API const std::error_category& system_category() noexcept;
+
+FMT_BEGIN_DETAIL_NAMESPACE
+// A converter from UTF-16 to UTF-8.
+// It is only provided for Windows since other systems support UTF-8 natively.
+class utf16_to_utf8 {
+ private:
+  memory_buffer buffer_;
+
+ public:
+  utf16_to_utf8() {}
+  FMT_API explicit utf16_to_utf8(basic_string_view<wchar_t> s);
+  operator string_view() const { return string_view(&buffer_[0], size()); }
+  size_t size() const { return buffer_.size() - 1; }
+  const char* c_str() const { return &buffer_[0]; }
+  std::string str() const { return std::string(&buffer_[0], size()); }
+
+  // Performs conversion returning a system error code instead of
+  // throwing exception on conversion error. This method may still throw
+  // in case of memory allocation error.
+  FMT_API int convert(basic_string_view<wchar_t> s);
+};
+
+FMT_API void format_windows_error(buffer<char>& out, int error_code,
+                                  const char* message) noexcept;
+FMT_END_DETAIL_NAMESPACE
+
+FMT_API std::system_error vwindows_error(int error_code, string_view format_str,
+                                         format_args args);
+
+/**
+ \rst
+ Constructs a :class:`std::system_error` object with the description
+ of the form
+
+ .. parsed-literal::
+   *<message>*: *<system-message>*
+
+ where *<message>* is the formatted message and *<system-message>* is the
+ system message corresponding to the error code.
+ *error_code* is a Windows error code as given by ``GetLastError``.
+ If *error_code* is not a valid error code such as -1, the system message
+ will look like "error -1".
+
+ **Example**::
+
+   // This throws a system_error with the description
+   //   cannot open file 'madeup': The system cannot find the file specified.
+   // or similar (system message may vary).
+   const char *filename = "madeup";
+   LPOFSTRUCT of = LPOFSTRUCT();
+   HFILE file = OpenFile(filename, &of, OF_READ);
+   if (file == HFILE_ERROR) {
+     throw fmt::windows_error(GetLastError(),
+                              "cannot open file '{}'", filename);
+   }
+ \endrst
+*/
+template <typename... Args>
+std::system_error windows_error(int error_code, string_view message,
+                                const Args&... args) {
+  return vwindows_error(error_code, message, fmt::make_format_args(args...));
+}
+
+// Reports a Windows error without throwing an exception.
+// Can be used to report errors from destructors.
+FMT_API void report_windows_error(int error_code, const char* message) noexcept;
+#else
+inline const std::error_category& system_category() noexcept {
+  return std::system_category();
+}
+#endif  // _WIN32
+
+// std::system is not available on some platforms such as iOS (#2248).
+#ifdef __OSX__
+template <typename S, typename... Args, typename Char = char_t<S>>
+void say(const S& format_str, Args&&... args) {
+  std::system(format("say \"{}\"", format(format_str, args...)).c_str());
+}
+#endif
+
+// A buffered file.
+class buffered_file {
+ private:
+  FILE* file_;
+
+  friend class file;
+
+  explicit buffered_file(FILE* f) : file_(f) {}
+
+ public:
+  buffered_file(const buffered_file&) = delete;
+  void operator=(const buffered_file&) = delete;
+
+  // Constructs a buffered_file object which doesn't represent any file.
+  buffered_file() noexcept : file_(nullptr) {}
+
+  // Destroys the object closing the file it represents if any.
+  FMT_API ~buffered_file() noexcept;
+
+ public:
+  buffered_file(buffered_file&& other) noexcept : file_(other.file_) {
+    other.file_ = nullptr;
+  }
+
+  buffered_file& operator=(buffered_file&& other) {
+    close();
+    file_ = other.file_;
+    other.file_ = nullptr;
+    return *this;
+  }
+
+  // Opens a file.
+  FMT_API buffered_file(cstring_view filename, cstring_view mode);
+
+  // Closes the file.
+  FMT_API void close();
+
+  // Returns the pointer to a FILE object representing this file.
+  FILE* get() const noexcept { return file_; }
+
+  FMT_API int descriptor() const;
+
+  void vprint(string_view format_str, format_args args) {
+    fmt::vprint(file_, format_str, args);
+  }
+
+  template <typename... Args>
+  inline void print(string_view format_str, const Args&... args) {
+    vprint(format_str, fmt::make_format_args(args...));
+  }
+};
+
+#if FMT_USE_FCNTL
+// A file. Closed file is represented by a file object with descriptor -1.
+// Methods that are not declared with noexcept may throw
+// fmt::system_error in case of failure. Note that some errors such as
+// closing the file multiple times will cause a crash on Windows rather
+// than an exception. You can get standard behavior by overriding the
+// invalid parameter handler with _set_invalid_parameter_handler.
+class FMT_API file {
+ private:
+  int fd_;  // File descriptor.
+
+  // Constructs a file object with a given descriptor.
+  explicit file(int fd) : fd_(fd) {}
+
+ public:
+  // Possible values for the oflag argument to the constructor.
+  enum {
+    RDONLY = FMT_POSIX(O_RDONLY),  // Open for reading only.
+    WRONLY = FMT_POSIX(O_WRONLY),  // Open for writing only.
+    RDWR = FMT_POSIX(O_RDWR),      // Open for reading and writing.
+    CREATE = FMT_POSIX(O_CREAT),   // Create if the file doesn't exist.
+    APPEND = FMT_POSIX(O_APPEND),  // Open in append mode.
+    TRUNC = FMT_POSIX(O_TRUNC)     // Truncate the content of the file.
+  };
+
+  // Constructs a file object which doesn't represent any file.
+  file() noexcept : fd_(-1) {}
+
+  // Opens a file and constructs a file object representing this file.
+  file(cstring_view path, int oflag);
+
+ public:
+  file(const file&) = delete;
+  void operator=(const file&) = delete;
+
+  file(file&& other) noexcept : fd_(other.fd_) { other.fd_ = -1; }
+
+  // Move assignment is not noexcept because close may throw.
+  file& operator=(file&& other) {
+    close();
+    fd_ = other.fd_;
+    other.fd_ = -1;
+    return *this;
+  }
+
+  // Destroys the object closing the file it represents if any.
+  ~file() noexcept;
+
+  // Returns the file descriptor.
+  int descriptor() const noexcept { return fd_; }
+
+  // Closes the file.
+  void close();
+
+  // Returns the file size. The size has signed type for consistency with
+  // stat::st_size.
+  long long size() const;
+
+  // Attempts to read count bytes from the file into the specified buffer.
+  size_t read(void* buffer, size_t count);
+
+  // Attempts to write count bytes from the specified buffer to the file.
+  size_t write(const void* buffer, size_t count);
+
+  // Duplicates a file descriptor with the dup function and returns
+  // the duplicate as a file object.
+  static file dup(int fd);
+
+  // Makes fd be the copy of this file descriptor, closing fd first if
+  // necessary.
+  void dup2(int fd);
+
+  // Makes fd be the copy of this file descriptor, closing fd first if
+  // necessary.
+  void dup2(int fd, std::error_code& ec) noexcept;
+
+  // Creates a pipe setting up read_end and write_end file objects for reading
+  // and writing respectively.
+  static void pipe(file& read_end, file& write_end);
+
+  // Creates a buffered_file object associated with this file and detaches
+  // this file object from the file.
+  buffered_file fdopen(const char* mode);
+};
+
+// Returns the memory page size.
+long getpagesize();
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+struct buffer_size {
+  buffer_size() = default;
+  size_t value = 0;
+  buffer_size operator=(size_t val) const {
+    auto bs = buffer_size();
+    bs.value = val;
+    return bs;
+  }
+};
+
+struct ostream_params {
+  int oflag = file::WRONLY | file::CREATE | file::TRUNC;
+  size_t buffer_size = BUFSIZ > 32768 ? BUFSIZ : 32768;
+
+  ostream_params() {}
+
+  template <typename... T>
+  ostream_params(T... params, int new_oflag) : ostream_params(params...) {
+    oflag = new_oflag;
+  }
+
+  template <typename... T>
+  ostream_params(T... params, detail::buffer_size bs)
+      : ostream_params(params...) {
+    this->buffer_size = bs.value;
+  }
+
+// Intel has a bug that results in failure to deduce a constructor
+// for empty parameter packs.
+#  if defined(__INTEL_COMPILER) && __INTEL_COMPILER < 2000
+  ostream_params(int new_oflag) : oflag(new_oflag) {}
+  ostream_params(detail::buffer_size bs) : buffer_size(bs.value) {}
+#  endif
+};
+
+FMT_END_DETAIL_NAMESPACE
+
+// Added {} below to work around default constructor error known to
+// occur in Xcode versions 7.2.1 and 8.2.1.
+constexpr detail::buffer_size buffer_size{};
+
+/** A fast output stream which is not thread-safe. */
+class FMT_API ostream final : private detail::buffer<char> {
+ private:
+  file file_;
+
+  void grow(size_t) override;
+
+  ostream(cstring_view path, const detail::ostream_params& params)
+      : file_(path, params.oflag) {
+    set(new char[params.buffer_size], params.buffer_size);
+  }
+
+ public:
+  ostream(ostream&& other)
+      : detail::buffer<char>(other.data(), other.size(), other.capacity()),
+        file_(std::move(other.file_)) {
+    other.clear();
+    other.set(nullptr, 0);
+  }
+  ~ostream() {
+    flush();
+    delete[] data();
+  }
+
+  void flush() {
+    if (size() == 0) return;
+    file_.write(data(), size());
+    clear();
+  }
+
+  template <typename... T>
+  friend ostream output_file(cstring_view path, T... params);
+
+  void close() {
+    flush();
+    file_.close();
+  }
+
+  /**
+    Formats ``args`` according to specifications in ``fmt`` and writes the
+    output to the file.
+   */
+  template <typename... T> void print(format_string<T...> fmt, T&&... args) {
+    vformat_to(detail::buffer_appender<char>(*this), fmt,
+               fmt::make_format_args(args...));
+  }
+};
+
+/**
+  \rst
+  Opens a file for writing. Supported parameters passed in *params*:
+
+  * ``<integer>``: Flags passed to `open
+    <https://pubs.opengroup.org/onlinepubs/007904875/functions/open.html>`_
+    (``file::WRONLY | file::CREATE | file::TRUNC`` by default)
+  * ``buffer_size=<integer>``: Output buffer size
+
+  **Example**::
+
+    auto out = fmt::output_file("guide.txt");
+    out.print("Don't {}", "Panic");
+  \endrst
+ */
+template <typename... T>
+inline ostream output_file(cstring_view path, T... params) {
+  return {path, detail::ostream_params(params...)};
+}
+#endif  // FMT_USE_FCNTL
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_OS_H_
@@ -0,0 +1,237 @@
+// Formatting library for C++ - std::ostream support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_OSTREAM_H_
+#define FMT_OSTREAM_H_
+
+#include <fstream>
+#include <ostream>
+#if defined(_WIN32) && defined(__GLIBCXX__)
+#  include <ext/stdio_filebuf.h>
+#  include <ext/stdio_sync_filebuf.h>
+#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
+#  include <__std_stream>
+#endif
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+
+template <typename OutputIt, typename Char> class basic_printf_context;
+
+namespace detail {
+
+// Checks if T has a user-defined operator<<.
+template <typename T, typename Char, typename Enable = void>
+class is_streamable {
+ private:
+  template <typename U>
+  static auto test(int)
+      -> bool_constant<sizeof(std::declval<std::basic_ostream<Char>&>()
+                              << std::declval<U>()) != 0>;
+
+  template <typename> static auto test(...) -> std::false_type;
+
+  using result = decltype(test<T>(0));
+
+ public:
+  is_streamable() = default;
+
+  static const bool value = result::value;
+};
+
+// Formatting of built-in types and arrays is intentionally disabled because
+// it's handled by standard (non-ostream) formatters.
+template <typename T, typename Char>
+struct is_streamable<
+    T, Char,
+    enable_if_t<
+        std::is_arithmetic<T>::value || std::is_array<T>::value ||
+        std::is_pointer<T>::value || std::is_same<T, char8_type>::value ||
+        std::is_convertible<T, fmt::basic_string_view<Char>>::value ||
+        std::is_same<T, std_string_view<Char>>::value ||
+        (std::is_convertible<T, int>::value && !std::is_enum<T>::value)>>
+    : std::false_type {};
+
+// Generate a unique explicit instantion in every translation unit using a tag
+// type in an anonymous namespace.
+namespace {
+struct file_access_tag {};
+}  // namespace
+template <class Tag, class BufType, FILE* BufType::*FileMemberPtr>
+class file_access {
+  friend auto get_file(BufType& obj) -> FILE* { return obj.*FileMemberPtr; }
+};
+
+#if FMT_MSC_VERSION
+template class file_access<file_access_tag, std::filebuf,
+                           &std::filebuf::_Myfile>;
+auto get_file(std::filebuf&) -> FILE*;
+#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
+template class file_access<file_access_tag, std::__stdoutbuf<char>,
+                           &std::__stdoutbuf<char>::__file_>;
+auto get_file(std::__stdoutbuf<char>&) -> FILE*;
+#endif
+
+inline bool write_ostream_unicode(std::ostream& os, fmt::string_view data) {
+#if FMT_MSC_VERSION
+  if (auto* buf = dynamic_cast<std::filebuf*>(os.rdbuf()))
+    if (FILE* f = get_file(*buf)) return write_console(f, data);
+#elif defined(_WIN32) && defined(__GLIBCXX__)
+  auto* rdbuf = os.rdbuf();
+  FILE* c_file;
+  if (auto* fbuf = dynamic_cast<__gnu_cxx::stdio_sync_filebuf<char>*>(rdbuf))
+    c_file = fbuf->file();
+  else if (auto* fbuf = dynamic_cast<__gnu_cxx::stdio_filebuf<char>*>(rdbuf))
+    c_file = fbuf->file();
+  else
+    return false;
+  if (c_file) return write_console(c_file, data);
+#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
+  if (auto* buf = dynamic_cast<std::__stdoutbuf<char>*>(os.rdbuf()))
+    if (FILE* f = get_file(*buf)) return write_console(f, data);
+#else
+  ignore_unused(os, data);
+#endif
+  return false;
+}
+inline bool write_ostream_unicode(std::wostream&,
+                                  fmt::basic_string_view<wchar_t>) {
+  return false;
+}
+
+// Write the content of buf to os.
+// It is a separate function rather than a part of vprint to simplify testing.
+template <typename Char>
+void write_buffer(std::basic_ostream<Char>& os, buffer<Char>& buf) {
+  const Char* buf_data = buf.data();
+  using unsigned_streamsize = std::make_unsigned<std::streamsize>::type;
+  unsigned_streamsize size = buf.size();
+  unsigned_streamsize max_size = to_unsigned(max_value<std::streamsize>());
+  do {
+    unsigned_streamsize n = size <= max_size ? size : max_size;
+    os.write(buf_data, static_cast<std::streamsize>(n));
+    buf_data += n;
+    size -= n;
+  } while (size != 0);
+}
+
+template <typename Char, typename T>
+void format_value(buffer<Char>& buf, const T& value,
+                  locale_ref loc = locale_ref()) {
+  auto&& format_buf = formatbuf<std::basic_streambuf<Char>>(buf);
+  auto&& output = std::basic_ostream<Char>(&format_buf);
+#if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
+  if (loc) output.imbue(loc.get<std::locale>());
+#endif
+  output << value;
+  output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
+}
+
+template <typename T> struct streamed_view { const T& value; };
+
+}  // namespace detail
+
+// Formats an object of type T that has an overloaded ostream operator<<.
+template <typename Char>
+struct basic_ostream_formatter : formatter<basic_string_view<Char>, Char> {
+  void set_debug_format() = delete;
+
+  template <typename T, typename OutputIt>
+  auto format(const T& value, basic_format_context<OutputIt, Char>& ctx) const
+      -> OutputIt {
+    auto buffer = basic_memory_buffer<Char>();
+    format_value(buffer, value, ctx.locale());
+    return formatter<basic_string_view<Char>, Char>::format(
+        {buffer.data(), buffer.size()}, ctx);
+  }
+};
+
+using ostream_formatter = basic_ostream_formatter<char>;
+
+template <typename T, typename Char>
+struct formatter<detail::streamed_view<T>, Char>
+    : basic_ostream_formatter<Char> {
+  template <typename OutputIt>
+  auto format(detail::streamed_view<T> view,
+              basic_format_context<OutputIt, Char>& ctx) const -> OutputIt {
+    return basic_ostream_formatter<Char>::format(view.value, ctx);
+  }
+};
+
+/**
+  \rst
+  Returns a view that formats `value` via an ostream ``operator<<``.
+
+  **Example**::
+
+    fmt::print("Current thread id: {}\n",
+               fmt::streamed(std::this_thread::get_id()));
+  \endrst
+ */
+template <typename T>
+auto streamed(const T& value) -> detail::streamed_view<T> {
+  return {value};
+}
+
+namespace detail {
+
+// Formats an object of type T that has an overloaded ostream operator<<.
+template <typename T, typename Char>
+struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
+    : basic_ostream_formatter<Char> {
+  using basic_ostream_formatter<Char>::format;
+};
+
+inline void vprint_directly(std::ostream& os, string_view format_str,
+                            format_args args) {
+  auto buffer = memory_buffer();
+  detail::vformat_to(buffer, format_str, args);
+  detail::write_buffer(os, buffer);
+}
+
+}  // namespace detail
+
+FMT_MODULE_EXPORT template <typename Char>
+void vprint(std::basic_ostream<Char>& os,
+            basic_string_view<type_identity_t<Char>> format_str,
+            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  auto buffer = basic_memory_buffer<Char>();
+  detail::vformat_to(buffer, format_str, args);
+  if (detail::write_ostream_unicode(os, {buffer.data(), buffer.size()})) return;
+  detail::write_buffer(os, buffer);
+}
+
+/**
+  \rst
+  Prints formatted data to the stream *os*.
+
+  **Example**::
+
+    fmt::print(cerr, "Don't {}!", "panic");
+  \endrst
+ */
+FMT_MODULE_EXPORT template <typename... T>
+void print(std::ostream& os, format_string<T...> fmt, T&&... args) {
+  const auto& vargs = fmt::make_format_args(args...);
+  if (detail::is_utf8())
+    vprint(os, fmt, vargs);
+  else
+    detail::vprint_directly(os, fmt, vargs);
+}
+
+FMT_MODULE_EXPORT
+template <typename... Args>
+void print(std::wostream& os,
+           basic_format_string<wchar_t, type_identity_t<Args>...> fmt,
+           Args&&... args) {
+  vprint(os, fmt, fmt::make_format_args<buffer_context<wchar_t>>(args...));
+}
+
+FMT_END_NAMESPACE
+
+#endif  // FMT_OSTREAM_H_
@@ -0,0 +1,640 @@
+// Formatting library for C++ - legacy printf implementation
+//
+// Copyright (c) 2012 - 2016, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_PRINTF_H_
+#define FMT_PRINTF_H_
+
+#include <algorithm>  // std::max
+#include <limits>     // std::numeric_limits
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
+
+template <typename T> struct printf_formatter { printf_formatter() = delete; };
+
+template <typename Char>
+class basic_printf_parse_context : public basic_format_parse_context<Char> {
+  using basic_format_parse_context<Char>::basic_format_parse_context;
+};
+
+template <typename OutputIt, typename Char> class basic_printf_context {
+ private:
+  OutputIt out_;
+  basic_format_args<basic_printf_context> args_;
+
+ public:
+  using char_type = Char;
+  using format_arg = basic_format_arg<basic_printf_context>;
+  using parse_context_type = basic_printf_parse_context<Char>;
+  template <typename T> using formatter_type = printf_formatter<T>;
+
+  /**
+    \rst
+    Constructs a ``printf_context`` object. References to the arguments are
+    stored in the context object so make sure they have appropriate lifetimes.
+    \endrst
+   */
+  basic_printf_context(OutputIt out,
+                       basic_format_args<basic_printf_context> args)
+      : out_(out), args_(args) {}
+
+  OutputIt out() { return out_; }
+  void advance_to(OutputIt it) { out_ = it; }
+
+  detail::locale_ref locale() { return {}; }
+
+  format_arg arg(int id) const { return args_.get(id); }
+
+  FMT_CONSTEXPR void on_error(const char* message) {
+    detail::error_handler().on_error(message);
+  }
+};
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+// Checks if a value fits in int - used to avoid warnings about comparing
+// signed and unsigned integers.
+template <bool IsSigned> struct int_checker {
+  template <typename T> static bool fits_in_int(T value) {
+    unsigned max = max_value<int>();
+    return value <= max;
+  }
+  static bool fits_in_int(bool) { return true; }
+};
+
+template <> struct int_checker<true> {
+  template <typename T> static bool fits_in_int(T value) {
+    return value >= (std::numeric_limits<int>::min)() &&
+           value <= max_value<int>();
+  }
+  static bool fits_in_int(int) { return true; }
+};
+
+class printf_precision_handler {
+ public:
+  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  int operator()(T value) {
+    if (!int_checker<std::numeric_limits<T>::is_signed>::fits_in_int(value))
+      FMT_THROW(format_error("number is too big"));
+    return (std::max)(static_cast<int>(value), 0);
+  }
+
+  template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+  int operator()(T) {
+    FMT_THROW(format_error("precision is not integer"));
+    return 0;
+  }
+};
+
+// An argument visitor that returns true iff arg is a zero integer.
+class is_zero_int {
+ public:
+  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  bool operator()(T value) {
+    return value == 0;
+  }
+
+  template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+  bool operator()(T) {
+    return false;
+  }
+};
+
+template <typename T> struct make_unsigned_or_bool : std::make_unsigned<T> {};
+
+template <> struct make_unsigned_or_bool<bool> { using type = bool; };
+
+template <typename T, typename Context> class arg_converter {
+ private:
+  using char_type = typename Context::char_type;
+
+  basic_format_arg<Context>& arg_;
+  char_type type_;
+
+ public:
+  arg_converter(basic_format_arg<Context>& arg, char_type type)
+      : arg_(arg), type_(type) {}
+
+  void operator()(bool value) {
+    if (type_ != 's') operator()<bool>(value);
+  }
+
+  template <typename U, FMT_ENABLE_IF(std::is_integral<U>::value)>
+  void operator()(U value) {
+    bool is_signed = type_ == 'd' || type_ == 'i';
+    using target_type = conditional_t<std::is_same<T, void>::value, U, T>;
+    if (const_check(sizeof(target_type) <= sizeof(int))) {
+      // Extra casts are used to silence warnings.
+      if (is_signed) {
+        arg_ = detail::make_arg<Context>(
+            static_cast<int>(static_cast<target_type>(value)));
+      } else {
+        using unsigned_type = typename make_unsigned_or_bool<target_type>::type;
+        arg_ = detail::make_arg<Context>(
+            static_cast<unsigned>(static_cast<unsigned_type>(value)));
+      }
+    } else {
+      if (is_signed) {
+        // glibc's printf doesn't sign extend arguments of smaller types:
+        //   std::printf("%lld", -42);  // prints "4294967254"
+        // but we don't have to do the same because it's a UB.
+        arg_ = detail::make_arg<Context>(static_cast<long long>(value));
+      } else {
+        arg_ = detail::make_arg<Context>(
+            static_cast<typename make_unsigned_or_bool<U>::type>(value));
+      }
+    }
+  }
+
+  template <typename U, FMT_ENABLE_IF(!std::is_integral<U>::value)>
+  void operator()(U) {}  // No conversion needed for non-integral types.
+};
+
+// Converts an integer argument to T for printf, if T is an integral type.
+// If T is void, the argument is converted to corresponding signed or unsigned
+// type depending on the type specifier: 'd' and 'i' - signed, other -
+// unsigned).
+template <typename T, typename Context, typename Char>
+void convert_arg(basic_format_arg<Context>& arg, Char type) {
+  visit_format_arg(arg_converter<T, Context>(arg, type), arg);
+}
+
+// Converts an integer argument to char for printf.
+template <typename Context> class char_converter {
+ private:
+  basic_format_arg<Context>& arg_;
+
+ public:
+  explicit char_converter(basic_format_arg<Context>& arg) : arg_(arg) {}
+
+  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  void operator()(T value) {
+    arg_ = detail::make_arg<Context>(
+        static_cast<typename Context::char_type>(value));
+  }
+
+  template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+  void operator()(T) {}  // No conversion needed for non-integral types.
+};
+
+// An argument visitor that return a pointer to a C string if argument is a
+// string or null otherwise.
+template <typename Char> struct get_cstring {
+  template <typename T> const Char* operator()(T) { return nullptr; }
+  const Char* operator()(const Char* s) { return s; }
+};
+
+// Checks if an argument is a valid printf width specifier and sets
+// left alignment if it is negative.
+template <typename Char> class printf_width_handler {
+ private:
+  using format_specs = basic_format_specs<Char>;
+
+  format_specs& specs_;
+
+ public:
+  explicit printf_width_handler(format_specs& specs) : specs_(specs) {}
+
+  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  unsigned operator()(T value) {
+    auto width = static_cast<uint32_or_64_or_128_t<T>>(value);
+    if (detail::is_negative(value)) {
+      specs_.align = align::left;
+      width = 0 - width;
+    }
+    unsigned int_max = max_value<int>();
+    if (width > int_max) FMT_THROW(format_error("number is too big"));
+    return static_cast<unsigned>(width);
+  }
+
+  template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+  unsigned operator()(T) {
+    FMT_THROW(format_error("width is not integer"));
+    return 0;
+  }
+};
+
+// The ``printf`` argument formatter.
+template <typename OutputIt, typename Char>
+class printf_arg_formatter : public arg_formatter<Char> {
+ private:
+  using base = arg_formatter<Char>;
+  using context_type = basic_printf_context<OutputIt, Char>;
+  using format_specs = basic_format_specs<Char>;
+
+  context_type& context_;
+
+  OutputIt write_null_pointer(bool is_string = false) {
+    auto s = this->specs;
+    s.type = presentation_type::none;
+    return write_bytes(this->out, is_string ? "(null)" : "(nil)", s);
+  }
+
+ public:
+  printf_arg_formatter(OutputIt iter, format_specs& s, context_type& ctx)
+      : base{iter, s, locale_ref()}, context_(ctx) {}
+
+  OutputIt operator()(monostate value) { return base::operator()(value); }
+
+  template <typename T, FMT_ENABLE_IF(detail::is_integral<T>::value)>
+  OutputIt operator()(T value) {
+    // MSVC2013 fails to compile separate overloads for bool and Char so use
+    // std::is_same instead.
+    if (std::is_same<T, Char>::value) {
+      format_specs fmt_specs = this->specs;
+      if (fmt_specs.type != presentation_type::none &&
+          fmt_specs.type != presentation_type::chr) {
+        return (*this)(static_cast<int>(value));
+      }
+      fmt_specs.sign = sign::none;
+      fmt_specs.alt = false;
+      fmt_specs.fill[0] = ' ';  // Ignore '0' flag for char types.
+      // align::numeric needs to be overwritten here since the '0' flag is
+      // ignored for non-numeric types
+      if (fmt_specs.align == align::none || fmt_specs.align == align::numeric)
+        fmt_specs.align = align::right;
+      return write<Char>(this->out, static_cast<Char>(value), fmt_specs);
+    }
+    return base::operator()(value);
+  }
+
+  template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
+  OutputIt operator()(T value) {
+    return base::operator()(value);
+  }
+
+  /** Formats a null-terminated C string. */
+  OutputIt operator()(const char* value) {
+    if (value) return base::operator()(value);
+    return write_null_pointer(this->specs.type != presentation_type::pointer);
+  }
+
+  /** Formats a null-terminated wide C string. */
+  OutputIt operator()(const wchar_t* value) {
+    if (value) return base::operator()(value);
+    return write_null_pointer(this->specs.type != presentation_type::pointer);
+  }
+
+  OutputIt operator()(basic_string_view<Char> value) {
+    return base::operator()(value);
+  }
+
+  /** Formats a pointer. */
+  OutputIt operator()(const void* value) {
+    return value ? base::operator()(value) : write_null_pointer();
+  }
+
+  /** Formats an argument of a custom (user-defined) type. */
+  OutputIt operator()(typename basic_format_arg<context_type>::handle handle) {
+    auto parse_ctx =
+        basic_printf_parse_context<Char>(basic_string_view<Char>());
+    handle.format(parse_ctx, context_);
+    return this->out;
+  }
+};
+
+template <typename Char>
+void parse_flags(basic_format_specs<Char>& specs, const Char*& it,
+                 const Char* end) {
+  for (; it != end; ++it) {
+    switch (*it) {
+    case '-':
+      specs.align = align::left;
+      break;
+    case '+':
+      specs.sign = sign::plus;
+      break;
+    case '0':
+      specs.fill[0] = '0';
+      break;
+    case ' ':
+      if (specs.sign != sign::plus) {
+        specs.sign = sign::space;
+      }
+      break;
+    case '#':
+      specs.alt = true;
+      break;
+    default:
+      return;
+    }
+  }
+}
+
+template <typename Char, typename GetArg>
+int parse_header(const Char*& it, const Char* end,
+                 basic_format_specs<Char>& specs, GetArg get_arg) {
+  int arg_index = -1;
+  Char c = *it;
+  if (c >= '0' && c <= '9') {
+    // Parse an argument index (if followed by '$') or a width possibly
+    // preceded with '0' flag(s).
+    int value = parse_nonnegative_int(it, end, -1);
+    if (it != end && *it == '$') {  // value is an argument index
+      ++it;
+      arg_index = value != -1 ? value : max_value<int>();
+    } else {
+      if (c == '0') specs.fill[0] = '0';
+      if (value != 0) {
+        // Nonzero value means that we parsed width and don't need to
+        // parse it or flags again, so return now.
+        if (value == -1) FMT_THROW(format_error("number is too big"));
+        specs.width = value;
+        return arg_index;
+      }
+    }
+  }
+  parse_flags(specs, it, end);
+  // Parse width.
+  if (it != end) {
+    if (*it >= '0' && *it <= '9') {
+      specs.width = parse_nonnegative_int(it, end, -1);
+      if (specs.width == -1) FMT_THROW(format_error("number is too big"));
+    } else if (*it == '*') {
+      ++it;
+      specs.width = static_cast<int>(visit_format_arg(
+          detail::printf_width_handler<Char>(specs), get_arg(-1)));
+    }
+  }
+  return arg_index;
+}
+
+template <typename Char, typename Context>
+void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
+             basic_format_args<Context> args) {
+  using OutputIt = buffer_appender<Char>;
+  auto out = OutputIt(buf);
+  auto context = basic_printf_context<OutputIt, Char>(out, args);
+  auto parse_ctx = basic_printf_parse_context<Char>(format);
+
+  // Returns the argument with specified index or, if arg_index is -1, the next
+  // argument.
+  auto get_arg = [&](int arg_index) {
+    if (arg_index < 0)
+      arg_index = parse_ctx.next_arg_id();
+    else
+      parse_ctx.check_arg_id(--arg_index);
+    return detail::get_arg(context, arg_index);
+  };
+
+  const Char* start = parse_ctx.begin();
+  const Char* end = parse_ctx.end();
+  auto it = start;
+  while (it != end) {
+    if (!detail::find<false, Char>(it, end, '%', it)) {
+      it = end;  // detail::find leaves it == nullptr if it doesn't find '%'
+      break;
+    }
+    Char c = *it++;
+    if (it != end && *it == c) {
+      out = detail::write(
+          out, basic_string_view<Char>(start, detail::to_unsigned(it - start)));
+      start = ++it;
+      continue;
+    }
+    out = detail::write(out, basic_string_view<Char>(
+                                 start, detail::to_unsigned(it - 1 - start)));
+
+    basic_format_specs<Char> specs;
+    specs.align = align::right;
+
+    // Parse argument index, flags and width.
+    int arg_index = parse_header(it, end, specs, get_arg);
+    if (arg_index == 0) parse_ctx.on_error("argument not found");
+
+    // Parse precision.
+    if (it != end && *it == '.') {
+      ++it;
+      c = it != end ? *it : 0;
+      if ('0' <= c && c <= '9') {
+        specs.precision = parse_nonnegative_int(it, end, 0);
+      } else if (c == '*') {
+        ++it;
+        specs.precision = static_cast<int>(
+            visit_format_arg(detail::printf_precision_handler(), get_arg(-1)));
+      } else {
+        specs.precision = 0;
+      }
+    }
+
+    auto arg = get_arg(arg_index);
+    // For d, i, o, u, x, and X conversion specifiers, if a precision is
+    // specified, the '0' flag is ignored
+    if (specs.precision >= 0 && arg.is_integral())
+      specs.fill[0] =
+          ' ';  // Ignore '0' flag for non-numeric types or if '-' present.
+    if (specs.precision >= 0 && arg.type() == detail::type::cstring_type) {
+      auto str = visit_format_arg(detail::get_cstring<Char>(), arg);
+      auto str_end = str + specs.precision;
+      auto nul = std::find(str, str_end, Char());
+      arg = detail::make_arg<basic_printf_context<OutputIt, Char>>(
+          basic_string_view<Char>(
+              str, detail::to_unsigned(nul != str_end ? nul - str
+                                                      : specs.precision)));
+    }
+    if (specs.alt && visit_format_arg(detail::is_zero_int(), arg))
+      specs.alt = false;
+    if (specs.fill[0] == '0') {
+      if (arg.is_arithmetic() && specs.align != align::left)
+        specs.align = align::numeric;
+      else
+        specs.fill[0] = ' ';  // Ignore '0' flag for non-numeric types or if '-'
+                              // flag is also present.
+    }
+
+    // Parse length and convert the argument to the required type.
+    c = it != end ? *it++ : 0;
+    Char t = it != end ? *it : 0;
+    using detail::convert_arg;
+    switch (c) {
+    case 'h':
+      if (t == 'h') {
+        ++it;
+        t = it != end ? *it : 0;
+        convert_arg<signed char>(arg, t);
+      } else {
+        convert_arg<short>(arg, t);
+      }
+      break;
+    case 'l':
+      if (t == 'l') {
+        ++it;
+        t = it != end ? *it : 0;
+        convert_arg<long long>(arg, t);
+      } else {
+        convert_arg<long>(arg, t);
+      }
+      break;
+    case 'j':
+      convert_arg<intmax_t>(arg, t);
+      break;
+    case 'z':
+      convert_arg<size_t>(arg, t);
+      break;
+    case 't':
+      convert_arg<std::ptrdiff_t>(arg, t);
+      break;
+    case 'L':
+      // printf produces garbage when 'L' is omitted for long double, no
+      // need to do the same.
+      break;
+    default:
+      --it;
+      convert_arg<void>(arg, c);
+    }
+
+    // Parse type.
+    if (it == end) FMT_THROW(format_error("invalid format string"));
+    char type = static_cast<char>(*it++);
+    if (arg.is_integral()) {
+      // Normalize type.
+      switch (type) {
+      case 'i':
+      case 'u':
+        type = 'd';
+        break;
+      case 'c':
+        visit_format_arg(
+            detail::char_converter<basic_printf_context<OutputIt, Char>>(arg),
+            arg);
+        break;
+      }
+    }
+    specs.type = parse_presentation_type(type);
+    if (specs.type == presentation_type::none)
+      parse_ctx.on_error("invalid type specifier");
+
+    start = it;
+
+    // Format argument.
+    out = visit_format_arg(
+        detail::printf_arg_formatter<OutputIt, Char>(out, specs, context), arg);
+  }
+  detail::write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
+}
+FMT_END_DETAIL_NAMESPACE
+
+template <typename Char>
+using basic_printf_context_t =
+    basic_printf_context<detail::buffer_appender<Char>, Char>;
+
+using printf_context = basic_printf_context_t<char>;
+using wprintf_context = basic_printf_context_t<wchar_t>;
+
+using printf_args = basic_format_args<printf_context>;
+using wprintf_args = basic_format_args<wprintf_context>;
+
+/**
+  \rst
+  Constructs an `~fmt::format_arg_store` object that contains references to
+  arguments and can be implicitly converted to `~fmt::printf_args`.
+  \endrst
+ */
+template <typename... T>
+inline auto make_printf_args(const T&... args)
+    -> format_arg_store<printf_context, T...> {
+  return {args...};
+}
+
+/**
+  \rst
+  Constructs an `~fmt::format_arg_store` object that contains references to
+  arguments and can be implicitly converted to `~fmt::wprintf_args`.
+  \endrst
+ */
+template <typename... T>
+inline auto make_wprintf_args(const T&... args)
+    -> format_arg_store<wprintf_context, T...> {
+  return {args...};
+}
+
+template <typename S, typename Char = char_t<S>>
+inline auto vsprintf(
+    const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  basic_memory_buffer<Char> buffer;
+  vprintf(buffer, detail::to_string_view(fmt), args);
+  return to_string(buffer);
+}
+
+/**
+  \rst
+  Formats arguments and returns the result as a string.
+
+  **Example**::
+
+    std::string message = fmt::sprintf("The answer is %d", 42);
+  \endrst
+*/
+template <typename S, typename... T,
+          typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
+inline auto sprintf(const S& fmt, const T&... args) -> std::basic_string<Char> {
+  using context = basic_printf_context_t<Char>;
+  return vsprintf(detail::to_string_view(fmt),
+                  fmt::make_format_args<context>(args...));
+}
+
+template <typename S, typename Char = char_t<S>>
+inline auto vfprintf(
+    std::FILE* f, const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
+  basic_memory_buffer<Char> buffer;
+  vprintf(buffer, detail::to_string_view(fmt), args);
+  size_t size = buffer.size();
+  return std::fwrite(buffer.data(), sizeof(Char), size, f) < size
+             ? -1
+             : static_cast<int>(size);
+}
+
+/**
+  \rst
+  Prints formatted data to the file *f*.
+
+  **Example**::
+
+    fmt::fprintf(stderr, "Don't %s!", "panic");
+  \endrst
+ */
+template <typename S, typename... T, typename Char = char_t<S>>
+inline auto fprintf(std::FILE* f, const S& fmt, const T&... args) -> int {
+  using context = basic_printf_context_t<Char>;
+  return vfprintf(f, detail::to_string_view(fmt),
+                  fmt::make_format_args<context>(args...));
+}
+
+template <typename S, typename Char = char_t<S>>
+inline auto vprintf(
+    const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
+  return vfprintf(stdout, detail::to_string_view(fmt), args);
+}
+
+/**
+  \rst
+  Prints formatted data to ``stdout``.
+
+  **Example**::
+
+    fmt::printf("Elapsed time: %.2f seconds", 1.23);
+  \endrst
+ */
+template <typename S, typename... T, FMT_ENABLE_IF(detail::is_string<S>::value)>
+inline auto printf(const S& fmt, const T&... args) -> int {
+  return vprintf(
+      detail::to_string_view(fmt),
+      fmt::make_format_args<basic_printf_context_t<char_t<S>>>(args...));
+}
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_PRINTF_H_
@@ -0,0 +1,722 @@
+// Formatting library for C++ - experimental range support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+//
+// Copyright (c) 2018 - present, Remotion (Igor Schulz)
+// All Rights Reserved
+// {fmt} support for ranges, containers and types tuple interface.
+
+#ifndef FMT_RANGES_H_
+#define FMT_RANGES_H_
+
+#include <initializer_list>
+#include <tuple>
+#include <type_traits>
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+
+namespace detail {
+
+template <typename RangeT, typename OutputIterator>
+OutputIterator copy(const RangeT& range, OutputIterator out) {
+  for (auto it = range.begin(), end = range.end(); it != end; ++it)
+    *out++ = *it;
+  return out;
+}
+
+template <typename OutputIterator>
+OutputIterator copy(const char* str, OutputIterator out) {
+  while (*str) *out++ = *str++;
+  return out;
+}
+
+template <typename OutputIterator>
+OutputIterator copy(char ch, OutputIterator out) {
+  *out++ = ch;
+  return out;
+}
+
+template <typename OutputIterator>
+OutputIterator copy(wchar_t ch, OutputIterator out) {
+  *out++ = ch;
+  return out;
+}
+
+// Returns true if T has a std::string-like interface, like std::string_view.
+template <typename T> class is_std_string_like {
+  template <typename U>
+  static auto check(U* p)
+      -> decltype((void)p->find('a'), p->length(), (void)p->data(), int());
+  template <typename> static void check(...);
+
+ public:
+  static constexpr const bool value =
+      is_string<T>::value ||
+      std::is_convertible<T, std_string_view<char>>::value ||
+      !std::is_void<decltype(check<T>(nullptr))>::value;
+};
+
+template <typename Char>
+struct is_std_string_like<fmt::basic_string_view<Char>> : std::true_type {};
+
+template <typename T> class is_map {
+  template <typename U> static auto check(U*) -> typename U::mapped_type;
+  template <typename> static void check(...);
+
+ public:
+#ifdef FMT_FORMAT_MAP_AS_LIST
+  static constexpr const bool value = false;
+#else
+  static constexpr const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value;
+#endif
+};
+
+template <typename T> class is_set {
+  template <typename U> static auto check(U*) -> typename U::key_type;
+  template <typename> static void check(...);
+
+ public:
+#ifdef FMT_FORMAT_SET_AS_LIST
+  static constexpr const bool value = false;
+#else
+  static constexpr const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value && !is_map<T>::value;
+#endif
+};
+
+template <typename... Ts> struct conditional_helper {};
+
+template <typename T, typename _ = void> struct is_range_ : std::false_type {};
+
+#if !FMT_MSC_VERSION || FMT_MSC_VERSION > 1800
+
+#  define FMT_DECLTYPE_RETURN(val)  \
+    ->decltype(val) { return val; } \
+    static_assert(                  \
+        true, "")  // This makes it so that a semicolon is required after the
+                   // macro, which helps clang-format handle the formatting.
+
+// C array overload
+template <typename T, std::size_t N>
+auto range_begin(const T (&arr)[N]) -> const T* {
+  return arr;
+}
+template <typename T, std::size_t N>
+auto range_end(const T (&arr)[N]) -> const T* {
+  return arr + N;
+}
+
+template <typename T, typename Enable = void>
+struct has_member_fn_begin_end_t : std::false_type {};
+
+template <typename T>
+struct has_member_fn_begin_end_t<T, void_t<decltype(std::declval<T>().begin()),
+                                           decltype(std::declval<T>().end())>>
+    : std::true_type {};
+
+// Member function overload
+template <typename T>
+auto range_begin(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).begin());
+template <typename T>
+auto range_end(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).end());
+
+// ADL overload. Only participates in overload resolution if member functions
+// are not found.
+template <typename T>
+auto range_begin(T&& rng)
+    -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
+                   decltype(begin(static_cast<T&&>(rng)))> {
+  return begin(static_cast<T&&>(rng));
+}
+template <typename T>
+auto range_end(T&& rng) -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
+                                       decltype(end(static_cast<T&&>(rng)))> {
+  return end(static_cast<T&&>(rng));
+}
+
+template <typename T, typename Enable = void>
+struct has_const_begin_end : std::false_type {};
+template <typename T, typename Enable = void>
+struct has_mutable_begin_end : std::false_type {};
+
+template <typename T>
+struct has_const_begin_end<
+    T,
+    void_t<
+        decltype(detail::range_begin(std::declval<const remove_cvref_t<T>&>())),
+        decltype(detail::range_end(std::declval<const remove_cvref_t<T>&>()))>>
+    : std::true_type {};
+
+template <typename T>
+struct has_mutable_begin_end<
+    T, void_t<decltype(detail::range_begin(std::declval<T>())),
+              decltype(detail::range_end(std::declval<T>())),
+              enable_if_t<std::is_copy_constructible<T>::value>>>
+    : std::true_type {};
+
+template <typename T>
+struct is_range_<T, void>
+    : std::integral_constant<bool, (has_const_begin_end<T>::value ||
+                                    has_mutable_begin_end<T>::value)> {};
+#  undef FMT_DECLTYPE_RETURN
+#endif
+
+// tuple_size and tuple_element check.
+template <typename T> class is_tuple_like_ {
+  template <typename U>
+  static auto check(U* p) -> decltype(std::tuple_size<U>::value, int());
+  template <typename> static void check(...);
+
+ public:
+  static constexpr const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value;
+};
+
+// Check for integer_sequence
+#if defined(__cpp_lib_integer_sequence) || FMT_MSC_VERSION >= 1900
+template <typename T, T... N>
+using integer_sequence = std::integer_sequence<T, N...>;
+template <size_t... N> using index_sequence = std::index_sequence<N...>;
+template <size_t N> using make_index_sequence = std::make_index_sequence<N>;
+#else
+template <typename T, T... N> struct integer_sequence {
+  using value_type = T;
+
+  static FMT_CONSTEXPR size_t size() { return sizeof...(N); }
+};
+
+template <size_t... N> using index_sequence = integer_sequence<size_t, N...>;
+
+template <typename T, size_t N, T... Ns>
+struct make_integer_sequence : make_integer_sequence<T, N - 1, N - 1, Ns...> {};
+template <typename T, T... Ns>
+struct make_integer_sequence<T, 0, Ns...> : integer_sequence<T, Ns...> {};
+
+template <size_t N>
+using make_index_sequence = make_integer_sequence<size_t, N>;
+#endif
+
+template <typename T>
+using tuple_index_sequence = make_index_sequence<std::tuple_size<T>::value>;
+
+template <typename T, typename C, bool = is_tuple_like_<T>::value>
+class is_tuple_formattable_ {
+ public:
+  static constexpr const bool value = false;
+};
+template <typename T, typename C> class is_tuple_formattable_<T, C, true> {
+  template <std::size_t... I>
+  static std::true_type check2(index_sequence<I...>,
+                               integer_sequence<bool, (I == I)...>);
+  static std::false_type check2(...);
+  template <std::size_t... I>
+  static decltype(check2(
+      index_sequence<I...>{},
+      integer_sequence<
+          bool, (is_formattable<typename std::tuple_element<I, T>::type,
+                                C>::value)...>{})) check(index_sequence<I...>);
+
+ public:
+  static constexpr const bool value =
+      decltype(check(tuple_index_sequence<T>{}))::value;
+};
+
+template <class Tuple, class F, size_t... Is>
+void for_each(index_sequence<Is...>, Tuple&& tup, F&& f) noexcept {
+  using std::get;
+  // using free function get<I>(T) now.
+  const int _[] = {0, ((void)f(get<Is>(tup)), 0)...};
+  (void)_;  // blocks warnings
+}
+
+template <class T>
+FMT_CONSTEXPR make_index_sequence<std::tuple_size<T>::value> get_indexes(
+    T const&) {
+  return {};
+}
+
+template <class Tuple, class F> void for_each(Tuple&& tup, F&& f) {
+  const auto indexes = get_indexes(tup);
+  for_each(indexes, std::forward<Tuple>(tup), std::forward<F>(f));
+}
+
+#if FMT_MSC_VERSION && FMT_MSC_VERSION < 1920
+// Older MSVC doesn't get the reference type correctly for arrays.
+template <typename R> struct range_reference_type_impl {
+  using type = decltype(*detail::range_begin(std::declval<R&>()));
+};
+
+template <typename T, std::size_t N> struct range_reference_type_impl<T[N]> {
+  using type = T&;
+};
+
+template <typename T>
+using range_reference_type = typename range_reference_type_impl<T>::type;
+#else
+template <typename Range>
+using range_reference_type =
+    decltype(*detail::range_begin(std::declval<Range&>()));
+#endif
+
+// We don't use the Range's value_type for anything, but we do need the Range's
+// reference type, with cv-ref stripped.
+template <typename Range>
+using uncvref_type = remove_cvref_t<range_reference_type<Range>>;
+
+template <typename Range>
+using uncvref_first_type =
+    remove_cvref_t<decltype(std::declval<range_reference_type<Range>>().first)>;
+
+template <typename Range>
+using uncvref_second_type = remove_cvref_t<
+    decltype(std::declval<range_reference_type<Range>>().second)>;
+
+template <typename OutputIt> OutputIt write_delimiter(OutputIt out) {
+  *out++ = ',';
+  *out++ = ' ';
+  return out;
+}
+
+template <typename Char, typename OutputIt>
+auto write_range_entry(OutputIt out, basic_string_view<Char> str) -> OutputIt {
+  return write_escaped_string(out, str);
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(std::is_convertible<T, std_string_view<char>>::value)>
+inline auto write_range_entry(OutputIt out, const T& str) -> OutputIt {
+  auto sv = std_string_view<Char>(str);
+  return write_range_entry<Char>(out, basic_string_view<Char>(sv));
+}
+
+template <typename Char, typename OutputIt, typename Arg,
+          FMT_ENABLE_IF(std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg v) {
+  return write_escaped_char(out, v);
+}
+
+template <
+    typename Char, typename OutputIt, typename Arg,
+    FMT_ENABLE_IF(!is_std_string_like<typename std::decay<Arg>::type>::value &&
+                  !std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg& v) {
+  return write<Char>(out, v);
+}
+
+}  // namespace detail
+
+template <typename T> struct is_tuple_like {
+  static constexpr const bool value =
+      detail::is_tuple_like_<T>::value && !detail::is_range_<T>::value;
+};
+
+template <typename T, typename C> struct is_tuple_formattable {
+  static constexpr const bool value =
+      detail::is_tuple_formattable_<T, C>::value;
+};
+
+template <typename TupleT, typename Char>
+struct formatter<TupleT, Char,
+                 enable_if_t<fmt::is_tuple_like<TupleT>::value &&
+                             fmt::is_tuple_formattable<TupleT, Char>::value>> {
+ private:
+  basic_string_view<Char> separator_ = detail::string_literal<Char, ',', ' '>{};
+  basic_string_view<Char> opening_bracket_ =
+      detail::string_literal<Char, '('>{};
+  basic_string_view<Char> closing_bracket_ =
+      detail::string_literal<Char, ')'>{};
+
+  // C++11 generic lambda for format().
+  template <typename FormatContext> struct format_each {
+    template <typename T> void operator()(const T& v) {
+      if (i > 0) out = detail::copy_str<Char>(separator, out);
+      out = detail::write_range_entry<Char>(out, v);
+      ++i;
+    }
+    int i;
+    typename FormatContext::iterator& out;
+    basic_string_view<Char> separator;
+  };
+
+ public:
+  FMT_CONSTEXPR formatter() {}
+
+  FMT_CONSTEXPR void set_separator(basic_string_view<Char> sep) {
+    separator_ = sep;
+  }
+
+  FMT_CONSTEXPR void set_brackets(basic_string_view<Char> open,
+                                  basic_string_view<Char> close) {
+    opening_bracket_ = open;
+    closing_bracket_ = close;
+  }
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext = format_context>
+  auto format(const TupleT& values, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    out = detail::copy_str<Char>(opening_bracket_, out);
+    detail::for_each(values, format_each<FormatContext>{0, out, separator_});
+    out = detail::copy_str<Char>(closing_bracket_, out);
+    return out;
+  }
+};
+
+template <typename T, typename Char> struct is_range {
+  static constexpr const bool value =
+      detail::is_range_<T>::value && !detail::is_std_string_like<T>::value &&
+      !std::is_convertible<T, std::basic_string<Char>>::value &&
+      !std::is_convertible<T, detail::std_string_view<Char>>::value;
+};
+
+namespace detail {
+template <typename Context> struct range_mapper {
+  using mapper = arg_mapper<Context>;
+
+  template <typename T,
+            FMT_ENABLE_IF(has_formatter<remove_cvref_t<T>, Context>::value)>
+  static auto map(T&& value) -> T&& {
+    return static_cast<T&&>(value);
+  }
+  template <typename T,
+            FMT_ENABLE_IF(!has_formatter<remove_cvref_t<T>, Context>::value)>
+  static auto map(T&& value)
+      -> decltype(mapper().map(static_cast<T&&>(value))) {
+    return mapper().map(static_cast<T&&>(value));
+  }
+};
+
+template <typename Char, typename Element>
+using range_formatter_type = conditional_t<
+    is_formattable<Element, Char>::value,
+    formatter<remove_cvref_t<decltype(range_mapper<buffer_context<Char>>{}.map(
+                  std::declval<Element>()))>,
+              Char>,
+    fallback_formatter<Element, Char>>;
+
+template <typename R>
+using maybe_const_range =
+    conditional_t<has_const_begin_end<R>::value, const R, R>;
+
+// Workaround a bug in MSVC 2015 and earlier.
+#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910
+template <typename R, typename Char>
+struct is_formattable_delayed
+    : disjunction<
+          is_formattable<uncvref_type<maybe_const_range<R>>, Char>,
+          has_fallback_formatter<uncvref_type<maybe_const_range<R>>, Char>> {};
+#endif
+
+}  // namespace detail
+
+template <typename T, typename Char, typename Enable = void>
+struct range_formatter;
+
+template <typename T, typename Char>
+struct range_formatter<
+    T, Char,
+    enable_if_t<conjunction<
+        std::is_same<T, remove_cvref_t<T>>,
+        disjunction<is_formattable<T, Char>,
+                    detail::has_fallback_formatter<T, Char>>>::value>> {
+ private:
+  detail::range_formatter_type<Char, T> underlying_;
+  bool custom_specs_ = false;
+  basic_string_view<Char> separator_ = detail::string_literal<Char, ',', ' '>{};
+  basic_string_view<Char> opening_bracket_ =
+      detail::string_literal<Char, '['>{};
+  basic_string_view<Char> closing_bracket_ =
+      detail::string_literal<Char, ']'>{};
+
+  template <class U>
+  FMT_CONSTEXPR static auto maybe_set_debug_format(U& u, int)
+      -> decltype(u.set_debug_format()) {
+    u.set_debug_format();
+  }
+
+  template <class U>
+  FMT_CONSTEXPR static void maybe_set_debug_format(U&, ...) {}
+
+  FMT_CONSTEXPR void maybe_set_debug_format() {
+    maybe_set_debug_format(underlying_, 0);
+  }
+
+ public:
+  FMT_CONSTEXPR range_formatter() {}
+
+  FMT_CONSTEXPR auto underlying() -> detail::range_formatter_type<Char, T>& {
+    return underlying_;
+  }
+
+  FMT_CONSTEXPR void set_separator(basic_string_view<Char> sep) {
+    separator_ = sep;
+  }
+
+  FMT_CONSTEXPR void set_brackets(basic_string_view<Char> open,
+                                  basic_string_view<Char> close) {
+    opening_bracket_ = open;
+    closing_bracket_ = close;
+  }
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    auto it = ctx.begin();
+    auto end = ctx.end();
+    if (it == end || *it == '}') {
+      maybe_set_debug_format();
+      return it;
+    }
+
+    if (*it == 'n') {
+      set_brackets({}, {});
+      ++it;
+    }
+
+    if (*it == '}') {
+      maybe_set_debug_format();
+      return it;
+    }
+
+    if (*it != ':')
+      FMT_THROW(format_error("no other top-level range formatters supported"));
+
+    custom_specs_ = true;
+    ++it;
+    ctx.advance_to(it);
+    return underlying_.parse(ctx);
+  }
+
+  template <typename R, class FormatContext>
+  auto format(R&& range, FormatContext& ctx) const -> decltype(ctx.out()) {
+    detail::range_mapper<buffer_context<Char>> mapper;
+    auto out = ctx.out();
+    out = detail::copy_str<Char>(opening_bracket_, out);
+    int i = 0;
+    auto it = detail::range_begin(range);
+    auto end = detail::range_end(range);
+    for (; it != end; ++it) {
+      if (i > 0) out = detail::copy_str<Char>(separator_, out);
+      ;
+      ctx.advance_to(out);
+      out = underlying_.format(mapper.map(*it), ctx);
+      ++i;
+    }
+    out = detail::copy_str<Char>(closing_bracket_, out);
+    return out;
+  }
+};
+
+enum class range_format { disabled, map, set, sequence, string, debug_string };
+
+namespace detail {
+template <typename T> struct range_format_kind_ {
+  static constexpr auto value = std::is_same<range_reference_type<T>, T>::value
+                                    ? range_format::disabled
+                                : is_map<T>::value ? range_format::map
+                                : is_set<T>::value ? range_format::set
+                                                   : range_format::sequence;
+};
+
+template <range_format K, typename R, typename Char, typename Enable = void>
+struct range_default_formatter;
+
+template <range_format K>
+using range_format_constant = std::integral_constant<range_format, K>;
+
+template <range_format K, typename R, typename Char>
+struct range_default_formatter<
+    K, R, Char,
+    enable_if_t<(K == range_format::sequence || K == range_format::map ||
+                 K == range_format::set)>> {
+  using range_type = detail::maybe_const_range<R>;
+  range_formatter<detail::uncvref_type<range_type>, Char> underlying_;
+
+  FMT_CONSTEXPR range_default_formatter() { init(range_format_constant<K>()); }
+
+  FMT_CONSTEXPR void init(range_format_constant<range_format::set>) {
+    underlying_.set_brackets(detail::string_literal<Char, '{'>{},
+                             detail::string_literal<Char, '}'>{});
+  }
+
+  FMT_CONSTEXPR void init(range_format_constant<range_format::map>) {
+    underlying_.set_brackets(detail::string_literal<Char, '{'>{},
+                             detail::string_literal<Char, '}'>{});
+    underlying_.underlying().set_brackets({}, {});
+    underlying_.underlying().set_separator(
+        detail::string_literal<Char, ':', ' '>{});
+  }
+
+  FMT_CONSTEXPR void init(range_format_constant<range_format::sequence>) {}
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return underlying_.parse(ctx);
+  }
+
+  template <typename FormatContext>
+  auto format(range_type& range, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    return underlying_.format(range, ctx);
+  }
+};
+}  // namespace detail
+
+template <typename T, typename Char, typename Enable = void>
+struct range_format_kind
+    : conditional_t<
+          is_range<T, Char>::value, detail::range_format_kind_<T>,
+          std::integral_constant<range_format, range_format::disabled>> {};
+
+template <typename R, typename Char>
+struct formatter<
+    R, Char,
+    enable_if_t<conjunction<bool_constant<range_format_kind<R, Char>::value !=
+                                          range_format::disabled>
+// Workaround a bug in MSVC 2015 and earlier.
+#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910
+                            ,
+                            detail::is_formattable_delayed<R, Char>
+#endif
+                            >::value>>
+    : detail::range_default_formatter<range_format_kind<R, Char>::value, R,
+                                      Char> {
+};
+
+template <typename Char, typename... T> struct tuple_join_view : detail::view {
+  const std::tuple<T...>& tuple;
+  basic_string_view<Char> sep;
+
+  tuple_join_view(const std::tuple<T...>& t, basic_string_view<Char> s)
+      : tuple(t), sep{s} {}
+};
+
+template <typename Char, typename... T>
+using tuple_arg_join = tuple_join_view<Char, T...>;
+
+// Define FMT_TUPLE_JOIN_SPECIFIERS to enable experimental format specifiers
+// support in tuple_join. It is disabled by default because of issues with
+// the dynamic width and precision.
+#ifndef FMT_TUPLE_JOIN_SPECIFIERS
+#  define FMT_TUPLE_JOIN_SPECIFIERS 0
+#endif
+
+template <typename Char, typename... T>
+struct formatter<tuple_join_view<Char, T...>, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return do_parse(ctx, std::integral_constant<size_t, sizeof...(T)>());
+  }
+
+  template <typename FormatContext>
+  auto format(const tuple_join_view<Char, T...>& value,
+              FormatContext& ctx) const -> typename FormatContext::iterator {
+    return do_format(value, ctx,
+                     std::integral_constant<size_t, sizeof...(T)>());
+  }
+
+ private:
+  std::tuple<formatter<typename std::decay<T>::type, Char>...> formatters_;
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
+                              std::integral_constant<size_t, 0>)
+      -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename ParseContext, size_t N>
+  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
+                              std::integral_constant<size_t, N>)
+      -> decltype(ctx.begin()) {
+    auto end = ctx.begin();
+#if FMT_TUPLE_JOIN_SPECIFIERS
+    end = std::get<sizeof...(T) - N>(formatters_).parse(ctx);
+    if (N > 1) {
+      auto end1 = do_parse(ctx, std::integral_constant<size_t, N - 1>());
+      if (end != end1)
+        FMT_THROW(format_error("incompatible format specs for tuple elements"));
+    }
+#endif
+    return end;
+  }
+
+  template <typename FormatContext>
+  auto do_format(const tuple_join_view<Char, T...>&, FormatContext& ctx,
+                 std::integral_constant<size_t, 0>) const ->
+      typename FormatContext::iterator {
+    return ctx.out();
+  }
+
+  template <typename FormatContext, size_t N>
+  auto do_format(const tuple_join_view<Char, T...>& value, FormatContext& ctx,
+                 std::integral_constant<size_t, N>) const ->
+      typename FormatContext::iterator {
+    auto out = std::get<sizeof...(T) - N>(formatters_)
+                   .format(std::get<sizeof...(T) - N>(value.tuple), ctx);
+    if (N > 1) {
+      out = std::copy(value.sep.begin(), value.sep.end(), out);
+      ctx.advance_to(out);
+      return do_format(value, ctx, std::integral_constant<size_t, N - 1>());
+    }
+    return out;
+  }
+};
+
+FMT_MODULE_EXPORT_BEGIN
+
+/**
+  \rst
+  Returns an object that formats `tuple` with elements separated by `sep`.
+
+  **Example**::
+
+    std::tuple<int, char> t = {1, 'a'};
+    fmt::print("{}", fmt::join(t, ", "));
+    // Output: "1, a"
+  \endrst
+ */
+template <typename... T>
+FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple, string_view sep)
+    -> tuple_join_view<char, T...> {
+  return {tuple, sep};
+}
+
+template <typename... T>
+FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple,
+                        basic_string_view<wchar_t> sep)
+    -> tuple_join_view<wchar_t, T...> {
+  return {tuple, sep};
+}
+
+/**
+  \rst
+  Returns an object that formats `initializer_list` with elements separated by
+  `sep`.
+
+  **Example**::
+
+    fmt::print("{}", fmt::join({1, 2, 3}, ", "));
+    // Output: "1, 2, 3"
+  \endrst
+ */
+template <typename T>
+auto join(std::initializer_list<T> list, string_view sep)
+    -> join_view<const T*, const T*> {
+  return join(std::begin(list), std::end(list), sep);
+}
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_RANGES_H_
@@ -0,0 +1,171 @@
+// Formatting library for C++ - formatters for standard library types
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_STD_H_
+#define FMT_STD_H_
+
+#include <thread>
+#include <type_traits>
+#include <utility>
+
+#include "ostream.h"
+
+#if FMT_HAS_INCLUDE(<version>)
+#  include <version>
+#endif
+// Checking FMT_CPLUSPLUS for warning suppression in MSVC.
+#if FMT_CPLUSPLUS >= 201703L
+#  if FMT_HAS_INCLUDE(<filesystem>)
+#    include <filesystem>
+#  endif
+#  if FMT_HAS_INCLUDE(<variant>)
+#    include <variant>
+#  endif
+#endif
+
+#ifdef __cpp_lib_filesystem
+FMT_BEGIN_NAMESPACE
+
+namespace detail {
+
+template <typename Char>
+void write_escaped_path(basic_memory_buffer<Char>& quoted,
+                        const std::filesystem::path& p) {
+  write_escaped_string<Char>(std::back_inserter(quoted), p.string<Char>());
+}
+#  ifdef _WIN32
+template <>
+inline void write_escaped_path<char>(basic_memory_buffer<char>& quoted,
+                                     const std::filesystem::path& p) {
+  auto s = p.u8string();
+  write_escaped_string<char>(
+      std::back_inserter(quoted),
+      string_view(reinterpret_cast<const char*>(s.c_str()), s.size()));
+}
+#  endif
+template <>
+inline void write_escaped_path<std::filesystem::path::value_type>(
+    basic_memory_buffer<std::filesystem::path::value_type>& quoted,
+    const std::filesystem::path& p) {
+  write_escaped_string<std::filesystem::path::value_type>(
+      std::back_inserter(quoted), p.native());
+}
+
+}  // namespace detail
+
+template <typename Char>
+struct formatter<std::filesystem::path, Char>
+    : formatter<basic_string_view<Char>> {
+  template <typename FormatContext>
+  auto format(const std::filesystem::path& p, FormatContext& ctx) const ->
+      typename FormatContext::iterator {
+    basic_memory_buffer<Char> quoted;
+    detail::write_escaped_path(quoted, p);
+    return formatter<basic_string_view<Char>>::format(
+        basic_string_view<Char>(quoted.data(), quoted.size()), ctx);
+  }
+};
+FMT_END_NAMESPACE
+#endif
+
+FMT_BEGIN_NAMESPACE
+template <typename Char>
+struct formatter<std::thread::id, Char> : basic_ostream_formatter<Char> {};
+FMT_END_NAMESPACE
+
+#ifdef __cpp_lib_variant
+FMT_BEGIN_NAMESPACE
+template <typename Char> struct formatter<std::monostate, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  auto format(const std::monostate&, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    out = detail::write<Char>(out, "monostate");
+    return out;
+  }
+};
+
+namespace detail {
+
+template <typename T>
+using variant_index_sequence =
+    std::make_index_sequence<std::variant_size<T>::value>;
+
+// variant_size and variant_alternative check.
+template <typename T, typename U = void>
+struct is_variant_like_ : std::false_type {};
+template <typename T>
+struct is_variant_like_<T, std::void_t<decltype(std::variant_size<T>::value)>>
+    : std::true_type {};
+
+// formattable element check
+template <typename T, typename C> class is_variant_formattable_ {
+  template <std::size_t... I>
+  static std::conjunction<
+      is_formattable<std::variant_alternative_t<I, T>, C>...>
+      check(std::index_sequence<I...>);
+
+ public:
+  static constexpr const bool value =
+      decltype(check(variant_index_sequence<T>{}))::value;
+};
+
+template <typename Char, typename OutputIt, typename T>
+auto write_variant_alternative(OutputIt out, const T& v) -> OutputIt {
+  if constexpr (is_string<T>::value)
+    return write_escaped_string<Char>(out, detail::to_string_view(v));
+  else if constexpr (std::is_same_v<T, Char>)
+    return write_escaped_char(out, v);
+  else
+    return write<Char>(out, v);
+}
+
+}  // namespace detail
+
+template <typename T> struct is_variant_like {
+  static constexpr const bool value = detail::is_variant_like_<T>::value;
+};
+
+template <typename T, typename C> struct is_variant_formattable {
+  static constexpr const bool value =
+      detail::is_variant_formattable_<T, C>::value;
+};
+
+template <typename Variant, typename Char>
+struct formatter<
+    Variant, Char,
+    std::enable_if_t<std::conjunction_v<
+        is_variant_like<Variant>, is_variant_formattable<Variant, Char>>>> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  auto format(const Variant& value, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+
+    out = detail::write<Char>(out, "variant(");
+    std::visit(
+        [&](const auto& v) {
+          out = detail::write_variant_alternative<Char>(out, v);
+        },
+        value);
+    *out++ = ')';
+    return out;
+  }
+};
+FMT_END_NAMESPACE
+#endif
+
+#endif  // FMT_STD_H_
@@ -0,0 +1,229 @@
+// Formatting library for C++ - optional wchar_t and exotic character support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_XCHAR_H_
+#define FMT_XCHAR_H_
+
+#include <cwchar>
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+template <typename T>
+using is_exotic_char = bool_constant<!std::is_same<T, char>::value>;
+}
+
+FMT_MODULE_EXPORT_BEGIN
+
+using wstring_view = basic_string_view<wchar_t>;
+using wformat_parse_context = basic_format_parse_context<wchar_t>;
+using wformat_context = buffer_context<wchar_t>;
+using wformat_args = basic_format_args<wformat_context>;
+using wmemory_buffer = basic_memory_buffer<wchar_t>;
+
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+// Workaround broken conversion on older gcc.
+template <typename... Args> using wformat_string = wstring_view;
+inline auto runtime(wstring_view s) -> wstring_view { return s; }
+#else
+template <typename... Args>
+using wformat_string = basic_format_string<wchar_t, type_identity_t<Args>...>;
+inline auto runtime(wstring_view s) -> basic_runtime<wchar_t> { return {{s}}; }
+#endif
+
+template <> struct is_char<wchar_t> : std::true_type {};
+template <> struct is_char<detail::char8_type> : std::true_type {};
+template <> struct is_char<char16_t> : std::true_type {};
+template <> struct is_char<char32_t> : std::true_type {};
+
+template <typename... Args>
+constexpr format_arg_store<wformat_context, Args...> make_wformat_args(
+    const Args&... args) {
+  return {args...};
+}
+
+inline namespace literals {
+#if FMT_USE_USER_DEFINED_LITERALS && !FMT_USE_NONTYPE_TEMPLATE_ARGS
+constexpr detail::udl_arg<wchar_t> operator"" _a(const wchar_t* s, size_t) {
+  return {s};
+}
+#endif
+}  // namespace literals
+
+template <typename It, typename Sentinel>
+auto join(It begin, Sentinel end, wstring_view sep)
+    -> join_view<It, Sentinel, wchar_t> {
+  return {begin, end, sep};
+}
+
+template <typename Range>
+auto join(Range&& range, wstring_view sep)
+    -> join_view<detail::iterator_t<Range>, detail::sentinel_t<Range>,
+                 wchar_t> {
+  return join(std::begin(range), std::end(range), sep);
+}
+
+template <typename T>
+auto join(std::initializer_list<T> list, wstring_view sep)
+    -> join_view<const T*, const T*, wchar_t> {
+  return join(std::begin(list), std::end(list), sep);
+}
+
+template <typename Char, FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
+auto vformat(basic_string_view<Char> format_str,
+             basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  basic_memory_buffer<Char> buffer;
+  detail::vformat_to(buffer, format_str, args);
+  return to_string(buffer);
+}
+
+template <typename... T>
+auto format(wformat_string<T...> fmt, T&&... args) -> std::wstring {
+  return vformat(fmt::wstring_view(fmt), fmt::make_wformat_args(args...));
+}
+
+// Pass char_t as a default template parameter instead of using
+// std::basic_string<char_t<S>> to reduce the symbol size.
+template <typename S, typename... Args, typename Char = char_t<S>,
+          FMT_ENABLE_IF(!std::is_same<Char, char>::value &&
+                        !std::is_same<Char, wchar_t>::value)>
+auto format(const S& format_str, Args&&... args) -> std::basic_string<Char> {
+  return vformat(detail::to_string_view(format_str),
+                 fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename Locale, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto vformat(
+    const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  return detail::vformat(loc, detail::to_string_view(format_str), args);
+}
+
+template <typename Locale, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format(const Locale& loc, const S& format_str, Args&&... args)
+    -> std::basic_string<Char> {
+  return detail::vformat(loc, detail::to_string_view(format_str),
+                         fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename OutputIt, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+auto vformat_to(OutputIt out, const S& format_str,
+                basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> OutputIt {
+  auto&& buf = detail::get_buffer<Char>(out);
+  detail::vformat_to(buf, detail::to_string_view(format_str), args);
+  return detail::get_iterator(buf);
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format_to(OutputIt out, const S& fmt, Args&&... args) -> OutputIt {
+  return vformat_to(out, detail::to_string_view(fmt),
+                    fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename Locale, typename S, typename OutputIt, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_locale<Locale>::value&&
+                                detail::is_exotic_char<Char>::value)>
+inline auto vformat_to(
+    OutputIt out, const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) -> OutputIt {
+  auto&& buf = detail::get_buffer<Char>(out);
+  vformat_to(buf, detail::to_string_view(format_str), args,
+             detail::locale_ref(loc));
+  return detail::get_iterator(buf);
+}
+
+template <
+    typename OutputIt, typename Locale, typename S, typename... Args,
+    typename Char = char_t<S>,
+    bool enable = detail::is_output_iterator<OutputIt, Char>::value&&
+        detail::is_locale<Locale>::value&& detail::is_exotic_char<Char>::value>
+inline auto format_to(OutputIt out, const Locale& loc, const S& format_str,
+                      Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  return vformat_to(out, loc, to_string_view(format_str),
+                    fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename OutputIt, typename Char, typename... Args,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto vformat_to_n(
+    OutputIt out, size_t n, basic_string_view<Char> format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> format_to_n_result<OutputIt> {
+  detail::iterator_buffer<OutputIt, Char, detail::fixed_buffer_traits> buf(out,
+                                                                           n);
+  detail::vformat_to(buf, format_str, args);
+  return {buf.out(), buf.count()};
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format_to_n(OutputIt out, size_t n, const S& fmt,
+                        const Args&... args) -> format_to_n_result<OutputIt> {
+  return vformat_to_n(out, n, detail::to_string_view(fmt),
+                      fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename S, typename... Args, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_exotic_char<Char>::value)>
+inline auto formatted_size(const S& fmt, Args&&... args) -> size_t {
+  detail::counting_buffer<Char> buf;
+  detail::vformat_to(buf, detail::to_string_view(fmt),
+                     fmt::make_format_args<buffer_context<Char>>(args...));
+  return buf.count();
+}
+
+inline void vprint(std::FILE* f, wstring_view fmt, wformat_args args) {
+  wmemory_buffer buffer;
+  detail::vformat_to(buffer, fmt, args);
+  buffer.push_back(L'\0');
+  if (std::fputws(buffer.data(), f) == -1)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+inline void vprint(wstring_view fmt, wformat_args args) {
+  vprint(stdout, fmt, args);
+}
+
+template <typename... T>
+void print(std::FILE* f, wformat_string<T...> fmt, T&&... args) {
+  return vprint(f, wstring_view(fmt), fmt::make_wformat_args(args...));
+}
+
+template <typename... T> void print(wformat_string<T...> fmt, T&&... args) {
+  return vprint(wstring_view(fmt), fmt::make_wformat_args(args...));
+}
+
+/**
+  Converts *value* to ``std::wstring`` using the default format for type *T*.
+ */
+template <typename T> inline auto to_wstring(const T& value) -> std::wstring {
+  return format(FMT_STRING(L"{}"), value);
+}
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_XCHAR_H_
@@ -0,0 +1,47 @@
+// Formatting library for C++
+//
+// Copyright (c) 2012 - 2016, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#include "fmt/format-inl.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+
+template FMT_API auto dragonbox::to_decimal(float x) noexcept
+    -> dragonbox::decimal_fp<float>;
+template FMT_API auto dragonbox::to_decimal(double x) noexcept
+    -> dragonbox::decimal_fp<double>;
+
+#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+template FMT_API locale_ref::locale_ref(const std::locale& loc);
+template FMT_API auto locale_ref::get<std::locale>() const -> std::locale;
+#endif
+
+// Explicit instantiations for char.
+
+template FMT_API auto thousands_sep_impl(locale_ref)
+    -> thousands_sep_result<char>;
+template FMT_API auto decimal_point_impl(locale_ref) -> char;
+
+template FMT_API void buffer<char>::append(const char*, const char*);
+
+// DEPRECATED!
+// There is no correspondent extern template in format.h because of
+// incompatibility between clang and gcc (#2377).
+template FMT_API void vformat_to(buffer<char>&, string_view,
+                                 basic_format_args<FMT_BUFFER_CONTEXT(char)>,
+                                 locale_ref);
+
+// Explicit instantiations for wchar_t.
+
+template FMT_API auto thousands_sep_impl(locale_ref)
+    -> thousands_sep_result<wchar_t>;
+template FMT_API auto decimal_point_impl(locale_ref) -> wchar_t;
+
+template FMT_API void buffer<wchar_t>::append(const wchar_t*, const wchar_t*);
+
+}  // namespace detail
+FMT_END_NAMESPACE
@@ -10,24 +10,25 @@

 #include "fuse.h"
 #include "fuse_lowlevel.h"
+#include "fuse_msgbuf.h"
+
+#include "extern_c.h"

 struct fuse_chan;
 struct fuse_ll;

 struct fuse_session
 {
-  struct fuse_session_ops op;
+  int (*receive_buf)(struct fuse_session *se,
+                     fuse_msgbuf_t       *msgbuf);

-  int (*receive_buf)(struct fuse_session *se, struct fuse_buf *buf,
-                     struct fuse_chan **chp);
+  void (*process_buf)(struct fuse_session *se,
+                      const fuse_msgbuf_t *msgbuf);

-  void (*process_buf)(void *data, const struct fuse_buf *buf,
-                      struct fuse_chan *ch);
-
-  void *data;
+  void (*destroy)(void *data);

+  struct fuse_ll *f;
  volatile int exited;
-
  struct fuse_chan *ch;
 };

@@ -46,8 +47,7 @@ struct fuse_notify_req
  void (*reply)(struct fuse_notify_req *,
                fuse_req_t,
                uint64_t,
-                const void *,
-                const struct fuse_buf *);
+                const void *);
  struct fuse_notify_req *next;
  struct fuse_notify_req *prev;
 };
@@ -58,18 +58,12 @@ struct fuse_ll
  int no_remote_posix_lock;
  int no_remote_flock;
  int big_writes;
-  int splice_write;
-  int splice_move;
-  int splice_read;
-  int no_splice_write;
-  int no_splice_move;
-  int no_splice_read;
  struct fuse_lowlevel_ops op;
-  int got_init;
  void *userdata;
  uid_t owner;
  struct fuse_conn_info conn;
  pthread_mutex_t lock;
+  int got_init;
  int got_destroy;
  pthread_key_t pipe_key;
  int broken_splice_nonblock;
@@ -84,6 +78,8 @@ struct fuse_cmd
  struct fuse_chan *ch;
 };

+EXTERN_C_BEGIN
+
 struct fuse *fuse_new_common(struct fuse_chan *ch, struct fuse_args *args,
 			     const struct fuse_operations *op,
 			     size_t op_size);
@@ -111,3 +107,5 @@ struct fuse *fuse_setup_common(int argc, char *argv[],
 			       int *fd);

 int fuse_start_thread(pthread_t *thread_id, void *(*func)(void *), void *arg);
+
+EXTERN_C_END
@@ -1,103 +0,0 @@
-/*
-  FUSE: Filesystem in Userspace
-  Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>
-
-  This program can be distributed under the terms of the GNU LGPLv2.
-  See the file COPYING.LIB
-*/
-
-#include "fuse_lowlevel.h"
-#include "fuse_kernel.h"
-#include "fuse_i.h"
-
-#include <stdio.h>
-#include <errno.h>
-#include <unistd.h>
-#include <assert.h>
-
-static int fuse_kern_chan_receive(struct fuse_chan **chp, char *buf,
-				  size_t size)
-{
-  struct fuse_chan *ch = *chp;
-  int err;
-  ssize_t res;
-  struct fuse_session *se = fuse_chan_session(ch);
-  assert(se != NULL);
-
- restart:
-  res = read(fuse_chan_fd(ch), buf, size);
-  err = errno;
-
-  if (fuse_session_exited(se))
-    return 0;
-  if (res == -1) {
-    /* ENOENT means the operation was interrupted, it's safe
-       to restart */
-    if (err == ENOENT)
-      goto restart;
-
-    if (err == ENODEV) {
-      fuse_session_exit(se);
-      return 0;
-    }
-    /* Errors occurring during normal operation: EINTR (read
-       interrupted), EAGAIN (nonblocking I/O), ENODEV (filesystem
-       umounted) */
-    if (err != EINTR && err != EAGAIN)
-      perror("fuse: reading device");
-    return -err;
-  }
-  if ((size_t) res < sizeof(struct fuse_in_header)) {
-    fprintf(stderr, "short read on fuse device\n");
-    return -EIO;
-  }
-  return res;
-}
-
-static int fuse_kern_chan_send(struct fuse_chan *ch, const struct iovec iov[],
-			       size_t count)
-{
-  if (iov) {
-    ssize_t res = writev(fuse_chan_fd(ch), iov, count);
-    int err = errno;
-
-    if (res == -1) {
-      struct fuse_session *se = fuse_chan_session(ch);
-
-      assert(se != NULL);
-
-      /* ENOENT means the operation was interrupted */
-      if (!fuse_session_exited(se) && err != ENOENT)
-        perror("fuse: writing device");
-      return -err;
-    }
-  }
-  return 0;
-}
-
-static void fuse_kern_chan_destroy(struct fuse_chan *ch)
-{
-  int fd = fuse_chan_fd(ch);
-
-  if (fd != -1)
-    close(fd);
-}
-
-struct fuse_chan *
-fuse_kern_chan_new(int fd_)
-{
-  long pagesize;
-  size_t bufsize;
-  struct fuse_chan_ops op =
-    {
-      .receive = fuse_kern_chan_receive,
-      .send    = fuse_kern_chan_send,
-      .destroy = fuse_kern_chan_destroy,
-    };
-
-  pagesize = sysconf(_SC_PAGESIZE);
-
-  bufsize = ((FUSE_MAX_MAX_PAGES * pagesize) + 0x1000);
-
-  return fuse_chan_new(&op, fd_, bufsize, NULL);
-}
@@ -0,0 +1,9 @@
+#pragma once
+
+#include "fuse_msgbuf.h"
+
+int fuse_receive_buf(struct fuse_session *se,
+                     fuse_msgbuf_t       *msgbuf);
+void fuse_process_buf(void *data,
+                      const fuse_msgbuf_t *msgbuf,
+                      struct fuse_chan *ch);
@@ -1,232 +0,0 @@
-/*
-  FUSE: Filesystem in Userspace
-  Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>
-
-  This program can be distributed under the terms of the GNU LGPLv2.
-  See the file COPYING.LIB.
-*/
-
-#include "fuse_i.h"
-#include "fuse_kernel.h"
-#include "fuse_lowlevel.h"
-#include "fuse_misc.h"
-
-#include <errno.h>
-#include <semaphore.h>
-#include <signal.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/time.h>
-#include <unistd.h>
-#include <unistd.h>
-
-/* Environment var controlling the thread stack size */
-#define ENVNAME_THREAD_STACK "FUSE_THREAD_STACK"
-
-struct fuse_worker
-{
-  struct fuse_worker *prev;
-  struct fuse_worker *next;
-  pthread_t thread_id;
-  size_t bufsize;
-  char *buf;
-  struct fuse_mt *mt;
-};
-
-struct fuse_mt
-{
-  struct fuse_session *se;
-  struct fuse_chan *prevch;
-  struct fuse_worker main;
-  sem_t finish;
-  int exit;
-  int error;
-};
-
-static
-void
-list_add_worker(struct fuse_worker *w,
-                struct fuse_worker *next)
-{
-  struct fuse_worker *prev = next->prev;
-  w->next = next;
-  w->prev = prev;
-  prev->next = w;
-  next->prev = w;
-}
-
-static void list_del_worker(struct fuse_worker *w)
-{
-  struct fuse_worker *prev = w->prev;
-  struct fuse_worker *next = w->next;
-  prev->next = next;
-  next->prev = prev;
-}
-
-static int fuse_loop_start_thread(struct fuse_mt *mt);
-
-static
-void*
-fuse_do_work(void *data)
-{
-  struct fuse_worker *w  = (struct fuse_worker *) data;
-  struct fuse_mt     *mt = w->mt;
-
-  while(!fuse_session_exited(mt->se))
-    {
-      int res;
-      struct fuse_buf fbuf;
-      struct fuse_chan *ch = mt->prevch;
-
-      fbuf = (struct fuse_buf){ .mem  = w->buf,
-                                .size = w->bufsize };
-
-      pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
-      res = fuse_session_receive_buf(mt->se, &fbuf, &ch);
-      pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
-      if(res == -EINTR)
-        continue;
-      if(res <= 0) {
-        if(res < 0) {
-          fuse_session_exit(mt->se);
-          mt->error = -1;
-        }
-        break;
-      }
-
-      if(mt->exit)
-        return NULL;
-
-      fuse_session_process_buf(mt->se, &fbuf, ch);
-    }
-
-  sem_post(&mt->finish);
-
-  return NULL;
-}
-
-int fuse_start_thread(pthread_t *thread_id, void *(*func)(void *), void *arg)
-{
-  sigset_t oldset;
-  sigset_t newset;
-  int res;
-  pthread_attr_t attr;
-  char *stack_size;
-
-  /* Override default stack size */
-  pthread_attr_init(&attr);
-  stack_size = getenv(ENVNAME_THREAD_STACK);
-  if(stack_size && pthread_attr_setstacksize(&attr, atoi(stack_size)))
-    fprintf(stderr, "fuse: invalid stack size: %s\n", stack_size);
-
-  /* Disallow signal reception in worker threads */
-  sigfillset(&newset);
-  pthread_sigmask(SIG_BLOCK,&newset,&oldset);
-  res = pthread_create(thread_id, &attr, func, arg);
-  pthread_sigmask(SIG_SETMASK,&oldset,NULL);
-  pthread_attr_destroy(&attr);
-  if(res != 0) {
-    fprintf(stderr, "fuse: error creating thread: %s\n",
-            strerror(res));
-    return -1;
-  }
-
-  return 0;
-}
-
-static int fuse_loop_start_thread(struct fuse_mt *mt)
-{
-  int res;
-  struct fuse_worker *w = malloc(sizeof(struct fuse_worker));
-  if(!w) {
-    fprintf(stderr, "fuse: failed to allocate worker structure\n");
-    return -1;
-  }
-  memset(w, 0, sizeof(struct fuse_worker));
-  w->bufsize = fuse_chan_bufsize(mt->prevch);
-  w->buf = calloc(w->bufsize,1);
-  w->mt = mt;
-  if(!w->buf) {
-    fprintf(stderr, "fuse: failed to allocate read buffer\n");
-    free(w);
-    return -1;
-  }
-
-  res = fuse_start_thread(&w->thread_id, fuse_do_work, w);
-  if(res == -1) {
-    free(w->buf);
-    free(w);
-    return -1;
-  }
-  list_add_worker(w, &mt->main);
-
-  return 0;
-}
-
-static void fuse_join_worker(struct fuse_worker *w)
-{
-  pthread_join(w->thread_id, NULL);
-  list_del_worker(w);
-  free(w->buf);
-  free(w);
-}
-
-static int number_of_threads(void)
-{
-#ifdef _SC_NPROCESSORS_ONLN
-  return sysconf(_SC_NPROCESSORS_ONLN);
-#endif
-
-  return 4;
-}
-
-int
-fuse_session_loop_mt(struct fuse_session *se_,
-                     const int            threads_)
-{
-  int i;
-  int err;
-  int threads;
-  struct fuse_mt mt;
-  struct fuse_worker *w;
-
-  memset(&mt,0,sizeof(struct fuse_mt));
-  mt.se = se_;
-  mt.prevch = fuse_session_next_chan(se_,NULL);
-  mt.error = 0;
-  mt.main.thread_id = pthread_self();
-  mt.main.prev = mt.main.next = &mt.main;
-  sem_init(&mt.finish,0,0);
-
-  threads = ((threads_ > 0) ? threads_ : number_of_threads());
-  if(threads_ < 0)
-    threads /= -threads_;
-  if(threads == 0)
-    threads = 1;
-
-  err = 0;
-  for(i = 0; (i < threads) && !err; i++)
-    err = fuse_loop_start_thread(&mt);
-
-  if(!err)
-    {
-      /* sem_wait() is interruptible */
-      while(!fuse_session_exited(se_))
-        sem_wait(&mt.finish);
-
-      for(w = mt.main.next; w != &mt.main; w = w->next)
-        pthread_cancel(w->thread_id);
-      mt.exit = 1;
-
-      while(mt.main.next != &mt.main)
-        fuse_join_worker(mt.main.next);
-
-      err = mt.error;
-    }
-
-  sem_destroy(&mt.finish);
-  fuse_session_reset(se_);
-
-  return err;
-}
@@ -0,0 +1,487 @@
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include "thread_pool.hpp"
+#include "cpu.hpp"
+#include "fmt/core.h"
+
+#include "fuse_i.h"
+#include "fuse_kernel.h"
+#include "fuse_lowlevel.h"
+#include "fuse_misc.h"
+
+#include "fuse_msgbuf.hpp"
+#include "fuse_ll.hpp"
+
+#include <errno.h>
+#include <pthread.h>
+#include <semaphore.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+#include <unistd.h>
+
+#include <cassert>
+#include <vector>
+
+
+struct fuse_worker_data_t
+{
+  struct fuse_session *se;
+  sem_t finished;
+  std::function<void(fuse_worker_data_t*,fuse_msgbuf_t*)> msgbuf_processor;
+  std::shared_ptr<ThreadPool> tp;
+};
+
+class WorkerCleanup
+{
+public:
+  WorkerCleanup(fuse_worker_data_t *wd_)
+    : _wd(wd_)
+  {
+  }
+
+  ~WorkerCleanup()
+  {
+    fuse_session_exit(_wd->se);
+    sem_post(&_wd->finished);
+  }
+
+private:
+  fuse_worker_data_t *_wd;
+};
+
+static
+bool
+retriable_receive_error(const int err_)
+{
+  switch(err_)
+    {
+    case -EINTR:
+    case -EAGAIN:
+    case -ENOENT:
+      return true;
+    default:
+      return false;
+    }
+}
+
+static
+bool
+fatal_receive_error(const int err_)
+{
+  return (err_ < 0);
+}
+
+static
+void*
+handle_receive_error(const int      rv_,
+                     fuse_msgbuf_t *msgbuf_)
+{
+  msgbuf_free(msgbuf_);
+
+  fprintf(stderr,
+          "mergerfs: error reading from /dev/fuse - %s (%d)\n",
+          strerror(-rv_),
+          -rv_);
+
+  return NULL;
+}
+
+static
+void*
+fuse_do_work(void *data)
+{
+  fuse_worker_data_t *wd = (fuse_worker_data_t*)data;
+  fuse_session       *se = wd->se;
+  auto               &process_msgbuf = wd->msgbuf_processor;
+  WorkerCleanup       workercleanup(wd);
+
+  while(!fuse_session_exited(se))
+    {
+      int rv;
+      fuse_msgbuf_t *msgbuf;
+
+      msgbuf = msgbuf_alloc();
+
+      do
+        {
+          pthread_setcancelstate(PTHREAD_CANCEL_ENABLE,NULL);
+          rv = se->receive_buf(se,msgbuf);
+          pthread_setcancelstate(PTHREAD_CANCEL_DISABLE,NULL);
+          if(rv == 0)
+            return NULL;
+          if(retriable_receive_error(rv))
+            continue;
+          if(fatal_receive_error(rv))
+            return handle_receive_error(rv,msgbuf);
+        } while(false);
+
+      process_msgbuf(wd,msgbuf);
+    }
+
+  return NULL;
+}
+
+int
+fuse_start_thread(pthread_t *thread_id,
+                  void      *(*func)(void *),
+                  void      *arg)
+{
+  int res;
+  sigset_t oldset;
+  sigset_t newset;
+
+  sigfillset(&newset);
+  pthread_sigmask(SIG_BLOCK,&newset,&oldset);
+  res = pthread_create(thread_id,NULL,func,arg);
+  pthread_sigmask(SIG_SETMASK,&oldset,NULL);
+
+  if(res != 0)
+    {
+      fprintf(stderr,
+              "fuse: error creating thread: %s\n",
+              strerror(res));
+      return -1;
+    }
+
+  return 0;
+}
+
+static
+int
+calculate_thread_count(const int raw_thread_count_)
+{
+  int thread_count;
+
+  thread_count = 4;
+  if(raw_thread_count_ == 0)
+    thread_count = std::thread::hardware_concurrency();
+  else if(raw_thread_count_ < 0)
+    thread_count = (std::thread::hardware_concurrency() / -raw_thread_count_);
+  else if(raw_thread_count_ > 0)
+    thread_count = raw_thread_count_;
+
+  if(thread_count <= 0)
+    thread_count = 1;
+
+  return thread_count;
+}
+
+static
+void
+calculate_thread_counts(int *read_thread_count_,
+                        int *process_thread_count_)
+{
+  if((*read_thread_count_ == -1) && (*process_thread_count_ == -1))
+    {
+      int nproc;
+
+      nproc = std::thread::hardware_concurrency();
+      *read_thread_count_ = 2;
+      *process_thread_count_ = std::max(2,(nproc - 2));
+    }
+  else
+    {
+      *read_thread_count_ = ::calculate_thread_count(*read_thread_count_);
+      if(*process_thread_count_ != -1)
+        *process_thread_count_ = ::calculate_thread_count(*process_thread_count_);
+    }
+}
+
+static
+void
+process_msgbuf_sync(fuse_worker_data_t *wd_,
+                    fuse_msgbuf_t      *msgbuf_)
+{
+  wd_->se->process_buf(wd_->se,msgbuf_);
+  msgbuf_free(msgbuf_);
+}
+
+static
+void
+process_msgbuf_async(fuse_worker_data_t *wd_,
+                     fuse_msgbuf_t      *msgbuf_)
+{
+  const auto func = [=] {
+    process_msgbuf_sync(wd_,msgbuf_);
+  };
+
+  wd_->tp->enqueue_work(func);
+}
+
+static
+void
+pin_threads_R1L(const CPU::ThreadIdVec read_threads_)
+{
+  CPU::CPUVec cpus;
+
+  cpus = CPU::cpus();
+  if(cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,cpus.front());
+}
+
+static
+void
+pin_threads_R1P(const CPU::ThreadIdVec read_threads_)
+{
+  CPU::Core2CPUsMap core2cpus;
+
+  core2cpus = CPU::core2cpus();
+  if(core2cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,core2cpus.begin()->second);
+}
+
+static
+void
+pin_threads_RP1L(const CPU::ThreadIdVec read_threads_,
+                 const CPU::ThreadIdVec process_threads_)
+{
+  CPU::CPUVec cpus;
+
+  cpus = CPU::cpus();
+  if(cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,cpus.front());
+  for(auto const thread_id : process_threads_)
+    CPU::setaffinity(thread_id,cpus.front());
+}
+
+static
+void
+pin_threads_RP1P(const CPU::ThreadIdVec read_threads_,
+                 const CPU::ThreadIdVec process_threads_)
+{
+  CPU::Core2CPUsMap core2cpus;
+
+  core2cpus = CPU::core2cpus();
+  if(core2cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,core2cpus.begin()->second);
+  for(auto const thread_id : process_threads_)
+    CPU::setaffinity(thread_id,core2cpus.begin()->second);
+}
+
+static
+void
+pin_threads_R1LP1L(const std::vector<pthread_t> read_threads_,
+                   const std::vector<pthread_t> process_threads_)
+{
+  CPU::CPUVec cpus;
+
+  cpus = CPU::cpus();
+  if(cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,cpus.front());
+
+  for(auto const thread_id : process_threads_)
+    CPU::setaffinity(thread_id,cpus.back());
+}
+
+static
+void
+pin_threads_R1PP1P(const std::vector<pthread_t> read_threads_,
+                   const std::vector<pthread_t> process_threads_)
+{
+  CPU::Core2CPUsMap core2cpus;
+
+  core2cpus = CPU::core2cpus();
+  if(core2cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,core2cpus.begin()->second);
+
+  if(core2cpus.size() > 1)
+    core2cpus.erase(core2cpus.begin());
+
+  for(auto const thread_id : process_threads_)
+    CPU::setaffinity(thread_id,core2cpus.begin()->second);
+}
+
+static
+void
+pin_threads_RPSL(const std::vector<pthread_t> read_threads_,
+                 const std::vector<pthread_t> process_threads_)
+{
+  CPU::CPUVec cpus;
+
+  cpus = CPU::cpus();
+  if(cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    {
+      if(cpus.empty())
+        cpus = CPU::cpus();
+      CPU::setaffinity(thread_id,cpus.back());
+      cpus.pop_back();
+    }
+
+  for(auto const thread_id : process_threads_)
+    {
+      if(cpus.empty())
+        cpus = CPU::cpus();
+      CPU::setaffinity(thread_id,cpus.back());
+      cpus.pop_back();
+    }
+}
+
+static
+void
+pin_threads_RPSP(const std::vector<pthread_t> read_threads_,
+                 const std::vector<pthread_t> process_threads_)
+{
+  CPU::Core2CPUsMap core2cpus;
+
+  core2cpus = CPU::core2cpus();
+  if(core2cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    {
+      if(core2cpus.empty())
+        core2cpus = CPU::core2cpus();
+      CPU::setaffinity(thread_id,core2cpus.begin()->second);
+      core2cpus.erase(core2cpus.begin());
+    }
+
+  for(auto const thread_id : process_threads_)
+    {
+      if(core2cpus.empty())
+        core2cpus = CPU::core2cpus();
+      CPU::setaffinity(thread_id,core2cpus.begin()->second);
+      core2cpus.erase(core2cpus.begin());
+    }
+}
+
+static
+void
+pin_threads_R1PPSP(const std::vector<pthread_t> read_threads_,
+                   const std::vector<pthread_t> process_threads_)
+{
+  CPU::Core2CPUsMap core2cpus;
+  CPU::Core2CPUsMap leftover;
+
+  core2cpus = CPU::core2cpus();
+  if(core2cpus.empty())
+    return;
+
+  for(auto const thread_id : read_threads_)
+    CPU::setaffinity(thread_id,core2cpus.begin()->second);
+
+  core2cpus.erase(core2cpus.begin());
+  if(core2cpus.empty())
+    core2cpus = CPU::core2cpus();
+  leftover = core2cpus;
+
+  for(auto const thread_id : process_threads_)
+    {
+      if(core2cpus.empty())
+        core2cpus = leftover;
+      CPU::setaffinity(thread_id,core2cpus.begin()->second);
+      core2cpus.erase(core2cpus.begin());
+    }
+}
+
+static
+void
+pin_threads(const std::vector<pthread_t>  read_threads_,
+            const std::vector<pthread_t>  process_threads_,
+            const std::string             type_)
+{
+  if(type_ == "R1L")
+    return ::pin_threads_R1L(read_threads_);
+  if(type_ == "R1P")
+    return ::pin_threads_R1P(read_threads_);
+  if(type_ == "RP1L")
+    return ::pin_threads_RP1L(read_threads_,process_threads_);
+  if(type_ == "RP1P")
+    return ::pin_threads_RP1P(read_threads_,process_threads_);
+  if(type_ == "R1LP1L")
+    return ::pin_threads_R1LP1L(read_threads_,process_threads_);
+  if(type_ == "R1PP1P")
+    return ::pin_threads_R1PP1P(read_threads_,process_threads_);
+  if(type_ == "RPSL")
+    return ::pin_threads_RPSL(read_threads_,process_threads_);
+  if(type_ == "RPSP")
+    return ::pin_threads_RPSP(read_threads_,process_threads_);
+  if(type_ == "R1PPSP")
+    return ::pin_threads_R1PPSP(read_threads_,process_threads_);
+}
+
+int
+fuse_session_loop_mt(struct fuse_session *se_,
+                     const int            raw_read_thread_count_,
+                     const int            raw_process_thread_count_,
+                     const char          *pin_threads_type_)
+{
+  int err;
+  int read_thread_count;
+  int process_thread_count;
+  fuse_worker_data_t wd = {0};
+  std::vector<pthread_t> read_threads;
+  std::vector<pthread_t> process_threads;
+
+  read_thread_count    = raw_read_thread_count_;
+  process_thread_count = raw_process_thread_count_;
+  ::calculate_thread_counts(&read_thread_count,&process_thread_count);
+
+  if(process_thread_count > 0)
+    {
+      wd.tp = std::make_shared<ThreadPool>(process_thread_count);
+      wd.msgbuf_processor = process_msgbuf_async;
+      process_threads = wd.tp->threads();
+    }
+  else
+    {
+      wd.msgbuf_processor = process_msgbuf_sync;
+    }
+
+  wd.se = se_;
+  sem_init(&wd.finished,0,0);
+
+  err = 0;
+  for(int i = 0; i < read_thread_count; i++)
+    {
+      pthread_t thread_id;
+      err = fuse_start_thread(&thread_id,fuse_do_work,&wd);
+      assert(err == 0);
+      read_threads.push_back(thread_id);
+    }
+
+  if(pin_threads_type_ != NULL)
+    ::pin_threads(read_threads,process_threads,pin_threads_type_);
+
+  if(!err)
+    {
+      /* sem_wait() is interruptible */
+      while(!fuse_session_exited(se_))
+        sem_wait(&wd.finished);
+
+      for(const auto &thread_id : read_threads)
+        pthread_cancel(thread_id);
+
+      for(const auto &thread_id : read_threads)
+        pthread_join(thread_id,NULL);
+    }
+
+  sem_destroy(&wd.finished);
+
+  return err;
+}
@@ -0,0 +1,124 @@
+/*
+  ISC License
+
+  Copyright (c) 2022, Antonio SJ Musumeci <trapexit@spawn.link>
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "fuse_msgbuf.hpp"
+#include "fuse.h"
+
+#include <unistd.h>
+
+#include <cstdint>
+#include <cstdlib>
+#include <mutex>
+#include <stack>
+
+
+static std::uint32_t g_PAGESIZE = 0;
+static std::uint32_t g_BUFSIZE  = 0;
+
+static std::mutex g_MUTEX;
+static std::stack<fuse_msgbuf_t*> g_MSGBUF_STACK;
+
+static
+__attribute__((constructor))
+void
+msgbuf_constructor()
+{
+  g_PAGESIZE = sysconf(_SC_PAGESIZE);
+  g_BUFSIZE  = (g_PAGESIZE * (FUSE_MAX_MAX_PAGES + 2));
+}
+
+static
+__attribute__((destructor))
+void
+msgbuf_destroy()
+{
+  // TODO: cleanup?
+}
+
+uint32_t
+msgbuf_get_bufsize()
+{
+  return g_BUFSIZE;
+}
+
+void
+msgbuf_set_bufsize(const uint32_t size_in_pages_)
+{
+  g_BUFSIZE = (size_in_pages_ * g_PAGESIZE);
+}
+
+static
+void*
+page_aligned_malloc(const uint64_t size_)
+{
+  int rv;
+  void *buf = NULL;
+
+  rv = posix_memalign(&buf,g_PAGESIZE,size_);
+  if(rv != 0)
+    return NULL;
+
+  return buf;
+}
+
+fuse_msgbuf_t*
+msgbuf_alloc()
+{
+  fuse_msgbuf_t *msgbuf;
+
+  g_MUTEX.lock();
+  if(g_MSGBUF_STACK.empty())
+    {
+      g_MUTEX.unlock();
+
+      msgbuf = (fuse_msgbuf_t*)malloc(sizeof(fuse_msgbuf_t));
+      if(msgbuf == NULL)
+        return NULL;
+
+      msgbuf->mem = (char*)page_aligned_malloc(g_BUFSIZE);
+      if(msgbuf->mem == NULL)
+        {
+          free(msgbuf);
+          return NULL;
+        }
+
+      msgbuf->size = g_BUFSIZE;
+    }
+  else
+    {
+      msgbuf = g_MSGBUF_STACK.top();
+      g_MSGBUF_STACK.pop();
+      g_MUTEX.unlock();
+    }
+
+  return msgbuf;
+}
+
+void
+msgbuf_free(fuse_msgbuf_t *msgbuf_)
+{
+  std::lock_guard<std::mutex> lck(g_MUTEX);
+
+  if(msgbuf_->size != g_BUFSIZE)
+    {
+      free(msgbuf_->mem);
+      free(msgbuf_);
+      return;
+    }
+
+  g_MSGBUF_STACK.push(msgbuf_);
+}
@@ -0,0 +1,33 @@
+/*
+  ISC License
+
+  Copyright (c) 2022, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#pragma once
+
+#include "fuse_msgbuf.h"
+#include "extern_c.h"
+
+EXTERN_C_BEGIN
+
+void     msgbuf_set_bufsize(const uint32_t size);
+uint32_t msgbuf_get_bufsize();
+
+fuse_msgbuf_t* msgbuf_alloc();
+fuse_msgbuf_t* msgbuf_alloc_memonly();
+void           msgbuf_free(fuse_msgbuf_t *msgbuf);
+
+EXTERN_C_END
@@ -16,98 +16,8 @@
 #include <pthread.h>
 #include <assert.h>

-struct procdata
-{
-  struct fuse *f;
-  struct fuse_chan *prevch;
-  struct fuse_session *prevse;
-  fuse_processor_t proc;
-  void *data;
-};
-
-static void mt_session_proc(void *data, const char *buf, size_t len,
-			    struct fuse_chan *ch)
-{
-  struct procdata *pd = (struct procdata *) data;
-  struct fuse_cmd *cmd = *(struct fuse_cmd **) buf;
-
-  (void) len;
-  (void) ch;
-  pd->proc(pd->f, cmd, pd->data);
-}
-
-static void mt_session_exit(void *data, int val)
-{
-  struct procdata *pd = (struct procdata *) data;
-  if (val)
-    fuse_session_exit(pd->prevse);
-  else
-    fuse_session_reset(pd->prevse);
-}
-
-static int mt_session_exited(void *data)
-{
-  struct procdata *pd = (struct procdata *) data;
-  return fuse_session_exited(pd->prevse);
-}
-
-static int mt_chan_receive(struct fuse_chan **chp, char *buf, size_t size)
-{
-  struct fuse_cmd *cmd;
-  struct procdata *pd = (struct procdata *) fuse_chan_data(*chp);
-
-  assert(size >= sizeof(cmd));
-
-  cmd = fuse_read_cmd(pd->f);
-  if (cmd == NULL)
-    return 0;
-
-  *(struct fuse_cmd **)buf = cmd;
-
-  return sizeof(cmd);
-}
-
-int fuse_loop_mt_proc(struct fuse *f, fuse_processor_t proc, void *data)
-{
-  int res;
-  struct procdata pd;
-  struct fuse_session *prevse = fuse_get_session(f);
-  struct fuse_session *se;
-  struct fuse_chan *prevch = fuse_session_next_chan(prevse, NULL);
-  struct fuse_chan *ch;
-  struct fuse_session_ops sop = {
-    .exit = mt_session_exit,
-    .exited = mt_session_exited,
-    .process = mt_session_proc,
-  };
-  struct fuse_chan_ops cop = {
-    .receive = mt_chan_receive,
-  };
-
-  pd.f = f;
-  pd.prevch = prevch;
-  pd.prevse = prevse;
-  pd.proc = proc;
-  pd.data = data;
-
-  se = fuse_session_new(&sop, &pd);
-  if (se == NULL)
-    return -1;
-
-  ch = fuse_chan_new(&cop, fuse_chan_fd(prevch),
-                     sizeof(struct fuse_cmd *), &pd);
-  if (ch == NULL) {
-    fuse_session_destroy(se);
-    return -1;
-  }
-  fuse_session_add_chan(se, ch);
-  res = fuse_session_loop_mt(se,
-                             fuse_config_num_threads(f));
-  fuse_session_destroy(se);
-  return res;
-}
-
-int fuse_loop_mt(struct fuse *f)
+int
+fuse_loop_mt(struct fuse *f)
 {
  if (f == NULL)
    return -1;
@@ -117,7 +27,9 @@ int fuse_loop_mt(struct fuse *f)
    return -1;

  res = fuse_session_loop_mt(fuse_get_session(f),
-                             fuse_config_num_threads(f));
+                             fuse_config_read_thread_count(f),
+                             fuse_config_process_thread_count(f),
+                             fuse_config_pin_threads(f));

  fuse_stop_maintenance_thread(f);

@@ -8,23 +8,29 @@

 #include "fuse_i.h"
 #include "fuse_misc.h"
+#include "fuse_kernel.h"

+#include <assert.h>
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <assert.h>
-#include <errno.h>
+#include <unistd.h>
+#include <sys/uio.h>
+

 struct fuse_chan
 {
-  struct fuse_chan_ops op;
  struct fuse_session *se;
  int fd;
  size_t bufsize;
-  void *data;
 };

-struct fuse_session *fuse_session_new(struct fuse_session_ops *op, void *data)
+struct fuse_session *
+fuse_session_new(void *data,
+                 void *receive_buf,
+                 void *process_buf,
+                 void *destroy)
 {
  struct fuse_session *se = (struct fuse_session *) malloc(sizeof(*se));
  if (se == NULL) {
@@ -33,8 +39,10 @@ struct fuse_session *fuse_session_new(struct fuse_session_ops *op, void *data)
  }

  memset(se, 0, sizeof(*se));
-  se->op = *op;
-  se->data = data;
+  se->f           = data;
+  se->receive_buf = receive_buf;
+  se->process_buf = process_buf;
+  se->destroy     = destroy;

  return se;
 }
@@ -57,110 +65,59 @@ void fuse_session_remove_chan(struct fuse_chan *ch)
  }
 }

-struct fuse_chan *fuse_session_next_chan(struct fuse_session *se,
-					 struct fuse_chan *ch)
+void
+fuse_session_destroy(struct fuse_session *se)
 {
-  assert(ch == NULL || ch == se->ch);
-  if (ch == NULL)
-    return se->ch;
-  else
-    return NULL;
-}
-
-void fuse_session_process(struct fuse_session *se, const char *buf, size_t len,
-			  struct fuse_chan *ch)
-{
-  se->op.process(se->data, buf, len, ch);
-}
-
-void fuse_session_process_buf(struct fuse_session *se,
-			      const struct fuse_buf *buf, struct fuse_chan *ch)
-{
-  if (se->process_buf) {
-    se->process_buf(se->data, buf, ch);
-  } else {
-    assert(!(buf->flags & FUSE_BUF_IS_FD));
-    fuse_session_process(se->data, buf->mem, buf->size, ch);
-  }
-}
-
-int fuse_session_receive_buf(struct fuse_session *se, struct fuse_buf *buf,
-			     struct fuse_chan **chp)
-{
-  int res;
-
-  if (se->receive_buf) {
-    res = se->receive_buf(se, buf, chp);
-  } else {
-    res = fuse_chan_recv(chp, buf->mem, buf->size);
-    if (res > 0)
-      buf->size = res;
-  }
-
-  return res;
-}
-
-
-void fuse_session_destroy(struct fuse_session *se)
-{
-  if (se->op.destroy)
-    se->op.destroy(se->data);
-  if (se->ch != NULL)
+  se->destroy(se->f);
+  if(se->ch != NULL)
    fuse_chan_destroy(se->ch);
  free(se);
 }

-void fuse_session_exit(struct fuse_session *se)
-{
-  if (se->op.exit)
-    se->op.exit(se->data, 1);
-  se->exited = 1;
-}
-
 void fuse_session_reset(struct fuse_session *se)
 {
-  if (se->op.exit)
-    se->op.exit(se->data, 0);
  se->exited = 0;
 }

-int fuse_session_exited(struct fuse_session *se)
+int
+fuse_session_exited(struct fuse_session *se)
 {
-  if (se->op.exited)
-    return se->op.exited(se->data);
-  else
-    return se->exited;
+  return se->exited;
 }

-void *fuse_session_data(struct fuse_session *se)
+void
+fuse_session_exit(struct fuse_session *se_)
 {
-  return se->data;
+  se_->exited = 1;
 }

-static struct fuse_chan *fuse_chan_new_common(struct fuse_chan_ops *op, int fd,
-					      size_t bufsize, void *data)
+void*
+fuse_session_data(struct fuse_session *se)
 {
-  struct fuse_chan *ch = (struct fuse_chan *) malloc(sizeof(*ch));
-  if (ch == NULL) {
-    fprintf(stderr, "fuse: failed to allocate channel\n");
-    return NULL;
-  }
+  return se->f;
+}
+
+struct fuse_chan *
+fuse_chan_new(int fd,
+              size_t bufsize)
+{
+  struct fuse_chan *ch;
+
+  ch = (struct fuse_chan*)malloc(sizeof(*ch));
+  if(ch == NULL)
+    {
+      fprintf(stderr, "fuse: failed to allocate channel\n");
+      return NULL;
+    }

  memset(ch, 0, sizeof(*ch));
-  ch->op = *op;
+
  ch->fd = fd;
  ch->bufsize = bufsize;
-  ch->data = data;

  return ch;
 }

-struct fuse_chan *fuse_chan_new(struct fuse_chan_ops *op, int fd,
-				size_t bufsize, void *data)
-{
-  return fuse_chan_new_common(op, fd, bufsize, data);
-}
-
 int fuse_chan_fd(struct fuse_chan *ch)
 {
  return ch->fd;
@@ -178,40 +135,21 @@ size_t fuse_chan_bufsize(struct fuse_chan *ch)
  return ch->bufsize;
 }

-void *fuse_chan_data(struct fuse_chan *ch)
-{
-  return ch->data;
-}
-
 struct fuse_session *fuse_chan_session(struct fuse_chan *ch)
 {
  return ch->se;
 }

-int fuse_chan_recv(struct fuse_chan **chp, char *buf, size_t size)
+void
+fuse_chan_destroy(struct fuse_chan *ch)
 {
-  struct fuse_chan *ch = *chp;
+  int fd;

-  return ch->op.receive(chp, buf, size);
-}
-
-int fuse_chan_receive(struct fuse_chan *ch, char *buf, size_t size)
-{
-  int res;
-
-  res = fuse_chan_recv(&ch, buf, size);
-  return res >= 0 ? res : (res != -EINTR && res != -EAGAIN) ? -1 : 0;
-}
-
-int fuse_chan_send(struct fuse_chan *ch, const struct iovec iov[], size_t count)
-{
-  return ch->op.send(ch, iov, count);
-}
-
-void fuse_chan_destroy(struct fuse_chan *ch)
-{
  fuse_session_remove_chan(ch);
-  if (ch->op.destroy)
-    ch->op.destroy(ch);
+
+  fd = fuse_chan_fd(ch);
+  if(fd != -1)
+    close(fd);
+
  free(ch);
 }
@@ -237,8 +237,10 @@ struct fuse_chan *
 fuse_mount_common(const char       *mountpoint_,
                  struct fuse_args *args_)
 {
-  struct fuse_chan *ch;
  int fd;
+  long bufsize;
+  long pagesize;
+  struct fuse_chan *ch;

  /*
   * Make sure file descriptors 0, 1 and 2 are open, otherwise chaos
@@ -255,7 +257,10 @@ fuse_mount_common(const char       *mountpoint_,
  if(fd == -1)
    return NULL;

-  ch = fuse_kern_chan_new(fd);
+  pagesize = sysconf(_SC_PAGESIZE);
+  bufsize  = ((FUSE_MAX_MAX_PAGES + 1) * pagesize);
+
+  ch = fuse_chan_new(fd,bufsize);
  if(!ch)
    fuse_kern_unmount(mountpoint_, fd);

@@ -284,11 +289,13 @@ void fuse_unmount(const char *mountpoint, struct fuse_chan *ch)
  fuse_unmount_common(mountpoint, ch);
 }

-struct fuse *fuse_setup_common(int argc, char *argv[],
-			       const struct fuse_operations *op,
-			       size_t op_size,
-			       char **mountpoint,
-			       int *fd)
+struct fuse *
+fuse_setup_common(int argc,
+                  char *argv[],
+                  const struct fuse_operations *op,
+                  size_t op_size,
+                  char **mountpoint,
+                  int *fd)
 {
  struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
  struct fuse_chan *ch;
@@ -344,7 +351,7 @@ struct fuse *fuse_setup(int argc, char *argv[],
 static void fuse_teardown_common(struct fuse *fuse, char *mountpoint)
 {
  struct fuse_session *se = fuse_get_session(fuse);
-  struct fuse_chan *ch = fuse_session_next_chan(se, NULL);
+  struct fuse_chan *ch = se->ch;
  fuse_remove_signal_handlers(se);
  fuse_unmount_common(mountpoint, ch);
  fuse_destroy(fuse);
@@ -90,7 +90,6 @@ static const struct fuse_opt fuse_mount_opts[] = {
   * handle them
   */
  FUSE_OPT_KEY("fsname=",			KEY_KERN),
-  FUSE_OPT_KEY("nonempty",		KEY_KERN),
  FUSE_OPT_KEY("large_read",		KEY_KERN),
  FUSE_OPT_END
 };
@@ -61,10 +61,8 @@ enum {
 };

 struct mount_opts {
-  int allow_other;
  int ishelp;
  int flags;
-  int nonempty;
  int auto_unmount;
  int blkdev;
  char *fsname;
@@ -78,14 +76,10 @@ struct mount_opts {
 #define FUSE_MOUNT_OPT(t, p) { t, offsetof(struct mount_opts, p), 1 }

 static const struct fuse_opt fuse_mount_opts[] = {
-  FUSE_MOUNT_OPT("allow_other",		allow_other),
-  FUSE_MOUNT_OPT("nonempty",		nonempty),
  FUSE_MOUNT_OPT("blkdev",		blkdev),
  FUSE_MOUNT_OPT("auto_unmount",		auto_unmount),
  FUSE_MOUNT_OPT("fsname=%s",		fsname),
  FUSE_MOUNT_OPT("subtype=%s",		subtype),
-  FUSE_OPT_KEY("allow_other",		KEY_KERN_OPT),
-  FUSE_OPT_KEY("nonempty",		KEY_FUSERMOUNT_OPT),
  FUSE_OPT_KEY("auto_unmount",		KEY_FUSERMOUNT_OPT),
  FUSE_OPT_KEY("blkdev",			KEY_FUSERMOUNT_OPT),
  FUSE_OPT_KEY("fsname=",			KEY_FUSERMOUNT_OPT),
@@ -124,9 +118,7 @@ static const struct fuse_opt fuse_mount_opts[] = {
 static void mount_help(void)
 {
  fprintf(stderr,
-          "    -o allow_other         allow access to other users\n"
          "    -o auto_unmount        auto unmount on process termination\n"
-          "    -o nonempty            allow mounts over non-empty file/dir\n"
          "    -o default_permissions enable permission checking by kernel\n"
          "    -o fsname=NAME         set filesystem name\n"
          "    -o subtype=NAME        set filesystem type\n"
@@ -424,13 +416,6 @@ static int fuse_mount_sys(const char *mnt, struct mount_opts *mo,
    return -1;
  }

-  if (!mo->nonempty) {
-    res = fuse_mnt_check_empty("fuse", mnt, stbuf.st_mode,
-                               stbuf.st_size);
-    if (res == -1)
-      return -1;
-  }
-
  if (mo->auto_unmount) {
    /* Tell the caller to fallback to fusermount because
       auto-unmount does not work otherwise. */
@@ -564,6 +549,8 @@ int fuse_kern_mount(const char *mountpoint, struct fuse_args *args)
      fuse_opt_parse(args, &mo, fuse_mount_opts, fuse_mount_opt_proc) == -1)
    return -1;

+  fuse_opt_add_opt(&mo.kernel_opts,"allow_other");
+
  res = 0;
  if (mo.ishelp)
    goto out;
@@ -312,39 +312,6 @@ char *fuse_mnt_resolve_path(const char *progname, const char *orig)
  return dst;
 }

-int fuse_mnt_check_empty(const char *progname, const char *mnt,
-			 mode_t rootmode, off_t rootsize)
-{
-  int isempty = 1;
-
-  if (S_ISDIR(rootmode)) {
-    struct dirent *ent;
-    DIR *dp = opendir(mnt);
-    if (dp == NULL) {
-      fprintf(stderr,
-              "%s: failed to open mountpoint for reading: %s\n",
-              progname, strerror(errno));
-      return -1;
-    }
-    while ((ent = readdir(dp)) != NULL) {
-      if (strcmp(ent->d_name, ".") != 0 &&
-          strcmp(ent->d_name, "..") != 0) {
-        isempty = 0;
-        break;
-      }
-    }
-    closedir(dp);
-  } else if (rootsize)
-    isempty = 0;
-
-  if (!isempty) {
-    fprintf(stderr, "%s: mountpoint is not empty\n", progname);
-    fprintf(stderr, "%s: if you are sure this is safe, use the 'nonempty' mount option\n", progname);
-    return -1;
-  }
-  return 0;
-}
-
 int fuse_mnt_check_fuseblk(void)
 {
  char buf[256];
@@ -16,6 +16,4 @@ int fuse_mnt_remove_mount(const char *progname, const char *mnt);
 int fuse_mnt_umount(const char *progname, const char *abs_mnt,
 		    const char *rel_mnt, int lazy);
 char *fuse_mnt_resolve_path(const char *progname, const char *orig);
-int fuse_mnt_check_empty(const char *progname, const char *mnt,
-			 mode_t rootmode, off_t rootsize);
 int fuse_mnt_check_fuseblk(void);
@@ -0,0 +1,361 @@
+// Formatting library for C++ - optional OS-specific functionality
+//
+// Copyright (c) 2012 - 2016, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+// Disable bogus MSVC warnings.
+#if !defined(_CRT_SECURE_NO_WARNINGS) && defined(_MSC_VER)
+#  define _CRT_SECURE_NO_WARNINGS
+#endif
+
+#include "fmt/os.h"
+
+#include <climits>
+
+#if FMT_USE_FCNTL
+#  include <sys/stat.h>
+#  include <sys/types.h>
+
+#  ifndef _WIN32
+#    include <unistd.h>
+#  else
+#    ifndef WIN32_LEAN_AND_MEAN
+#      define WIN32_LEAN_AND_MEAN
+#    endif
+#    include <io.h>
+
+#    ifndef S_IRUSR
+#      define S_IRUSR _S_IREAD
+#    endif
+#    ifndef S_IWUSR
+#      define S_IWUSR _S_IWRITE
+#    endif
+#    ifndef S_IRGRP
+#      define S_IRGRP 0
+#    endif
+#    ifndef S_IWGRP
+#      define S_IWGRP 0
+#    endif
+#    ifndef S_IROTH
+#      define S_IROTH 0
+#    endif
+#    ifndef S_IWOTH
+#      define S_IWOTH 0
+#    endif
+#  endif  // _WIN32
+#endif    // FMT_USE_FCNTL
+
+#ifdef _WIN32
+#  include <windows.h>
+#endif
+
+namespace {
+#ifdef _WIN32
+// Return type of read and write functions.
+using rwresult = int;
+
+// On Windows the count argument to read and write is unsigned, so convert
+// it from size_t preventing integer overflow.
+inline unsigned convert_rwcount(std::size_t count) {
+  return count <= UINT_MAX ? static_cast<unsigned>(count) : UINT_MAX;
+}
+#elif FMT_USE_FCNTL
+// Return type of read and write functions.
+using rwresult = ssize_t;
+
+inline std::size_t convert_rwcount(std::size_t count) { return count; }
+#endif
+}  // namespace
+
+FMT_BEGIN_NAMESPACE
+
+#ifdef _WIN32
+detail::utf16_to_utf8::utf16_to_utf8(basic_string_view<wchar_t> s) {
+  if (int error_code = convert(s)) {
+    FMT_THROW(windows_error(error_code,
+                            "cannot convert string from UTF-16 to UTF-8"));
+  }
+}
+
+int detail::utf16_to_utf8::convert(basic_string_view<wchar_t> s) {
+  if (s.size() > INT_MAX) return ERROR_INVALID_PARAMETER;
+  int s_size = static_cast<int>(s.size());
+  if (s_size == 0) {
+    // WideCharToMultiByte does not support zero length, handle separately.
+    buffer_.resize(1);
+    buffer_[0] = 0;
+    return 0;
+  }
+
+  int length = WideCharToMultiByte(CP_UTF8, 0, s.data(), s_size, nullptr, 0,
+                                   nullptr, nullptr);
+  if (length == 0) return GetLastError();
+  buffer_.resize(length + 1);
+  length = WideCharToMultiByte(CP_UTF8, 0, s.data(), s_size, &buffer_[0],
+                               length, nullptr, nullptr);
+  if (length == 0) return GetLastError();
+  buffer_[length] = 0;
+  return 0;
+}
+
+namespace detail {
+
+class system_message {
+  system_message(const system_message&) = delete;
+  void operator=(const system_message&) = delete;
+
+  unsigned long result_;
+  wchar_t* message_;
+
+  static bool is_whitespace(wchar_t c) noexcept {
+    return c == L' ' || c == L'\n' || c == L'\r' || c == L'\t' || c == L'\0';
+  }
+
+ public:
+  explicit system_message(unsigned long error_code)
+      : result_(0), message_(nullptr) {
+    result_ = FormatMessageW(
+        FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
+            FORMAT_MESSAGE_IGNORE_INSERTS,
+        nullptr, error_code, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+        reinterpret_cast<wchar_t*>(&message_), 0, nullptr);
+    if (result_ != 0) {
+      while (result_ != 0 && is_whitespace(message_[result_ - 1])) {
+        --result_;
+      }
+    }
+  }
+  ~system_message() { LocalFree(message_); }
+  explicit operator bool() const noexcept { return result_ != 0; }
+  operator basic_string_view<wchar_t>() const noexcept {
+    return basic_string_view<wchar_t>(message_, result_);
+  }
+};
+
+class utf8_system_category final : public std::error_category {
+ public:
+  const char* name() const noexcept override { return "system"; }
+  std::string message(int error_code) const override {
+    system_message msg(error_code);
+    if (msg) {
+      utf16_to_utf8 utf8_message;
+      if (utf8_message.convert(msg) == ERROR_SUCCESS) {
+        return utf8_message.str();
+      }
+    }
+    return "unknown error";
+  }
+};
+
+}  // namespace detail
+
+FMT_API const std::error_category& system_category() noexcept {
+  static const detail::utf8_system_category category;
+  return category;
+}
+
+std::system_error vwindows_error(int err_code, string_view format_str,
+                                 format_args args) {
+  auto ec = std::error_code(err_code, system_category());
+  return std::system_error(ec, vformat(format_str, args));
+}
+
+void detail::format_windows_error(detail::buffer<char>& out, int error_code,
+                                  const char* message) noexcept {
+  FMT_TRY {
+    system_message msg(error_code);
+    if (msg) {
+      utf16_to_utf8 utf8_message;
+      if (utf8_message.convert(msg) == ERROR_SUCCESS) {
+        fmt::format_to(buffer_appender<char>(out), "{}: {}", message, utf8_message);
+        return;
+      }
+    }
+  }
+  FMT_CATCH(...) {}
+  format_error_code(out, error_code, message);
+}
+
+void report_windows_error(int error_code, const char* message) noexcept {
+  report_error(detail::format_windows_error, error_code, message);
+}
+#endif  // _WIN32
+
+buffered_file::~buffered_file() noexcept {
+  if (file_ && FMT_SYSTEM(fclose(file_)) != 0)
+    report_system_error(errno, "cannot close file");
+}
+
+buffered_file::buffered_file(cstring_view filename, cstring_view mode) {
+  FMT_RETRY_VAL(file_, FMT_SYSTEM(fopen(filename.c_str(), mode.c_str())),
+                nullptr);
+  if (!file_)
+    FMT_THROW(system_error(errno, "cannot open file {}", filename.c_str()));
+}
+
+void buffered_file::close() {
+  if (!file_) return;
+  int result = FMT_SYSTEM(fclose(file_));
+  file_ = nullptr;
+  if (result != 0) FMT_THROW(system_error(errno, "cannot close file"));
+}
+
+int buffered_file::descriptor() const {
+  int fd = FMT_POSIX_CALL(fileno(file_));
+  if (fd == -1) FMT_THROW(system_error(errno, "cannot get file descriptor"));
+  return fd;
+}
+
+#if FMT_USE_FCNTL
+file::file(cstring_view path, int oflag) {
+#  ifdef _WIN32
+  using mode_t = int;
+#  endif
+  constexpr mode_t mode =
+      S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
+#  if defined(_WIN32) && !defined(__MINGW32__)
+  fd_ = -1;
+  FMT_POSIX_CALL(sopen_s(&fd_, path.c_str(), oflag, _SH_DENYNO, mode));
+#  else
+  FMT_RETRY(fd_, FMT_POSIX_CALL(open(path.c_str(), oflag, mode)));
+#  endif
+  if (fd_ == -1)
+    FMT_THROW(system_error(errno, "cannot open file {}", path.c_str()));
+}
+
+file::~file() noexcept {
+  // Don't retry close in case of EINTR!
+  // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
+  if (fd_ != -1 && FMT_POSIX_CALL(close(fd_)) != 0)
+    report_system_error(errno, "cannot close file");
+}
+
+void file::close() {
+  if (fd_ == -1) return;
+  // Don't retry close in case of EINTR!
+  // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
+  int result = FMT_POSIX_CALL(close(fd_));
+  fd_ = -1;
+  if (result != 0) FMT_THROW(system_error(errno, "cannot close file"));
+}
+
+long long file::size() const {
+#  ifdef _WIN32
+  // Use GetFileSize instead of GetFileSizeEx for the case when _WIN32_WINNT
+  // is less than 0x0500 as is the case with some default MinGW builds.
+  // Both functions support large file sizes.
+  DWORD size_upper = 0;
+  HANDLE handle = reinterpret_cast<HANDLE>(_get_osfhandle(fd_));
+  DWORD size_lower = FMT_SYSTEM(GetFileSize(handle, &size_upper));
+  if (size_lower == INVALID_FILE_SIZE) {
+    DWORD error = GetLastError();
+    if (error != NO_ERROR)
+      FMT_THROW(windows_error(GetLastError(), "cannot get file size"));
+  }
+  unsigned long long long_size = size_upper;
+  return (long_size << sizeof(DWORD) * CHAR_BIT) | size_lower;
+#  else
+  using Stat = struct stat;
+  Stat file_stat = Stat();
+  if (FMT_POSIX_CALL(fstat(fd_, &file_stat)) == -1)
+    FMT_THROW(system_error(errno, "cannot get file attributes"));
+  static_assert(sizeof(long long) >= sizeof(file_stat.st_size),
+                "return type of file::size is not large enough");
+  return file_stat.st_size;
+#  endif
+}
+
+std::size_t file::read(void* buffer, std::size_t count) {
+  rwresult result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(read(fd_, buffer, convert_rwcount(count))));
+  if (result < 0) FMT_THROW(system_error(errno, "cannot read from file"));
+  return detail::to_unsigned(result);
+}
+
+std::size_t file::write(const void* buffer, std::size_t count) {
+  rwresult result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(write(fd_, buffer, convert_rwcount(count))));
+  if (result < 0) FMT_THROW(system_error(errno, "cannot write to file"));
+  return detail::to_unsigned(result);
+}
+
+file file::dup(int fd) {
+  // Don't retry as dup doesn't return EINTR.
+  // http://pubs.opengroup.org/onlinepubs/009695399/functions/dup.html
+  int new_fd = FMT_POSIX_CALL(dup(fd));
+  if (new_fd == -1)
+    FMT_THROW(system_error(errno, "cannot duplicate file descriptor {}", fd));
+  return file(new_fd);
+}
+
+void file::dup2(int fd) {
+  int result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
+  if (result == -1) {
+    FMT_THROW(system_error(errno, "cannot duplicate file descriptor {} to {}",
+                           fd_, fd));
+  }
+}
+
+void file::dup2(int fd, std::error_code& ec) noexcept {
+  int result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
+  if (result == -1) ec = std::error_code(errno, std::generic_category());
+}
+
+void file::pipe(file& read_end, file& write_end) {
+  // Close the descriptors first to make sure that assignments don't throw
+  // and there are no leaks.
+  read_end.close();
+  write_end.close();
+  int fds[2] = {};
+#  ifdef _WIN32
+  // Make the default pipe capacity same as on Linux 2.6.11+.
+  enum { DEFAULT_CAPACITY = 65536 };
+  int result = FMT_POSIX_CALL(pipe(fds, DEFAULT_CAPACITY, _O_BINARY));
+#  else
+  // Don't retry as the pipe function doesn't return EINTR.
+  // http://pubs.opengroup.org/onlinepubs/009696799/functions/pipe.html
+  int result = FMT_POSIX_CALL(pipe(fds));
+#  endif
+  if (result != 0) FMT_THROW(system_error(errno, "cannot create pipe"));
+  // The following assignments don't throw because read_fd and write_fd
+  // are closed.
+  read_end = file(fds[0]);
+  write_end = file(fds[1]);
+}
+
+buffered_file file::fdopen(const char* mode) {
+// Don't retry as fdopen doesn't return EINTR.
+#  if defined(__MINGW32__) && defined(_POSIX_)
+  FILE* f = ::fdopen(fd_, mode);
+#  else
+  FILE* f = FMT_POSIX_CALL(fdopen(fd_, mode));
+#  endif
+  if (!f)
+    FMT_THROW(
+        system_error(errno, "cannot associate stream with file descriptor"));
+  buffered_file bf(f);
+  fd_ = -1;
+  return bf;
+}
+
+long getpagesize() {
+#  ifdef _WIN32
+  SYSTEM_INFO si;
+  GetSystemInfo(&si);
+  return si.dwPageSize;
+#  else
+  long size = FMT_POSIX_CALL(sysconf(_SC_PAGESIZE));
+  if (size < 0) FMT_THROW(system_error(errno, "cannot get memory page size"));
+  return size;
+#  endif
+}
+
+FMT_API void ostream::grow(size_t) {
+  if (this->size() == this->capacity()) flush();
+}
+#endif  // FMT_USE_FCNTL
+FMT_END_NAMESPACE
@@ -0,0 +1,124 @@
+#pragma once
+
+#include "unbounded_queue.hpp"
+
+#include <tuple>
+#include <atomic>
+#include <vector>
+#include <thread>
+#include <memory>
+#include <future>
+#include <utility>
+#include <functional>
+#include <type_traits>
+
+
+class ThreadPool
+{
+public:
+  explicit
+  ThreadPool(const std::size_t thread_count_ = std::thread::hardware_concurrency())
+    : _queues(thread_count_),
+      _count(thread_count_)
+  {
+    auto worker = [this](std::size_t i)
+    {
+      while(true)
+        {
+          Proc f;
+
+          for(std::size_t n = 0; n < (_count * K); ++n)
+            {
+              if(_queues[(i + n) % _count].try_pop(f))
+                break;
+            }
+
+          if(!f && !_queues[i].pop(f))
+            break;
+
+          f();
+        }
+    };
+
+    _threads.reserve(thread_count_);
+    for(std::size_t i = 0; i < thread_count_; ++i)
+      _threads.emplace_back(worker, i);
+  }
+
+  ~ThreadPool()
+  {
+    for(auto& queue : _queues)
+      queue.unblock();
+    for(auto& thread : _threads)
+      thread.join();
+  }
+
+  template<typename F>
+  void
+  enqueue_work(F&& f_)
+  {
+    auto i = _index++;
+
+    for(std::size_t n = 0; n < (_count * K); ++n)
+      {
+        if(_queues[(i + n) % _count].try_push(f_))
+          return;
+      }
+
+    _queues[i % _count].push(std::move(f_));
+  }
+
+  template<typename F>
+  [[nodiscard]]
+  std::future<typename std::result_of<F()>::type>
+  enqueue_task(F&& f_)
+  {
+    using TaskReturnType = typename std::result_of<F()>::type;
+    using Promise        = std::promise<TaskReturnType>;
+
+    auto i       = _index++;
+    auto promise = std::make_shared<Promise>();
+    auto future  = promise->get_future();
+    auto work    = [=]() {
+      auto rv = f_();
+      promise->set_value(rv);
+    };
+
+    for(std::size_t n = 0; n < (_count * K); ++n)
+      {
+        if(_queues[(i + n) % _count].try_push(work))
+          return future;
+      }
+
+    _queues[i % _count].push(std::move(work));
+
+    return future;
+  }
+
+public:
+  std::vector<pthread_t>
+  threads()
+  {
+    std::vector<pthread_t> rv;
+
+    for(auto &thread : _threads)
+      rv.push_back(thread.native_handle());
+
+    return rv;
+  }
+
+private:
+  using Proc   = std::function<void(void)>;
+  using Queue  = UnboundedQueue<Proc>;
+  using Queues = std::vector<Queue>;
+  Queues _queues;
+
+private:
+  std::vector<std::thread> _threads;
+
+private:
+  const std::size_t _count;
+  std::atomic_uint _index;
+
+  static const unsigned int K = 2;
+};
@@ -0,0 +1,161 @@
+#pragma once
+
+#include <condition_variable>
+#include <mutex>
+#include <queue>
+#include <utility>
+
+
+template<typename T>
+class UnboundedQueue
+{
+public:
+  explicit
+  UnboundedQueue(bool block_ = true)
+    : _block(block_)
+  {
+  }
+
+  void
+  push(const T& item_)
+  {
+    {
+      std::lock_guard<std::mutex> guard(_queue_lock);
+      _queue.push(item_);
+    }
+    _condition.notify_one();
+  }
+
+  void
+  push(T&& item_)
+  {
+    {
+      std::lock_guard<std::mutex> guard(_queue_lock);
+      _queue.push(std::move(item_));
+    }
+
+    _condition.notify_one();
+  }
+
+  template<typename... Args>
+  void
+  emplace(Args&&... args_)
+  {
+    {
+      std::lock_guard<std::mutex> guard(_queue_lock);
+      _queue.emplace(std::forward<Args>(args_)...);
+    }
+
+    _condition.notify_one();
+  }
+
+  bool
+  try_push(const T& item_)
+  {
+    {
+      std::unique_lock<std::mutex> lock(_queue_lock, std::try_to_lock);
+      if(!lock)
+        return false;
+      _queue.push(item_);
+    }
+
+    _condition.notify_one();
+
+    return true;
+  }
+
+  bool
+  try_push(T&& item_)
+  {
+    {
+      std::unique_lock<std::mutex> lock(_queue_lock, std::try_to_lock);
+      if(!lock)
+        return false;
+      _queue.push(std::move(item_));
+    }
+
+    _condition.notify_one();
+
+    return true;
+  }
+
+  //TODO: push multiple T at once
+
+  bool
+  pop(T& item_)
+  {
+    std::unique_lock<std::mutex> guard(_queue_lock);
+
+    _condition.wait(guard, [&]() { return !_queue.empty() || !_block; });
+    if(_queue.empty())
+      return false;
+
+    item_ = std::move(_queue.front());
+    _queue.pop();
+
+    return true;
+  }
+
+  bool
+  try_pop(T& item_)
+  {
+    std::unique_lock<std::mutex> lock(_queue_lock, std::try_to_lock);
+    if(!lock || _queue.empty())
+      return false;
+
+    item_ = std::move(_queue.front());
+    _queue.pop();
+
+    return true;
+  }
+
+  std::size_t
+  size() const
+  {
+    std::lock_guard<std::mutex> guard(_queue_lock);
+
+    return _queue.size();
+  }
+
+  bool
+  empty() const
+  {
+    std::lock_guard<std::mutex> guard(_queue_lock);
+
+    return _queue.empty();
+  }
+
+  void
+  block()
+  {
+    std::lock_guard<std::mutex> guard(_queue_lock);
+    _block = true;
+  }
+
+  void
+  unblock()
+  {
+    {
+      std::lock_guard<std::mutex> guard(_queue_lock);
+      _block = false;
+    }
+
+    _condition.notify_all();
+  }
+
+  bool
+  blocking() const
+  {
+    std::lock_guard<std::mutex> guard(_queue_lock);
+
+    return _block;
+  }
+
+private:
+  mutable std::mutex _queue_lock;
+
+private:
+  bool _block;
+  std::queue<T> _queue;
+  std::condition_variable _condition;
+};
@@ -726,7 +726,6 @@ static int do_mount(const char *mnt, char **typep, mode_t rootmode,
 	char *subtype = NULL;
 	char *source = NULL;
 	char *type = NULL;
-	int check_empty = 1;
 	int blkdev = 0;

 	optbuf = (char *) malloc(strlen(opts) + 128);
@@ -759,8 +758,6 @@ static int do_mount(const char *mnt, char **typep, mode_t rootmode,
 				goto err;
 			}
 			blkdev = 1;
-		} else if (opt_eq(s, len, "nonempty")) {
-			check_empty = 0;
 		} else if (opt_eq(s, len, "auto_unmount")) {
 			auto_unmount = 1;
 		} else if (!begins_with(s, "fd=") &&
@@ -811,10 +808,6 @@ static int do_mount(const char *mnt, char **typep, mode_t rootmode,
 	sprintf(d, "fd=%i,rootmode=%o,user_id=%u,group_id=%u",
 		fd, rootmode, getuid(), getgid());

-	if (check_empty &&
-	    fuse_mnt_check_empty(progname, mnt, rootmode, rootsize) == -1)
-		goto err;
-
 	source = malloc((fsname ? strlen(fsname) : 0) +
 			(subtype ? strlen(subtype) : 0) + strlen(dev) + 32);

@@ -312,39 +312,6 @@ char *fuse_mnt_resolve_path(const char *progname, const char *orig)
 	return dst;
 }

-int fuse_mnt_check_empty(const char *progname, const char *mnt,
-			 mode_t rootmode, off_t rootsize)
-{
-	int isempty = 1;
-
-	if (S_ISDIR(rootmode)) {
-		struct dirent *ent;
-		DIR *dp = opendir(mnt);
-		if (dp == NULL) {
-			fprintf(stderr,
-				"%s: failed to open mountpoint for reading: %s\n",
-				progname, strerror(errno));
-			return -1;
-		}
-		while ((ent = readdir(dp)) != NULL) {
-			if (strcmp(ent->d_name, ".") != 0 &&
-			    strcmp(ent->d_name, "..") != 0) {
-				isempty = 0;
-				break;
-			}
-		}
-		closedir(dp);
-	} else if (rootsize)
-		isempty = 0;
-
-	if (!isempty) {
-		fprintf(stderr, "%s: mountpoint is not empty\n", progname);
-		fprintf(stderr, "%s: if you are sure this is safe, use the 'nonempty' mount option\n", progname);
-		return -1;
-	}
-	return 0;
-}
-
 int fuse_mnt_check_fuseblk(void)
 {
 	char buf[256];
@@ -80,11 +80,14 @@ namespace l
    uint64_t offset;

    offset = s_.find_first_not_of("+<>-=");
+    if (offset == std::string::npos) {
+      return;
+    }
+
    if(offset > 1)
      offset = 2;
    *instr_ = s_.substr(0,offset);
-    if(offset != std::string::npos)
-      *values_ = s_.substr(offset);
+    *values_ = s_.substr(offset);
  }

  static
@@ -185,6 +188,9 @@ namespace l
      branch.set_minfreespace(minfreespace.value());

    fs::glob(glob,&paths);
+    if(paths.empty())
+      paths.push_back(glob);
+
    fs::realpathize(&paths);
    for(auto &path : paths)
      {
@@ -363,6 +369,17 @@ Branches::Impl::to_paths(StrVec &paths_) const
    }
 }

+fs::PathVector
+Branches::Impl::to_paths() const
+{
+  fs::PathVector vp;
+
+  for(const auto &branch : *this)
+    vp.emplace_back(branch.path);
+
+  return vp;
+}
+
 int
 Branches::from_string(const std::string &str_)
 {
@@ -19,7 +19,7 @@
 #pragma once

 #include "branch.hpp"
-#include "nonstd/optional.hpp"
+#include "fs_pathvector.hpp"
 #include "strvec.hpp"
 #include "tofrom_string.hpp"

@@ -49,6 +49,7 @@ public:
  public:
    const uint64_t& minfreespace(void) const;
    void to_paths(StrVec &strvec) const;
+    fs::PathVector to_paths() const;

  public:
    Impl& operator=(Impl &impl_);
@@ -42,7 +42,7 @@ Category::Base::to_string(void) const
 {
  std::set<std::string> rv;

-  for(auto func : funcs)
+  for(const auto func : funcs)
    rv.insert(func->to_string());

  return str::join(rv,',');
@@ -37,11 +37,13 @@

 #define MINFREESPACE_DEFAULT (4294967295ULL)

-using std::string;
-
 #define IFERT(S) if(S == s_) return true

 const std::string CONTROLFILE = "/.mergerfs";
+constexpr static const char CACHE_FILES_PROCESS_NAMES_DEFAULT[] =
+  "rtorrent|"
+  "qbittorrent-nox";
+

 Config Config::_singleton;

@@ -53,6 +55,7 @@ namespace l
  readonly(const std::string &s_)
  {
    IFERT("async_read");
+    IFERT("branches-mount-timeout");
    IFERT("cache.symlinks");
    IFERT("cache.writeback");
    IFERT("fsname");
@@ -60,7 +63,11 @@ namespace l
    IFERT("mount");
    IFERT("nullrw");
    IFERT("pid");
+    IFERT("pin-threads");
+    IFERT("process-thread-count");
+    IFERT("read-thread-count");
    IFERT("readdirplus");
+    IFERT("scheduling-priority");
    IFERT("threads");
    IFERT("version");

@@ -73,9 +80,11 @@ Config::Config()
    auto_cache(false),
    minfreespace(MINFREESPACE_DEFAULT),
    branches(minfreespace),
+    branches_mount_timeout(0),
    cache_attr(1),
    cache_entry(1),
    cache_files(CacheFiles::ENUM::LIBFUSE),
+    cache_files_process_names(CACHE_FILES_PROCESS_NAMES_DEFAULT),
    cache_negative_entry(0),
    cache_readdir(false),
    cache_statfs(0),
@@ -89,93 +98,107 @@ Config::Config()
    fuse_msg_size(FUSE_MAX_MAX_PAGES),
    ignorepponrename(false),
    inodecalc("hybrid-hash"),
+    lazy_umount_mountpoint(false),
    link_cow(false),
    link_exdev(LinkEXDEV::ENUM::PASSTHROUGH),
    log_metrics(false),
-    mount(),
+    mountpoint(),
    moveonenospc(false),
    nfsopenhack(NFSOpenHack::ENUM::OFF),
    nullrw(false),
    pid(::getpid()),
    posix_acl(false),
+    readahead(0),
    readdir(ReadDir::ENUM::POSIX),
    readdirplus(false),
    rename_exdev(RenameEXDEV::ENUM::PASSTHROUGH),
+    scheduling_priority(-10),
    security_capability(true),
    srcmounts(branches),
    statfs(StatFS::ENUM::BASE),
    statfs_ignore(StatFSIgnore::ENUM::NONE),
    symlinkify(false),
    symlinkify_timeout(3600),
-    threads(0),
+    fuse_read_thread_count(0),
+    fuse_process_thread_count(-1),
+    fuse_pin_threads("false"),
    version(MERGERFS_VERSION),
    writeback_cache(false),
-    xattr(XAttr::ENUM::PASSTHROUGH)
+    xattr(XAttr::ENUM::PASSTHROUGH),
+    _initialized(false)
 {
-  _map["async_read"]           = &async_read;
-  _map["auto_cache"]           = &auto_cache;
-  _map["branches"]             = &branches;
-  _map["cache.attr"]           = &cache_attr;
-  _map["cache.entry"]          = &cache_entry;
-  _map["cache.files"]          = &cache_files;
-  _map["cache.negative_entry"] = &cache_negative_entry;
-  _map["cache.readdir"]        = &cache_readdir;
-  _map["cache.statfs"]         = &cache_statfs;
-  _map["cache.symlinks"]       = &cache_symlinks;
-  _map["cache.writeback"]      = &writeback_cache;
-  _map["category.action"]      = &category.action;
-  _map["category.create"]      = &category.create;
-  _map["category.search"]      = &category.search;
-  _map["direct_io"]            = &direct_io;
-  _map["dropcacheonclose"]     = &dropcacheonclose;
-  _map["follow-symlinks"]      = &follow_symlinks;
-  _map["fsname"]               = &fsname;
-  _map["func.access"]          = &func.access;
-  _map["func.chmod"]           = &func.chmod;
-  _map["func.chown"]           = &func.chown;
-  _map["func.create"]          = &func.create;
-  _map["func.getattr"]         = &func.getattr;
-  _map["func.getxattr"]        = &func.getxattr;
-  _map["func.link"]            = &func.link;
-  _map["func.listxattr"]       = &func.listxattr;
-  _map["func.mkdir"]           = &func.mkdir;
-  _map["func.mknod"]           = &func.mknod;
-  _map["func.open"]            = &func.open;
-  _map["func.readlink"]        = &func.readlink;
-  _map["func.removexattr"]     = &func.removexattr;
-  _map["func.rename"]          = &func.rename;
-  _map["func.rmdir"]           = &func.rmdir;
-  _map["func.setxattr"]        = &func.setxattr;
-  _map["func.symlink"]         = &func.symlink;
-  _map["func.truncate"]        = &func.truncate;
-  _map["func.unlink"]          = &func.unlink;
-  _map["func.utimens"]         = &func.utimens;
-  _map["fuse_msg_size"]        = &fuse_msg_size;
-  _map["ignorepponrename"]     = &ignorepponrename;
-  _map["inodecalc"]            = &inodecalc;
-  _map["kernel_cache"]         = &kernel_cache;
-  _map["link_cow"]             = &link_cow;
-  _map["link-exdev"]           = &link_exdev;
-  _map["log.metrics"]          = &log_metrics;
-  _map["minfreespace"]         = &minfreespace;
-  _map["mount"]                = &mount;
-  _map["moveonenospc"]         = &moveonenospc;
-  _map["nfsopenhack"]          = &nfsopenhack;
-  _map["nullrw"]               = &nullrw;
-  _map["pid"]                  = &pid;
-  _map["posix_acl"]            = &posix_acl;
-  //  _map["readdir"]              = &readdir;
-  _map["readdirplus"]          = &readdirplus;
-  _map["rename-exdev"]         = &rename_exdev;
-  _map["security_capability"]  = &security_capability;
-  _map["srcmounts"]            = &srcmounts;
-  _map["statfs"]               = &statfs;
-  _map["statfs_ignore"]        = &statfs_ignore;
-  _map["symlinkify"]           = &symlinkify;
-  _map["symlinkify_timeout"]   = &symlinkify_timeout;
-  _map["threads"]              = &threads;
-  _map["version"]              = &version;
-  _map["xattr"]                = &xattr;
+  _map["async_read"]             = &async_read;
+  _map["auto_cache"]             = &auto_cache;
+  _map["branches"]               = &branches;
+  _map["branches-mount-timeout"] = &branches_mount_timeout;
+  _map["cache.attr"]             = &cache_attr;
+  _map["cache.entry"]            = &cache_entry;
+  _map["cache.files"]            = &cache_files;
+  _map["cache.files.process-names"] = &cache_files_process_names;
+  _map["cache.negative_entry"]   = &cache_negative_entry;
+  _map["cache.readdir"]          = &cache_readdir;
+  _map["cache.statfs"]           = &cache_statfs;
+  _map["cache.symlinks"]         = &cache_symlinks;
+  _map["cache.writeback"]        = &writeback_cache;
+  _map["category.action"]        = &category.action;
+  _map["category.create"]        = &category.create;
+  _map["category.search"]        = &category.search;
+  _map["direct_io"]              = &direct_io;
+  _map["dropcacheonclose"]       = &dropcacheonclose;
+  _map["follow-symlinks"]        = &follow_symlinks;
+  _map["fsname"]                 = &fsname;
+  _map["func.access"]            = &func.access;
+  _map["func.chmod"]             = &func.chmod;
+  _map["func.chown"]             = &func.chown;
+  _map["func.create"]            = &func.create;
+  _map["func.getattr"]           = &func.getattr;
+  _map["func.getxattr"]          = &func.getxattr;
+  _map["func.link"]              = &func.link;
+  _map["func.listxattr"]         = &func.listxattr;
+  _map["func.mkdir"]             = &func.mkdir;
+  _map["func.mknod"]             = &func.mknod;
+  _map["func.open"]              = &func.open;
+  _map["func.readlink"]          = &func.readlink;
+  _map["func.removexattr"]       = &func.removexattr;
+  _map["func.rename"]            = &func.rename;
+  _map["func.rmdir"]             = &func.rmdir;
+  _map["func.setxattr"]          = &func.setxattr;
+  _map["func.symlink"]           = &func.symlink;
+  _map["func.truncate"]          = &func.truncate;
+  _map["func.unlink"]            = &func.unlink;
+  _map["func.utimens"]           = &func.utimens;
+  _map["fuse_msg_size"]          = &fuse_msg_size;
+  _map["ignorepponrename"]       = &ignorepponrename;
+  _map["inodecalc"]              = &inodecalc;
+  _map["kernel_cache"]           = &kernel_cache;
+  _map["lazy-umount-mountpoint"] = &lazy_umount_mountpoint;
+  _map["link_cow"]               = &link_cow;
+  _map["link-exdev"]             = &link_exdev;
+  _map["log.metrics"]            = &log_metrics;
+  _map["minfreespace"]           = &minfreespace;
+  _map["mount"]                  = &mountpoint;
+  _map["moveonenospc"]           = &moveonenospc;
+  _map["nfsopenhack"]            = &nfsopenhack;
+  _map["nullrw"]                 = &nullrw;
+  _map["pid"]                    = &pid;
+  _map["pin-threads"]            = &fuse_pin_threads;
+  _map["posix_acl"]              = &posix_acl;
+  _map["readahead"]              = &readahead;
+  //  _map["readdir"]            = &readdir;
+  _map["readdirplus"]            = &readdirplus;
+  _map["rename-exdev"]           = &rename_exdev;
+  _map["scheduling-priority"]    = &scheduling_priority;
+  _map["security_capability"]    = &security_capability;
+  _map["srcmounts"]              = &srcmounts;
+  _map["statfs"]                 = &statfs;
+  _map["statfs_ignore"]          = &statfs_ignore;
+  _map["symlinkify"]             = &symlinkify;
+  _map["symlinkify_timeout"]     = &symlinkify_timeout;
+  _map["threads"]                = &fuse_read_thread_count;
+  _map["read-thread-count"]      = &fuse_read_thread_count;
+  _map["process-thread-count"]   = &fuse_process_thread_count;
+  _map["version"]                = &version;
+  _map["xattr"]                  = &xattr;
 }

 Config&
@@ -270,7 +293,7 @@ int
 Config::set(const std::string &key_,
            const std::string &value_)
 {
-  if(l::readonly(key_))
+  if(_initialized && l::readonly(key_))
    return -EROFS;

  return set_raw(key_,value_);
@@ -345,6 +368,12 @@ Config::from_file(const std::string &filepath_,
  return rv;
 }

+void
+Config::finish_initializing()
+{
+  _initialized = true;
+}
+
 std::ostream&
 operator<<(std::ostream &os_,
           const Config &c_)
@@ -30,6 +30,7 @@
 #include "config_statfs.hpp"
 #include "config_statfsignore.hpp"
 #include "config_xattr.hpp"
+#include "config_set.hpp"
 #include "enum.hpp"
 #include "errno.hpp"
 #include "funcs.hpp"
@@ -103,9 +104,11 @@ public:
  ConfigBOOL     auto_cache;
  ConfigUINT64   minfreespace;
  Branches       branches;
+  ConfigUINT64   branches_mount_timeout;
  ConfigUINT64   cache_attr;
  ConfigUINT64   cache_entry;
  CacheFiles     cache_files;
+  ConfigSet      cache_files_process_names;
  ConfigUINT64   cache_negative_entry;
  ConfigBOOL     cache_readdir;
  ConfigUINT64   cache_statfs;
@@ -120,29 +123,41 @@ public:
  ConfigBOOL     ignorepponrename;
  InodeCalc      inodecalc;
  ConfigBOOL     kernel_cache;
+  ConfigBOOL     lazy_umount_mountpoint;
  ConfigBOOL     link_cow;
  LinkEXDEV      link_exdev;
  LogMetrics     log_metrics;
-  ConfigSTR      mount;
+  ConfigSTR      mountpoint;
  MoveOnENOSPC   moveonenospc;
  NFSOpenHack    nfsopenhack;
  ConfigBOOL     nullrw;
  ConfigUINT64   pid;
  ConfigBOOL     posix_acl;
+  ConfigUINT64   readahead;
  ReadDir        readdir;
  ConfigBOOL     readdirplus;
  RenameEXDEV    rename_exdev;
+  ConfigINT      scheduling_priority;
  ConfigBOOL     security_capability;
  SrcMounts      srcmounts;
  StatFS         statfs;
  StatFSIgnore   statfs_ignore;
  ConfigBOOL     symlinkify;
  ConfigUINT64   symlinkify_timeout;
-  ConfigINT      threads;
+  ConfigINT      fuse_read_thread_count;
+  ConfigINT      fuse_process_thread_count;
+  ConfigSTR      fuse_pin_threads;
  ConfigSTR      version;
  ConfigBOOL     writeback_cache;
  XAttr          xattr;

+
+private:
+  bool _initialized;
+
+public:
+  void finish_initializing();
+
 public:
  friend std::ostream& operator<<(std::ostream &s,
                                  const Config &c);
@@ -36,6 +36,8 @@ CacheFiles::to_string() const
      return "full";
    case CacheFiles::ENUM::AUTO_FULL:
      return "auto-full";
+    case CacheFiles::ENUM::PER_PROCESS:
+      return "per-process";
    }

  return "invalid";
@@ -55,6 +57,8 @@ CacheFiles::from_string(const std::string &s_)
    _data = CacheFiles::ENUM::FULL;
  ef(s_ == "auto-full")
    _data = CacheFiles::ENUM::AUTO_FULL;
+  ef(s_ == "per-process")
+    _data = CacheFiles::ENUM::PER_PROCESS;
  else
    return -EINVAL;

@@ -27,7 +27,8 @@ enum class CacheFilesEnum
    OFF,
    PARTIAL,
    FULL,
-    AUTO_FULL
+    AUTO_FULL,
+    PER_PROCESS
  };

 typedef Enum<CacheFilesEnum> CacheFiles;
@@ -0,0 +1,43 @@
+/*
+  ISC License
+
+  Copyright (c) 2023, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "config_set.hpp"
+
+#include "str.hpp"
+
+
+ConfigSet::ConfigSet(const std::string &str_)
+{
+  from_string(str_);
+}
+
+std::string
+ConfigSet::to_string(void) const
+{
+  return str::join(*this,'|');
+}
+
+int
+ConfigSet::from_string(const std::string &str_)
+{
+  this->clear();
+
+  str::split(str_,'|',this);
+
+  return 0;
+}
@@ -0,0 +1,35 @@
+/*
+  ISC License
+
+  Copyright (c) 2023, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#pragma once
+
+#include "tofrom_string.hpp"
+
+#include <set>
+#include <string>
+
+
+class ConfigSet : public std::set<std::string>, public ToFromString
+{
+public:
+  ConfigSet(const std::string &str);
+
+public:
+  std::string to_string(void) const final;
+  int from_string(const std::string &) final;
+};
@@ -0,0 +1,234 @@
+// Formatting library for C++ - dynamic format arguments
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_ARGS_H_
+#define FMT_ARGS_H_
+
+#include <functional>  // std::reference_wrapper
+#include <memory>      // std::unique_ptr
+#include <vector>
+
+#include "core.h"
+
+FMT_BEGIN_NAMESPACE
+
+namespace detail {
+
+template <typename T> struct is_reference_wrapper : std::false_type {};
+template <typename T>
+struct is_reference_wrapper<std::reference_wrapper<T>> : std::true_type {};
+
+template <typename T> const T& unwrap(const T& v) { return v; }
+template <typename T> const T& unwrap(const std::reference_wrapper<T>& v) {
+  return static_cast<const T&>(v);
+}
+
+class dynamic_arg_list {
+  // Workaround for clang's -Wweak-vtables. Unlike for regular classes, for
+  // templates it doesn't complain about inability to deduce single translation
+  // unit for placing vtable. So storage_node_base is made a fake template.
+  template <typename = void> struct node {
+    virtual ~node() = default;
+    std::unique_ptr<node<>> next;
+  };
+
+  template <typename T> struct typed_node : node<> {
+    T value;
+
+    template <typename Arg>
+    FMT_CONSTEXPR typed_node(const Arg& arg) : value(arg) {}
+
+    template <typename Char>
+    FMT_CONSTEXPR typed_node(const basic_string_view<Char>& arg)
+        : value(arg.data(), arg.size()) {}
+  };
+
+  std::unique_ptr<node<>> head_;
+
+ public:
+  template <typename T, typename Arg> const T& push(const Arg& arg) {
+    auto new_node = std::unique_ptr<typed_node<T>>(new typed_node<T>(arg));
+    auto& value = new_node->value;
+    new_node->next = std::move(head_);
+    head_ = std::move(new_node);
+    return value;
+  }
+};
+}  // namespace detail
+
+/**
+  \rst
+  A dynamic version of `fmt::format_arg_store`.
+  It's equipped with a storage to potentially temporary objects which lifetimes
+  could be shorter than the format arguments object.
+
+  It can be implicitly converted into `~fmt::basic_format_args` for passing
+  into type-erased formatting functions such as `~fmt::vformat`.
+  \endrst
+ */
+template <typename Context>
+class dynamic_format_arg_store
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+    // Workaround a GCC template argument substitution bug.
+    : public basic_format_args<Context>
+#endif
+{
+ private:
+  using char_type = typename Context::char_type;
+
+  template <typename T> struct need_copy {
+    static constexpr detail::type mapped_type =
+        detail::mapped_type_constant<T, Context>::value;
+
+    enum {
+      value = !(detail::is_reference_wrapper<T>::value ||
+                std::is_same<T, basic_string_view<char_type>>::value ||
+                std::is_same<T, detail::std_string_view<char_type>>::value ||
+                (mapped_type != detail::type::cstring_type &&
+                 mapped_type != detail::type::string_type &&
+                 mapped_type != detail::type::custom_type))
+    };
+  };
+
+  template <typename T>
+  using stored_type = conditional_t<
+      std::is_convertible<T, std::basic_string<char_type>>::value &&
+          !detail::is_reference_wrapper<T>::value,
+      std::basic_string<char_type>, T>;
+
+  // Storage of basic_format_arg must be contiguous.
+  std::vector<basic_format_arg<Context>> data_;
+  std::vector<detail::named_arg_info<char_type>> named_info_;
+
+  // Storage of arguments not fitting into basic_format_arg must grow
+  // without relocation because items in data_ refer to it.
+  detail::dynamic_arg_list dynamic_args_;
+
+  friend class basic_format_args<Context>;
+
+  unsigned long long get_types() const {
+    return detail::is_unpacked_bit | data_.size() |
+           (named_info_.empty()
+                ? 0ULL
+                : static_cast<unsigned long long>(detail::has_named_args_bit));
+  }
+
+  const basic_format_arg<Context>* data() const {
+    return named_info_.empty() ? data_.data() : data_.data() + 1;
+  }
+
+  template <typename T> void emplace_arg(const T& arg) {
+    data_.emplace_back(detail::make_arg<Context>(arg));
+  }
+
+  template <typename T>
+  void emplace_arg(const detail::named_arg<char_type, T>& arg) {
+    if (named_info_.empty()) {
+      constexpr const detail::named_arg_info<char_type>* zero_ptr{nullptr};
+      data_.insert(data_.begin(), {zero_ptr, 0});
+    }
+    data_.emplace_back(detail::make_arg<Context>(detail::unwrap(arg.value)));
+    auto pop_one = [](std::vector<basic_format_arg<Context>>* data) {
+      data->pop_back();
+    };
+    std::unique_ptr<std::vector<basic_format_arg<Context>>, decltype(pop_one)>
+        guard{&data_, pop_one};
+    named_info_.push_back({arg.name, static_cast<int>(data_.size() - 2u)});
+    data_[0].value_.named_args = {named_info_.data(), named_info_.size()};
+    guard.release();
+  }
+
+ public:
+  constexpr dynamic_format_arg_store() = default;
+
+  /**
+    \rst
+    Adds an argument into the dynamic store for later passing to a formatting
+    function.
+
+    Note that custom types and string types (but not string views) are copied
+    into the store dynamically allocating memory if necessary.
+
+    **Example**::
+
+      fmt::dynamic_format_arg_store<fmt::format_context> store;
+      store.push_back(42);
+      store.push_back("abc");
+      store.push_back(1.5f);
+      std::string result = fmt::vformat("{} and {} and {}", store);
+    \endrst
+  */
+  template <typename T> void push_back(const T& arg) {
+    if (detail::const_check(need_copy<T>::value))
+      emplace_arg(dynamic_args_.push<stored_type<T>>(arg));
+    else
+      emplace_arg(detail::unwrap(arg));
+  }
+
+  /**
+    \rst
+    Adds a reference to the argument into the dynamic store for later passing to
+    a formatting function.
+
+    **Example**::
+
+      fmt::dynamic_format_arg_store<fmt::format_context> store;
+      char band[] = "Rolling Stones";
+      store.push_back(std::cref(band));
+      band[9] = 'c'; // Changing str affects the output.
+      std::string result = fmt::vformat("{}", store);
+      // result == "Rolling Scones"
+    \endrst
+  */
+  template <typename T> void push_back(std::reference_wrapper<T> arg) {
+    static_assert(
+        need_copy<T>::value,
+        "objects of built-in types and string views are always copied");
+    emplace_arg(arg.get());
+  }
+
+  /**
+    Adds named argument into the dynamic store for later passing to a formatting
+    function. ``std::reference_wrapper`` is supported to avoid copying of the
+    argument. The name is always copied into the store.
+  */
+  template <typename T>
+  void push_back(const detail::named_arg<char_type, T>& arg) {
+    const char_type* arg_name =
+        dynamic_args_.push<std::basic_string<char_type>>(arg.name).c_str();
+    if (detail::const_check(need_copy<T>::value)) {
+      emplace_arg(
+          fmt::arg(arg_name, dynamic_args_.push<stored_type<T>>(arg.value)));
+    } else {
+      emplace_arg(fmt::arg(arg_name, arg.value));
+    }
+  }
+
+  /** Erase all elements from the store */
+  void clear() {
+    data_.clear();
+    named_info_.clear();
+    dynamic_args_ = detail::dynamic_arg_list();
+  }
+
+  /**
+    \rst
+    Reserves space to store at least *new_cap* arguments including
+    *new_cap_named* named arguments.
+    \endrst
+  */
+  void reserve(size_t new_cap, size_t new_cap_named) {
+    FMT_ASSERT(new_cap >= new_cap_named,
+               "Set of arguments includes set of named arguments");
+    data_.reserve(new_cap);
+    named_info_.reserve(new_cap_named);
+  }
+};
+
+FMT_END_NAMESPACE
+
+#endif  // FMT_ARGS_H_
@@ -0,0 +1,651 @@
+// Formatting library for C++ - color support
+//
+// Copyright (c) 2018 - present, Victor Zverovich and fmt contributors
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_COLOR_H_
+#define FMT_COLOR_H_
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
+
+enum class color : uint32_t {
+  alice_blue = 0xF0F8FF,               // rgb(240,248,255)
+  antique_white = 0xFAEBD7,            // rgb(250,235,215)
+  aqua = 0x00FFFF,                     // rgb(0,255,255)
+  aquamarine = 0x7FFFD4,               // rgb(127,255,212)
+  azure = 0xF0FFFF,                    // rgb(240,255,255)
+  beige = 0xF5F5DC,                    // rgb(245,245,220)
+  bisque = 0xFFE4C4,                   // rgb(255,228,196)
+  black = 0x000000,                    // rgb(0,0,0)
+  blanched_almond = 0xFFEBCD,          // rgb(255,235,205)
+  blue = 0x0000FF,                     // rgb(0,0,255)
+  blue_violet = 0x8A2BE2,              // rgb(138,43,226)
+  brown = 0xA52A2A,                    // rgb(165,42,42)
+  burly_wood = 0xDEB887,               // rgb(222,184,135)
+  cadet_blue = 0x5F9EA0,               // rgb(95,158,160)
+  chartreuse = 0x7FFF00,               // rgb(127,255,0)
+  chocolate = 0xD2691E,                // rgb(210,105,30)
+  coral = 0xFF7F50,                    // rgb(255,127,80)
+  cornflower_blue = 0x6495ED,          // rgb(100,149,237)
+  cornsilk = 0xFFF8DC,                 // rgb(255,248,220)
+  crimson = 0xDC143C,                  // rgb(220,20,60)
+  cyan = 0x00FFFF,                     // rgb(0,255,255)
+  dark_blue = 0x00008B,                // rgb(0,0,139)
+  dark_cyan = 0x008B8B,                // rgb(0,139,139)
+  dark_golden_rod = 0xB8860B,          // rgb(184,134,11)
+  dark_gray = 0xA9A9A9,                // rgb(169,169,169)
+  dark_green = 0x006400,               // rgb(0,100,0)
+  dark_khaki = 0xBDB76B,               // rgb(189,183,107)
+  dark_magenta = 0x8B008B,             // rgb(139,0,139)
+  dark_olive_green = 0x556B2F,         // rgb(85,107,47)
+  dark_orange = 0xFF8C00,              // rgb(255,140,0)
+  dark_orchid = 0x9932CC,              // rgb(153,50,204)
+  dark_red = 0x8B0000,                 // rgb(139,0,0)
+  dark_salmon = 0xE9967A,              // rgb(233,150,122)
+  dark_sea_green = 0x8FBC8F,           // rgb(143,188,143)
+  dark_slate_blue = 0x483D8B,          // rgb(72,61,139)
+  dark_slate_gray = 0x2F4F4F,          // rgb(47,79,79)
+  dark_turquoise = 0x00CED1,           // rgb(0,206,209)
+  dark_violet = 0x9400D3,              // rgb(148,0,211)
+  deep_pink = 0xFF1493,                // rgb(255,20,147)
+  deep_sky_blue = 0x00BFFF,            // rgb(0,191,255)
+  dim_gray = 0x696969,                 // rgb(105,105,105)
+  dodger_blue = 0x1E90FF,              // rgb(30,144,255)
+  fire_brick = 0xB22222,               // rgb(178,34,34)
+  floral_white = 0xFFFAF0,             // rgb(255,250,240)
+  forest_green = 0x228B22,             // rgb(34,139,34)
+  fuchsia = 0xFF00FF,                  // rgb(255,0,255)
+  gainsboro = 0xDCDCDC,                // rgb(220,220,220)
+  ghost_white = 0xF8F8FF,              // rgb(248,248,255)
+  gold = 0xFFD700,                     // rgb(255,215,0)
+  golden_rod = 0xDAA520,               // rgb(218,165,32)
+  gray = 0x808080,                     // rgb(128,128,128)
+  green = 0x008000,                    // rgb(0,128,0)
+  green_yellow = 0xADFF2F,             // rgb(173,255,47)
+  honey_dew = 0xF0FFF0,                // rgb(240,255,240)
+  hot_pink = 0xFF69B4,                 // rgb(255,105,180)
+  indian_red = 0xCD5C5C,               // rgb(205,92,92)
+  indigo = 0x4B0082,                   // rgb(75,0,130)
+  ivory = 0xFFFFF0,                    // rgb(255,255,240)
+  khaki = 0xF0E68C,                    // rgb(240,230,140)
+  lavender = 0xE6E6FA,                 // rgb(230,230,250)
+  lavender_blush = 0xFFF0F5,           // rgb(255,240,245)
+  lawn_green = 0x7CFC00,               // rgb(124,252,0)
+  lemon_chiffon = 0xFFFACD,            // rgb(255,250,205)
+  light_blue = 0xADD8E6,               // rgb(173,216,230)
+  light_coral = 0xF08080,              // rgb(240,128,128)
+  light_cyan = 0xE0FFFF,               // rgb(224,255,255)
+  light_golden_rod_yellow = 0xFAFAD2,  // rgb(250,250,210)
+  light_gray = 0xD3D3D3,               // rgb(211,211,211)
+  light_green = 0x90EE90,              // rgb(144,238,144)
+  light_pink = 0xFFB6C1,               // rgb(255,182,193)
+  light_salmon = 0xFFA07A,             // rgb(255,160,122)
+  light_sea_green = 0x20B2AA,          // rgb(32,178,170)
+  light_sky_blue = 0x87CEFA,           // rgb(135,206,250)
+  light_slate_gray = 0x778899,         // rgb(119,136,153)
+  light_steel_blue = 0xB0C4DE,         // rgb(176,196,222)
+  light_yellow = 0xFFFFE0,             // rgb(255,255,224)
+  lime = 0x00FF00,                     // rgb(0,255,0)
+  lime_green = 0x32CD32,               // rgb(50,205,50)
+  linen = 0xFAF0E6,                    // rgb(250,240,230)
+  magenta = 0xFF00FF,                  // rgb(255,0,255)
+  maroon = 0x800000,                   // rgb(128,0,0)
+  medium_aquamarine = 0x66CDAA,        // rgb(102,205,170)
+  medium_blue = 0x0000CD,              // rgb(0,0,205)
+  medium_orchid = 0xBA55D3,            // rgb(186,85,211)
+  medium_purple = 0x9370DB,            // rgb(147,112,219)
+  medium_sea_green = 0x3CB371,         // rgb(60,179,113)
+  medium_slate_blue = 0x7B68EE,        // rgb(123,104,238)
+  medium_spring_green = 0x00FA9A,      // rgb(0,250,154)
+  medium_turquoise = 0x48D1CC,         // rgb(72,209,204)
+  medium_violet_red = 0xC71585,        // rgb(199,21,133)
+  midnight_blue = 0x191970,            // rgb(25,25,112)
+  mint_cream = 0xF5FFFA,               // rgb(245,255,250)
+  misty_rose = 0xFFE4E1,               // rgb(255,228,225)
+  moccasin = 0xFFE4B5,                 // rgb(255,228,181)
+  navajo_white = 0xFFDEAD,             // rgb(255,222,173)
+  navy = 0x000080,                     // rgb(0,0,128)
+  old_lace = 0xFDF5E6,                 // rgb(253,245,230)
+  olive = 0x808000,                    // rgb(128,128,0)
+  olive_drab = 0x6B8E23,               // rgb(107,142,35)
+  orange = 0xFFA500,                   // rgb(255,165,0)
+  orange_red = 0xFF4500,               // rgb(255,69,0)
+  orchid = 0xDA70D6,                   // rgb(218,112,214)
+  pale_golden_rod = 0xEEE8AA,          // rgb(238,232,170)
+  pale_green = 0x98FB98,               // rgb(152,251,152)
+  pale_turquoise = 0xAFEEEE,           // rgb(175,238,238)
+  pale_violet_red = 0xDB7093,          // rgb(219,112,147)
+  papaya_whip = 0xFFEFD5,              // rgb(255,239,213)
+  peach_puff = 0xFFDAB9,               // rgb(255,218,185)
+  peru = 0xCD853F,                     // rgb(205,133,63)
+  pink = 0xFFC0CB,                     // rgb(255,192,203)
+  plum = 0xDDA0DD,                     // rgb(221,160,221)
+  powder_blue = 0xB0E0E6,              // rgb(176,224,230)
+  purple = 0x800080,                   // rgb(128,0,128)
+  rebecca_purple = 0x663399,           // rgb(102,51,153)
+  red = 0xFF0000,                      // rgb(255,0,0)
+  rosy_brown = 0xBC8F8F,               // rgb(188,143,143)
+  royal_blue = 0x4169E1,               // rgb(65,105,225)
+  saddle_brown = 0x8B4513,             // rgb(139,69,19)
+  salmon = 0xFA8072,                   // rgb(250,128,114)
+  sandy_brown = 0xF4A460,              // rgb(244,164,96)
+  sea_green = 0x2E8B57,                // rgb(46,139,87)
+  sea_shell = 0xFFF5EE,                // rgb(255,245,238)
+  sienna = 0xA0522D,                   // rgb(160,82,45)
+  silver = 0xC0C0C0,                   // rgb(192,192,192)
+  sky_blue = 0x87CEEB,                 // rgb(135,206,235)
+  slate_blue = 0x6A5ACD,               // rgb(106,90,205)
+  slate_gray = 0x708090,               // rgb(112,128,144)
+  snow = 0xFFFAFA,                     // rgb(255,250,250)
+  spring_green = 0x00FF7F,             // rgb(0,255,127)
+  steel_blue = 0x4682B4,               // rgb(70,130,180)
+  tan = 0xD2B48C,                      // rgb(210,180,140)
+  teal = 0x008080,                     // rgb(0,128,128)
+  thistle = 0xD8BFD8,                  // rgb(216,191,216)
+  tomato = 0xFF6347,                   // rgb(255,99,71)
+  turquoise = 0x40E0D0,                // rgb(64,224,208)
+  violet = 0xEE82EE,                   // rgb(238,130,238)
+  wheat = 0xF5DEB3,                    // rgb(245,222,179)
+  white = 0xFFFFFF,                    // rgb(255,255,255)
+  white_smoke = 0xF5F5F5,              // rgb(245,245,245)
+  yellow = 0xFFFF00,                   // rgb(255,255,0)
+  yellow_green = 0x9ACD32              // rgb(154,205,50)
+};                                     // enum class color
+
+enum class terminal_color : uint8_t {
+  black = 30,
+  red,
+  green,
+  yellow,
+  blue,
+  magenta,
+  cyan,
+  white,
+  bright_black = 90,
+  bright_red,
+  bright_green,
+  bright_yellow,
+  bright_blue,
+  bright_magenta,
+  bright_cyan,
+  bright_white
+};
+
+enum class emphasis : uint8_t {
+  bold = 1,
+  faint = 1 << 1,
+  italic = 1 << 2,
+  underline = 1 << 3,
+  blink = 1 << 4,
+  reverse = 1 << 5,
+  conceal = 1 << 6,
+  strikethrough = 1 << 7,
+};
+
+// rgb is a struct for red, green and blue colors.
+// Using the name "rgb" makes some editors show the color in a tooltip.
+struct rgb {
+  FMT_CONSTEXPR rgb() : r(0), g(0), b(0) {}
+  FMT_CONSTEXPR rgb(uint8_t r_, uint8_t g_, uint8_t b_) : r(r_), g(g_), b(b_) {}
+  FMT_CONSTEXPR rgb(uint32_t hex)
+      : r((hex >> 16) & 0xFF), g((hex >> 8) & 0xFF), b(hex & 0xFF) {}
+  FMT_CONSTEXPR rgb(color hex)
+      : r((uint32_t(hex) >> 16) & 0xFF),
+        g((uint32_t(hex) >> 8) & 0xFF),
+        b(uint32_t(hex) & 0xFF) {}
+  uint8_t r;
+  uint8_t g;
+  uint8_t b;
+};
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+// color is a struct of either a rgb color or a terminal color.
+struct color_type {
+  FMT_CONSTEXPR color_type() noexcept : is_rgb(), value{} {}
+  FMT_CONSTEXPR color_type(color rgb_color) noexcept : is_rgb(true), value{} {
+    value.rgb_color = static_cast<uint32_t>(rgb_color);
+  }
+  FMT_CONSTEXPR color_type(rgb rgb_color) noexcept : is_rgb(true), value{} {
+    value.rgb_color = (static_cast<uint32_t>(rgb_color.r) << 16) |
+                      (static_cast<uint32_t>(rgb_color.g) << 8) | rgb_color.b;
+  }
+  FMT_CONSTEXPR color_type(terminal_color term_color) noexcept
+      : is_rgb(), value{} {
+    value.term_color = static_cast<uint8_t>(term_color);
+  }
+  bool is_rgb;
+  union color_union {
+    uint8_t term_color;
+    uint32_t rgb_color;
+  } value;
+};
+
+FMT_END_DETAIL_NAMESPACE
+
+/** A text style consisting of foreground and background colors and emphasis. */
+class text_style {
+ public:
+  FMT_CONSTEXPR text_style(emphasis em = emphasis()) noexcept
+      : set_foreground_color(), set_background_color(), ems(em) {}
+
+  FMT_CONSTEXPR text_style& operator|=(const text_style& rhs) {
+    if (!set_foreground_color) {
+      set_foreground_color = rhs.set_foreground_color;
+      foreground_color = rhs.foreground_color;
+    } else if (rhs.set_foreground_color) {
+      if (!foreground_color.is_rgb || !rhs.foreground_color.is_rgb)
+        FMT_THROW(format_error("can't OR a terminal color"));
+      foreground_color.value.rgb_color |= rhs.foreground_color.value.rgb_color;
+    }
+
+    if (!set_background_color) {
+      set_background_color = rhs.set_background_color;
+      background_color = rhs.background_color;
+    } else if (rhs.set_background_color) {
+      if (!background_color.is_rgb || !rhs.background_color.is_rgb)
+        FMT_THROW(format_error("can't OR a terminal color"));
+      background_color.value.rgb_color |= rhs.background_color.value.rgb_color;
+    }
+
+    ems = static_cast<emphasis>(static_cast<uint8_t>(ems) |
+                                static_cast<uint8_t>(rhs.ems));
+    return *this;
+  }
+
+  friend FMT_CONSTEXPR text_style operator|(text_style lhs,
+                                            const text_style& rhs) {
+    return lhs |= rhs;
+  }
+
+  FMT_CONSTEXPR bool has_foreground() const noexcept {
+    return set_foreground_color;
+  }
+  FMT_CONSTEXPR bool has_background() const noexcept {
+    return set_background_color;
+  }
+  FMT_CONSTEXPR bool has_emphasis() const noexcept {
+    return static_cast<uint8_t>(ems) != 0;
+  }
+  FMT_CONSTEXPR detail::color_type get_foreground() const noexcept {
+    FMT_ASSERT(has_foreground(), "no foreground specified for this style");
+    return foreground_color;
+  }
+  FMT_CONSTEXPR detail::color_type get_background() const noexcept {
+    FMT_ASSERT(has_background(), "no background specified for this style");
+    return background_color;
+  }
+  FMT_CONSTEXPR emphasis get_emphasis() const noexcept {
+    FMT_ASSERT(has_emphasis(), "no emphasis specified for this style");
+    return ems;
+  }
+
+ private:
+  FMT_CONSTEXPR text_style(bool is_foreground,
+                           detail::color_type text_color) noexcept
+      : set_foreground_color(), set_background_color(), ems() {
+    if (is_foreground) {
+      foreground_color = text_color;
+      set_foreground_color = true;
+    } else {
+      background_color = text_color;
+      set_background_color = true;
+    }
+  }
+
+  friend FMT_CONSTEXPR text_style fg(detail::color_type foreground) noexcept;
+
+  friend FMT_CONSTEXPR text_style bg(detail::color_type background) noexcept;
+
+  detail::color_type foreground_color;
+  detail::color_type background_color;
+  bool set_foreground_color;
+  bool set_background_color;
+  emphasis ems;
+};
+
+/** Creates a text style from the foreground (text) color. */
+FMT_CONSTEXPR inline text_style fg(detail::color_type foreground) noexcept {
+  return text_style(true, foreground);
+}
+
+/** Creates a text style from the background color. */
+FMT_CONSTEXPR inline text_style bg(detail::color_type background) noexcept {
+  return text_style(false, background);
+}
+
+FMT_CONSTEXPR inline text_style operator|(emphasis lhs, emphasis rhs) noexcept {
+  return text_style(lhs) | rhs;
+}
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+template <typename Char> struct ansi_color_escape {
+  FMT_CONSTEXPR ansi_color_escape(detail::color_type text_color,
+                                  const char* esc) noexcept {
+    // If we have a terminal color, we need to output another escape code
+    // sequence.
+    if (!text_color.is_rgb) {
+      bool is_background = esc == string_view("\x1b[48;2;");
+      uint32_t value = text_color.value.term_color;
+      // Background ASCII codes are the same as the foreground ones but with
+      // 10 more.
+      if (is_background) value += 10u;
+
+      size_t index = 0;
+      buffer[index++] = static_cast<Char>('\x1b');
+      buffer[index++] = static_cast<Char>('[');
+
+      if (value >= 100u) {
+        buffer[index++] = static_cast<Char>('1');
+        value %= 100u;
+      }
+      buffer[index++] = static_cast<Char>('0' + value / 10u);
+      buffer[index++] = static_cast<Char>('0' + value % 10u);
+
+      buffer[index++] = static_cast<Char>('m');
+      buffer[index++] = static_cast<Char>('\0');
+      return;
+    }
+
+    for (int i = 0; i < 7; i++) {
+      buffer[i] = static_cast<Char>(esc[i]);
+    }
+    rgb color(text_color.value.rgb_color);
+    to_esc(color.r, buffer + 7, ';');
+    to_esc(color.g, buffer + 11, ';');
+    to_esc(color.b, buffer + 15, 'm');
+    buffer[19] = static_cast<Char>(0);
+  }
+  FMT_CONSTEXPR ansi_color_escape(emphasis em) noexcept {
+    uint8_t em_codes[num_emphases] = {};
+    if (has_emphasis(em, emphasis::bold)) em_codes[0] = 1;
+    if (has_emphasis(em, emphasis::faint)) em_codes[1] = 2;
+    if (has_emphasis(em, emphasis::italic)) em_codes[2] = 3;
+    if (has_emphasis(em, emphasis::underline)) em_codes[3] = 4;
+    if (has_emphasis(em, emphasis::blink)) em_codes[4] = 5;
+    if (has_emphasis(em, emphasis::reverse)) em_codes[5] = 7;
+    if (has_emphasis(em, emphasis::conceal)) em_codes[6] = 8;
+    if (has_emphasis(em, emphasis::strikethrough)) em_codes[7] = 9;
+
+    size_t index = 0;
+    for (size_t i = 0; i < num_emphases; ++i) {
+      if (!em_codes[i]) continue;
+      buffer[index++] = static_cast<Char>('\x1b');
+      buffer[index++] = static_cast<Char>('[');
+      buffer[index++] = static_cast<Char>('0' + em_codes[i]);
+      buffer[index++] = static_cast<Char>('m');
+    }
+    buffer[index++] = static_cast<Char>(0);
+  }
+  FMT_CONSTEXPR operator const Char*() const noexcept { return buffer; }
+
+  FMT_CONSTEXPR const Char* begin() const noexcept { return buffer; }
+  FMT_CONSTEXPR_CHAR_TRAITS const Char* end() const noexcept {
+    return buffer + std::char_traits<Char>::length(buffer);
+  }
+
+ private:
+  static constexpr size_t num_emphases = 8;
+  Char buffer[7u + 3u * num_emphases + 1u];
+
+  static FMT_CONSTEXPR void to_esc(uint8_t c, Char* out,
+                                   char delimiter) noexcept {
+    out[0] = static_cast<Char>('0' + c / 100);
+    out[1] = static_cast<Char>('0' + c / 10 % 10);
+    out[2] = static_cast<Char>('0' + c % 10);
+    out[3] = static_cast<Char>(delimiter);
+  }
+  static FMT_CONSTEXPR bool has_emphasis(emphasis em, emphasis mask) noexcept {
+    return static_cast<uint8_t>(em) & static_cast<uint8_t>(mask);
+  }
+};
+
+template <typename Char>
+FMT_CONSTEXPR ansi_color_escape<Char> make_foreground_color(
+    detail::color_type foreground) noexcept {
+  return ansi_color_escape<Char>(foreground, "\x1b[38;2;");
+}
+
+template <typename Char>
+FMT_CONSTEXPR ansi_color_escape<Char> make_background_color(
+    detail::color_type background) noexcept {
+  return ansi_color_escape<Char>(background, "\x1b[48;2;");
+}
+
+template <typename Char>
+FMT_CONSTEXPR ansi_color_escape<Char> make_emphasis(emphasis em) noexcept {
+  return ansi_color_escape<Char>(em);
+}
+
+template <typename Char> inline void fputs(const Char* chars, FILE* stream) {
+  int result = std::fputs(chars, stream);
+  if (result < 0)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+template <> inline void fputs<wchar_t>(const wchar_t* chars, FILE* stream) {
+  int result = std::fputws(chars, stream);
+  if (result < 0)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+template <typename Char> inline void reset_color(FILE* stream) {
+  fputs("\x1b[0m", stream);
+}
+
+template <> inline void reset_color<wchar_t>(FILE* stream) {
+  fputs(L"\x1b[0m", stream);
+}
+
+template <typename Char> inline void reset_color(buffer<Char>& buffer) {
+  auto reset_color = string_view("\x1b[0m");
+  buffer.append(reset_color.begin(), reset_color.end());
+}
+
+template <typename T> struct styled_arg {
+  const T& value;
+  text_style style;
+};
+
+template <typename Char>
+void vformat_to(buffer<Char>& buf, const text_style& ts,
+                basic_string_view<Char> format_str,
+                basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  bool has_style = false;
+  if (ts.has_emphasis()) {
+    has_style = true;
+    auto emphasis = detail::make_emphasis<Char>(ts.get_emphasis());
+    buf.append(emphasis.begin(), emphasis.end());
+  }
+  if (ts.has_foreground()) {
+    has_style = true;
+    auto foreground = detail::make_foreground_color<Char>(ts.get_foreground());
+    buf.append(foreground.begin(), foreground.end());
+  }
+  if (ts.has_background()) {
+    has_style = true;
+    auto background = detail::make_background_color<Char>(ts.get_background());
+    buf.append(background.begin(), background.end());
+  }
+  detail::vformat_to(buf, format_str, args, {});
+  if (has_style) detail::reset_color<Char>(buf);
+}
+
+FMT_END_DETAIL_NAMESPACE
+
+template <typename S, typename Char = char_t<S>>
+void vprint(std::FILE* f, const text_style& ts, const S& format,
+            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  basic_memory_buffer<Char> buf;
+  detail::vformat_to(buf, ts, detail::to_string_view(format), args);
+  if (detail::is_utf8()) {
+    detail::print(f, basic_string_view<Char>(buf.begin(), buf.size()));
+  } else {
+    buf.push_back(Char(0));
+    detail::fputs(buf.data(), f);
+  }
+}
+
+/**
+  \rst
+  Formats a string and prints it to the specified file stream using ANSI
+  escape sequences to specify text formatting.
+
+  **Example**::
+
+    fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
+               "Elapsed time: {0:.2f} seconds", 1.23);
+  \endrst
+ */
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_string<S>::value)>
+void print(std::FILE* f, const text_style& ts, const S& format_str,
+           const Args&... args) {
+  vprint(f, ts, format_str,
+         fmt::make_format_args<buffer_context<char_t<S>>>(args...));
+}
+
+/**
+  \rst
+  Formats a string and prints it to stdout using ANSI escape sequences to
+  specify text formatting.
+
+  **Example**::
+
+    fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
+               "Elapsed time: {0:.2f} seconds", 1.23);
+  \endrst
+ */
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_string<S>::value)>
+void print(const text_style& ts, const S& format_str, const Args&... args) {
+  return print(stdout, ts, format_str, args...);
+}
+
+template <typename S, typename Char = char_t<S>>
+inline std::basic_string<Char> vformat(
+    const text_style& ts, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  basic_memory_buffer<Char> buf;
+  detail::vformat_to(buf, ts, detail::to_string_view(format_str), args);
+  return fmt::to_string(buf);
+}
+
+/**
+  \rst
+  Formats arguments and returns the result as a string using ANSI
+  escape sequences to specify text formatting.
+
+  **Example**::
+
+    #include <fmt/color.h>
+    std::string message = fmt::format(fmt::emphasis::bold | fg(fmt::color::red),
+                                      "The answer is {}", 42);
+  \endrst
+*/
+template <typename S, typename... Args, typename Char = char_t<S>>
+inline std::basic_string<Char> format(const text_style& ts, const S& format_str,
+                                      const Args&... args) {
+  return fmt::vformat(ts, detail::to_string_view(format_str),
+                      fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+/**
+  Formats a string with the given text_style and writes the output to ``out``.
+ */
+template <typename OutputIt, typename Char,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value)>
+OutputIt vformat_to(
+    OutputIt out, const text_style& ts, basic_string_view<Char> format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  auto&& buf = detail::get_buffer<Char>(out);
+  detail::vformat_to(buf, ts, format_str, args);
+  return detail::get_iterator(buf);
+}
+
+/**
+  \rst
+  Formats arguments with the given text_style, writes the result to the output
+  iterator ``out`` and returns the iterator past the end of the output range.
+
+  **Example**::
+
+    std::vector<char> out;
+    fmt::format_to(std::back_inserter(out),
+                   fmt::emphasis::bold | fg(fmt::color::red), "{}", 42);
+  \endrst
+*/
+template <typename OutputIt, typename S, typename... Args,
+          bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value&&
+              detail::is_string<S>::value>
+inline auto format_to(OutputIt out, const text_style& ts, const S& format_str,
+                      Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  return vformat_to(out, ts, detail::to_string_view(format_str),
+                    fmt::make_format_args<buffer_context<char_t<S>>>(args...));
+}
+
+template <typename T, typename Char>
+struct formatter<detail::styled_arg<T>, Char> : formatter<T, Char> {
+  template <typename FormatContext>
+  auto format(const detail::styled_arg<T>& arg, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    const auto& ts = arg.style;
+    const auto& value = arg.value;
+    auto out = ctx.out();
+
+    bool has_style = false;
+    if (ts.has_emphasis()) {
+      has_style = true;
+      auto emphasis = detail::make_emphasis<Char>(ts.get_emphasis());
+      out = std::copy(emphasis.begin(), emphasis.end(), out);
+    }
+    if (ts.has_foreground()) {
+      has_style = true;
+      auto foreground =
+          detail::make_foreground_color<Char>(ts.get_foreground());
+      out = std::copy(foreground.begin(), foreground.end(), out);
+    }
+    if (ts.has_background()) {
+      has_style = true;
+      auto background =
+          detail::make_background_color<Char>(ts.get_background());
+      out = std::copy(background.begin(), background.end(), out);
+    }
+    out = formatter<T, Char>::format(value, ctx);
+    if (has_style) {
+      auto reset_color = string_view("\x1b[0m");
+      out = std::copy(reset_color.begin(), reset_color.end(), out);
+    }
+    return out;
+  }
+};
+
+/**
+  \rst
+  Returns an argument that will be formatted using ANSI escape sequences,
+  to be used in a formatting function.
+
+  **Example**::
+
+    fmt::print("Elapsed time: {0:.2f} seconds",
+               fmt::styled(1.23, fmt::fg(fmt::color::green) |
+                                 fmt::bg(fmt::color::blue)));
+  \endrst
+ */
+template <typename T>
+FMT_CONSTEXPR auto styled(const T& value, text_style ts)
+    -> detail::styled_arg<remove_cvref_t<T>> {
+  return detail::styled_arg<remove_cvref_t<T>>{value, ts};
+}
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_COLOR_H_
@@ -0,0 +1,611 @@
+// Formatting library for C++ - experimental format string compilation
+//
+// Copyright (c) 2012 - present, Victor Zverovich and fmt contributors
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_COMPILE_H_
+#define FMT_COMPILE_H_
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+
+template <typename Char, typename InputIt>
+FMT_CONSTEXPR inline counting_iterator copy_str(InputIt begin, InputIt end,
+                                                counting_iterator it) {
+  return it + (end - begin);
+}
+
+template <typename OutputIt> class truncating_iterator_base {
+ protected:
+  OutputIt out_;
+  size_t limit_;
+  size_t count_ = 0;
+
+  truncating_iterator_base() : out_(), limit_(0) {}
+
+  truncating_iterator_base(OutputIt out, size_t limit)
+      : out_(out), limit_(limit) {}
+
+ public:
+  using iterator_category = std::output_iterator_tag;
+  using value_type = typename std::iterator_traits<OutputIt>::value_type;
+  using difference_type = std::ptrdiff_t;
+  using pointer = void;
+  using reference = void;
+  FMT_UNCHECKED_ITERATOR(truncating_iterator_base);
+
+  OutputIt base() const { return out_; }
+  size_t count() const { return count_; }
+};
+
+// An output iterator that truncates the output and counts the number of objects
+// written to it.
+template <typename OutputIt,
+          typename Enable = typename std::is_void<
+              typename std::iterator_traits<OutputIt>::value_type>::type>
+class truncating_iterator;
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::false_type>
+    : public truncating_iterator_base<OutputIt> {
+  mutable typename truncating_iterator_base<OutputIt>::value_type blackhole_;
+
+ public:
+  using value_type = typename truncating_iterator_base<OutputIt>::value_type;
+
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  truncating_iterator& operator++() {
+    if (this->count_++ < this->limit_) ++this->out_;
+    return *this;
+  }
+
+  truncating_iterator operator++(int) {
+    auto it = *this;
+    ++*this;
+    return it;
+  }
+
+  value_type& operator*() const {
+    return this->count_ < this->limit_ ? *this->out_ : blackhole_;
+  }
+};
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::true_type>
+    : public truncating_iterator_base<OutputIt> {
+ public:
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  template <typename T> truncating_iterator& operator=(T val) {
+    if (this->count_++ < this->limit_) *this->out_++ = val;
+    return *this;
+  }
+
+  truncating_iterator& operator++() { return *this; }
+  truncating_iterator& operator++(int) { return *this; }
+  truncating_iterator& operator*() { return *this; }
+};
+
+// A compile-time string which is compiled into fast formatting code.
+class compiled_string {};
+
+template <typename S>
+struct is_compiled_string : std::is_base_of<compiled_string, S> {};
+
+/**
+  \rst
+  Converts a string literal *s* into a format string that will be parsed at
+  compile time and converted into efficient formatting code. Requires C++17
+  ``constexpr if`` compiler support.
+
+  **Example**::
+
+    // Converts 42 into std::string using the most efficient method and no
+    // runtime format string processing.
+    std::string s = fmt::format(FMT_COMPILE("{}"), 42);
+  \endrst
+ */
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+#  define FMT_COMPILE(s) \
+    FMT_STRING_IMPL(s, fmt::detail::compiled_string, explicit)
+#else
+#  define FMT_COMPILE(s) FMT_STRING(s)
+#endif
+
+#if FMT_USE_NONTYPE_TEMPLATE_ARGS
+template <typename Char, size_t N,
+          fmt::detail_exported::fixed_string<Char, N> Str>
+struct udl_compiled_string : compiled_string {
+  using char_type = Char;
+  explicit constexpr operator basic_string_view<char_type>() const {
+    return {Str.data, N - 1};
+  }
+};
+#endif
+
+template <typename T, typename... Tail>
+const T& first(const T& value, const Tail&...) {
+  return value;
+}
+
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+template <typename... Args> struct type_list {};
+
+// Returns a reference to the argument at index N from [first, rest...].
+template <int N, typename T, typename... Args>
+constexpr const auto& get([[maybe_unused]] const T& first,
+                          [[maybe_unused]] const Args&... rest) {
+  static_assert(N < 1 + sizeof...(Args), "index is out of bounds");
+  if constexpr (N == 0)
+    return first;
+  else
+    return detail::get<N - 1>(rest...);
+}
+
+template <typename Char, typename... Args>
+constexpr int get_arg_index_by_name(basic_string_view<Char> name,
+                                    type_list<Args...>) {
+  return get_arg_index_by_name<Args...>(name);
+}
+
+template <int N, typename> struct get_type_impl;
+
+template <int N, typename... Args> struct get_type_impl<N, type_list<Args...>> {
+  using type =
+      remove_cvref_t<decltype(detail::get<N>(std::declval<Args>()...))>;
+};
+
+template <int N, typename T>
+using get_type = typename get_type_impl<N, T>::type;
+
+template <typename T> struct is_compiled_format : std::false_type {};
+
+template <typename Char> struct text {
+  basic_string_view<Char> data;
+  using char_type = Char;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&...) const {
+    return write<Char>(out, data);
+  }
+};
+
+template <typename Char>
+struct is_compiled_format<text<Char>> : std::true_type {};
+
+template <typename Char>
+constexpr text<Char> make_text(basic_string_view<Char> s, size_t pos,
+                               size_t size) {
+  return {{&s[pos], size}};
+}
+
+template <typename Char> struct code_unit {
+  Char value;
+  using char_type = Char;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&...) const {
+    return write<Char>(out, value);
+  }
+};
+
+// This ensures that the argument type is convertible to `const T&`.
+template <typename T, int N, typename... Args>
+constexpr const T& get_arg_checked(const Args&... args) {
+  const auto& arg = detail::get<N>(args...);
+  if constexpr (detail::is_named_arg<remove_cvref_t<decltype(arg)>>()) {
+    return arg.value;
+  } else {
+    return arg;
+  }
+}
+
+template <typename Char>
+struct is_compiled_format<code_unit<Char>> : std::true_type {};
+
+// A replacement field that refers to argument N.
+template <typename Char, typename T, int N> struct field {
+  using char_type = Char;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+    return write<Char>(out, get_arg_checked<T, N>(args...));
+  }
+};
+
+template <typename Char, typename T, int N>
+struct is_compiled_format<field<Char, T, N>> : std::true_type {};
+
+// A replacement field that refers to argument with name.
+template <typename Char> struct runtime_named_field {
+  using char_type = Char;
+  basic_string_view<Char> name;
+
+  template <typename OutputIt, typename T>
+  constexpr static bool try_format_argument(
+      OutputIt& out,
+      // [[maybe_unused]] due to unused-but-set-parameter warning in GCC 7,8,9
+      [[maybe_unused]] basic_string_view<Char> arg_name, const T& arg) {
+    if constexpr (is_named_arg<typename std::remove_cv<T>::type>::value) {
+      if (arg_name == arg.name) {
+        out = write<Char>(out, arg.value);
+        return true;
+      }
+    }
+    return false;
+  }
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+    bool found = (try_format_argument(out, name, args) || ...);
+    if (!found) {
+      FMT_THROW(format_error("argument with specified name is not found"));
+    }
+    return out;
+  }
+};
+
+template <typename Char>
+struct is_compiled_format<runtime_named_field<Char>> : std::true_type {};
+
+// A replacement field that refers to argument N and has format specifiers.
+template <typename Char, typename T, int N> struct spec_field {
+  using char_type = Char;
+  formatter<T, Char> fmt;
+
+  template <typename OutputIt, typename... Args>
+  constexpr FMT_INLINE OutputIt format(OutputIt out,
+                                       const Args&... args) const {
+    const auto& vargs =
+        fmt::make_format_args<basic_format_context<OutputIt, Char>>(args...);
+    basic_format_context<OutputIt, Char> ctx(out, vargs);
+    return fmt.format(get_arg_checked<T, N>(args...), ctx);
+  }
+};
+
+template <typename Char, typename T, int N>
+struct is_compiled_format<spec_field<Char, T, N>> : std::true_type {};
+
+template <typename L, typename R> struct concat {
+  L lhs;
+  R rhs;
+  using char_type = typename L::char_type;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+    out = lhs.format(out, args...);
+    return rhs.format(out, args...);
+  }
+};
+
+template <typename L, typename R>
+struct is_compiled_format<concat<L, R>> : std::true_type {};
+
+template <typename L, typename R>
+constexpr concat<L, R> make_concat(L lhs, R rhs) {
+  return {lhs, rhs};
+}
+
+struct unknown_format {};
+
+template <typename Char>
+constexpr size_t parse_text(basic_string_view<Char> str, size_t pos) {
+  for (size_t size = str.size(); pos != size; ++pos) {
+    if (str[pos] == '{' || str[pos] == '}') break;
+  }
+  return pos;
+}
+
+template <typename Args, size_t POS, int ID, typename S>
+constexpr auto compile_format_string(S format_str);
+
+template <typename Args, size_t POS, int ID, typename T, typename S>
+constexpr auto parse_tail(T head, S format_str) {
+  if constexpr (POS !=
+                basic_string_view<typename S::char_type>(format_str).size()) {
+    constexpr auto tail = compile_format_string<Args, POS, ID>(format_str);
+    if constexpr (std::is_same<remove_cvref_t<decltype(tail)>,
+                               unknown_format>())
+      return tail;
+    else
+      return make_concat(head, tail);
+  } else {
+    return head;
+  }
+}
+
+template <typename T, typename Char> struct parse_specs_result {
+  formatter<T, Char> fmt;
+  size_t end;
+  int next_arg_id;
+};
+
+constexpr int manual_indexing_id = -1;
+
+template <typename T, typename Char>
+constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,
+                                                  size_t pos, int next_arg_id) {
+  str.remove_prefix(pos);
+  auto ctx = compile_parse_context<Char>(str, max_value<int>(), nullptr, {},
+                                         next_arg_id);
+  auto f = formatter<T, Char>();
+  auto end = f.parse(ctx);
+  return {f, pos + fmt::detail::to_unsigned(end - str.data()),
+          next_arg_id == 0 ? manual_indexing_id : ctx.next_arg_id()};
+}
+
+template <typename Char> struct arg_id_handler {
+  arg_ref<Char> arg_id;
+
+  constexpr int operator()() {
+    FMT_ASSERT(false, "handler cannot be used with automatic indexing");
+    return 0;
+  }
+  constexpr int operator()(int id) {
+    arg_id = arg_ref<Char>(id);
+    return 0;
+  }
+  constexpr int operator()(basic_string_view<Char> id) {
+    arg_id = arg_ref<Char>(id);
+    return 0;
+  }
+
+  constexpr void on_error(const char* message) {
+    FMT_THROW(format_error(message));
+  }
+};
+
+template <typename Char> struct parse_arg_id_result {
+  arg_ref<Char> arg_id;
+  const Char* arg_id_end;
+};
+
+template <int ID, typename Char>
+constexpr auto parse_arg_id(const Char* begin, const Char* end) {
+  auto handler = arg_id_handler<Char>{arg_ref<Char>{}};
+  auto arg_id_end = parse_arg_id(begin, end, handler);
+  return parse_arg_id_result<Char>{handler.arg_id, arg_id_end};
+}
+
+template <typename T, typename Enable = void> struct field_type {
+  using type = remove_cvref_t<T>;
+};
+
+template <typename T>
+struct field_type<T, enable_if_t<detail::is_named_arg<T>::value>> {
+  using type = remove_cvref_t<decltype(T::value)>;
+};
+
+template <typename T, typename Args, size_t END_POS, int ARG_INDEX, int NEXT_ID,
+          typename S>
+constexpr auto parse_replacement_field_then_tail(S format_str) {
+  using char_type = typename S::char_type;
+  constexpr auto str = basic_string_view<char_type>(format_str);
+  constexpr char_type c = END_POS != str.size() ? str[END_POS] : char_type();
+  if constexpr (c == '}') {
+    return parse_tail<Args, END_POS + 1, NEXT_ID>(
+        field<char_type, typename field_type<T>::type, ARG_INDEX>(),
+        format_str);
+  } else if constexpr (c != ':') {
+    FMT_THROW(format_error("expected ':'"));
+  } else {
+    constexpr auto result = parse_specs<typename field_type<T>::type>(
+        str, END_POS + 1, NEXT_ID == manual_indexing_id ? 0 : NEXT_ID);
+    if constexpr (result.end >= str.size() || str[result.end] != '}') {
+      FMT_THROW(format_error("expected '}'"));
+      return 0;
+    } else {
+      return parse_tail<Args, result.end + 1, result.next_arg_id>(
+          spec_field<char_type, typename field_type<T>::type, ARG_INDEX>{
+              result.fmt},
+          format_str);
+    }
+  }
+}
+
+// Compiles a non-empty format string and returns the compiled representation
+// or unknown_format() on unrecognized input.
+template <typename Args, size_t POS, int ID, typename S>
+constexpr auto compile_format_string(S format_str) {
+  using char_type = typename S::char_type;
+  constexpr auto str = basic_string_view<char_type>(format_str);
+  if constexpr (str[POS] == '{') {
+    if constexpr (POS + 1 == str.size())
+      FMT_THROW(format_error("unmatched '{' in format string"));
+    if constexpr (str[POS + 1] == '{') {
+      return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+    } else if constexpr (str[POS + 1] == '}' || str[POS + 1] == ':') {
+      static_assert(ID != manual_indexing_id,
+                    "cannot switch from manual to automatic argument indexing");
+      constexpr auto next_id =
+          ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
+      return parse_replacement_field_then_tail<get_type<ID, Args>, Args,
+                                               POS + 1, ID, next_id>(
+          format_str);
+    } else {
+      constexpr auto arg_id_result =
+          parse_arg_id<ID>(str.data() + POS + 1, str.data() + str.size());
+      constexpr auto arg_id_end_pos = arg_id_result.arg_id_end - str.data();
+      constexpr char_type c =
+          arg_id_end_pos != str.size() ? str[arg_id_end_pos] : char_type();
+      static_assert(c == '}' || c == ':', "missing '}' in format string");
+      if constexpr (arg_id_result.arg_id.kind == arg_id_kind::index) {
+        static_assert(
+            ID == manual_indexing_id || ID == 0,
+            "cannot switch from automatic to manual argument indexing");
+        constexpr auto arg_index = arg_id_result.arg_id.val.index;
+        return parse_replacement_field_then_tail<get_type<arg_index, Args>,
+                                                 Args, arg_id_end_pos,
+                                                 arg_index, manual_indexing_id>(
+            format_str);
+      } else if constexpr (arg_id_result.arg_id.kind == arg_id_kind::name) {
+        constexpr auto arg_index =
+            get_arg_index_by_name(arg_id_result.arg_id.val.name, Args{});
+        if constexpr (arg_index != invalid_arg_index) {
+          constexpr auto next_id =
+              ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
+          return parse_replacement_field_then_tail<
+              decltype(get_type<arg_index, Args>::value), Args, arg_id_end_pos,
+              arg_index, next_id>(format_str);
+        } else {
+          if constexpr (c == '}') {
+            return parse_tail<Args, arg_id_end_pos + 1, ID>(
+                runtime_named_field<char_type>{arg_id_result.arg_id.val.name},
+                format_str);
+          } else if constexpr (c == ':') {
+            return unknown_format();  // no type info for specs parsing
+          }
+        }
+      }
+    }
+  } else if constexpr (str[POS] == '}') {
+    if constexpr (POS + 1 == str.size())
+      FMT_THROW(format_error("unmatched '}' in format string"));
+    return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+  } else {
+    constexpr auto end = parse_text(str, POS + 1);
+    if constexpr (end - POS > 1) {
+      return parse_tail<Args, end, ID>(make_text(str, POS, end - POS),
+                                       format_str);
+    } else {
+      return parse_tail<Args, end, ID>(code_unit<char_type>{str[POS]},
+                                       format_str);
+    }
+  }
+}
+
+template <typename... Args, typename S,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+constexpr auto compile(S format_str) {
+  constexpr auto str = basic_string_view<typename S::char_type>(format_str);
+  if constexpr (str.size() == 0) {
+    return detail::make_text(str, 0, 0);
+  } else {
+    constexpr auto result =
+        detail::compile_format_string<detail::type_list<Args...>, 0, 0>(
+            format_str);
+    return result;
+  }
+}
+#endif  // defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+}  // namespace detail
+
+FMT_MODULE_EXPORT_BEGIN
+
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+
+template <typename CompiledFormat, typename... Args,
+          typename Char = typename CompiledFormat::char_type,
+          FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
+FMT_INLINE std::basic_string<Char> format(const CompiledFormat& cf,
+                                          const Args&... args) {
+  auto s = std::basic_string<Char>();
+  cf.format(std::back_inserter(s), args...);
+  return s;
+}
+
+template <typename OutputIt, typename CompiledFormat, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
+constexpr FMT_INLINE OutputIt format_to(OutputIt out, const CompiledFormat& cf,
+                                        const Args&... args) {
+  return cf.format(out, args...);
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+FMT_INLINE std::basic_string<typename S::char_type> format(const S&,
+                                                           Args&&... args) {
+  if constexpr (std::is_same<typename S::char_type, char>::value) {
+    constexpr auto str = basic_string_view<typename S::char_type>(S());
+    if constexpr (str.size() == 2 && str[0] == '{' && str[1] == '}') {
+      const auto& first = detail::first(args...);
+      if constexpr (detail::is_named_arg<
+                        remove_cvref_t<decltype(first)>>::value) {
+        return fmt::to_string(first.value);
+      } else {
+        return fmt::to_string(first);
+      }
+    }
+  }
+  constexpr auto compiled = detail::compile<Args...>(S());
+  if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
+                             detail::unknown_format>()) {
+    return fmt::format(
+        static_cast<basic_string_view<typename S::char_type>>(S()),
+        std::forward<Args>(args)...);
+  } else {
+    return fmt::format(compiled, std::forward<Args>(args)...);
+  }
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+FMT_CONSTEXPR OutputIt format_to(OutputIt out, const S&, Args&&... args) {
+  constexpr auto compiled = detail::compile<Args...>(S());
+  if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
+                             detail::unknown_format>()) {
+    return fmt::format_to(
+        out, static_cast<basic_string_view<typename S::char_type>>(S()),
+        std::forward<Args>(args)...);
+  } else {
+    return fmt::format_to(out, compiled, std::forward<Args>(args)...);
+  }
+}
+#endif
+
+template <typename OutputIt, typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n,
+                                         const S& format_str, Args&&... args) {
+  auto it = fmt::format_to(detail::truncating_iterator<OutputIt>(out, n),
+                           format_str, std::forward<Args>(args)...);
+  return {it.base(), it.count()};
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+FMT_CONSTEXPR20 size_t formatted_size(const S& format_str,
+                                      const Args&... args) {
+  return fmt::format_to(detail::counting_iterator(), format_str, args...)
+      .count();
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(std::FILE* f, const S& format_str, const Args&... args) {
+  memory_buffer buffer;
+  fmt::format_to(std::back_inserter(buffer), format_str, args...);
+  detail::print(f, {buffer.data(), buffer.size()});
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(const S& format_str, const Args&... args) {
+  print(stdout, format_str, args...);
+}
+
+#if FMT_USE_NONTYPE_TEMPLATE_ARGS
+inline namespace literals {
+template <detail_exported::fixed_string Str> constexpr auto operator""_cf() {
+  using char_t = remove_cvref_t<decltype(Str.data[0])>;
+  return detail::udl_compiled_string<char_t, sizeof(Str.data) / sizeof(char_t),
+                                     Str>();
+}
+}  // namespace literals
+#endif
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_COMPILE_H_
@@ -0,0 +1,478 @@
+// Formatting library for C++ - optional OS-specific functionality
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_OS_H_
+#define FMT_OS_H_
+
+#include <cerrno>
+#include <cstddef>
+#include <cstdio>
+#include <system_error>  // std::system_error
+
+#if defined __APPLE__ || defined(__FreeBSD__)
+#  include <xlocale.h>  // for LC_NUMERIC_MASK on OS X
+#endif
+
+#include "format.h"
+
+#ifndef FMT_USE_FCNTL
+// UWP doesn't provide _pipe.
+#  if FMT_HAS_INCLUDE("winapifamily.h")
+#    include <winapifamily.h>
+#  endif
+#  if (FMT_HAS_INCLUDE(<fcntl.h>) || defined(__APPLE__) || \
+       defined(__linux__)) &&                              \
+      (!defined(WINAPI_FAMILY) ||                          \
+       (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
+#    include <fcntl.h>  // for O_RDONLY
+#    define FMT_USE_FCNTL 1
+#  else
+#    define FMT_USE_FCNTL 0
+#  endif
+#endif
+
+#ifndef FMT_POSIX
+#  if defined(_WIN32) && !defined(__MINGW32__)
+// Fix warnings about deprecated symbols.
+#    define FMT_POSIX(call) _##call
+#  else
+#    define FMT_POSIX(call) call
+#  endif
+#endif
+
+// Calls to system functions are wrapped in FMT_SYSTEM for testability.
+#ifdef FMT_SYSTEM
+#  define FMT_POSIX_CALL(call) FMT_SYSTEM(call)
+#else
+#  define FMT_SYSTEM(call) ::call
+#  ifdef _WIN32
+// Fix warnings about deprecated symbols.
+#    define FMT_POSIX_CALL(call) ::_##call
+#  else
+#    define FMT_POSIX_CALL(call) ::call
+#  endif
+#endif
+
+// Retries the expression while it evaluates to error_result and errno
+// equals to EINTR.
+#ifndef _WIN32
+#  define FMT_RETRY_VAL(result, expression, error_result) \
+    do {                                                  \
+      (result) = (expression);                            \
+    } while ((result) == (error_result) && errno == EINTR)
+#else
+#  define FMT_RETRY_VAL(result, expression, error_result) result = (expression)
+#endif
+
+#define FMT_RETRY(result, expression) FMT_RETRY_VAL(result, expression, -1)
+
+FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
+
+/**
+  \rst
+  A reference to a null-terminated string. It can be constructed from a C
+  string or ``std::string``.
+
+  You can use one of the following type aliases for common character types:
+
+  +---------------+-----------------------------+
+  | Type          | Definition                  |
+  +===============+=============================+
+  | cstring_view  | basic_cstring_view<char>    |
+  +---------------+-----------------------------+
+  | wcstring_view | basic_cstring_view<wchar_t> |
+  +---------------+-----------------------------+
+
+  This class is most useful as a parameter type to allow passing
+  different types of strings to a function, for example::
+
+    template <typename... Args>
+    std::string format(cstring_view format_str, const Args & ... args);
+
+    format("{}", 42);
+    format(std::string("{}"), 42);
+  \endrst
+ */
+template <typename Char> class basic_cstring_view {
+ private:
+  const Char* data_;
+
+ public:
+  /** Constructs a string reference object from a C string. */
+  basic_cstring_view(const Char* s) : data_(s) {}
+
+  /**
+    \rst
+    Constructs a string reference from an ``std::string`` object.
+    \endrst
+   */
+  basic_cstring_view(const std::basic_string<Char>& s) : data_(s.c_str()) {}
+
+  /** Returns the pointer to a C string. */
+  const Char* c_str() const { return data_; }
+};
+
+using cstring_view = basic_cstring_view<char>;
+using wcstring_view = basic_cstring_view<wchar_t>;
+
+template <typename Char> struct formatter<std::error_code, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  FMT_CONSTEXPR auto format(const std::error_code& ec, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    out = detail::write_bytes(out, ec.category().name(),
+                              basic_format_specs<Char>());
+    out = detail::write<Char>(out, Char(':'));
+    out = detail::write<Char>(out, ec.value());
+    return out;
+  }
+};
+
+#ifdef _WIN32
+FMT_API const std::error_category& system_category() noexcept;
+
+FMT_BEGIN_DETAIL_NAMESPACE
+// A converter from UTF-16 to UTF-8.
+// It is only provided for Windows since other systems support UTF-8 natively.
+class utf16_to_utf8 {
+ private:
+  memory_buffer buffer_;
+
+ public:
+  utf16_to_utf8() {}
+  FMT_API explicit utf16_to_utf8(basic_string_view<wchar_t> s);
+  operator string_view() const { return string_view(&buffer_[0], size()); }
+  size_t size() const { return buffer_.size() - 1; }
+  const char* c_str() const { return &buffer_[0]; }
+  std::string str() const { return std::string(&buffer_[0], size()); }
+
+  // Performs conversion returning a system error code instead of
+  // throwing exception on conversion error. This method may still throw
+  // in case of memory allocation error.
+  FMT_API int convert(basic_string_view<wchar_t> s);
+};
+
+FMT_API void format_windows_error(buffer<char>& out, int error_code,
+                                  const char* message) noexcept;
+FMT_END_DETAIL_NAMESPACE
+
+FMT_API std::system_error vwindows_error(int error_code, string_view format_str,
+                                         format_args args);
+
+/**
+ \rst
+ Constructs a :class:`std::system_error` object with the description
+ of the form
+
+ .. parsed-literal::
+   *<message>*: *<system-message>*
+
+ where *<message>* is the formatted message and *<system-message>* is the
+ system message corresponding to the error code.
+ *error_code* is a Windows error code as given by ``GetLastError``.
+ If *error_code* is not a valid error code such as -1, the system message
+ will look like "error -1".
+
+ **Example**::
+
+   // This throws a system_error with the description
+   //   cannot open file 'madeup': The system cannot find the file specified.
+   // or similar (system message may vary).
+   const char *filename = "madeup";
+   LPOFSTRUCT of = LPOFSTRUCT();
+   HFILE file = OpenFile(filename, &of, OF_READ);
+   if (file == HFILE_ERROR) {
+     throw fmt::windows_error(GetLastError(),
+                              "cannot open file '{}'", filename);
+   }
+ \endrst
+*/
+template <typename... Args>
+std::system_error windows_error(int error_code, string_view message,
+                                const Args&... args) {
+  return vwindows_error(error_code, message, fmt::make_format_args(args...));
+}
+
+// Reports a Windows error without throwing an exception.
+// Can be used to report errors from destructors.
+FMT_API void report_windows_error(int error_code, const char* message) noexcept;
+#else
+inline const std::error_category& system_category() noexcept {
+  return std::system_category();
+}
+#endif  // _WIN32
+
+// std::system is not available on some platforms such as iOS (#2248).
+#ifdef __OSX__
+template <typename S, typename... Args, typename Char = char_t<S>>
+void say(const S& format_str, Args&&... args) {
+  std::system(format("say \"{}\"", format(format_str, args...)).c_str());
+}
+#endif
+
+// A buffered file.
+class buffered_file {
+ private:
+  FILE* file_;
+
+  friend class file;
+
+  explicit buffered_file(FILE* f) : file_(f) {}
+
+ public:
+  buffered_file(const buffered_file&) = delete;
+  void operator=(const buffered_file&) = delete;
+
+  // Constructs a buffered_file object which doesn't represent any file.
+  buffered_file() noexcept : file_(nullptr) {}
+
+  // Destroys the object closing the file it represents if any.
+  FMT_API ~buffered_file() noexcept;
+
+ public:
+  buffered_file(buffered_file&& other) noexcept : file_(other.file_) {
+    other.file_ = nullptr;
+  }
+
+  buffered_file& operator=(buffered_file&& other) {
+    close();
+    file_ = other.file_;
+    other.file_ = nullptr;
+    return *this;
+  }
+
+  // Opens a file.
+  FMT_API buffered_file(cstring_view filename, cstring_view mode);
+
+  // Closes the file.
+  FMT_API void close();
+
+  // Returns the pointer to a FILE object representing this file.
+  FILE* get() const noexcept { return file_; }
+
+  FMT_API int descriptor() const;
+
+  void vprint(string_view format_str, format_args args) {
+    fmt::vprint(file_, format_str, args);
+  }
+
+  template <typename... Args>
+  inline void print(string_view format_str, const Args&... args) {
+    vprint(format_str, fmt::make_format_args(args...));
+  }
+};
+
+#if FMT_USE_FCNTL
+// A file. Closed file is represented by a file object with descriptor -1.
+// Methods that are not declared with noexcept may throw
+// fmt::system_error in case of failure. Note that some errors such as
+// closing the file multiple times will cause a crash on Windows rather
+// than an exception. You can get standard behavior by overriding the
+// invalid parameter handler with _set_invalid_parameter_handler.
+class FMT_API file {
+ private:
+  int fd_;  // File descriptor.
+
+  // Constructs a file object with a given descriptor.
+  explicit file(int fd) : fd_(fd) {}
+
+ public:
+  // Possible values for the oflag argument to the constructor.
+  enum {
+    RDONLY = FMT_POSIX(O_RDONLY),  // Open for reading only.
+    WRONLY = FMT_POSIX(O_WRONLY),  // Open for writing only.
+    RDWR = FMT_POSIX(O_RDWR),      // Open for reading and writing.
+    CREATE = FMT_POSIX(O_CREAT),   // Create if the file doesn't exist.
+    APPEND = FMT_POSIX(O_APPEND),  // Open in append mode.
+    TRUNC = FMT_POSIX(O_TRUNC)     // Truncate the content of the file.
+  };
+
+  // Constructs a file object which doesn't represent any file.
+  file() noexcept : fd_(-1) {}
+
+  // Opens a file and constructs a file object representing this file.
+  file(cstring_view path, int oflag);
+
+ public:
+  file(const file&) = delete;
+  void operator=(const file&) = delete;
+
+  file(file&& other) noexcept : fd_(other.fd_) { other.fd_ = -1; }
+
+  // Move assignment is not noexcept because close may throw.
+  file& operator=(file&& other) {
+    close();
+    fd_ = other.fd_;
+    other.fd_ = -1;
+    return *this;
+  }
+
+  // Destroys the object closing the file it represents if any.
+  ~file() noexcept;
+
+  // Returns the file descriptor.
+  int descriptor() const noexcept { return fd_; }
+
+  // Closes the file.
+  void close();
+
+  // Returns the file size. The size has signed type for consistency with
+  // stat::st_size.
+  long long size() const;
+
+  // Attempts to read count bytes from the file into the specified buffer.
+  size_t read(void* buffer, size_t count);
+
+  // Attempts to write count bytes from the specified buffer to the file.
+  size_t write(const void* buffer, size_t count);
+
+  // Duplicates a file descriptor with the dup function and returns
+  // the duplicate as a file object.
+  static file dup(int fd);
+
+  // Makes fd be the copy of this file descriptor, closing fd first if
+  // necessary.
+  void dup2(int fd);
+
+  // Makes fd be the copy of this file descriptor, closing fd first if
+  // necessary.
+  void dup2(int fd, std::error_code& ec) noexcept;
+
+  // Creates a pipe setting up read_end and write_end file objects for reading
+  // and writing respectively.
+  static void pipe(file& read_end, file& write_end);
+
+  // Creates a buffered_file object associated with this file and detaches
+  // this file object from the file.
+  buffered_file fdopen(const char* mode);
+};
+
+// Returns the memory page size.
+long getpagesize();
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+struct buffer_size {
+  buffer_size() = default;
+  size_t value = 0;
+  buffer_size operator=(size_t val) const {
+    auto bs = buffer_size();
+    bs.value = val;
+    return bs;
+  }
+};
+
+struct ostream_params {
+  int oflag = file::WRONLY | file::CREATE | file::TRUNC;
+  size_t buffer_size = BUFSIZ > 32768 ? BUFSIZ : 32768;
+
+  ostream_params() {}
+
+  template <typename... T>
+  ostream_params(T... params, int new_oflag) : ostream_params(params...) {
+    oflag = new_oflag;
+  }
+
+  template <typename... T>
+  ostream_params(T... params, detail::buffer_size bs)
+      : ostream_params(params...) {
+    this->buffer_size = bs.value;
+  }
+
+// Intel has a bug that results in failure to deduce a constructor
+// for empty parameter packs.
+#  if defined(__INTEL_COMPILER) && __INTEL_COMPILER < 2000
+  ostream_params(int new_oflag) : oflag(new_oflag) {}
+  ostream_params(detail::buffer_size bs) : buffer_size(bs.value) {}
+#  endif
+};
+
+FMT_END_DETAIL_NAMESPACE
+
+// Added {} below to work around default constructor error known to
+// occur in Xcode versions 7.2.1 and 8.2.1.
+constexpr detail::buffer_size buffer_size{};
+
+/** A fast output stream which is not thread-safe. */
+class FMT_API ostream final : private detail::buffer<char> {
+ private:
+  file file_;
+
+  void grow(size_t) override;
+
+  ostream(cstring_view path, const detail::ostream_params& params)
+      : file_(path, params.oflag) {
+    set(new char[params.buffer_size], params.buffer_size);
+  }
+
+ public:
+  ostream(ostream&& other)
+      : detail::buffer<char>(other.data(), other.size(), other.capacity()),
+        file_(std::move(other.file_)) {
+    other.clear();
+    other.set(nullptr, 0);
+  }
+  ~ostream() {
+    flush();
+    delete[] data();
+  }
+
+  void flush() {
+    if (size() == 0) return;
+    file_.write(data(), size());
+    clear();
+  }
+
+  template <typename... T>
+  friend ostream output_file(cstring_view path, T... params);
+
+  void close() {
+    flush();
+    file_.close();
+  }
+
+  /**
+    Formats ``args`` according to specifications in ``fmt`` and writes the
+    output to the file.
+   */
+  template <typename... T> void print(format_string<T...> fmt, T&&... args) {
+    vformat_to(detail::buffer_appender<char>(*this), fmt,
+               fmt::make_format_args(args...));
+  }
+};
+
+/**
+  \rst
+  Opens a file for writing. Supported parameters passed in *params*:
+
+  * ``<integer>``: Flags passed to `open
+    <https://pubs.opengroup.org/onlinepubs/007904875/functions/open.html>`_
+    (``file::WRONLY | file::CREATE | file::TRUNC`` by default)
+  * ``buffer_size=<integer>``: Output buffer size
+
+  **Example**::
+
+    auto out = fmt::output_file("guide.txt");
+    out.print("Don't {}", "Panic");
+  \endrst
+ */
+template <typename... T>
+inline ostream output_file(cstring_view path, T... params) {
+  return {path, detail::ostream_params(params...)};
+}
+#endif  // FMT_USE_FCNTL
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_OS_H_
@@ -0,0 +1,237 @@
+// Formatting library for C++ - std::ostream support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_OSTREAM_H_
+#define FMT_OSTREAM_H_
+
+#include <fstream>
+#include <ostream>
+#if defined(_WIN32) && defined(__GLIBCXX__)
+#  include <ext/stdio_filebuf.h>
+#  include <ext/stdio_sync_filebuf.h>
+#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
+#  include <__std_stream>
+#endif
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+
+template <typename OutputIt, typename Char> class basic_printf_context;
+
+namespace detail {
+
+// Checks if T has a user-defined operator<<.
+template <typename T, typename Char, typename Enable = void>
+class is_streamable {
+ private:
+  template <typename U>
+  static auto test(int)
+      -> bool_constant<sizeof(std::declval<std::basic_ostream<Char>&>()
+                              << std::declval<U>()) != 0>;
+
+  template <typename> static auto test(...) -> std::false_type;
+
+  using result = decltype(test<T>(0));
+
+ public:
+  is_streamable() = default;
+
+  static const bool value = result::value;
+};
+
+// Formatting of built-in types and arrays is intentionally disabled because
+// it's handled by standard (non-ostream) formatters.
+template <typename T, typename Char>
+struct is_streamable<
+    T, Char,
+    enable_if_t<
+        std::is_arithmetic<T>::value || std::is_array<T>::value ||
+        std::is_pointer<T>::value || std::is_same<T, char8_type>::value ||
+        std::is_convertible<T, fmt::basic_string_view<Char>>::value ||
+        std::is_same<T, std_string_view<Char>>::value ||
+        (std::is_convertible<T, int>::value && !std::is_enum<T>::value)>>
+    : std::false_type {};
+
+// Generate a unique explicit instantion in every translation unit using a tag
+// type in an anonymous namespace.
+namespace {
+struct file_access_tag {};
+}  // namespace
+template <class Tag, class BufType, FILE* BufType::*FileMemberPtr>
+class file_access {
+  friend auto get_file(BufType& obj) -> FILE* { return obj.*FileMemberPtr; }
+};
+
+#if FMT_MSC_VERSION
+template class file_access<file_access_tag, std::filebuf,
+                           &std::filebuf::_Myfile>;
+auto get_file(std::filebuf&) -> FILE*;
+#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
+template class file_access<file_access_tag, std::__stdoutbuf<char>,
+                           &std::__stdoutbuf<char>::__file_>;
+auto get_file(std::__stdoutbuf<char>&) -> FILE*;
+#endif
+
+inline bool write_ostream_unicode(std::ostream& os, fmt::string_view data) {
+#if FMT_MSC_VERSION
+  if (auto* buf = dynamic_cast<std::filebuf*>(os.rdbuf()))
+    if (FILE* f = get_file(*buf)) return write_console(f, data);
+#elif defined(_WIN32) && defined(__GLIBCXX__)
+  auto* rdbuf = os.rdbuf();
+  FILE* c_file;
+  if (auto* fbuf = dynamic_cast<__gnu_cxx::stdio_sync_filebuf<char>*>(rdbuf))
+    c_file = fbuf->file();
+  else if (auto* fbuf = dynamic_cast<__gnu_cxx::stdio_filebuf<char>*>(rdbuf))
+    c_file = fbuf->file();
+  else
+    return false;
+  if (c_file) return write_console(c_file, data);
+#elif defined(_WIN32) && defined(_LIBCPP_VERSION)
+  if (auto* buf = dynamic_cast<std::__stdoutbuf<char>*>(os.rdbuf()))
+    if (FILE* f = get_file(*buf)) return write_console(f, data);
+#else
+  ignore_unused(os, data);
+#endif
+  return false;
+}
+inline bool write_ostream_unicode(std::wostream&,
+                                  fmt::basic_string_view<wchar_t>) {
+  return false;
+}
+
+// Write the content of buf to os.
+// It is a separate function rather than a part of vprint to simplify testing.
+template <typename Char>
+void write_buffer(std::basic_ostream<Char>& os, buffer<Char>& buf) {
+  const Char* buf_data = buf.data();
+  using unsigned_streamsize = std::make_unsigned<std::streamsize>::type;
+  unsigned_streamsize size = buf.size();
+  unsigned_streamsize max_size = to_unsigned(max_value<std::streamsize>());
+  do {
+    unsigned_streamsize n = size <= max_size ? size : max_size;
+    os.write(buf_data, static_cast<std::streamsize>(n));
+    buf_data += n;
+    size -= n;
+  } while (size != 0);
+}
+
+template <typename Char, typename T>
+void format_value(buffer<Char>& buf, const T& value,
+                  locale_ref loc = locale_ref()) {
+  auto&& format_buf = formatbuf<std::basic_streambuf<Char>>(buf);
+  auto&& output = std::basic_ostream<Char>(&format_buf);
+#if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
+  if (loc) output.imbue(loc.get<std::locale>());
+#endif
+  output << value;
+  output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
+}
+
+template <typename T> struct streamed_view { const T& value; };
+
+}  // namespace detail
+
+// Formats an object of type T that has an overloaded ostream operator<<.
+template <typename Char>
+struct basic_ostream_formatter : formatter<basic_string_view<Char>, Char> {
+  void set_debug_format() = delete;
+
+  template <typename T, typename OutputIt>
+  auto format(const T& value, basic_format_context<OutputIt, Char>& ctx) const
+      -> OutputIt {
+    auto buffer = basic_memory_buffer<Char>();
+    format_value(buffer, value, ctx.locale());
+    return formatter<basic_string_view<Char>, Char>::format(
+        {buffer.data(), buffer.size()}, ctx);
+  }
+};
+
+using ostream_formatter = basic_ostream_formatter<char>;
+
+template <typename T, typename Char>
+struct formatter<detail::streamed_view<T>, Char>
+    : basic_ostream_formatter<Char> {
+  template <typename OutputIt>
+  auto format(detail::streamed_view<T> view,
+              basic_format_context<OutputIt, Char>& ctx) const -> OutputIt {
+    return basic_ostream_formatter<Char>::format(view.value, ctx);
+  }
+};
+
+/**
+  \rst
+  Returns a view that formats `value` via an ostream ``operator<<``.
+
+  **Example**::
+
+    fmt::print("Current thread id: {}\n",
+               fmt::streamed(std::this_thread::get_id()));
+  \endrst
+ */
+template <typename T>
+auto streamed(const T& value) -> detail::streamed_view<T> {
+  return {value};
+}
+
+namespace detail {
+
+// Formats an object of type T that has an overloaded ostream operator<<.
+template <typename T, typename Char>
+struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
+    : basic_ostream_formatter<Char> {
+  using basic_ostream_formatter<Char>::format;
+};
+
+inline void vprint_directly(std::ostream& os, string_view format_str,
+                            format_args args) {
+  auto buffer = memory_buffer();
+  detail::vformat_to(buffer, format_str, args);
+  detail::write_buffer(os, buffer);
+}
+
+}  // namespace detail
+
+FMT_MODULE_EXPORT template <typename Char>
+void vprint(std::basic_ostream<Char>& os,
+            basic_string_view<type_identity_t<Char>> format_str,
+            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  auto buffer = basic_memory_buffer<Char>();
+  detail::vformat_to(buffer, format_str, args);
+  if (detail::write_ostream_unicode(os, {buffer.data(), buffer.size()})) return;
+  detail::write_buffer(os, buffer);
+}
+
+/**
+  \rst
+  Prints formatted data to the stream *os*.
+
+  **Example**::
+
+    fmt::print(cerr, "Don't {}!", "panic");
+  \endrst
+ */
+FMT_MODULE_EXPORT template <typename... T>
+void print(std::ostream& os, format_string<T...> fmt, T&&... args) {
+  const auto& vargs = fmt::make_format_args(args...);
+  if (detail::is_utf8())
+    vprint(os, fmt, vargs);
+  else
+    detail::vprint_directly(os, fmt, vargs);
+}
+
+FMT_MODULE_EXPORT
+template <typename... Args>
+void print(std::wostream& os,
+           basic_format_string<wchar_t, type_identity_t<Args>...> fmt,
+           Args&&... args) {
+  vprint(os, fmt, fmt::make_format_args<buffer_context<wchar_t>>(args...));
+}
+
+FMT_END_NAMESPACE
+
+#endif  // FMT_OSTREAM_H_
@@ -0,0 +1,640 @@
+// Formatting library for C++ - legacy printf implementation
+//
+// Copyright (c) 2012 - 2016, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_PRINTF_H_
+#define FMT_PRINTF_H_
+
+#include <algorithm>  // std::max
+#include <limits>     // std::numeric_limits
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
+
+template <typename T> struct printf_formatter { printf_formatter() = delete; };
+
+template <typename Char>
+class basic_printf_parse_context : public basic_format_parse_context<Char> {
+  using basic_format_parse_context<Char>::basic_format_parse_context;
+};
+
+template <typename OutputIt, typename Char> class basic_printf_context {
+ private:
+  OutputIt out_;
+  basic_format_args<basic_printf_context> args_;
+
+ public:
+  using char_type = Char;
+  using format_arg = basic_format_arg<basic_printf_context>;
+  using parse_context_type = basic_printf_parse_context<Char>;
+  template <typename T> using formatter_type = printf_formatter<T>;
+
+  /**
+    \rst
+    Constructs a ``printf_context`` object. References to the arguments are
+    stored in the context object so make sure they have appropriate lifetimes.
+    \endrst
+   */
+  basic_printf_context(OutputIt out,
+                       basic_format_args<basic_printf_context> args)
+      : out_(out), args_(args) {}
+
+  OutputIt out() { return out_; }
+  void advance_to(OutputIt it) { out_ = it; }
+
+  detail::locale_ref locale() { return {}; }
+
+  format_arg arg(int id) const { return args_.get(id); }
+
+  FMT_CONSTEXPR void on_error(const char* message) {
+    detail::error_handler().on_error(message);
+  }
+};
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+// Checks if a value fits in int - used to avoid warnings about comparing
+// signed and unsigned integers.
+template <bool IsSigned> struct int_checker {
+  template <typename T> static bool fits_in_int(T value) {
+    unsigned max = max_value<int>();
+    return value <= max;
+  }
+  static bool fits_in_int(bool) { return true; }
+};
+
+template <> struct int_checker<true> {
+  template <typename T> static bool fits_in_int(T value) {
+    return value >= (std::numeric_limits<int>::min)() &&
+           value <= max_value<int>();
+  }
+  static bool fits_in_int(int) { return true; }
+};
+
+class printf_precision_handler {
+ public:
+  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  int operator()(T value) {
+    if (!int_checker<std::numeric_limits<T>::is_signed>::fits_in_int(value))
+      FMT_THROW(format_error("number is too big"));
+    return (std::max)(static_cast<int>(value), 0);
+  }
+
+  template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+  int operator()(T) {
+    FMT_THROW(format_error("precision is not integer"));
+    return 0;
+  }
+};
+
+// An argument visitor that returns true iff arg is a zero integer.
+class is_zero_int {
+ public:
+  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  bool operator()(T value) {
+    return value == 0;
+  }
+
+  template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+  bool operator()(T) {
+    return false;
+  }
+};
+
+template <typename T> struct make_unsigned_or_bool : std::make_unsigned<T> {};
+
+template <> struct make_unsigned_or_bool<bool> { using type = bool; };
+
+template <typename T, typename Context> class arg_converter {
+ private:
+  using char_type = typename Context::char_type;
+
+  basic_format_arg<Context>& arg_;
+  char_type type_;
+
+ public:
+  arg_converter(basic_format_arg<Context>& arg, char_type type)
+      : arg_(arg), type_(type) {}
+
+  void operator()(bool value) {
+    if (type_ != 's') operator()<bool>(value);
+  }
+
+  template <typename U, FMT_ENABLE_IF(std::is_integral<U>::value)>
+  void operator()(U value) {
+    bool is_signed = type_ == 'd' || type_ == 'i';
+    using target_type = conditional_t<std::is_same<T, void>::value, U, T>;
+    if (const_check(sizeof(target_type) <= sizeof(int))) {
+      // Extra casts are used to silence warnings.
+      if (is_signed) {
+        arg_ = detail::make_arg<Context>(
+            static_cast<int>(static_cast<target_type>(value)));
+      } else {
+        using unsigned_type = typename make_unsigned_or_bool<target_type>::type;
+        arg_ = detail::make_arg<Context>(
+            static_cast<unsigned>(static_cast<unsigned_type>(value)));
+      }
+    } else {
+      if (is_signed) {
+        // glibc's printf doesn't sign extend arguments of smaller types:
+        //   std::printf("%lld", -42);  // prints "4294967254"
+        // but we don't have to do the same because it's a UB.
+        arg_ = detail::make_arg<Context>(static_cast<long long>(value));
+      } else {
+        arg_ = detail::make_arg<Context>(
+            static_cast<typename make_unsigned_or_bool<U>::type>(value));
+      }
+    }
+  }
+
+  template <typename U, FMT_ENABLE_IF(!std::is_integral<U>::value)>
+  void operator()(U) {}  // No conversion needed for non-integral types.
+};
+
+// Converts an integer argument to T for printf, if T is an integral type.
+// If T is void, the argument is converted to corresponding signed or unsigned
+// type depending on the type specifier: 'd' and 'i' - signed, other -
+// unsigned).
+template <typename T, typename Context, typename Char>
+void convert_arg(basic_format_arg<Context>& arg, Char type) {
+  visit_format_arg(arg_converter<T, Context>(arg, type), arg);
+}
+
+// Converts an integer argument to char for printf.
+template <typename Context> class char_converter {
+ private:
+  basic_format_arg<Context>& arg_;
+
+ public:
+  explicit char_converter(basic_format_arg<Context>& arg) : arg_(arg) {}
+
+  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  void operator()(T value) {
+    arg_ = detail::make_arg<Context>(
+        static_cast<typename Context::char_type>(value));
+  }
+
+  template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+  void operator()(T) {}  // No conversion needed for non-integral types.
+};
+
+// An argument visitor that return a pointer to a C string if argument is a
+// string or null otherwise.
+template <typename Char> struct get_cstring {
+  template <typename T> const Char* operator()(T) { return nullptr; }
+  const Char* operator()(const Char* s) { return s; }
+};
+
+// Checks if an argument is a valid printf width specifier and sets
+// left alignment if it is negative.
+template <typename Char> class printf_width_handler {
+ private:
+  using format_specs = basic_format_specs<Char>;
+
+  format_specs& specs_;
+
+ public:
+  explicit printf_width_handler(format_specs& specs) : specs_(specs) {}
+
+  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  unsigned operator()(T value) {
+    auto width = static_cast<uint32_or_64_or_128_t<T>>(value);
+    if (detail::is_negative(value)) {
+      specs_.align = align::left;
+      width = 0 - width;
+    }
+    unsigned int_max = max_value<int>();
+    if (width > int_max) FMT_THROW(format_error("number is too big"));
+    return static_cast<unsigned>(width);
+  }
+
+  template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
+  unsigned operator()(T) {
+    FMT_THROW(format_error("width is not integer"));
+    return 0;
+  }
+};
+
+// The ``printf`` argument formatter.
+template <typename OutputIt, typename Char>
+class printf_arg_formatter : public arg_formatter<Char> {
+ private:
+  using base = arg_formatter<Char>;
+  using context_type = basic_printf_context<OutputIt, Char>;
+  using format_specs = basic_format_specs<Char>;
+
+  context_type& context_;
+
+  OutputIt write_null_pointer(bool is_string = false) {
+    auto s = this->specs;
+    s.type = presentation_type::none;
+    return write_bytes(this->out, is_string ? "(null)" : "(nil)", s);
+  }
+
+ public:
+  printf_arg_formatter(OutputIt iter, format_specs& s, context_type& ctx)
+      : base{iter, s, locale_ref()}, context_(ctx) {}
+
+  OutputIt operator()(monostate value) { return base::operator()(value); }
+
+  template <typename T, FMT_ENABLE_IF(detail::is_integral<T>::value)>
+  OutputIt operator()(T value) {
+    // MSVC2013 fails to compile separate overloads for bool and Char so use
+    // std::is_same instead.
+    if (std::is_same<T, Char>::value) {
+      format_specs fmt_specs = this->specs;
+      if (fmt_specs.type != presentation_type::none &&
+          fmt_specs.type != presentation_type::chr) {
+        return (*this)(static_cast<int>(value));
+      }
+      fmt_specs.sign = sign::none;
+      fmt_specs.alt = false;
+      fmt_specs.fill[0] = ' ';  // Ignore '0' flag for char types.
+      // align::numeric needs to be overwritten here since the '0' flag is
+      // ignored for non-numeric types
+      if (fmt_specs.align == align::none || fmt_specs.align == align::numeric)
+        fmt_specs.align = align::right;
+      return write<Char>(this->out, static_cast<Char>(value), fmt_specs);
+    }
+    return base::operator()(value);
+  }
+
+  template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
+  OutputIt operator()(T value) {
+    return base::operator()(value);
+  }
+
+  /** Formats a null-terminated C string. */
+  OutputIt operator()(const char* value) {
+    if (value) return base::operator()(value);
+    return write_null_pointer(this->specs.type != presentation_type::pointer);
+  }
+
+  /** Formats a null-terminated wide C string. */
+  OutputIt operator()(const wchar_t* value) {
+    if (value) return base::operator()(value);
+    return write_null_pointer(this->specs.type != presentation_type::pointer);
+  }
+
+  OutputIt operator()(basic_string_view<Char> value) {
+    return base::operator()(value);
+  }
+
+  /** Formats a pointer. */
+  OutputIt operator()(const void* value) {
+    return value ? base::operator()(value) : write_null_pointer();
+  }
+
+  /** Formats an argument of a custom (user-defined) type. */
+  OutputIt operator()(typename basic_format_arg<context_type>::handle handle) {
+    auto parse_ctx =
+        basic_printf_parse_context<Char>(basic_string_view<Char>());
+    handle.format(parse_ctx, context_);
+    return this->out;
+  }
+};
+
+template <typename Char>
+void parse_flags(basic_format_specs<Char>& specs, const Char*& it,
+                 const Char* end) {
+  for (; it != end; ++it) {
+    switch (*it) {
+    case '-':
+      specs.align = align::left;
+      break;
+    case '+':
+      specs.sign = sign::plus;
+      break;
+    case '0':
+      specs.fill[0] = '0';
+      break;
+    case ' ':
+      if (specs.sign != sign::plus) {
+        specs.sign = sign::space;
+      }
+      break;
+    case '#':
+      specs.alt = true;
+      break;
+    default:
+      return;
+    }
+  }
+}
+
+template <typename Char, typename GetArg>
+int parse_header(const Char*& it, const Char* end,
+                 basic_format_specs<Char>& specs, GetArg get_arg) {
+  int arg_index = -1;
+  Char c = *it;
+  if (c >= '0' && c <= '9') {
+    // Parse an argument index (if followed by '$') or a width possibly
+    // preceded with '0' flag(s).
+    int value = parse_nonnegative_int(it, end, -1);
+    if (it != end && *it == '$') {  // value is an argument index
+      ++it;
+      arg_index = value != -1 ? value : max_value<int>();
+    } else {
+      if (c == '0') specs.fill[0] = '0';
+      if (value != 0) {
+        // Nonzero value means that we parsed width and don't need to
+        // parse it or flags again, so return now.
+        if (value == -1) FMT_THROW(format_error("number is too big"));
+        specs.width = value;
+        return arg_index;
+      }
+    }
+  }
+  parse_flags(specs, it, end);
+  // Parse width.
+  if (it != end) {
+    if (*it >= '0' && *it <= '9') {
+      specs.width = parse_nonnegative_int(it, end, -1);
+      if (specs.width == -1) FMT_THROW(format_error("number is too big"));
+    } else if (*it == '*') {
+      ++it;
+      specs.width = static_cast<int>(visit_format_arg(
+          detail::printf_width_handler<Char>(specs), get_arg(-1)));
+    }
+  }
+  return arg_index;
+}
+
+template <typename Char, typename Context>
+void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
+             basic_format_args<Context> args) {
+  using OutputIt = buffer_appender<Char>;
+  auto out = OutputIt(buf);
+  auto context = basic_printf_context<OutputIt, Char>(out, args);
+  auto parse_ctx = basic_printf_parse_context<Char>(format);
+
+  // Returns the argument with specified index or, if arg_index is -1, the next
+  // argument.
+  auto get_arg = [&](int arg_index) {
+    if (arg_index < 0)
+      arg_index = parse_ctx.next_arg_id();
+    else
+      parse_ctx.check_arg_id(--arg_index);
+    return detail::get_arg(context, arg_index);
+  };
+
+  const Char* start = parse_ctx.begin();
+  const Char* end = parse_ctx.end();
+  auto it = start;
+  while (it != end) {
+    if (!detail::find<false, Char>(it, end, '%', it)) {
+      it = end;  // detail::find leaves it == nullptr if it doesn't find '%'
+      break;
+    }
+    Char c = *it++;
+    if (it != end && *it == c) {
+      out = detail::write(
+          out, basic_string_view<Char>(start, detail::to_unsigned(it - start)));
+      start = ++it;
+      continue;
+    }
+    out = detail::write(out, basic_string_view<Char>(
+                                 start, detail::to_unsigned(it - 1 - start)));
+
+    basic_format_specs<Char> specs;
+    specs.align = align::right;
+
+    // Parse argument index, flags and width.
+    int arg_index = parse_header(it, end, specs, get_arg);
+    if (arg_index == 0) parse_ctx.on_error("argument not found");
+
+    // Parse precision.
+    if (it != end && *it == '.') {
+      ++it;
+      c = it != end ? *it : 0;
+      if ('0' <= c && c <= '9') {
+        specs.precision = parse_nonnegative_int(it, end, 0);
+      } else if (c == '*') {
+        ++it;
+        specs.precision = static_cast<int>(
+            visit_format_arg(detail::printf_precision_handler(), get_arg(-1)));
+      } else {
+        specs.precision = 0;
+      }
+    }
+
+    auto arg = get_arg(arg_index);
+    // For d, i, o, u, x, and X conversion specifiers, if a precision is
+    // specified, the '0' flag is ignored
+    if (specs.precision >= 0 && arg.is_integral())
+      specs.fill[0] =
+          ' ';  // Ignore '0' flag for non-numeric types or if '-' present.
+    if (specs.precision >= 0 && arg.type() == detail::type::cstring_type) {
+      auto str = visit_format_arg(detail::get_cstring<Char>(), arg);
+      auto str_end = str + specs.precision;
+      auto nul = std::find(str, str_end, Char());
+      arg = detail::make_arg<basic_printf_context<OutputIt, Char>>(
+          basic_string_view<Char>(
+              str, detail::to_unsigned(nul != str_end ? nul - str
+                                                      : specs.precision)));
+    }
+    if (specs.alt && visit_format_arg(detail::is_zero_int(), arg))
+      specs.alt = false;
+    if (specs.fill[0] == '0') {
+      if (arg.is_arithmetic() && specs.align != align::left)
+        specs.align = align::numeric;
+      else
+        specs.fill[0] = ' ';  // Ignore '0' flag for non-numeric types or if '-'
+                              // flag is also present.
+    }
+
+    // Parse length and convert the argument to the required type.
+    c = it != end ? *it++ : 0;
+    Char t = it != end ? *it : 0;
+    using detail::convert_arg;
+    switch (c) {
+    case 'h':
+      if (t == 'h') {
+        ++it;
+        t = it != end ? *it : 0;
+        convert_arg<signed char>(arg, t);
+      } else {
+        convert_arg<short>(arg, t);
+      }
+      break;
+    case 'l':
+      if (t == 'l') {
+        ++it;
+        t = it != end ? *it : 0;
+        convert_arg<long long>(arg, t);
+      } else {
+        convert_arg<long>(arg, t);
+      }
+      break;
+    case 'j':
+      convert_arg<intmax_t>(arg, t);
+      break;
+    case 'z':
+      convert_arg<size_t>(arg, t);
+      break;
+    case 't':
+      convert_arg<std::ptrdiff_t>(arg, t);
+      break;
+    case 'L':
+      // printf produces garbage when 'L' is omitted for long double, no
+      // need to do the same.
+      break;
+    default:
+      --it;
+      convert_arg<void>(arg, c);
+    }
+
+    // Parse type.
+    if (it == end) FMT_THROW(format_error("invalid format string"));
+    char type = static_cast<char>(*it++);
+    if (arg.is_integral()) {
+      // Normalize type.
+      switch (type) {
+      case 'i':
+      case 'u':
+        type = 'd';
+        break;
+      case 'c':
+        visit_format_arg(
+            detail::char_converter<basic_printf_context<OutputIt, Char>>(arg),
+            arg);
+        break;
+      }
+    }
+    specs.type = parse_presentation_type(type);
+    if (specs.type == presentation_type::none)
+      parse_ctx.on_error("invalid type specifier");
+
+    start = it;
+
+    // Format argument.
+    out = visit_format_arg(
+        detail::printf_arg_formatter<OutputIt, Char>(out, specs, context), arg);
+  }
+  detail::write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
+}
+FMT_END_DETAIL_NAMESPACE
+
+template <typename Char>
+using basic_printf_context_t =
+    basic_printf_context<detail::buffer_appender<Char>, Char>;
+
+using printf_context = basic_printf_context_t<char>;
+using wprintf_context = basic_printf_context_t<wchar_t>;
+
+using printf_args = basic_format_args<printf_context>;
+using wprintf_args = basic_format_args<wprintf_context>;
+
+/**
+  \rst
+  Constructs an `~fmt::format_arg_store` object that contains references to
+  arguments and can be implicitly converted to `~fmt::printf_args`.
+  \endrst
+ */
+template <typename... T>
+inline auto make_printf_args(const T&... args)
+    -> format_arg_store<printf_context, T...> {
+  return {args...};
+}
+
+/**
+  \rst
+  Constructs an `~fmt::format_arg_store` object that contains references to
+  arguments and can be implicitly converted to `~fmt::wprintf_args`.
+  \endrst
+ */
+template <typename... T>
+inline auto make_wprintf_args(const T&... args)
+    -> format_arg_store<wprintf_context, T...> {
+  return {args...};
+}
+
+template <typename S, typename Char = char_t<S>>
+inline auto vsprintf(
+    const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  basic_memory_buffer<Char> buffer;
+  vprintf(buffer, detail::to_string_view(fmt), args);
+  return to_string(buffer);
+}
+
+/**
+  \rst
+  Formats arguments and returns the result as a string.
+
+  **Example**::
+
+    std::string message = fmt::sprintf("The answer is %d", 42);
+  \endrst
+*/
+template <typename S, typename... T,
+          typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
+inline auto sprintf(const S& fmt, const T&... args) -> std::basic_string<Char> {
+  using context = basic_printf_context_t<Char>;
+  return vsprintf(detail::to_string_view(fmt),
+                  fmt::make_format_args<context>(args...));
+}
+
+template <typename S, typename Char = char_t<S>>
+inline auto vfprintf(
+    std::FILE* f, const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
+  basic_memory_buffer<Char> buffer;
+  vprintf(buffer, detail::to_string_view(fmt), args);
+  size_t size = buffer.size();
+  return std::fwrite(buffer.data(), sizeof(Char), size, f) < size
+             ? -1
+             : static_cast<int>(size);
+}
+
+/**
+  \rst
+  Prints formatted data to the file *f*.
+
+  **Example**::
+
+    fmt::fprintf(stderr, "Don't %s!", "panic");
+  \endrst
+ */
+template <typename S, typename... T, typename Char = char_t<S>>
+inline auto fprintf(std::FILE* f, const S& fmt, const T&... args) -> int {
+  using context = basic_printf_context_t<Char>;
+  return vfprintf(f, detail::to_string_view(fmt),
+                  fmt::make_format_args<context>(args...));
+}
+
+template <typename S, typename Char = char_t<S>>
+inline auto vprintf(
+    const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
+  return vfprintf(stdout, detail::to_string_view(fmt), args);
+}
+
+/**
+  \rst
+  Prints formatted data to ``stdout``.
+
+  **Example**::
+
+    fmt::printf("Elapsed time: %.2f seconds", 1.23);
+  \endrst
+ */
+template <typename S, typename... T, FMT_ENABLE_IF(detail::is_string<S>::value)>
+inline auto printf(const S& fmt, const T&... args) -> int {
+  return vprintf(
+      detail::to_string_view(fmt),
+      fmt::make_format_args<basic_printf_context_t<char_t<S>>>(args...));
+}
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_PRINTF_H_
@@ -0,0 +1,722 @@
+// Formatting library for C++ - experimental range support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+//
+// Copyright (c) 2018 - present, Remotion (Igor Schulz)
+// All Rights Reserved
+// {fmt} support for ranges, containers and types tuple interface.
+
+#ifndef FMT_RANGES_H_
+#define FMT_RANGES_H_
+
+#include <initializer_list>
+#include <tuple>
+#include <type_traits>
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+
+namespace detail {
+
+template <typename RangeT, typename OutputIterator>
+OutputIterator copy(const RangeT& range, OutputIterator out) {
+  for (auto it = range.begin(), end = range.end(); it != end; ++it)
+    *out++ = *it;
+  return out;
+}
+
+template <typename OutputIterator>
+OutputIterator copy(const char* str, OutputIterator out) {
+  while (*str) *out++ = *str++;
+  return out;
+}
+
+template <typename OutputIterator>
+OutputIterator copy(char ch, OutputIterator out) {
+  *out++ = ch;
+  return out;
+}
+
+template <typename OutputIterator>
+OutputIterator copy(wchar_t ch, OutputIterator out) {
+  *out++ = ch;
+  return out;
+}
+
+// Returns true if T has a std::string-like interface, like std::string_view.
+template <typename T> class is_std_string_like {
+  template <typename U>
+  static auto check(U* p)
+      -> decltype((void)p->find('a'), p->length(), (void)p->data(), int());
+  template <typename> static void check(...);
+
+ public:
+  static constexpr const bool value =
+      is_string<T>::value ||
+      std::is_convertible<T, std_string_view<char>>::value ||
+      !std::is_void<decltype(check<T>(nullptr))>::value;
+};
+
+template <typename Char>
+struct is_std_string_like<fmt::basic_string_view<Char>> : std::true_type {};
+
+template <typename T> class is_map {
+  template <typename U> static auto check(U*) -> typename U::mapped_type;
+  template <typename> static void check(...);
+
+ public:
+#ifdef FMT_FORMAT_MAP_AS_LIST
+  static constexpr const bool value = false;
+#else
+  static constexpr const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value;
+#endif
+};
+
+template <typename T> class is_set {
+  template <typename U> static auto check(U*) -> typename U::key_type;
+  template <typename> static void check(...);
+
+ public:
+#ifdef FMT_FORMAT_SET_AS_LIST
+  static constexpr const bool value = false;
+#else
+  static constexpr const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value && !is_map<T>::value;
+#endif
+};
+
+template <typename... Ts> struct conditional_helper {};
+
+template <typename T, typename _ = void> struct is_range_ : std::false_type {};
+
+#if !FMT_MSC_VERSION || FMT_MSC_VERSION > 1800
+
+#  define FMT_DECLTYPE_RETURN(val)  \
+    ->decltype(val) { return val; } \
+    static_assert(                  \
+        true, "")  // This makes it so that a semicolon is required after the
+                   // macro, which helps clang-format handle the formatting.
+
+// C array overload
+template <typename T, std::size_t N>
+auto range_begin(const T (&arr)[N]) -> const T* {
+  return arr;
+}
+template <typename T, std::size_t N>
+auto range_end(const T (&arr)[N]) -> const T* {
+  return arr + N;
+}
+
+template <typename T, typename Enable = void>
+struct has_member_fn_begin_end_t : std::false_type {};
+
+template <typename T>
+struct has_member_fn_begin_end_t<T, void_t<decltype(std::declval<T>().begin()),
+                                           decltype(std::declval<T>().end())>>
+    : std::true_type {};
+
+// Member function overload
+template <typename T>
+auto range_begin(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).begin());
+template <typename T>
+auto range_end(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).end());
+
+// ADL overload. Only participates in overload resolution if member functions
+// are not found.
+template <typename T>
+auto range_begin(T&& rng)
+    -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
+                   decltype(begin(static_cast<T&&>(rng)))> {
+  return begin(static_cast<T&&>(rng));
+}
+template <typename T>
+auto range_end(T&& rng) -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
+                                       decltype(end(static_cast<T&&>(rng)))> {
+  return end(static_cast<T&&>(rng));
+}
+
+template <typename T, typename Enable = void>
+struct has_const_begin_end : std::false_type {};
+template <typename T, typename Enable = void>
+struct has_mutable_begin_end : std::false_type {};
+
+template <typename T>
+struct has_const_begin_end<
+    T,
+    void_t<
+        decltype(detail::range_begin(std::declval<const remove_cvref_t<T>&>())),
+        decltype(detail::range_end(std::declval<const remove_cvref_t<T>&>()))>>
+    : std::true_type {};
+
+template <typename T>
+struct has_mutable_begin_end<
+    T, void_t<decltype(detail::range_begin(std::declval<T>())),
+              decltype(detail::range_end(std::declval<T>())),
+              enable_if_t<std::is_copy_constructible<T>::value>>>
+    : std::true_type {};
+
+template <typename T>
+struct is_range_<T, void>
+    : std::integral_constant<bool, (has_const_begin_end<T>::value ||
+                                    has_mutable_begin_end<T>::value)> {};
+#  undef FMT_DECLTYPE_RETURN
+#endif
+
+// tuple_size and tuple_element check.
+template <typename T> class is_tuple_like_ {
+  template <typename U>
+  static auto check(U* p) -> decltype(std::tuple_size<U>::value, int());
+  template <typename> static void check(...);
+
+ public:
+  static constexpr const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value;
+};
+
+// Check for integer_sequence
+#if defined(__cpp_lib_integer_sequence) || FMT_MSC_VERSION >= 1900
+template <typename T, T... N>
+using integer_sequence = std::integer_sequence<T, N...>;
+template <size_t... N> using index_sequence = std::index_sequence<N...>;
+template <size_t N> using make_index_sequence = std::make_index_sequence<N>;
+#else
+template <typename T, T... N> struct integer_sequence {
+  using value_type = T;
+
+  static FMT_CONSTEXPR size_t size() { return sizeof...(N); }
+};
+
+template <size_t... N> using index_sequence = integer_sequence<size_t, N...>;
+
+template <typename T, size_t N, T... Ns>
+struct make_integer_sequence : make_integer_sequence<T, N - 1, N - 1, Ns...> {};
+template <typename T, T... Ns>
+struct make_integer_sequence<T, 0, Ns...> : integer_sequence<T, Ns...> {};
+
+template <size_t N>
+using make_index_sequence = make_integer_sequence<size_t, N>;
+#endif
+
+template <typename T>
+using tuple_index_sequence = make_index_sequence<std::tuple_size<T>::value>;
+
+template <typename T, typename C, bool = is_tuple_like_<T>::value>
+class is_tuple_formattable_ {
+ public:
+  static constexpr const bool value = false;
+};
+template <typename T, typename C> class is_tuple_formattable_<T, C, true> {
+  template <std::size_t... I>
+  static std::true_type check2(index_sequence<I...>,
+                               integer_sequence<bool, (I == I)...>);
+  static std::false_type check2(...);
+  template <std::size_t... I>
+  static decltype(check2(
+      index_sequence<I...>{},
+      integer_sequence<
+          bool, (is_formattable<typename std::tuple_element<I, T>::type,
+                                C>::value)...>{})) check(index_sequence<I...>);
+
+ public:
+  static constexpr const bool value =
+      decltype(check(tuple_index_sequence<T>{}))::value;
+};
+
+template <class Tuple, class F, size_t... Is>
+void for_each(index_sequence<Is...>, Tuple&& tup, F&& f) noexcept {
+  using std::get;
+  // using free function get<I>(T) now.
+  const int _[] = {0, ((void)f(get<Is>(tup)), 0)...};
+  (void)_;  // blocks warnings
+}
+
+template <class T>
+FMT_CONSTEXPR make_index_sequence<std::tuple_size<T>::value> get_indexes(
+    T const&) {
+  return {};
+}
+
+template <class Tuple, class F> void for_each(Tuple&& tup, F&& f) {
+  const auto indexes = get_indexes(tup);
+  for_each(indexes, std::forward<Tuple>(tup), std::forward<F>(f));
+}
+
+#if FMT_MSC_VERSION && FMT_MSC_VERSION < 1920
+// Older MSVC doesn't get the reference type correctly for arrays.
+template <typename R> struct range_reference_type_impl {
+  using type = decltype(*detail::range_begin(std::declval<R&>()));
+};
+
+template <typename T, std::size_t N> struct range_reference_type_impl<T[N]> {
+  using type = T&;
+};
+
+template <typename T>
+using range_reference_type = typename range_reference_type_impl<T>::type;
+#else
+template <typename Range>
+using range_reference_type =
+    decltype(*detail::range_begin(std::declval<Range&>()));
+#endif
+
+// We don't use the Range's value_type for anything, but we do need the Range's
+// reference type, with cv-ref stripped.
+template <typename Range>
+using uncvref_type = remove_cvref_t<range_reference_type<Range>>;
+
+template <typename Range>
+using uncvref_first_type =
+    remove_cvref_t<decltype(std::declval<range_reference_type<Range>>().first)>;
+
+template <typename Range>
+using uncvref_second_type = remove_cvref_t<
+    decltype(std::declval<range_reference_type<Range>>().second)>;
+
+template <typename OutputIt> OutputIt write_delimiter(OutputIt out) {
+  *out++ = ',';
+  *out++ = ' ';
+  return out;
+}
+
+template <typename Char, typename OutputIt>
+auto write_range_entry(OutputIt out, basic_string_view<Char> str) -> OutputIt {
+  return write_escaped_string(out, str);
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(std::is_convertible<T, std_string_view<char>>::value)>
+inline auto write_range_entry(OutputIt out, const T& str) -> OutputIt {
+  auto sv = std_string_view<Char>(str);
+  return write_range_entry<Char>(out, basic_string_view<Char>(sv));
+}
+
+template <typename Char, typename OutputIt, typename Arg,
+          FMT_ENABLE_IF(std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg v) {
+  return write_escaped_char(out, v);
+}
+
+template <
+    typename Char, typename OutputIt, typename Arg,
+    FMT_ENABLE_IF(!is_std_string_like<typename std::decay<Arg>::type>::value &&
+                  !std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg& v) {
+  return write<Char>(out, v);
+}
+
+}  // namespace detail
+
+template <typename T> struct is_tuple_like {
+  static constexpr const bool value =
+      detail::is_tuple_like_<T>::value && !detail::is_range_<T>::value;
+};
+
+template <typename T, typename C> struct is_tuple_formattable {
+  static constexpr const bool value =
+      detail::is_tuple_formattable_<T, C>::value;
+};
+
+template <typename TupleT, typename Char>
+struct formatter<TupleT, Char,
+                 enable_if_t<fmt::is_tuple_like<TupleT>::value &&
+                             fmt::is_tuple_formattable<TupleT, Char>::value>> {
+ private:
+  basic_string_view<Char> separator_ = detail::string_literal<Char, ',', ' '>{};
+  basic_string_view<Char> opening_bracket_ =
+      detail::string_literal<Char, '('>{};
+  basic_string_view<Char> closing_bracket_ =
+      detail::string_literal<Char, ')'>{};
+
+  // C++11 generic lambda for format().
+  template <typename FormatContext> struct format_each {
+    template <typename T> void operator()(const T& v) {
+      if (i > 0) out = detail::copy_str<Char>(separator, out);
+      out = detail::write_range_entry<Char>(out, v);
+      ++i;
+    }
+    int i;
+    typename FormatContext::iterator& out;
+    basic_string_view<Char> separator;
+  };
+
+ public:
+  FMT_CONSTEXPR formatter() {}
+
+  FMT_CONSTEXPR void set_separator(basic_string_view<Char> sep) {
+    separator_ = sep;
+  }
+
+  FMT_CONSTEXPR void set_brackets(basic_string_view<Char> open,
+                                  basic_string_view<Char> close) {
+    opening_bracket_ = open;
+    closing_bracket_ = close;
+  }
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext = format_context>
+  auto format(const TupleT& values, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    out = detail::copy_str<Char>(opening_bracket_, out);
+    detail::for_each(values, format_each<FormatContext>{0, out, separator_});
+    out = detail::copy_str<Char>(closing_bracket_, out);
+    return out;
+  }
+};
+
+template <typename T, typename Char> struct is_range {
+  static constexpr const bool value =
+      detail::is_range_<T>::value && !detail::is_std_string_like<T>::value &&
+      !std::is_convertible<T, std::basic_string<Char>>::value &&
+      !std::is_convertible<T, detail::std_string_view<Char>>::value;
+};
+
+namespace detail {
+template <typename Context> struct range_mapper {
+  using mapper = arg_mapper<Context>;
+
+  template <typename T,
+            FMT_ENABLE_IF(has_formatter<remove_cvref_t<T>, Context>::value)>
+  static auto map(T&& value) -> T&& {
+    return static_cast<T&&>(value);
+  }
+  template <typename T,
+            FMT_ENABLE_IF(!has_formatter<remove_cvref_t<T>, Context>::value)>
+  static auto map(T&& value)
+      -> decltype(mapper().map(static_cast<T&&>(value))) {
+    return mapper().map(static_cast<T&&>(value));
+  }
+};
+
+template <typename Char, typename Element>
+using range_formatter_type = conditional_t<
+    is_formattable<Element, Char>::value,
+    formatter<remove_cvref_t<decltype(range_mapper<buffer_context<Char>>{}.map(
+                  std::declval<Element>()))>,
+              Char>,
+    fallback_formatter<Element, Char>>;
+
+template <typename R>
+using maybe_const_range =
+    conditional_t<has_const_begin_end<R>::value, const R, R>;
+
+// Workaround a bug in MSVC 2015 and earlier.
+#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910
+template <typename R, typename Char>
+struct is_formattable_delayed
+    : disjunction<
+          is_formattable<uncvref_type<maybe_const_range<R>>, Char>,
+          has_fallback_formatter<uncvref_type<maybe_const_range<R>>, Char>> {};
+#endif
+
+}  // namespace detail
+
+template <typename T, typename Char, typename Enable = void>
+struct range_formatter;
+
+template <typename T, typename Char>
+struct range_formatter<
+    T, Char,
+    enable_if_t<conjunction<
+        std::is_same<T, remove_cvref_t<T>>,
+        disjunction<is_formattable<T, Char>,
+                    detail::has_fallback_formatter<T, Char>>>::value>> {
+ private:
+  detail::range_formatter_type<Char, T> underlying_;
+  bool custom_specs_ = false;
+  basic_string_view<Char> separator_ = detail::string_literal<Char, ',', ' '>{};
+  basic_string_view<Char> opening_bracket_ =
+      detail::string_literal<Char, '['>{};
+  basic_string_view<Char> closing_bracket_ =
+      detail::string_literal<Char, ']'>{};
+
+  template <class U>
+  FMT_CONSTEXPR static auto maybe_set_debug_format(U& u, int)
+      -> decltype(u.set_debug_format()) {
+    u.set_debug_format();
+  }
+
+  template <class U>
+  FMT_CONSTEXPR static void maybe_set_debug_format(U&, ...) {}
+
+  FMT_CONSTEXPR void maybe_set_debug_format() {
+    maybe_set_debug_format(underlying_, 0);
+  }
+
+ public:
+  FMT_CONSTEXPR range_formatter() {}
+
+  FMT_CONSTEXPR auto underlying() -> detail::range_formatter_type<Char, T>& {
+    return underlying_;
+  }
+
+  FMT_CONSTEXPR void set_separator(basic_string_view<Char> sep) {
+    separator_ = sep;
+  }
+
+  FMT_CONSTEXPR void set_brackets(basic_string_view<Char> open,
+                                  basic_string_view<Char> close) {
+    opening_bracket_ = open;
+    closing_bracket_ = close;
+  }
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    auto it = ctx.begin();
+    auto end = ctx.end();
+    if (it == end || *it == '}') {
+      maybe_set_debug_format();
+      return it;
+    }
+
+    if (*it == 'n') {
+      set_brackets({}, {});
+      ++it;
+    }
+
+    if (*it == '}') {
+      maybe_set_debug_format();
+      return it;
+    }
+
+    if (*it != ':')
+      FMT_THROW(format_error("no other top-level range formatters supported"));
+
+    custom_specs_ = true;
+    ++it;
+    ctx.advance_to(it);
+    return underlying_.parse(ctx);
+  }
+
+  template <typename R, class FormatContext>
+  auto format(R&& range, FormatContext& ctx) const -> decltype(ctx.out()) {
+    detail::range_mapper<buffer_context<Char>> mapper;
+    auto out = ctx.out();
+    out = detail::copy_str<Char>(opening_bracket_, out);
+    int i = 0;
+    auto it = detail::range_begin(range);
+    auto end = detail::range_end(range);
+    for (; it != end; ++it) {
+      if (i > 0) out = detail::copy_str<Char>(separator_, out);
+      ;
+      ctx.advance_to(out);
+      out = underlying_.format(mapper.map(*it), ctx);
+      ++i;
+    }
+    out = detail::copy_str<Char>(closing_bracket_, out);
+    return out;
+  }
+};
+
+enum class range_format { disabled, map, set, sequence, string, debug_string };
+
+namespace detail {
+template <typename T> struct range_format_kind_ {
+  static constexpr auto value = std::is_same<range_reference_type<T>, T>::value
+                                    ? range_format::disabled
+                                : is_map<T>::value ? range_format::map
+                                : is_set<T>::value ? range_format::set
+                                                   : range_format::sequence;
+};
+
+template <range_format K, typename R, typename Char, typename Enable = void>
+struct range_default_formatter;
+
+template <range_format K>
+using range_format_constant = std::integral_constant<range_format, K>;
+
+template <range_format K, typename R, typename Char>
+struct range_default_formatter<
+    K, R, Char,
+    enable_if_t<(K == range_format::sequence || K == range_format::map ||
+                 K == range_format::set)>> {
+  using range_type = detail::maybe_const_range<R>;
+  range_formatter<detail::uncvref_type<range_type>, Char> underlying_;
+
+  FMT_CONSTEXPR range_default_formatter() { init(range_format_constant<K>()); }
+
+  FMT_CONSTEXPR void init(range_format_constant<range_format::set>) {
+    underlying_.set_brackets(detail::string_literal<Char, '{'>{},
+                             detail::string_literal<Char, '}'>{});
+  }
+
+  FMT_CONSTEXPR void init(range_format_constant<range_format::map>) {
+    underlying_.set_brackets(detail::string_literal<Char, '{'>{},
+                             detail::string_literal<Char, '}'>{});
+    underlying_.underlying().set_brackets({}, {});
+    underlying_.underlying().set_separator(
+        detail::string_literal<Char, ':', ' '>{});
+  }
+
+  FMT_CONSTEXPR void init(range_format_constant<range_format::sequence>) {}
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return underlying_.parse(ctx);
+  }
+
+  template <typename FormatContext>
+  auto format(range_type& range, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    return underlying_.format(range, ctx);
+  }
+};
+}  // namespace detail
+
+template <typename T, typename Char, typename Enable = void>
+struct range_format_kind
+    : conditional_t<
+          is_range<T, Char>::value, detail::range_format_kind_<T>,
+          std::integral_constant<range_format, range_format::disabled>> {};
+
+template <typename R, typename Char>
+struct formatter<
+    R, Char,
+    enable_if_t<conjunction<bool_constant<range_format_kind<R, Char>::value !=
+                                          range_format::disabled>
+// Workaround a bug in MSVC 2015 and earlier.
+#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910
+                            ,
+                            detail::is_formattable_delayed<R, Char>
+#endif
+                            >::value>>
+    : detail::range_default_formatter<range_format_kind<R, Char>::value, R,
+                                      Char> {
+};
+
+template <typename Char, typename... T> struct tuple_join_view : detail::view {
+  const std::tuple<T...>& tuple;
+  basic_string_view<Char> sep;
+
+  tuple_join_view(const std::tuple<T...>& t, basic_string_view<Char> s)
+      : tuple(t), sep{s} {}
+};
+
+template <typename Char, typename... T>
+using tuple_arg_join = tuple_join_view<Char, T...>;
+
+// Define FMT_TUPLE_JOIN_SPECIFIERS to enable experimental format specifiers
+// support in tuple_join. It is disabled by default because of issues with
+// the dynamic width and precision.
+#ifndef FMT_TUPLE_JOIN_SPECIFIERS
+#  define FMT_TUPLE_JOIN_SPECIFIERS 0
+#endif
+
+template <typename Char, typename... T>
+struct formatter<tuple_join_view<Char, T...>, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return do_parse(ctx, std::integral_constant<size_t, sizeof...(T)>());
+  }
+
+  template <typename FormatContext>
+  auto format(const tuple_join_view<Char, T...>& value,
+              FormatContext& ctx) const -> typename FormatContext::iterator {
+    return do_format(value, ctx,
+                     std::integral_constant<size_t, sizeof...(T)>());
+  }
+
+ private:
+  std::tuple<formatter<typename std::decay<T>::type, Char>...> formatters_;
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
+                              std::integral_constant<size_t, 0>)
+      -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename ParseContext, size_t N>
+  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
+                              std::integral_constant<size_t, N>)
+      -> decltype(ctx.begin()) {
+    auto end = ctx.begin();
+#if FMT_TUPLE_JOIN_SPECIFIERS
+    end = std::get<sizeof...(T) - N>(formatters_).parse(ctx);
+    if (N > 1) {
+      auto end1 = do_parse(ctx, std::integral_constant<size_t, N - 1>());
+      if (end != end1)
+        FMT_THROW(format_error("incompatible format specs for tuple elements"));
+    }
+#endif
+    return end;
+  }
+
+  template <typename FormatContext>
+  auto do_format(const tuple_join_view<Char, T...>&, FormatContext& ctx,
+                 std::integral_constant<size_t, 0>) const ->
+      typename FormatContext::iterator {
+    return ctx.out();
+  }
+
+  template <typename FormatContext, size_t N>
+  auto do_format(const tuple_join_view<Char, T...>& value, FormatContext& ctx,
+                 std::integral_constant<size_t, N>) const ->
+      typename FormatContext::iterator {
+    auto out = std::get<sizeof...(T) - N>(formatters_)
+                   .format(std::get<sizeof...(T) - N>(value.tuple), ctx);
+    if (N > 1) {
+      out = std::copy(value.sep.begin(), value.sep.end(), out);
+      ctx.advance_to(out);
+      return do_format(value, ctx, std::integral_constant<size_t, N - 1>());
+    }
+    return out;
+  }
+};
+
+FMT_MODULE_EXPORT_BEGIN
+
+/**
+  \rst
+  Returns an object that formats `tuple` with elements separated by `sep`.
+
+  **Example**::
+
+    std::tuple<int, char> t = {1, 'a'};
+    fmt::print("{}", fmt::join(t, ", "));
+    // Output: "1, a"
+  \endrst
+ */
+template <typename... T>
+FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple, string_view sep)
+    -> tuple_join_view<char, T...> {
+  return {tuple, sep};
+}
+
+template <typename... T>
+FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple,
+                        basic_string_view<wchar_t> sep)
+    -> tuple_join_view<wchar_t, T...> {
+  return {tuple, sep};
+}
+
+/**
+  \rst
+  Returns an object that formats `initializer_list` with elements separated by
+  `sep`.
+
+  **Example**::
+
+    fmt::print("{}", fmt::join({1, 2, 3}, ", "));
+    // Output: "1, 2, 3"
+  \endrst
+ */
+template <typename T>
+auto join(std::initializer_list<T> list, string_view sep)
+    -> join_view<const T*, const T*> {
+  return join(std::begin(list), std::end(list), sep);
+}
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_RANGES_H_
@@ -0,0 +1,171 @@
+// Formatting library for C++ - formatters for standard library types
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_STD_H_
+#define FMT_STD_H_
+
+#include <thread>
+#include <type_traits>
+#include <utility>
+
+#include "ostream.h"
+
+#if FMT_HAS_INCLUDE(<version>)
+#  include <version>
+#endif
+// Checking FMT_CPLUSPLUS for warning suppression in MSVC.
+#if FMT_CPLUSPLUS >= 201703L
+#  if FMT_HAS_INCLUDE(<filesystem>)
+#    include <filesystem>
+#  endif
+#  if FMT_HAS_INCLUDE(<variant>)
+#    include <variant>
+#  endif
+#endif
+
+#ifdef __cpp_lib_filesystem
+FMT_BEGIN_NAMESPACE
+
+namespace detail {
+
+template <typename Char>
+void write_escaped_path(basic_memory_buffer<Char>& quoted,
+                        const std::filesystem::path& p) {
+  write_escaped_string<Char>(std::back_inserter(quoted), p.string<Char>());
+}
+#  ifdef _WIN32
+template <>
+inline void write_escaped_path<char>(basic_memory_buffer<char>& quoted,
+                                     const std::filesystem::path& p) {
+  auto s = p.u8string();
+  write_escaped_string<char>(
+      std::back_inserter(quoted),
+      string_view(reinterpret_cast<const char*>(s.c_str()), s.size()));
+}
+#  endif
+template <>
+inline void write_escaped_path<std::filesystem::path::value_type>(
+    basic_memory_buffer<std::filesystem::path::value_type>& quoted,
+    const std::filesystem::path& p) {
+  write_escaped_string<std::filesystem::path::value_type>(
+      std::back_inserter(quoted), p.native());
+}
+
+}  // namespace detail
+
+template <typename Char>
+struct formatter<std::filesystem::path, Char>
+    : formatter<basic_string_view<Char>> {
+  template <typename FormatContext>
+  auto format(const std::filesystem::path& p, FormatContext& ctx) const ->
+      typename FormatContext::iterator {
+    basic_memory_buffer<Char> quoted;
+    detail::write_escaped_path(quoted, p);
+    return formatter<basic_string_view<Char>>::format(
+        basic_string_view<Char>(quoted.data(), quoted.size()), ctx);
+  }
+};
+FMT_END_NAMESPACE
+#endif
+
+FMT_BEGIN_NAMESPACE
+template <typename Char>
+struct formatter<std::thread::id, Char> : basic_ostream_formatter<Char> {};
+FMT_END_NAMESPACE
+
+#ifdef __cpp_lib_variant
+FMT_BEGIN_NAMESPACE
+template <typename Char> struct formatter<std::monostate, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  auto format(const std::monostate&, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    out = detail::write<Char>(out, "monostate");
+    return out;
+  }
+};
+
+namespace detail {
+
+template <typename T>
+using variant_index_sequence =
+    std::make_index_sequence<std::variant_size<T>::value>;
+
+// variant_size and variant_alternative check.
+template <typename T, typename U = void>
+struct is_variant_like_ : std::false_type {};
+template <typename T>
+struct is_variant_like_<T, std::void_t<decltype(std::variant_size<T>::value)>>
+    : std::true_type {};
+
+// formattable element check
+template <typename T, typename C> class is_variant_formattable_ {
+  template <std::size_t... I>
+  static std::conjunction<
+      is_formattable<std::variant_alternative_t<I, T>, C>...>
+      check(std::index_sequence<I...>);
+
+ public:
+  static constexpr const bool value =
+      decltype(check(variant_index_sequence<T>{}))::value;
+};
+
+template <typename Char, typename OutputIt, typename T>
+auto write_variant_alternative(OutputIt out, const T& v) -> OutputIt {
+  if constexpr (is_string<T>::value)
+    return write_escaped_string<Char>(out, detail::to_string_view(v));
+  else if constexpr (std::is_same_v<T, Char>)
+    return write_escaped_char(out, v);
+  else
+    return write<Char>(out, v);
+}
+
+}  // namespace detail
+
+template <typename T> struct is_variant_like {
+  static constexpr const bool value = detail::is_variant_like_<T>::value;
+};
+
+template <typename T, typename C> struct is_variant_formattable {
+  static constexpr const bool value =
+      detail::is_variant_formattable_<T, C>::value;
+};
+
+template <typename Variant, typename Char>
+struct formatter<
+    Variant, Char,
+    std::enable_if_t<std::conjunction_v<
+        is_variant_like<Variant>, is_variant_formattable<Variant, Char>>>> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  auto format(const Variant& value, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+
+    out = detail::write<Char>(out, "variant(");
+    std::visit(
+        [&](const auto& v) {
+          out = detail::write_variant_alternative<Char>(out, v);
+        },
+        value);
+    *out++ = ')';
+    return out;
+  }
+};
+FMT_END_NAMESPACE
+#endif
+
+#endif  // FMT_STD_H_
@@ -0,0 +1,229 @@
+// Formatting library for C++ - optional wchar_t and exotic character support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_XCHAR_H_
+#define FMT_XCHAR_H_
+
+#include <cwchar>
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+template <typename T>
+using is_exotic_char = bool_constant<!std::is_same<T, char>::value>;
+}
+
+FMT_MODULE_EXPORT_BEGIN
+
+using wstring_view = basic_string_view<wchar_t>;
+using wformat_parse_context = basic_format_parse_context<wchar_t>;
+using wformat_context = buffer_context<wchar_t>;
+using wformat_args = basic_format_args<wformat_context>;
+using wmemory_buffer = basic_memory_buffer<wchar_t>;
+
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+// Workaround broken conversion on older gcc.
+template <typename... Args> using wformat_string = wstring_view;
+inline auto runtime(wstring_view s) -> wstring_view { return s; }
+#else
+template <typename... Args>
+using wformat_string = basic_format_string<wchar_t, type_identity_t<Args>...>;
+inline auto runtime(wstring_view s) -> basic_runtime<wchar_t> { return {{s}}; }
+#endif
+
+template <> struct is_char<wchar_t> : std::true_type {};
+template <> struct is_char<detail::char8_type> : std::true_type {};
+template <> struct is_char<char16_t> : std::true_type {};
+template <> struct is_char<char32_t> : std::true_type {};
+
+template <typename... Args>
+constexpr format_arg_store<wformat_context, Args...> make_wformat_args(
+    const Args&... args) {
+  return {args...};
+}
+
+inline namespace literals {
+#if FMT_USE_USER_DEFINED_LITERALS && !FMT_USE_NONTYPE_TEMPLATE_ARGS
+constexpr detail::udl_arg<wchar_t> operator"" _a(const wchar_t* s, size_t) {
+  return {s};
+}
+#endif
+}  // namespace literals
+
+template <typename It, typename Sentinel>
+auto join(It begin, Sentinel end, wstring_view sep)
+    -> join_view<It, Sentinel, wchar_t> {
+  return {begin, end, sep};
+}
+
+template <typename Range>
+auto join(Range&& range, wstring_view sep)
+    -> join_view<detail::iterator_t<Range>, detail::sentinel_t<Range>,
+                 wchar_t> {
+  return join(std::begin(range), std::end(range), sep);
+}
+
+template <typename T>
+auto join(std::initializer_list<T> list, wstring_view sep)
+    -> join_view<const T*, const T*, wchar_t> {
+  return join(std::begin(list), std::end(list), sep);
+}
+
+template <typename Char, FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
+auto vformat(basic_string_view<Char> format_str,
+             basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  basic_memory_buffer<Char> buffer;
+  detail::vformat_to(buffer, format_str, args);
+  return to_string(buffer);
+}
+
+template <typename... T>
+auto format(wformat_string<T...> fmt, T&&... args) -> std::wstring {
+  return vformat(fmt::wstring_view(fmt), fmt::make_wformat_args(args...));
+}
+
+// Pass char_t as a default template parameter instead of using
+// std::basic_string<char_t<S>> to reduce the symbol size.
+template <typename S, typename... Args, typename Char = char_t<S>,
+          FMT_ENABLE_IF(!std::is_same<Char, char>::value &&
+                        !std::is_same<Char, wchar_t>::value)>
+auto format(const S& format_str, Args&&... args) -> std::basic_string<Char> {
+  return vformat(detail::to_string_view(format_str),
+                 fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename Locale, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto vformat(
+    const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  return detail::vformat(loc, detail::to_string_view(format_str), args);
+}
+
+template <typename Locale, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format(const Locale& loc, const S& format_str, Args&&... args)
+    -> std::basic_string<Char> {
+  return detail::vformat(loc, detail::to_string_view(format_str),
+                         fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename OutputIt, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+auto vformat_to(OutputIt out, const S& format_str,
+                basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> OutputIt {
+  auto&& buf = detail::get_buffer<Char>(out);
+  detail::vformat_to(buf, detail::to_string_view(format_str), args);
+  return detail::get_iterator(buf);
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format_to(OutputIt out, const S& fmt, Args&&... args) -> OutputIt {
+  return vformat_to(out, detail::to_string_view(fmt),
+                    fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename Locale, typename S, typename OutputIt, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_locale<Locale>::value&&
+                                detail::is_exotic_char<Char>::value)>
+inline auto vformat_to(
+    OutputIt out, const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) -> OutputIt {
+  auto&& buf = detail::get_buffer<Char>(out);
+  vformat_to(buf, detail::to_string_view(format_str), args,
+             detail::locale_ref(loc));
+  return detail::get_iterator(buf);
+}
+
+template <
+    typename OutputIt, typename Locale, typename S, typename... Args,
+    typename Char = char_t<S>,
+    bool enable = detail::is_output_iterator<OutputIt, Char>::value&&
+        detail::is_locale<Locale>::value&& detail::is_exotic_char<Char>::value>
+inline auto format_to(OutputIt out, const Locale& loc, const S& format_str,
+                      Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  return vformat_to(out, loc, to_string_view(format_str),
+                    fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename OutputIt, typename Char, typename... Args,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto vformat_to_n(
+    OutputIt out, size_t n, basic_string_view<Char> format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> format_to_n_result<OutputIt> {
+  detail::iterator_buffer<OutputIt, Char, detail::fixed_buffer_traits> buf(out,
+                                                                           n);
+  detail::vformat_to(buf, format_str, args);
+  return {buf.out(), buf.count()};
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format_to_n(OutputIt out, size_t n, const S& fmt,
+                        const Args&... args) -> format_to_n_result<OutputIt> {
+  return vformat_to_n(out, n, detail::to_string_view(fmt),
+                      fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+template <typename S, typename... Args, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_exotic_char<Char>::value)>
+inline auto formatted_size(const S& fmt, Args&&... args) -> size_t {
+  detail::counting_buffer<Char> buf;
+  detail::vformat_to(buf, detail::to_string_view(fmt),
+                     fmt::make_format_args<buffer_context<Char>>(args...));
+  return buf.count();
+}
+
+inline void vprint(std::FILE* f, wstring_view fmt, wformat_args args) {
+  wmemory_buffer buffer;
+  detail::vformat_to(buffer, fmt, args);
+  buffer.push_back(L'\0');
+  if (std::fputws(buffer.data(), f) == -1)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+inline void vprint(wstring_view fmt, wformat_args args) {
+  vprint(stdout, fmt, args);
+}
+
+template <typename... T>
+void print(std::FILE* f, wformat_string<T...> fmt, T&&... args) {
+  return vprint(f, wstring_view(fmt), fmt::make_wformat_args(args...));
+}
+
+template <typename... T> void print(wformat_string<T...> fmt, T&&... args) {
+  return vprint(wstring_view(fmt), fmt::make_wformat_args(args...));
+}
+
+/**
+  Converts *value* to ``std::wstring`` using the default format for type *T*.
+ */
+template <typename T> inline auto to_wstring(const T& value) -> std::wstring {
+  return format(FMT_STRING(L"{}"), value);
+}
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_XCHAR_H_
@@ -1,5 +1,7 @@
 /*
-  Copyright (c) 2016, Antonio SJ Musumeci <trapexit@spawn.link>
+  ISC License
+
+  Copyright (c) 2023, Antonio SJ Musumeci <trapexit@spawn.link>

  Permission to use, copy, modify, and/or distribute this software for any
  purpose with or without fee is hereby granted, provided that the above
@@ -16,22 +18,24 @@

 #pragma once

-#include "fuse.h"
-
 #include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>

-
-namespace FUSE
+namespace fs
 {
+  static
+  inline
  int
-  read_buf(const fuse_file_info_t  *ffi,
-           struct fuse_bufvec     **buf,
-           size_t                   size,
-           off_t                    offset);
+  openat(const int   dirfd_,
+         const char *pathname_,
+         const int   flags_)
+  {
+    int rv;

-  int
-  read_buf_null(const fuse_file_info_t  *ffi,
-                struct fuse_bufvec     **buf,
-                size_t                   size,
-                off_t                    offset);
+    rv = ::openat(dirfd_,pathname_,flags_);
+
+    return ((rv == -1) ? -errno : rv);
+  }
 }
@@ -16,12 +16,16 @@

 #pragma once

+#include "ghc/filesystem.hpp"
+
 #include <string>
 #include <vector>


 namespace fs
 {
+  typedef ghc::filesystem::path Path;
+
  namespace path
  {
    std::string dirname(const char *path);
@@ -0,0 +1,10 @@
+#pragma once
+
+#include "fs_path.hpp"
+
+#include <vector>
+
+namespace fs
+{
+  typedef std::vector<fs::Path> PathVector;
+}
@@ -0,0 +1,38 @@
+/*
+  ISC License
+
+  Copyright (c) 2023, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#pragma once
+
+#include <unistd.h>
+
+namespace fs
+{
+  static
+  int
+  pread(const int     fd_,
+        void         *buf_,
+        const size_t  count_,
+        const off_t   offset_)
+  {
+    int rv;
+
+    rv = ::pread(fd_,buf_,count_,offset_);
+
+    return ((rv == -1) ? -errno : rv);
+  }
+}
@@ -0,0 +1,86 @@
+/*
+  ISC License
+
+  Copyright (c) 2023, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "fs_readahead.hpp"
+
+#include "fmt/core.h"
+#include "fs_lstat.hpp"
+
+#include <cstdint>
+#include <fstream>
+#include <string>
+
+#include <sys/sysmacros.h>
+
+namespace l
+{
+  static
+  std::string
+  generate_readahead_sys_path(const std::uint64_t major_,
+                              const std::uint64_t minor_)
+  {
+    return fmt::format("/sys/class/bdi/{}:{}/read_ahead_kb",major_,minor_);
+  }
+}
+
+int
+fs::readahead(const std::uint64_t major_dev_,
+              const std::uint64_t minor_dev_,
+              const std::uint64_t size_in_kb_)
+{
+  std::string syspath;
+  std::ofstream ofs;
+
+  syspath = l::generate_readahead_sys_path(major_dev_,minor_dev_);
+
+  ofs.open(syspath);
+  if(ofs)
+    {
+      ofs << fmt::format("{}\n",size_in_kb_);
+      ofs.close();
+    }
+
+  return 0;
+}
+
+int
+fs::readahead(const std::uint64_t dev_,
+              const std::uint64_t size_in_kb_)
+{
+  std::uint32_t major_dev;
+  std::uint32_t minor_dev;
+
+  major_dev = major(dev_);
+  minor_dev = minor(dev_);
+
+  return fs::readahead(major_dev,minor_dev,size_in_kb_);
+}
+
+int
+fs::readahead(const std::string   path_,
+              const std::uint64_t size_in_kb_)
+{
+  int rv;
+  struct stat st;
+
+  rv = fs::lstat(path_,&st);
+  if(rv == -1)
+    return -errno;
+
+  return fs::readahead(st.st_dev,size_in_kb_);
+}
@@ -0,0 +1,39 @@
+/*
+  ISC License
+
+  Copyright (c) 2023, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#pragma once
+
+#include <cstdint>
+#include <string>
+
+
+namespace fs
+{
+  int
+  readahead(const std::uint64_t major_dev,
+            const std::uint64_t minor_dev,
+            const std::uint64_t size_in_kb);
+
+  int
+  readahead(const std::uint64_t dev,
+            const std::uint64_t size_in_kb);
+
+  int
+  readahead(const std::string   path,
+            const std::uint64_t size_in_kb);
+}
@@ -0,0 +1,49 @@
+/*
+  ISC License
+
+  Copyright (c) 2023, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#pragma once
+
+#include <errno.h>
+#include <sys/mount.h>
+
+#include <string>
+
+namespace fs
+{
+  static
+  inline
+  int
+  umount2(const std::string target_,
+          const int         flags_)
+  {
+    int rv;
+
+    rv = ::umount2(target_.c_str(),
+                   flags_);
+
+    return ((rv == -1) ? -errno : rv);
+  }
+
+  static
+  inline
+  int
+  umount_lazy(const std::string target_)
+  {
+    return fs::umount2(target_,MNT_DETACH);
+  }
+}
@@ -0,0 +1,136 @@
+/*
+  ISC License
+
+  Copyright (c) 2023, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "fs_wait_for_mount.hpp"
+#include "syslog.hpp"
+
+#include <functional>
+#include <thread>
+#include <unordered_set>
+
+
+namespace fs
+{
+  typedef std::unordered_set<fs::Path> PathSet;
+}
+
+constexpr std::chrono::milliseconds SLEEP_DURATION = std::chrono::milliseconds(333);
+
+namespace std
+{
+  template<>
+  struct hash<fs::Path>
+  {
+    std::size_t
+    operator()(fs::Path const &path_) const noexcept
+    {
+      return std::hash<std::string>{}(path_.string());
+    }
+  };
+}
+
+static
+void
+_check_mounted(const struct stat &src_st_,
+               const fs::PathSet &tgt_paths_,
+               fs::PathVector    *successes_,
+               fs::PathVector    *failures_)
+{
+  fs::PathVector &successes = *successes_;
+  fs::PathVector &failures  = *failures_;
+
+  for(auto const &tgt_path : tgt_paths_)
+    {
+      int         rv;
+      struct stat tgt_st;
+
+      rv = fs::stat(tgt_path,&tgt_st);
+      if(rv == 0)
+        {
+          if(tgt_st.st_dev != src_st_.st_dev)
+            successes.push_back(tgt_path);
+          else
+            failures.push_back(tgt_path);
+        }
+      else
+        {
+          failures.push_back(tgt_path);
+        }
+    }
+}
+
+static
+void
+_wait_for_mount(const struct stat               &src_st_,
+                const fs::PathVector            &tgt_paths_,
+                const std::chrono::milliseconds &timeout_)
+{
+  fs::PathVector                                     successes;
+  fs::PathVector                                     failures;
+  std::unordered_set<fs::Path>                       tgt_paths;
+  std::chrono::time_point<std::chrono::steady_clock> now;
+  std::chrono::time_point<std::chrono::steady_clock> deadline;
+
+  tgt_paths.insert(tgt_paths_.begin(),tgt_paths_.end());
+  now      = std::chrono::steady_clock::now();
+  deadline = now + timeout_;
+
+  while(true)
+    {
+      if(tgt_paths.empty())
+        break;
+      if(now >= deadline)
+        break;
+
+      successes.clear();
+      failures.clear();
+      ::_check_mounted(src_st_,tgt_paths,&successes,&failures);
+      for(auto const &path : successes)
+        {
+          tgt_paths.erase(path);
+          syslog_info("%s is mounted",path.string().c_str());
+        }
+
+      std::this_thread::sleep_for(SLEEP_DURATION);
+      now = std::chrono::steady_clock::now();
+    }
+
+  for(auto const &path : failures)
+    syslog_notice("%s not mounted within timeout",path.string().c_str());
+  if(!failures.empty())
+    syslog_warning("Continuing to mount mergerfs despite %u branches not "
+                   "being different from the mountpoint filesystem",
+                   failures.size());
+}
+
+void
+fs::wait_for_mount(const fs::Path                  &src_path_,
+                   const fs::PathVector            &tgt_paths_,
+                   const std::chrono::milliseconds &timeout_)
+{
+  int rv;
+  struct stat src_st;
+
+  rv = fs::stat(src_path_,&src_st);
+  if(rv == -1)
+    return syslog_error("Error stat'ing mount path: %s (%s)",
+                        src_path_.c_str(),
+                        strerror(errno));
+
+  ::_wait_for_mount(src_st,tgt_paths_,timeout_);
+}
@@ -0,0 +1,36 @@
+/*
+  ISC License
+
+  Copyright (c) 2023, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#pragma once
+
+#include "ghc/filesystem.hpp"
+
+#include "fs_pathvector.hpp"
+#include "fs_stat.hpp"
+
+#include <chrono>
+#include <vector>
+
+
+namespace fs
+{
+  void
+  wait_for_mount(const fs::Path                  &srcpath,
+                 const fs::PathVector            &tgtpaths,
+                 const std::chrono::milliseconds &timeout);
+}
@@ -23,6 +23,8 @@ int
 Func::Base::Action::from_string(const std::string &policyname_)
 {
  policy = Policies::Action::find(policyname_);
+  if(!policy)
+    return -EINVAL;

  return 0;
 }
@@ -37,6 +39,8 @@ int
 Func::Base::Create::from_string(const std::string &policyname_)
 {
  policy = Policies::Create::find(policyname_);
+  if(!policy)
+    return -EINVAL;

  return 0;
 }
@@ -51,6 +55,8 @@ int
 Func::Base::Search::from_string(const std::string &policyname_)
 {
  policy = Policies::Search::find(policyname_);
+  if(!policy)
+    return -EINVAL;

  return 0;
 }
@@ -21,6 +21,7 @@
 #include "fs_clonepath.hpp"
 #include "fs_open.hpp"
 #include "fs_path.hpp"
+#include "procfs_get_name.hpp"
 #include "ugid.hpp"

 #include "fuse.h"
@@ -28,9 +29,6 @@
 #include <string>
 #include <vector>

-using std::string;
-using std::vector;
-

 namespace l
 {
@@ -56,6 +54,7 @@ namespace l
  static
  void
  config_to_ffi_flags(Config::Read     &cfg_,
+                      const int         tid_,
                      fuse_file_info_t *ffi_)
  {
    switch(cfg_->cache_files)
@@ -85,15 +84,32 @@ namespace l
        ffi_->keep_cache = 0;
        ffi_->auto_cache = 1;
        break;
+      case CacheFiles::ENUM::PER_PROCESS:
+        std::string proc_name;
+
+        proc_name = procfs::get_name(tid_);
+        if(cfg_->cache_files_process_names.count(proc_name) == 0)
+          {
+            ffi_->direct_io  = 1;
+            ffi_->keep_cache = 0;
+            ffi_->auto_cache = 0;
+          }
+        else
+          {
+            ffi_->direct_io  = 0;
+            ffi_->keep_cache = 0;
+            ffi_->auto_cache = 0;
+          }
+        break;
      }
  }

  static
  int
-  create_core(const string &fullpath_,
-              mode_t        mode_,
-              const mode_t  umask_,
-              const int     flags_)
+  create_core(const std::string &fullpath_,
+              mode_t             mode_,
+              const mode_t       umask_,
+              const int          flags_)
  {
    if(!fs::acl::dir_has_defaults(fullpath_))
      mode_ &= ~umask_;
@@ -103,15 +119,15 @@ namespace l

  static
  int
-  create_core(const string &createpath_,
-              const char   *fusepath_,
-              const mode_t  mode_,
-              const mode_t  umask_,
-              const int     flags_,
-              uint64_t     *fh_)
+  create_core(const std::string &createpath_,
+              const char        *fusepath_,
+              const mode_t       mode_,
+              const mode_t       umask_,
+              const int          flags_,
+              uint64_t          *fh_)
  {
    int rv;
-    string fullpath;
+    std::string fullpath;

    fullpath = fs::path::make(createpath_,fusepath_);

@@ -136,8 +152,8 @@ namespace l
         uint64_t             *fh_)
  {
    int rv;
-    string fullpath;
-    string fusedirpath;
+    std::string fullpath;
+    std::string fusedirpath;
    StrVec createpaths;
    StrVec existingpaths;

@@ -175,7 +191,7 @@ namespace FUSE
    const fuse_context *fc = fuse_get_context();
    const ugid::Set     ugid(fc->uid,fc->gid);

-    l::config_to_ffi_flags(cfg,ffi_);
+    l::config_to_ffi_flags(cfg,fc->pid,ffi_);

    if(cfg->writeback_cache)
      l::tweak_flags_writeback_cache(&ffi_->flags);
@@ -139,7 +139,7 @@ namespace l
      return -errno;

    if(symlinkify_ && symlinkify::can_be_symlink(*st_,symlinkify_timeout_))
-      st_->st_mode = symlinkify::convert(st_->st_mode);
+      symlinkify::convert(fullpath,st_);

    fs::inode::calc(fusepath_,st_);

@@ -16,9 +16,15 @@

 #include "config.hpp"
 #include "ugid.hpp"
+#include "fs_readahead.hpp"
+#include "syslog.hpp"
+
+#include "fmt/core.h"

 #include "fuse.h"

+#include <thread>
+

 namespace l
 {
@@ -77,6 +83,49 @@ namespace l
        cfg_->fuse_msg_size = FUSE_DEFAULT_MAX_PAGES_PER_REQ;
      }
  }
+
+  static
+  void
+  readahead(const std::string path_,
+            const int         readahead_)
+  {
+    int rv;
+
+    rv = fs::readahead(path_,readahead_);
+    if(rv == 0)
+      syslog_info("%s - readahead set to %d",path_.c_str(),readahead_);
+    else
+      syslog_error("%s - unable to set readahead",path_.c_str());
+  }
+
+  static
+  void
+  set_readahead_on_mount_and_branches()
+  {
+    Config::Read cfg;
+    Branches::CPtr branches;
+
+    if((uint64_t)cfg->readahead == 0)
+      return;
+
+    l::readahead(cfg->mountpoint,cfg->readahead);
+
+    branches = cfg->branches;
+    for(auto const &branch : *branches)
+      l::readahead(branch.path,cfg->readahead);
+  }
+
+  // Spawn a thread to do this because before init returns calls to
+  // set the value will block leading to a deadlock. This is just
+  // easier.
+  static
+  void
+  spawn_thread_to_set_readahead()
+  {
+    std::thread readahead_thread(l::set_readahead_on_mount_and_branches);
+
+    readahead_thread.detach();
+  }
 }

 namespace FUSE
@@ -104,6 +153,8 @@ namespace FUSE
    conn_->want &= ~FUSE_CAP_POSIX_LOCKS;
    conn_->want &= ~FUSE_CAP_FLOCK_LOCKS;

+    l::spawn_thread_to_set_readahead();
+
    return NULL;
  }
 }
@@ -44,6 +44,9 @@ typedef char IOCTL_BUF[4096];
 #define IOCTL_APP_TYPE  0xDF
 #define IOCTL_FILE_INFO _IOWR(IOCTL_APP_TYPE,0,IOCTL_BUF)

+// From linux/btrfs.h
+#define BTRFS_IOCTL_MAGIC 0x94
+
 #ifndef FS_IOC_GETFLAGS
 # define FS_IOC_GETFLAGS _IOR('f',1,long)
 #endif
@@ -314,6 +317,13 @@ namespace l
    return (_IOC_TYPE(cmd_) == IOCTL_APP_TYPE);
  }

+  static
+  bool
+  is_btrfs_ioctl_cmd(const unsigned long cmd_)
+  {
+    return (_IOC_TYPE(cmd_) == BTRFS_IOCTL_MAGIC);
+  }
+
  static
  int
  ioctl_custom(const fuse_file_info_t *ffi_,
@@ -340,6 +350,8 @@ namespace FUSE
        void                   *data_,
        uint32_t               *out_bufsz_)
  {
+    if(l::is_btrfs_ioctl_cmd(cmd_))
+      return -ENOTTY;
    if(l::is_mergerfs_ioctl_cmd(cmd_))
      return l::ioctl_custom(ffi_,cmd_,data_);

@@ -326,7 +326,7 @@ namespace l
                                              st_,
                                              timeouts_);
      case LinkEXDEV::ENUM::ABS_POOL_SYMLINK:
-        return l::link_exdev_abs_pool_symlink(cfg_->mount,
+        return l::link_exdev_abs_pool_symlink(cfg_->mountpoint,
                                              oldpath_,
                                              newpath_,
                                              st_,
@@ -17,23 +17,22 @@
 #include "config.hpp"
 #include "errno.hpp"
 #include "fileinfo.hpp"
-#include "fs_lchmod.hpp"
 #include "fs_cow.hpp"
 #include "fs_fchmod.hpp"
+#include "fs_lchmod.hpp"
 #include "fs_open.hpp"
 #include "fs_path.hpp"
 #include "fs_stat.hpp"
+#include "procfs_get_name.hpp"
 #include "stat_util.hpp"
 #include "ugid.hpp"

 #include "fuse.h"

+#include <set>
 #include <string>
 #include <vector>

-using std::string;
-using std::vector;
-

 namespace l
 {
@@ -46,8 +45,8 @@ namespace l

  static
  int
-  lchmod_and_open_if_not_writable_and_empty(const string &fullpath_,
-                                            const int     flags_)
+  lchmod_and_open_if_not_writable_and_empty(const std::string &fullpath_,
+                                            const int          flags_)
  {
    int rv;
    struct stat st;
@@ -86,7 +85,7 @@ namespace l
      case NFSOpenHack::ENUM::GIT:
        if(l::rdonly(flags_))
          return (errno=EACCES,-1);
-        if(fullpath_.find("/.git/") == string::npos)
+        if(fullpath_.find("/.git/") == std::string::npos)
          return (errno=EACCES,-1);
        return l::lchmod_and_open_if_not_writable_and_empty(fullpath_,flags_);
      case NFSOpenHack::ENUM::ALL:
@@ -118,6 +117,7 @@ namespace l
  static
  void
  config_to_ffi_flags(Config::Read     &cfg_,
+                      const int         tid_,
                      fuse_file_info_t *ffi_)
  {
    switch(cfg_->cache_files)
@@ -147,12 +147,29 @@ namespace l
        ffi_->keep_cache = 0;
        ffi_->auto_cache = 1;
        break;
+      case CacheFiles::ENUM::PER_PROCESS:
+        std::string proc_name;
+
+        proc_name = procfs::get_name(tid_);
+        if(cfg_->cache_files_process_names.count(proc_name) == 0)
+          {
+            ffi_->direct_io  = 1;
+            ffi_->keep_cache = 0;
+            ffi_->auto_cache = 0;
+          }
+        else
+          {
+            ffi_->direct_io  = 0;
+            ffi_->keep_cache = 0;
+            ffi_->auto_cache = 0;
+          }
+        break;
      }
  }

  static
  int
-  open_core(const string      &basepath_,
+  open_core(const std::string &basepath_,
            const char        *fusepath_,
            const int          flags_,
            const bool         link_cow_,
@@ -160,7 +177,7 @@ namespace l
            uint64_t          *fh_)
  {
    int fd;
-    string fullpath;
+    std::string fullpath;

    fullpath = fs::path::make(basepath_,fusepath_);

@@ -209,7 +226,7 @@ namespace FUSE
    const fuse_context *fc  = fuse_get_context();
    const ugid::Set     ugid(fc->uid,fc->gid);

-    l::config_to_ffi_flags(cfg,ffi_);
+    l::config_to_ffi_flags(cfg,fc->pid,ffi_);

    if(cfg->writeback_cache)
      l::tweak_flags_writeback_cache(&ffi_->flags);
@@ -0,0 +1,70 @@
+/*
+  Copyright (c) 2016, Antonio SJ Musumeci <trapexit@spawn.link>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "errno.hpp"
+#include "fileinfo.hpp"
+#include "fs_pread.hpp"
+
+#include "fuse.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct fuse_bufvec fuse_bufvec;
+
+
+namespace l
+{
+  static
+  int
+  read(const int     fd_,
+       char         *buf_,
+       const size_t  size_,
+       const off_t   offset_)
+  {
+    int rv;
+
+    rv = fs::pread(fd_,buf_,size_,offset_);
+
+    return rv;
+  }
+}
+
+namespace FUSE
+{
+  int
+  read(const fuse_file_info_t *ffi_,
+       char                   *buf_,
+       size_t                  size_,
+       off_t                   offset_)
+  {
+    FileInfo *fi = reinterpret_cast<FileInfo*>(ffi_->fh);
+
+    return l::read(fi->fd,
+                   buf_,
+                   size_,
+                   offset_);
+  }
+
+  int
+  read_null(const fuse_file_info_t *ffi_,
+            char                   *buf_,
+            size_t                  size_,
+            off_t                   offset_)
+  {
+    return size_;
+  }
+}
@@ -24,12 +24,14 @@
 namespace FUSE
 {
  int
-  write_buf(const fuse_file_info_t *ffi,
-            struct fuse_bufvec     *buf,
-            off_t                   offset);
+  read(const fuse_file_info_t *ffi,
+       char                   *buf,
+       size_t                  size,
+       off_t                   offset);

  int
-  write_buf_null(const fuse_file_info_t *ffi,
-                 struct fuse_bufvec     *buf,
-                 off_t                   offset);
+  read_null(const fuse_file_info_t *ffi,
+            char                   *buf,
+            size_t                  size,
+            off_t                   offset);
 }
@@ -1,98 +0,0 @@
-/*
-  Copyright (c) 2016, Antonio SJ Musumeci <trapexit@spawn.link>
-
-  Permission to use, copy, modify, and/or distribute this software for any
-  purpose with or without fee is hereby granted, provided that the above
-  copyright notice and this permission notice appear in all copies.
-
-  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
-  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-*/
-
-#include "errno.hpp"
-#include "fileinfo.hpp"
-
-#include "fuse.h"
-
-#include <stdlib.h>
-#include <string.h>
-
-typedef struct fuse_bufvec fuse_bufvec;
-
-
-namespace l
-{
-  static
-  int
-  read_buf(const int      fd_,
-           fuse_bufvec  **bufp_,
-           const size_t   size_,
-           const off_t    offset_)
-  {
-    fuse_bufvec *src;
-
-    src = (fuse_bufvec*)malloc(sizeof(fuse_bufvec));
-    if(src == NULL)
-      return -ENOMEM;
-
-    *src = FUSE_BUFVEC_INIT(size_);
-
-    src->buf->flags = (fuse_buf_flags)(FUSE_BUF_IS_FD|FUSE_BUF_FD_SEEK|FUSE_BUF_FD_RETRY);
-    src->buf->fd    = fd_;
-    src->buf->pos   = offset_;
-
-    *bufp_ = src;
-
-    return 0;
-  }
-}
-
-namespace FUSE
-{
-  int
-  read_buf(const fuse_file_info_t  *ffi_,
-           fuse_bufvec            **bufp_,
-           size_t                   size_,
-           off_t                    offset_)
-  {
-    FileInfo *fi = reinterpret_cast<FileInfo*>(ffi_->fh);
-
-    return l::read_buf(fi->fd,
-                     bufp_,
-                     size_,
-                     offset_);
-  }
-
-  int
-  read_buf_null(const fuse_file_info_t  *ffi_,
-                fuse_bufvec            **bufp_,
-                size_t                   size_,
-                off_t                    offset_)
-  {
-    void *mem;
-    struct fuse_bufvec *buf;
-
-    buf = (struct fuse_bufvec*)malloc(sizeof(struct fuse_bufvec));
-    if(buf == NULL)
-      return -ENOMEM;
-
-    mem = (void*)calloc(1,size_);
-    if(mem == NULL)
-      {
-        free(buf);
-        return -ENOMEM;
-      }
-
-    *buf = FUSE_BUFVEC_INIT(size_);
-    buf->buf[0].mem = mem;
-
-    *bufp_ = buf;
-
-    return 0;
-  }
-}
@@ -358,7 +358,7 @@ namespace l
      case RenameEXDEV::ENUM::ABS_SYMLINK:
        return l::rename_exdev_abs_symlink(cfg_->func.rename.policy,
                                           cfg_->branches,
-                                           cfg_->mount,
+                                           cfg_->mountpoint,
                                           oldfusepath_,
                                           newfusepath_);
      }
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
trapexit	c266bae96d	Merge pull request #1166 from trapexit/docs Remove duplicate entries in docs	2023-04-01 14:41:33 -04:00
Antonio SJ Musumeci	cdcfef2ceb	Remove duplicate entries in docs	2023-04-01 14:40:49 -04:00
trapexit	7a62a629b9	Merge pull request #1165 from trapexit/thread-defaults Change default read-thread-count from -1 to 0 as documented	2023-03-31 13:38:08 -04:00
Antonio SJ Musumeci	0a64d74b4b	Change default read-thread-count from -1 to 0 as documented	2023-03-31 12:54:57 -04:00
trapexit	26c8b5c642	Merge pull request #1161 from trapexit/fix Workaround older gcc bug with namespacing std::hash	2023-03-28 21:57:51 -04:00
Antonio SJ Musumeci	26fd11cb4d	Workaround older gcc bug with namespacing std::hash	2023-03-28 21:53:38 -04:00
trapexit	cdceade1ae	Merge pull request #1159 from trapexit/wait More actively report to syslog when waiting for branches to mount	2023-03-28 19:03:50 -04:00
Antonio SJ Musumeci	eebd6e9eb4	Actively report to syslog when waiting for mounts	2023-03-28 19:01:21 -04:00
trapexit	9744eab819	Merge pull request #1156 from trapexit/options Fix loading readonly / write once options from file	2023-03-19 23:41:15 -04:00
Antonio SJ Musumeci	1c5b0f2f5f	Fix loading readonly / write once options from file	2023-03-19 23:40:32 -04:00
trapexit	d9033b7713	Merge pull request #1155 from trapexit/mover-scripts Fix mover script link typo	2023-03-19 22:08:31 -04:00
Antonio SJ Musumeci	b1d11779f0	Fix mover script link typo	2023-03-19 22:07:03 -04:00
trapexit	be19b9ce71	Merge pull request #1154 from trapexit/mover-scripts Move tiered cache mover scripts to files in tools dir	2023-03-19 22:03:31 -04:00
Antonio SJ Musumeci	9fcaf6a674	Move tiered cache mover scripts to files in tools dir	2023-03-19 01:23:19 -04:00
trapexit	2dd4b788ce	Merge pull request #1153 from trapexit/readme Misc README updates	2023-03-18 21:48:16 -04:00
Antonio SJ Musumeci	5152c63480	Misc README updates	2023-03-18 21:47:37 -04:00
trapexit	bd02bfd54c	Merge pull request #1151 from kephir4eg/master Fix config file parsing	2023-03-11 00:45:24 -05:00
Ilya Taranov	d04e04e89a	Fix config file parsing	2023-03-10 20:55:20 -08:00
trapexit	10a9969a64	Merge pull request #1149 from trapexit/readahead Add ability to set readahead of mergerfs and branches	2023-03-09 00:13:49 -05:00
Antonio SJ Musumeci	486c5d3734	Add ability to set readahead of mergerfs and branches	2023-03-09 00:12:57 -05:00
trapexit	55bd0ca25a	Merge pull request #1147 from trapexit/readme Update README regarding why epmfs is default	2023-03-06 23:26:00 -05:00
Antonio SJ Musumeci	ee2855bb38	Update README regarding why epmfs is default	2023-03-06 23:25:42 -05:00
trapexit	65c004a309	Merge pull request #1146 from jonaswinkler/master Fix typo in basic setup options	2023-03-06 09:26:21 -05:00
Jonas Winkler	a598f63235	Update README.md	2023-03-06 15:17:00 +01:00
trapexit	6e845b337a	Merge pull request #1145 from trapexit/readme Lots of misc README updates	2023-03-05 01:43:08 -05:00
Antonio SJ Musumeci	e25fa1954e	Lots of misc README updates	2023-03-05 01:42:42 -05:00
trapexit	b48d368130	Merge pull request #1143 from trapexit/rework-read Rework fuse read to use same buffers as messages	2023-02-26 23:37:14 -05:00
Antonio SJ Musumeci	373d331f39	Rework fuse read to use same buffers as messages	2023-02-26 23:31:44 -05:00
trapexit	4a647beec1	Merge pull request #1142 from trapexit/remove-splice Remove splicing features	2023-02-26 01:45:29 -05:00
Antonio SJ Musumeci	84592a9f13	Remove splicing features After numerous tests it was found the splice features were at best the same performance as standard IO and at worse actually slower. To simplify the code all splice features are removed.	2023-02-26 01:42:58 -05:00
trapexit	09fbb80f8c	Merge pull request #1140 from trapexit/pinthreads Add ability to pin read and processing threads	2023-02-20 22:45:54 -05:00
Antonio SJ Musumeci	34310170ac	Add ability to pin read and processing threads	2023-02-19 17:52:29 -05:00
trapexit	e39ace0eba	Merge pull request #1139 from trapexit/per-process-page-cache Add "per-process" file caching feature	2023-02-18 01:34:37 -05:00
Antonio SJ Musumeci	9effeb6869	Add "per-process" file caching feature Allows chosing page caching based on process name.	2023-02-18 01:16:36 -05:00
trapexit	b51a5970b2	Merge pull request #1137 from trapexit/btrfs-ioctl Return NOTTY for all btrfs ioctl calls	2023-02-11 10:25:09 -05:00
Antonio SJ Musumeci	2d9c915641	Return NOTTY for all btrfs ioctl calls mergerfs tries to pass through ioctl calls but due to the complexity of btrfs calls their is risk of segfaults. In the future it may be required to whitelist all supported ioctl calls.	2023-02-11 10:07:55 -05:00
trapexit	737e59d232	Merge pull request #1133 from trapexit/lazy-umount Add option to lazy umount target mount point	2023-02-02 22:12:17 -05:00
Antonio SJ Musumeci	9adddfc66d	Add option to lazy umount target mount point	2023-02-02 21:20:23 -05:00
trapexit	9a6b7835f4	Merge pull request #1131 from trapexit/docs Add more apps to section on sqlite3 mmap problems	2023-01-29 23:57:46 -05:00
Antonio SJ Musumeci	ac4e097511	Add more apps to section on sqlite3 mmap problems	2023-01-29 23:56:50 -05:00
trapexit	3d73c6a596	Merge pull request #1130 from trapexit/docs Update README regarding requesting support and policy descriptions	2023-01-29 23:24:33 -05:00
Antonio SJ Musumeci	9670fb9704	Update README regarding requesting support and policy descriptions	2023-01-29 23:24:09 -05:00
trapexit	e2ece936e6	Merge pull request #1129 from trapexit/fuse-version Remove FUSE_USE_VERSION, no longer used	2023-01-29 18:27:26 -05:00
Antonio SJ Musumeci	a4491169b0	Remove FUSE_USE_VERSION, no longer used	2023-01-29 17:04:08 -05:00
trapexit	0d566befba	Merge pull request #1128 from trapexit/checkbranches Forbid adding mountpoint to branch list	2023-01-29 15:50:25 -05:00
Antonio SJ Musumeci	3e313cd605	Forbid adding mountpoint to branch list	2023-01-29 11:51:56 -05:00
trapexit	5bf2a2be59	Merge pull request #1127 from trapexit/bugfixes Backport bug fixes from libfuse3	2023-01-28 01:17:50 -05:00
Antonio SJ Musumeci	7ed91c1668	Backport bug fixes from libfuse3	2023-01-28 01:17:07 -05:00
trapexit	041e3f50d5	Merge pull request #1126 from trapexit/removeallowother Hard code setting of allow_other, ignore when set	2023-01-26 23:40:12 -05:00
Antonio SJ Musumeci	92ccfd3c89	Hard code setting of allow_other, ignore when set	2023-01-26 23:37:37 -05:00
trapexit	24f2d3c94d	Merge pull request #1125 from trapexit/scheduling-priority Allow setting of scheduling priority	2023-01-25 23:42:20 -05:00
Antonio SJ Musumeci	a7113bb163	Allow setting of scheduling priority	2023-01-25 23:38:31 -05:00
trapexit	ec5ac0c517	Merge pull request #1124 from trapexit/builds Update CirrusCI setup	2023-01-25 20:24:52 -05:00
Antonio SJ Musumeci	fdec3355a1	Update CirrusCI setup	2023-01-25 20:12:53 -05:00
trapexit	16e9ba2f19	Merge pull request #1123 from trapexit/wait Add option to wait for branches to become new mounts	2023-01-25 19:51:58 -05:00
Antonio SJ Musumeci	939eb3996a	Add option to wait for branches to become new mounts branches-mount-timeout=UINT64 in seconds (default: 0)	2023-01-25 11:59:14 -05:00
trapexit	2d8d0f7ad6	Merge pull request #1120 from trapexit/nonempty Remove 'nonempty' argument	2023-01-16 23:41:51 -05:00
Antonio SJ Musumeci	3ee93d4c56	Remove 'nonempty' argument This makes it like all other filesystems and brings it into alignment with libfuse3's behavior.	2023-01-16 23:33:36 -05:00
trapexit	0b2afda30e	Merge pull request #1119 from trapexit/useino Remove use_ino option and make behavior same as if set	2023-01-16 16:53:30 -05:00
Antonio SJ Musumeci	d11807ef7c	Remove use_ino option and make behavior same as if set	2023-01-16 16:21:44 -05:00
trapexit	3e725a66e3	Merge pull request #1118 from trapexit/msghandling Add async message processing	2023-01-16 13:41:00 -05:00
Antonio SJ Musumeci	24423b8d2a	Add async message processing	2023-01-16 13:15:53 -05:00
trapexit	c89fbde48d	Merge pull request #1116 from davidkaufman/patch-1 small grammar correction to README file	2023-01-13 13:47:07 -05:00
David Kaufman	b65e52d56b	small grammar correction to README file sorry, i'm a grammar nerd with ocd :-)	2023-01-03 00:58:08 -05:00
trapexit	6c2db76b92	Merge pull request #1109 from trapexit/fixes Fix regression testing for implemented functions	2022-12-11 14:44:54 -05:00
Antonio SJ Musumeci	094ad862e7	Fix regression testing for implemented functions	2022-12-11 14:44:19 -05:00
trapexit	e81b1a6b9d	Merge pull request #1107 from trapexit/32bitfixes Fix printf for 32bit systems	2022-12-08 22:06:15 -05:00
Antonio SJ Musumeci	a6ca96fa08	Fix printf for 32bit systems	2022-12-08 22:04:15 -05:00
trapexit	a449829d5f	Merge pull request #1106 from trapexit/xattrfix Fix reading of setxattr name	2022-12-08 18:40:57 -05:00
Antonio SJ Musumeci	d14427ad9e	Fix reading of setxattr name	2022-12-08 18:40:08 -05:00
trapexit	ac1f4b4d52	Merge pull request #1105 from trapexit/ll Misc cleanup	2022-11-27 23:29:53 -05:00
Antonio SJ Musumeci	ddf5e53aa4	Misc cleanup	2022-11-27 22:23:38 -06:00
trapexit	a2a12afb34	Merge pull request #1104 from trapexit/ll Remove libfuse abstraction in prep for adding request data	2022-11-27 00:39:05 -05:00
Antonio SJ Musumeci	7606430188	Remove libfuse abstraction in prep for adding request data	2022-11-26 23:30:27 -06:00
trapexit	629806e896	Merge pull request #1093 from lgtm-migrator/codeql Add CodeQL workflow for GitHub code scanning	2022-11-11 09:53:27 -05:00
LGTM Migrator	50fbf14e1e	Add CodeQL workflow for GitHub code scanning	2022-11-11 07:59:54 +00:00
trapexit	4a67bbdc71	Merge pull request #1092 from trapexit/cleanup Remove write_buf, simplify FUSE msg dispatching	2022-11-10 23:24:25 -05:00
Antonio SJ Musumeci	dba9c4451a	Remove write_buf, simplify FUSE msg dispatching	2022-11-10 22:43:02 -05:00
trapexit	fea499e220	Merge pull request #1091 from trapexit/cleanup Remove unnecessary libfuse abstractions	2022-11-07 23:35:18 -05:00
Antonio SJ Musumeci	9d056d609f	Remove unnecessary libfuse abstractions	2022-11-07 23:09:25 -05:00
trapexit	9a839dd8ba	Merge pull request #1089 from trapexit/32bit Tweaks for 32bit systems	2022-11-05 23:37:19 -04:00
Antonio SJ Musumeci	32e2c9c48e	Tweaks for 32bit systems	2022-11-05 23:28:10 -04:00
trapexit	83d7886a0a	Merge pull request #1087 from trapexit/kernelh Update fuse_kernel.h	2022-11-03 23:29:22 -04:00
Antonio SJ Musumeci	316abba0ac	Update fuse_kernel.h	2022-11-03 23:28:44 -04:00
trapexit	8001c58c36	Merge pull request #1085 from trapexit/symlinkify Fix setting of stat vars for symlinkify	2022-10-31 19:47:36 -04:00
Antonio SJ Musumeci	3b0d7fb26e	Fix setting of stat vars for symlinkify	2022-10-30 22:27:33 -04:00
trapexit	5d3c5002e0	Merge pull request #1058 from trapexit/docs Support doc update	2022-08-08 14:09:22 -04:00
Antonio SJ Musumeci	9082285cc8	Support doc update	2022-08-08 13:40:43 -04:00
trapexit	d1762b2bac	Merge pull request #1057 from trapexit/cfgerrs Error when given invalid policy names	2022-08-06 23:08:10 -04:00
Antonio SJ Musumeci	46ce28b149	Error when given invalid policy names	2022-08-06 23:01:23 -04:00
trapexit	faadeb75e0	Merge pull request #1045 from Gelma/master Fix typos	2022-06-22 14:27:13 -04:00
Andrea Gelmini	338e559e53	Fix typos	2022-06-22 11:51:23 +02:00
trapexit	3db673410f	Merge pull request #1039 from trapexit/docs Add details about usage of FUSE to docs	2022-05-23 12:49:06 -04:00
Antonio SJ Musumeci	77f098614f	Add details about usage of FUSE to docs	2022-05-23 12:40:00 -04:00
trapexit	9589846e9a	Merge pull request #1032 from trapexit/support Rework support section in readme	2022-04-25 17:44:16 -04:00
Antonio SJ Musumeci	e2dda3c1b1	Rework support section in readme	2022-04-25 17:42:31 -04:00