Merge remote-tracking branch 'upstream/master' into locale-format
This commit is contained in:
Jin S
commit
69eadea399
@ -283,7 +283,7 @@ if (FMT_OS)
|
||||
endif ()
|
||||
|
||||
add_module_library(fmt src/fmt.cc FALLBACK
|
||||
${FMT_SOURCES} ${FMT_HEADERS} README.rst ChangeLog.md
|
||||
${FMT_SOURCES} ${FMT_HEADERS} README.md ChangeLog.md
|
||||
IF FMT_MODULE)
|
||||
add_library(fmt::fmt ALIAS fmt)
|
||||
if (FMT_MODULE)
|
||||
@ -448,6 +448,6 @@ if (FMT_MASTER_PROJECT AND EXISTS ${gitignore})
|
||||
set(CPACK_SOURCE_IGNORE_FILES ${ignored_files})
|
||||
set(CPACK_SOURCE_PACKAGE_FILE_NAME fmt-${FMT_VERSION})
|
||||
set(CPACK_PACKAGE_NAME fmt)
|
||||
set(CPACK_RESOURCE_FILE_README ${PROJECT_SOURCE_DIR}/README.rst)
|
||||
set(CPACK_RESOURCE_FILE_README ${PROJECT_SOURCE_DIR}/README.md)
|
||||
include(CPack)
|
||||
endif ()
|
||||
|
||||
488
README.md
Normal file
488
README.md
Normal file
@ -0,0 +1,488 @@
|
||||
<img src="https://user-images.githubusercontent.com/576385/156254208-f5b743a9-88cf-439d-b0c0-923d53e8d551.png" alt="{fmt}" width="25%"/>
|
||||
|
||||
[](https://github.com/fmtlib/fmt/actions?query=workflow%3Alinux)
|
||||
[](https://github.com/fmtlib/fmt/actions?query=workflow%3Amacos)
|
||||
[](https://github.com/fmtlib/fmt/actions?query=workflow%3Awindows)
|
||||
[](https://bugs.chromium.org/p/oss-fuzz/issues/list?\%0Acolspec=ID%20Type%20Component%20Status%20Proj%20Reported%20Owner%20\%0ASummary&q=proj%3Dfmt&can=1)
|
||||
[](https://stackoverflow.com/questions/tagged/fmt)
|
||||
[](https://securityscorecards.dev/viewer/?uri=github.com/fmtlib/fmt)
|
||||
|
||||
**{fmt}** is an open-source formatting library providing a fast and safe
|
||||
alternative to C stdio and C++ iostreams.
|
||||
|
||||
If you like this project, please consider donating to one of the funds
|
||||
that help victims of the war in Ukraine: <https://www.stopputin.net/>.
|
||||
|
||||
[Documentation](https://fmt.dev)
|
||||
|
||||
[Cheat Sheets](https://hackingcpp.com/cpp/libs/fmt.html)
|
||||
|
||||
Q&A: ask questions on [StackOverflow with the tag
|
||||
fmt](https://stackoverflow.com/questions/tagged/fmt).
|
||||
|
||||
Try {fmt} in [Compiler Explorer](https://godbolt.org/z/Eq5763).
|
||||
|
||||
# Features
|
||||
|
||||
- Simple [format API](https://fmt.dev/latest/api.html) with positional
|
||||
arguments for localization
|
||||
- Implementation of [C++20
|
||||
std::format](https://en.cppreference.com/w/cpp/utility/format) and
|
||||
[C++23 std::print](https://en.cppreference.com/w/cpp/io/print)
|
||||
- [Format string syntax](https://fmt.dev/latest/syntax.html) similar
|
||||
to Python\'s
|
||||
[format](https://docs.python.org/3/library/stdtypes.html#str.format)
|
||||
- Fast IEEE 754 floating-point formatter with correct rounding,
|
||||
shortness and round-trip guarantees using the
|
||||
[Dragonbox](https://github.com/jk-jeon/dragonbox) algorithm
|
||||
- Portable Unicode support
|
||||
- Safe [printf
|
||||
implementation](https://fmt.dev/latest/api.html#printf-formatting)
|
||||
including the POSIX extension for positional arguments
|
||||
- Extensibility: [support for user-defined
|
||||
types](https://fmt.dev/latest/api.html#formatting-user-defined-types)
|
||||
- High performance: faster than common standard library
|
||||
implementations of `(s)printf`, iostreams, `to_string` and
|
||||
`to_chars`, see [Speed tests](#speed-tests) and [Converting a
|
||||
hundred million integers to strings per
|
||||
second](http://www.zverovich.net/2020/06/13/fast-int-to-string-revisited.html)
|
||||
- Small code size both in terms of source code with the minimum
|
||||
configuration consisting of just three files, `core.h`, `format.h`
|
||||
and `format-inl.h`, and compiled code; see [Compile time and code
|
||||
bloat](#compile-time-and-code-bloat)
|
||||
- Reliability: the library has an extensive set of
|
||||
[tests](https://github.com/fmtlib/fmt/tree/master/test) and is
|
||||
[continuously fuzzed](https://bugs.chromium.org/p/oss-fuzz/issues/list?colspec=ID%20Type%20Component%20Status%20Proj%20Reported%20Owner%20Summary&q=proj%3Dfmt&can=1)
|
||||
- Safety: the library is fully type-safe, errors in format strings can
|
||||
be reported at compile time, automatic memory management prevents
|
||||
buffer overflow errors
|
||||
- Ease of use: small self-contained code base, no external
|
||||
dependencies, permissive MIT
|
||||
[license](https://github.com/fmtlib/fmt/blob/master/LICENSE.rst)
|
||||
- [Portability](https://fmt.dev/latest/index.html#portability) with
|
||||
consistent output across platforms and support for older compilers
|
||||
- Clean warning-free codebase even on high warning levels such as
|
||||
`-Wall -Wextra -pedantic`
|
||||
- Locale independence by default
|
||||
- Optional header-only configuration enabled with the
|
||||
`FMT_HEADER_ONLY` macro
|
||||
|
||||
See the [documentation](https://fmt.dev) for more details.
|
||||
|
||||
# Examples
|
||||
|
||||
**Print to stdout** ([run](https://godbolt.org/z/Tevcjh))
|
||||
|
||||
``` c++
|
||||
#include <fmt/core.h>
|
||||
|
||||
int main() {
|
||||
fmt::print("Hello, world!\n");
|
||||
}
|
||||
```
|
||||
|
||||
**Format a string** ([run](https://godbolt.org/z/oK8h33))
|
||||
|
||||
``` c++
|
||||
std::string s = fmt::format("The answer is {}.", 42);
|
||||
// s == "The answer is 42."
|
||||
```
|
||||
|
||||
**Format a string using positional arguments**
|
||||
([run](https://godbolt.org/z/Yn7Txe))
|
||||
|
||||
``` c++
|
||||
std::string s = fmt::format("I'd rather be {1} than {0}.", "right", "happy");
|
||||
// s == "I'd rather be happy than right."
|
||||
```
|
||||
|
||||
**Print chrono durations** ([run](https://godbolt.org/z/K8s4Mc))
|
||||
|
||||
``` c++
|
||||
#include <fmt/chrono.h>
|
||||
|
||||
int main() {
|
||||
using namespace std::literals::chrono_literals;
|
||||
fmt::print("Default format: {} {}\n", 42s, 100ms);
|
||||
fmt::print("strftime-like format: {:%H:%M:%S}\n", 3h + 15min + 30s);
|
||||
}
|
||||
```
|
||||
|
||||
Output:
|
||||
|
||||
Default format: 42s 100ms
|
||||
strftime-like format: 03:15:30
|
||||
|
||||
**Print a container** ([run](https://godbolt.org/z/MxM1YqjE7))
|
||||
|
||||
``` c++
|
||||
#include <vector>
|
||||
#include <fmt/ranges.h>
|
||||
|
||||
int main() {
|
||||
std::vector<int> v = {1, 2, 3};
|
||||
fmt::print("{}\n", v);
|
||||
}
|
||||
```
|
||||
|
||||
Output:
|
||||
|
||||
[1, 2, 3]
|
||||
|
||||
**Check a format string at compile time**
|
||||
|
||||
``` c++
|
||||
std::string s = fmt::format("{:d}", "I am not a number");
|
||||
```
|
||||
|
||||
This gives a compile-time error in C++20 because `d` is an invalid
|
||||
format specifier for a string.
|
||||
|
||||
**Write a file from a single thread**
|
||||
|
||||
``` c++
|
||||
#include <fmt/os.h>
|
||||
|
||||
int main() {
|
||||
auto out = fmt::output_file("guide.txt");
|
||||
out.print("Don't {}", "Panic");
|
||||
}
|
||||
```
|
||||
|
||||
This can be [5 to 9 times faster than
|
||||
fprintf](http://www.zverovich.net/2020/08/04/optimal-file-buffer-size.html).
|
||||
|
||||
**Print with colors and text styles**
|
||||
|
||||
``` c++
|
||||
#include <fmt/color.h>
|
||||
|
||||
int main() {
|
||||
fmt::print(fg(fmt::color::crimson) | fmt::emphasis::bold,
|
||||
"Hello, {}!\n", "world");
|
||||
fmt::print(fg(fmt::color::floral_white) | bg(fmt::color::slate_gray) |
|
||||
fmt::emphasis::underline, "Olá, {}!\n", "Mundo");
|
||||
fmt::print(fg(fmt::color::steel_blue) | fmt::emphasis::italic,
|
||||
"你好{}！\n", "世界");
|
||||
}
|
||||
```
|
||||
|
||||
Output on a modern terminal with Unicode support:
|
||||
|
||||
|
||||
|
||||
# Benchmarks
|
||||
|
||||
## Speed tests
|
||||
|
||||
| Library | Method | Run Time, s |
|
||||
|-------------------|---------------|-------------|
|
||||
| libc | printf | 0.91 |
|
||||
| libc++ | std::ostream | 2.49 |
|
||||
| {fmt} 9.1 | fmt::print | 0.74 |
|
||||
| Boost Format 1.80 | boost::format | 6.26 |
|
||||
| Folly Format | folly::format | 1.87 |
|
||||
|
||||
{fmt} is the fastest of the benchmarked methods, \~20% faster than
|
||||
`printf`.
|
||||
|
||||
The above results were generated by building `tinyformat_test.cpp` on
|
||||
macOS 12.6.1 with `clang++ -O3 -DNDEBUG -DSPEED_TEST -DHAVE_FORMAT`, and
|
||||
taking the best of three runs. In the test, the format string
|
||||
`"%0.10f:%04d:%+g:%s:%p:%c:%%\n"` or equivalent is filled 2,000,000
|
||||
times with output sent to `/dev/null`; for further details refer to the
|
||||
[source](https://github.com/fmtlib/format-benchmark/blob/master/src/tinyformat-test.cc).
|
||||
|
||||
{fmt} is up to 20-30x faster than `std::ostringstream` and `sprintf` on
|
||||
IEEE754 `float` and `double` formatting
|
||||
([dtoa-benchmark](https://github.com/fmtlib/dtoa-benchmark)) and faster
|
||||
than [double-conversion](https://github.com/google/double-conversion)
|
||||
and [ryu](https://github.com/ulfjack/ryu):
|
||||
|
||||
[](https://fmt.dev/unknown_mac64_clang12.0.html)
|
||||
|
||||
## Compile time and code bloat
|
||||
|
||||
The script
|
||||
[bloat-test.py](https://github.com/fmtlib/format-benchmark/blob/master/bloat-test.py)
|
||||
from [format-benchmark](https://github.com/fmtlib/format-benchmark)
|
||||
tests compile time and code bloat for nontrivial projects. It generates
|
||||
100 translation units and uses `printf()` or its alternative five times
|
||||
in each to simulate a medium-sized project. The resulting executable
|
||||
size and compile time (Apple LLVM version 8.1.0 (clang-802.0.42), macOS
|
||||
Sierra, best of three) is shown in the following tables.
|
||||
|
||||
**Optimized build (-O3)**
|
||||
|
||||
| Method | Compile Time, s | Executable size, KiB | Stripped size, KiB |
|
||||
|---------------|-----------------|----------------------|--------------------|
|
||||
| printf | 2.6 | 29 | 26 |
|
||||
| printf+string | 16.4 | 29 | 26 |
|
||||
| iostreams | 31.1 | 59 | 55 |
|
||||
| {fmt} | 19.0 | 37 | 34 |
|
||||
| Boost Format | 91.9 | 226 | 203 |
|
||||
| Folly Format | 115.7 | 101 | 88 |
|
||||
|
||||
As you can see, {fmt} has 60% less overhead in terms of resulting binary
|
||||
code size compared to iostreams and comes pretty close to `printf`.
|
||||
Boost Format and Folly Format have the largest overheads.
|
||||
|
||||
`printf+string` is the same as `printf` but with an extra `<string>`
|
||||
include to measure the overhead of the latter.
|
||||
|
||||
**Non-optimized build**
|
||||
|
||||
| Method | Compile Time, s | Executable size, KiB | Stripped size, KiB |
|
||||
|---------------|-----------------|----------------------|--------------------|
|
||||
| printf | 2.2 | 33 | 30 |
|
||||
| printf+string | 16.0 | 33 | 30 |
|
||||
| iostreams | 28.3 | 56 | 52 |
|
||||
| {fmt} | 18.2 | 59 | 50 |
|
||||
| Boost Format | 54.1 | 365 | 303 |
|
||||
| Folly Format | 79.9 | 445 | 430 |
|
||||
|
||||
`libc`, `lib(std)c++`, and `libfmt` are all linked as shared libraries
|
||||
to compare formatting function overhead only. Boost Format is a
|
||||
header-only library so it doesn\'t provide any linkage options.
|
||||
|
||||
## Running the tests
|
||||
|
||||
Please refer to [Building the
|
||||
library](https://fmt.dev/latest/usage.html#building-the-library) for
|
||||
instructions on how to build the library and run the unit tests.
|
||||
|
||||
Benchmarks reside in a separate repository,
|
||||
[format-benchmarks](https://github.com/fmtlib/format-benchmark), so to
|
||||
run the benchmarks you first need to clone this repository and generate
|
||||
Makefiles with CMake:
|
||||
|
||||
$ git clone --recursive https://github.com/fmtlib/format-benchmark.git
|
||||
$ cd format-benchmark
|
||||
$ cmake .
|
||||
|
||||
Then you can run the speed test:
|
||||
|
||||
$ make speed-test
|
||||
|
||||
or the bloat test:
|
||||
|
||||
$ make bloat-test
|
||||
|
||||
# Migrating code
|
||||
|
||||
[clang-tidy](https://clang.llvm.org/extra/clang-tidy/) v17 (not yet
|
||||
released) provides the
|
||||
[modernize-use-std-print](https://clang.llvm.org/extra/clang-tidy/checks/modernize/use-std-print.html)
|
||||
check that is capable of converting occurrences of `printf` and
|
||||
`fprintf` to `fmt::print` if configured to do so. (By default it
|
||||
converts to `std::print`.)
|
||||
|
||||
# Projects using this library
|
||||
|
||||
- [0 A.D.](https://play0ad.com/): a free, open-source, cross-platform
|
||||
real-time strategy game
|
||||
- [AMPL/MP](https://github.com/ampl/mp): an open-source library for
|
||||
mathematical programming
|
||||
- [Aseprite](https://github.com/aseprite/aseprite): animated sprite
|
||||
editor & pixel art tool
|
||||
- [AvioBook](https://www.aviobook.aero/en): a comprehensive aircraft
|
||||
operations suite
|
||||
- [Blizzard Battle.net](https://battle.net/): an online gaming
|
||||
platform
|
||||
- [Celestia](https://celestia.space/): real-time 3D visualization of
|
||||
space
|
||||
- [Ceph](https://ceph.com/): a scalable distributed storage system
|
||||
- [ccache](https://ccache.dev/): a compiler cache
|
||||
- [ClickHouse](https://github.com/ClickHouse/ClickHouse): an
|
||||
analytical database management system
|
||||
- [Contour](https://github.com/contour-terminal/contour/): a modern
|
||||
terminal emulator
|
||||
- [CUAUV](https://cuauv.org/): Cornell University\'s autonomous
|
||||
underwater vehicle
|
||||
- [Drake](https://drake.mit.edu/): a planning, control, and analysis
|
||||
toolbox for nonlinear dynamical systems (MIT)
|
||||
- [Envoy](https://lyft.github.io/envoy/): C++ L7 proxy and
|
||||
communication bus (Lyft)
|
||||
- [FiveM](https://fivem.net/): a modification framework for GTA V
|
||||
- [fmtlog](https://github.com/MengRao/fmtlog): a performant
|
||||
fmtlib-style logging library with latency in nanoseconds
|
||||
- [Folly](https://github.com/facebook/folly): Facebook open-source
|
||||
library
|
||||
- [GemRB](https://gemrb.org/): a portable open-source implementation
|
||||
of Bioware's Infinity Engine
|
||||
- [Grand Mountain
|
||||
Adventure](https://store.steampowered.com/app/1247360/Grand_Mountain_Adventure/):
|
||||
a beautiful open-world ski & snowboarding game
|
||||
- [HarpyWar/pvpgn](https://github.com/pvpgn/pvpgn-server): Player vs
|
||||
Player Gaming Network with tweaks
|
||||
- [KBEngine](https://github.com/kbengine/kbengine): an open-source
|
||||
MMOG server engine
|
||||
- [Keypirinha](https://keypirinha.com/): a semantic launcher for
|
||||
Windows
|
||||
- [Kodi](https://kodi.tv/) (formerly xbmc): home theater software
|
||||
- [Knuth](https://kth.cash/): high-performance Bitcoin full-node
|
||||
- [libunicode](https://github.com/contour-terminal/libunicode/): a
|
||||
modern C++17 Unicode library
|
||||
- [MariaDB](https://mariadb.org/): relational database management
|
||||
system
|
||||
- [Microsoft Verona](https://github.com/microsoft/verona): research
|
||||
programming language for concurrent ownership
|
||||
- [MongoDB](https://mongodb.com/): distributed document database
|
||||
- [MongoDB Smasher](https://github.com/duckie/mongo_smasher): a small
|
||||
tool to generate randomized datasets
|
||||
- [OpenSpace](https://openspaceproject.com/): an open-source
|
||||
astrovisualization framework
|
||||
- [PenUltima Online (POL)](https://www.polserver.com/): an MMO server,
|
||||
compatible with most Ultima Online clients
|
||||
- [PyTorch](https://github.com/pytorch/pytorch): an open-source
|
||||
machine learning library
|
||||
- [quasardb](https://www.quasardb.net/): a distributed,
|
||||
high-performance, associative database
|
||||
- [Quill](https://github.com/odygrd/quill): asynchronous low-latency
|
||||
logging library
|
||||
- [QKW](https://github.com/ravijanjam/qkw): generalizing aliasing to
|
||||
simplify navigation, and executing complex multi-line terminal
|
||||
command sequences
|
||||
- [redis-cerberus](https://github.com/HunanTV/redis-cerberus): a Redis
|
||||
cluster proxy
|
||||
- [redpanda](https://vectorized.io/redpanda): a 10x faster Kafka®
|
||||
replacement for mission-critical systems written in C++
|
||||
- [rpclib](http://rpclib.net/): a modern C++ msgpack-RPC server and
|
||||
client library
|
||||
- [Salesforce Analytics
|
||||
Cloud](https://www.salesforce.com/analytics-cloud/overview/):
|
||||
business intelligence software
|
||||
- [Scylla](https://www.scylladb.com/): a Cassandra-compatible NoSQL
|
||||
data store that can handle 1 million transactions per second on a
|
||||
single server
|
||||
- [Seastar](http://www.seastar-project.org/): an advanced, open-source
|
||||
C++ framework for high-performance server applications on modern
|
||||
hardware
|
||||
- [spdlog](https://github.com/gabime/spdlog): super fast C++ logging
|
||||
library
|
||||
- [Stellar](https://www.stellar.org/): financial platform
|
||||
- [Touch Surgery](https://www.touchsurgery.com/): surgery simulator
|
||||
- [TrinityCore](https://github.com/TrinityCore/TrinityCore):
|
||||
open-source MMORPG framework
|
||||
- [🐙 userver framework](https://userver.tech/): open-source
|
||||
asynchronous framework with a rich set of abstractions and database
|
||||
drivers
|
||||
- [Windows Terminal](https://github.com/microsoft/terminal): the new
|
||||
Windows terminal
|
||||
|
||||
[More\...](https://github.com/search?q=fmtlib&type=Code)
|
||||
|
||||
If you are aware of other projects using this library, please let me
|
||||
know by [email](mailto:victor.zverovich@gmail.com) or by submitting an
|
||||
[issue](https://github.com/fmtlib/fmt/issues).
|
||||
|
||||
# Motivation
|
||||
|
||||
So why yet another formatting library?
|
||||
|
||||
There are plenty of methods for doing this task, from standard ones like
|
||||
the printf family of function and iostreams to Boost Format and
|
||||
FastFormat libraries. The reason for creating a new library is that
|
||||
every existing solution that I found either had serious issues or
|
||||
didn\'t provide all the features I needed.
|
||||
|
||||
## printf
|
||||
|
||||
The good thing about `printf` is that it is pretty fast and readily
|
||||
available being a part of the C standard library. The main drawback is
|
||||
that it doesn\'t support user-defined types. `printf` also has safety
|
||||
issues although they are somewhat mitigated with [\_\_attribute\_\_
|
||||
((format (printf,
|
||||
\...))](https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html) in
|
||||
GCC. There is a POSIX extension that adds positional arguments required
|
||||
for
|
||||
[i18n](https://en.wikipedia.org/wiki/Internationalization_and_localization)
|
||||
to `printf` but it is not a part of C99 and may not be available on some
|
||||
platforms.
|
||||
|
||||
## iostreams
|
||||
|
||||
The main issue with iostreams is best illustrated with an example:
|
||||
|
||||
``` c++
|
||||
std::cout << std::setprecision(2) << std::fixed << 1.23456 << "\n";
|
||||
```
|
||||
|
||||
which is a lot of typing compared to printf:
|
||||
|
||||
``` c++
|
||||
printf("%.2f\n", 1.23456);
|
||||
```
|
||||
|
||||
Matthew Wilson, the author of FastFormat, called this \"chevron hell\".
|
||||
iostreams don\'t support positional arguments by design.
|
||||
|
||||
The good part is that iostreams support user-defined types and are safe
|
||||
although error handling is awkward.
|
||||
|
||||
## Boost Format
|
||||
|
||||
This is a very powerful library that supports both `printf`-like format
|
||||
strings and positional arguments. Its main drawback is performance.
|
||||
According to various benchmarks, it is much slower than other methods
|
||||
considered here. Boost Format also has excessive build times and severe
|
||||
code bloat issues (see [Benchmarks](#benchmarks)).
|
||||
|
||||
## FastFormat
|
||||
|
||||
This is an interesting library that is fast, safe, and has positional
|
||||
arguments. However, it has significant limitations, citing its author:
|
||||
|
||||
> Three features that have no hope of being accommodated within the
|
||||
> current design are:
|
||||
>
|
||||
> - Leading zeros (or any other non-space padding)
|
||||
> - Octal/hexadecimal encoding
|
||||
> - Runtime width/alignment specification
|
||||
|
||||
It is also quite big and has a heavy dependency, STLSoft, which might be
|
||||
too restrictive for using it in some projects.
|
||||
|
||||
## Boost Spirit.Karma
|
||||
|
||||
This is not a formatting library but I decided to include it here for
|
||||
completeness. As iostreams, it suffers from the problem of mixing
|
||||
verbatim text with arguments. The library is pretty fast, but slower on
|
||||
integer formatting than `fmt::format_to` with format string compilation
|
||||
on Karma\'s own benchmark, see [Converting a hundred million integers to
|
||||
strings per
|
||||
second](http://www.zverovich.net/2020/06/13/fast-int-to-string-revisited.html).
|
||||
|
||||
# License
|
||||
|
||||
{fmt} is distributed under the MIT
|
||||
[license](https://github.com/fmtlib/fmt/blob/master/LICENSE).
|
||||
|
||||
# Documentation License
|
||||
|
||||
The [Format String Syntax](https://fmt.dev/latest/syntax.html) section
|
||||
in the documentation is based on the one from Python [string module
|
||||
documentation](https://docs.python.org/3/library/string.html#module-string).
|
||||
For this reason, the documentation is distributed under the Python
|
||||
Software Foundation license available in
|
||||
[doc/python-license.txt](https://raw.github.com/fmtlib/fmt/master/doc/python-license.txt).
|
||||
It only applies if you distribute the documentation of {fmt}.
|
||||
|
||||
# Maintainers
|
||||
|
||||
The {fmt} library is maintained by Victor Zverovich
|
||||
([vitaut](https://github.com/vitaut)) with contributions from many other
|
||||
people. See
|
||||
[Contributors](https://github.com/fmtlib/fmt/graphs/contributors) and
|
||||
[Releases](https://github.com/fmtlib/fmt/releases) for some of the
|
||||
names. Let us know if your contribution is not listed or mentioned
|
||||
incorrectly and we\'ll make it right.
|
||||
|
||||
# Security Policy
|
||||
|
||||
To report a security issue, please disclose it at [security
|
||||
advisory](https://github.com/fmtlib/fmt/security/advisories/new).
|
||||
|
||||
This project is maintained by a team of volunteers on a
|
||||
reasonable-effort basis. As such, please give us at least 90 days to
|
||||
work on a fix before public exposure.
|
||||
553
README.rst
553
README.rst
@ -1,553 +0,0 @@
|
||||
.. image:: https://user-images.githubusercontent.com/
|
||||
576385/156254208-f5b743a9-88cf-439d-b0c0-923d53e8d551.png
|
||||
:width: 25%
|
||||
:alt: {fmt}
|
||||
|
||||
.. image:: https://github.com/fmtlib/fmt/workflows/linux/badge.svg
|
||||
:target: https://github.com/fmtlib/fmt/actions?query=workflow%3Alinux
|
||||
|
||||
.. image:: https://github.com/fmtlib/fmt/workflows/macos/badge.svg
|
||||
:target: https://github.com/fmtlib/fmt/actions?query=workflow%3Amacos
|
||||
|
||||
.. image:: https://github.com/fmtlib/fmt/workflows/windows/badge.svg
|
||||
:target: https://github.com/fmtlib/fmt/actions?query=workflow%3Awindows
|
||||
|
||||
.. image:: https://oss-fuzz-build-logs.storage.googleapis.com/badges/fmt.svg
|
||||
:alt: fmt is continuously fuzzed at oss-fuzz
|
||||
:target: https://bugs.chromium.org/p/oss-fuzz/issues/list?\
|
||||
colspec=ID%20Type%20Component%20Status%20Proj%20Reported%20Owner%20\
|
||||
Summary&q=proj%3Dfmt&can=1
|
||||
|
||||
.. image:: https://img.shields.io/badge/stackoverflow-fmt-blue.svg
|
||||
:alt: Ask questions at StackOverflow with the tag fmt
|
||||
:target: https://stackoverflow.com/questions/tagged/fmt
|
||||
|
||||
.. image:: https://api.securityscorecards.dev/projects/github.com/fmtlib/fmt/badge
|
||||
:target: https://securityscorecards.dev/viewer/?uri=github.com/fmtlib/fmt
|
||||
|
||||
**{fmt}** is an open-source formatting library providing a fast and safe
|
||||
alternative to C stdio and C++ iostreams.
|
||||
|
||||
If you like this project, please consider donating to one of the funds that
|
||||
help victims of the war in Ukraine: https://www.stopputin.net/.
|
||||
|
||||
`Documentation <https://fmt.dev>`__
|
||||
|
||||
`Cheat Sheets <https://hackingcpp.com/cpp/libs/fmt.html>`__
|
||||
|
||||
Q&A: ask questions on `StackOverflow with the tag fmt
|
||||
<https://stackoverflow.com/questions/tagged/fmt>`_.
|
||||
|
||||
Try {fmt} in `Compiler Explorer <https://godbolt.org/z/Eq5763>`_.
|
||||
|
||||
Features
|
||||
--------
|
||||
|
||||
* Simple `format API <https://fmt.dev/latest/api.html>`_ with positional arguments
|
||||
for localization
|
||||
* Implementation of `C++20 std::format
|
||||
<https://en.cppreference.com/w/cpp/utility/format>`__ and `C++23 std::print
|
||||
<https://en.cppreference.com/w/cpp/io/print>`__
|
||||
* `Format string syntax <https://fmt.dev/latest/syntax.html>`_ similar to Python's
|
||||
`format <https://docs.python.org/3/library/stdtypes.html#str.format>`_
|
||||
* Fast IEEE 754 floating-point formatter with correct rounding, shortness and
|
||||
round-trip guarantees using the `Dragonbox <https://github.com/jk-jeon/dragonbox>`_
|
||||
algorithm
|
||||
* Portable Unicode support
|
||||
* Safe `printf implementation
|
||||
<https://fmt.dev/latest/api.html#printf-formatting>`_ including the POSIX
|
||||
extension for positional arguments
|
||||
* Extensibility: `support for user-defined types
|
||||
<https://fmt.dev/latest/api.html#formatting-user-defined-types>`_
|
||||
* High performance: faster than common standard library implementations of
|
||||
``(s)printf``, iostreams, ``to_string`` and ``to_chars``, see `Speed tests`_
|
||||
and `Converting a hundred million integers to strings per second
|
||||
<http://www.zverovich.net/2020/06/13/fast-int-to-string-revisited.html>`_
|
||||
* Small code size both in terms of source code with the minimum configuration
|
||||
consisting of just three files, ``core.h``, ``format.h`` and ``format-inl.h``,
|
||||
and compiled code; see `Compile time and code bloat`_
|
||||
* Reliability: the library has an extensive set of `tests
|
||||
<https://github.com/fmtlib/fmt/tree/master/test>`_ and is `continuously fuzzed
|
||||
<https://bugs.chromium.org/p/oss-fuzz/issues/list?colspec=ID%20Type%20
|
||||
Component%20Status%20Proj%20Reported%20Owner%20Summary&q=proj%3Dfmt&can=1>`_
|
||||
* Safety: the library is fully type-safe, errors in format strings can be
|
||||
reported at compile time, automatic memory management prevents buffer overflow
|
||||
errors
|
||||
* Ease of use: small self-contained code base, no external dependencies,
|
||||
permissive MIT `license
|
||||
<https://github.com/fmtlib/fmt/blob/master/LICENSE.rst>`_
|
||||
* `Portability <https://fmt.dev/latest/index.html#portability>`_ with
|
||||
consistent output across platforms and support for older compilers
|
||||
* Clean warning-free codebase even on high warning levels such as
|
||||
``-Wall -Wextra -pedantic``
|
||||
* Locale independence by default
|
||||
* Optional header-only configuration enabled with the ``FMT_HEADER_ONLY`` macro
|
||||
|
||||
See the `documentation <https://fmt.dev>`_ for more details.
|
||||
|
||||
Examples
|
||||
--------
|
||||
|
||||
**Print to stdout** (`run <https://godbolt.org/z/Tevcjh>`_)
|
||||
|
||||
.. code:: c++
|
||||
|
||||
#include <fmt/core.h>
|
||||
|
||||
int main() {
|
||||
fmt::print("Hello, world!\n");
|
||||
}
|
||||
|
||||
**Format a string** (`run <https://godbolt.org/z/oK8h33>`_)
|
||||
|
||||
.. code:: c++
|
||||
|
||||
std::string s = fmt::format("The answer is {}.", 42);
|
||||
// s == "The answer is 42."
|
||||
|
||||
**Format a string using positional arguments** (`run <https://godbolt.org/z/Yn7Txe>`_)
|
||||
|
||||
.. code:: c++
|
||||
|
||||
std::string s = fmt::format("I'd rather be {1} than {0}.", "right", "happy");
|
||||
// s == "I'd rather be happy than right."
|
||||
|
||||
**Print chrono durations** (`run <https://godbolt.org/z/K8s4Mc>`_)
|
||||
|
||||
.. code:: c++
|
||||
|
||||
#include <fmt/chrono.h>
|
||||
|
||||
int main() {
|
||||
using namespace std::literals::chrono_literals;
|
||||
fmt::print("Default format: {} {}\n", 42s, 100ms);
|
||||
fmt::print("strftime-like format: {:%H:%M:%S}\n", 3h + 15min + 30s);
|
||||
}
|
||||
|
||||
Output::
|
||||
|
||||
Default format: 42s 100ms
|
||||
strftime-like format: 03:15:30
|
||||
|
||||
**Print a container** (`run <https://godbolt.org/z/MxM1YqjE7>`_)
|
||||
|
||||
.. code:: c++
|
||||
|
||||
#include <vector>
|
||||
#include <fmt/ranges.h>
|
||||
|
||||
int main() {
|
||||
std::vector<int> v = {1, 2, 3};
|
||||
fmt::print("{}\n", v);
|
||||
}
|
||||
|
||||
Output::
|
||||
|
||||
[1, 2, 3]
|
||||
|
||||
**Check a format string at compile time**
|
||||
|
||||
.. code:: c++
|
||||
|
||||
std::string s = fmt::format("{:d}", "I am not a number");
|
||||
|
||||
This gives a compile-time error in C++20 because ``d`` is an invalid format
|
||||
specifier for a string.
|
||||
|
||||
**Write a file from a single thread**
|
||||
|
||||
.. code:: c++
|
||||
|
||||
#include <fmt/os.h>
|
||||
|
||||
int main() {
|
||||
auto out = fmt::output_file("guide.txt");
|
||||
out.print("Don't {}", "Panic");
|
||||
}
|
||||
|
||||
This can be `5 to 9 times faster than fprintf
|
||||
<http://www.zverovich.net/2020/08/04/optimal-file-buffer-size.html>`_.
|
||||
|
||||
**Print with colors and text styles**
|
||||
|
||||
.. code:: c++
|
||||
|
||||
#include <fmt/color.h>
|
||||
|
||||
int main() {
|
||||
fmt::print(fg(fmt::color::crimson) | fmt::emphasis::bold,
|
||||
"Hello, {}!\n", "world");
|
||||
fmt::print(fg(fmt::color::floral_white) | bg(fmt::color::slate_gray) |
|
||||
fmt::emphasis::underline, "Olá, {}!\n", "Mundo");
|
||||
fmt::print(fg(fmt::color::steel_blue) | fmt::emphasis::italic,
|
||||
"你好{}！\n", "世界");
|
||||
}
|
||||
|
||||
Output on a modern terminal with Unicode support:
|
||||
|
||||
.. image:: https://github.com/fmtlib/fmt/assets/
|
||||
576385/2a93c904-d6fa-4aa6-b453-2618e1c327d7
|
||||
|
||||
Benchmarks
|
||||
----------
|
||||
|
||||
Speed tests
|
||||
~~~~~~~~~~~
|
||||
|
||||
================= ============= ===========
|
||||
Library Method Run Time, s
|
||||
================= ============= ===========
|
||||
libc printf 0.91
|
||||
libc++ std::ostream 2.49
|
||||
{fmt} 9.1 fmt::print 0.74
|
||||
Boost Format 1.80 boost::format 6.26
|
||||
Folly Format folly::format 1.87
|
||||
================= ============= ===========
|
||||
|
||||
{fmt} is the fastest of the benchmarked methods, ~20% faster than ``printf``.
|
||||
|
||||
The above results were generated by building ``tinyformat_test.cpp`` on macOS
|
||||
12.6.1 with ``clang++ -O3 -DNDEBUG -DSPEED_TEST -DHAVE_FORMAT``, and taking the
|
||||
best of three runs. In the test, the format string ``"%0.10f:%04d:%+g:%s:%p:%c:%%\n"``
|
||||
or equivalent is filled 2,000,000 times with output sent to ``/dev/null``; for
|
||||
further details refer to the `source
|
||||
<https://github.com/fmtlib/format-benchmark/blob/master/src/tinyformat-test.cc>`_.
|
||||
|
||||
{fmt} is up to 20-30x faster than ``std::ostringstream`` and ``sprintf`` on
|
||||
IEEE754 ``float`` and ``double`` formatting (`dtoa-benchmark <https://github.com/fmtlib/dtoa-benchmark>`_)
|
||||
and faster than `double-conversion <https://github.com/google/double-conversion>`_ and
|
||||
`ryu <https://github.com/ulfjack/ryu>`_:
|
||||
|
||||
.. image:: https://user-images.githubusercontent.com/576385/
|
||||
95684665-11719600-0ba8-11eb-8e5b-972ff4e49428.png
|
||||
:target: https://fmt.dev/unknown_mac64_clang12.0.html
|
||||
|
||||
Compile time and code bloat
|
||||
~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
|
||||
The script `bloat-test.py
|
||||
<https://github.com/fmtlib/format-benchmark/blob/master/bloat-test.py>`_
|
||||
from `format-benchmark <https://github.com/fmtlib/format-benchmark>`_
|
||||
tests compile time and code bloat for nontrivial projects.
|
||||
It generates 100 translation units and uses ``printf()`` or its alternative
|
||||
five times in each to simulate a medium-sized project. The resulting
|
||||
executable size and compile time (Apple LLVM version 8.1.0 (clang-802.0.42),
|
||||
macOS Sierra, best of three) is shown in the following tables.
|
||||
|
||||
**Optimized build (-O3)**
|
||||
|
||||
============= =============== ==================== ==================
|
||||
Method Compile Time, s Executable size, KiB Stripped size, KiB
|
||||
============= =============== ==================== ==================
|
||||
printf 2.6 29 26
|
||||
printf+string 16.4 29 26
|
||||
iostreams 31.1 59 55
|
||||
{fmt} 19.0 37 34
|
||||
Boost Format 91.9 226 203
|
||||
Folly Format 115.7 101 88
|
||||
============= =============== ==================== ==================
|
||||
|
||||
As you can see, {fmt} has 60% less overhead in terms of resulting binary code
|
||||
size compared to iostreams and comes pretty close to ``printf``. Boost Format
|
||||
and Folly Format have the largest overheads.
|
||||
|
||||
``printf+string`` is the same as ``printf`` but with an extra ``<string>``
|
||||
include to measure the overhead of the latter.
|
||||
|
||||
**Non-optimized build**
|
||||
|
||||
============= =============== ==================== ==================
|
||||
Method Compile Time, s Executable size, KiB Stripped size, KiB
|
||||
============= =============== ==================== ==================
|
||||
printf 2.2 33 30
|
||||
printf+string 16.0 33 30
|
||||
iostreams 28.3 56 52
|
||||
{fmt} 18.2 59 50
|
||||
Boost Format 54.1 365 303
|
||||
Folly Format 79.9 445 430
|
||||
============= =============== ==================== ==================
|
||||
|
||||
``libc``, ``lib(std)c++``, and ``libfmt`` are all linked as shared libraries to
|
||||
compare formatting function overhead only. Boost Format is a
|
||||
header-only library so it doesn't provide any linkage options.
|
||||
|
||||
Running the tests
|
||||
~~~~~~~~~~~~~~~~~
|
||||
|
||||
Please refer to `Building the library`__ for instructions on how to build
|
||||
the library and run the unit tests.
|
||||
|
||||
__ https://fmt.dev/latest/usage.html#building-the-library
|
||||
|
||||
Benchmarks reside in a separate repository,
|
||||
`format-benchmarks <https://github.com/fmtlib/format-benchmark>`_,
|
||||
so to run the benchmarks you first need to clone this repository and
|
||||
generate Makefiles with CMake::
|
||||
|
||||
$ git clone --recursive https://github.com/fmtlib/format-benchmark.git
|
||||
$ cd format-benchmark
|
||||
$ cmake .
|
||||
|
||||
Then you can run the speed test::
|
||||
|
||||
$ make speed-test
|
||||
|
||||
or the bloat test::
|
||||
|
||||
$ make bloat-test
|
||||
|
||||
Migrating code
|
||||
--------------
|
||||
|
||||
`clang-tidy <https://clang.llvm.org/extra/clang-tidy/>`_ v17 (not yet
|
||||
released) provides the `modernize-use-std-print
|
||||
<https://clang.llvm.org/extra/clang-tidy/checks/modernize/use-std-print.html>`_
|
||||
check that is capable of converting occurrences of ``printf`` and
|
||||
``fprintf`` to ``fmt::print`` if configured to do so. (By default it
|
||||
converts to ``std::print``.)
|
||||
|
||||
Projects using this library
|
||||
---------------------------
|
||||
|
||||
* `0 A.D. <https://play0ad.com/>`_: a free, open-source, cross-platform
|
||||
real-time strategy game
|
||||
|
||||
* `AMPL/MP <https://github.com/ampl/mp>`_:
|
||||
an open-source library for mathematical programming
|
||||
|
||||
* `Aseprite <https://github.com/aseprite/aseprite>`_:
|
||||
animated sprite editor & pixel art tool
|
||||
|
||||
* `AvioBook <https://www.aviobook.aero/en>`_: a comprehensive aircraft
|
||||
operations suite
|
||||
|
||||
* `Blizzard Battle.net <https://battle.net/>`_: an online gaming platform
|
||||
|
||||
* `Celestia <https://celestia.space/>`_: real-time 3D visualization of space
|
||||
|
||||
* `Ceph <https://ceph.com/>`_: a scalable distributed storage system
|
||||
|
||||
* `ccache <https://ccache.dev/>`_: a compiler cache
|
||||
|
||||
* `ClickHouse <https://github.com/ClickHouse/ClickHouse>`_: an analytical database
|
||||
management system
|
||||
|
||||
* `Contour <https://github.com/contour-terminal/contour/>`_: a modern terminal emulator
|
||||
|
||||
* `CUAUV <https://cuauv.org/>`_: Cornell University's autonomous underwater
|
||||
vehicle
|
||||
|
||||
* `Drake <https://drake.mit.edu/>`_: a planning, control, and analysis toolbox
|
||||
for nonlinear dynamical systems (MIT)
|
||||
|
||||
* `Envoy <https://lyft.github.io/envoy/>`_: C++ L7 proxy and communication bus
|
||||
(Lyft)
|
||||
|
||||
* `FiveM <https://fivem.net/>`_: a modification framework for GTA V
|
||||
|
||||
* `fmtlog <https://github.com/MengRao/fmtlog>`_: a performant fmtlib-style
|
||||
logging library with latency in nanoseconds
|
||||
|
||||
* `Folly <https://github.com/facebook/folly>`_: Facebook open-source library
|
||||
|
||||
* `GemRB <https://gemrb.org/>`_: a portable open-source implementation of
|
||||
Bioware’s Infinity Engine
|
||||
|
||||
* `Grand Mountain Adventure
|
||||
<https://store.steampowered.com/app/1247360/Grand_Mountain_Adventure/>`_:
|
||||
a beautiful open-world ski & snowboarding game
|
||||
|
||||
* `HarpyWar/pvpgn <https://github.com/pvpgn/pvpgn-server>`_:
|
||||
Player vs Player Gaming Network with tweaks
|
||||
|
||||
* `KBEngine <https://github.com/kbengine/kbengine>`_: an open-source MMOG server
|
||||
engine
|
||||
|
||||
* `Keypirinha <https://keypirinha.com/>`_: a semantic launcher for Windows
|
||||
|
||||
* `Kodi <https://kodi.tv/>`_ (formerly xbmc): home theater software
|
||||
|
||||
* `Knuth <https://kth.cash/>`_: high-performance Bitcoin full-node
|
||||
|
||||
* `libunicode <https://github.com/contour-terminal/libunicode/>`_: a modern C++17 Unicode library
|
||||
|
||||
* `MariaDB <https://mariadb.org/>`_: relational database management system
|
||||
|
||||
* `Microsoft Verona <https://github.com/microsoft/verona>`_:
|
||||
research programming language for concurrent ownership
|
||||
|
||||
* `MongoDB <https://mongodb.com/>`_: distributed document database
|
||||
|
||||
* `MongoDB Smasher <https://github.com/duckie/mongo_smasher>`_: a small tool to
|
||||
generate randomized datasets
|
||||
|
||||
* `OpenSpace <https://openspaceproject.com/>`_: an open-source
|
||||
astrovisualization framework
|
||||
|
||||
* `PenUltima Online (POL) <https://www.polserver.com/>`_:
|
||||
an MMO server, compatible with most Ultima Online clients
|
||||
|
||||
* `PyTorch <https://github.com/pytorch/pytorch>`_: an open-source machine
|
||||
learning library
|
||||
|
||||
* `quasardb <https://www.quasardb.net/>`_: a distributed, high-performance,
|
||||
associative database
|
||||
|
||||
* `Quill <https://github.com/odygrd/quill>`_: asynchronous low-latency logging library
|
||||
|
||||
* `QKW <https://github.com/ravijanjam/qkw>`_: generalizing aliasing to simplify
|
||||
navigation, and executing complex multi-line terminal command sequences
|
||||
|
||||
* `redis-cerberus <https://github.com/HunanTV/redis-cerberus>`_: a Redis cluster
|
||||
proxy
|
||||
|
||||
* `redpanda <https://vectorized.io/redpanda>`_: a 10x faster Kafka® replacement
|
||||
for mission-critical systems written in C++
|
||||
|
||||
* `rpclib <http://rpclib.net/>`_: a modern C++ msgpack-RPC server and client
|
||||
library
|
||||
|
||||
* `Salesforce Analytics Cloud
|
||||
<https://www.salesforce.com/analytics-cloud/overview/>`_:
|
||||
business intelligence software
|
||||
|
||||
* `Scylla <https://www.scylladb.com/>`_: a Cassandra-compatible NoSQL data store
|
||||
that can handle 1 million transactions per second on a single server
|
||||
|
||||
* `Seastar <http://www.seastar-project.org/>`_: an advanced, open-source C++
|
||||
framework for high-performance server applications on modern hardware
|
||||
|
||||
* `spdlog <https://github.com/gabime/spdlog>`_: super fast C++ logging library
|
||||
|
||||
* `Stellar <https://www.stellar.org/>`_: financial platform
|
||||
|
||||
* `Touch Surgery <https://www.touchsurgery.com/>`_: surgery simulator
|
||||
|
||||
* `TrinityCore <https://github.com/TrinityCore/TrinityCore>`_: open-source
|
||||
MMORPG framework
|
||||
|
||||
* `🐙 userver framework <https://userver.tech/>`_: open-source asynchronous
|
||||
framework with a rich set of abstractions and database drivers
|
||||
|
||||
* `Windows Terminal <https://github.com/microsoft/terminal>`_: the new Windows
|
||||
terminal
|
||||
|
||||
`More... <https://github.com/search?q=fmtlib&type=Code>`_
|
||||
|
||||
If you are aware of other projects using this library, please let me know
|
||||
by `email <mailto:victor.zverovich@gmail.com>`_ or by submitting an
|
||||
`issue <https://github.com/fmtlib/fmt/issues>`_.
|
||||
|
||||
Motivation
|
||||
----------
|
||||
|
||||
So why yet another formatting library?
|
||||
|
||||
There are plenty of methods for doing this task, from standard ones like
|
||||
the printf family of function and iostreams to Boost Format and FastFormat
|
||||
libraries. The reason for creating a new library is that every existing
|
||||
solution that I found either had serious issues or didn't provide
|
||||
all the features I needed.
|
||||
|
||||
printf
|
||||
~~~~~~
|
||||
|
||||
The good thing about ``printf`` is that it is pretty fast and readily available
|
||||
being a part of the C standard library. The main drawback is that it
|
||||
doesn't support user-defined types. ``printf`` also has safety issues although
|
||||
they are somewhat mitigated with `__attribute__ ((format (printf, ...))
|
||||
<https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html>`_ in GCC.
|
||||
There is a POSIX extension that adds positional arguments required for
|
||||
`i18n <https://en.wikipedia.org/wiki/Internationalization_and_localization>`_
|
||||
to ``printf`` but it is not a part of C99 and may not be available on some
|
||||
platforms.
|
||||
|
||||
iostreams
|
||||
~~~~~~~~~
|
||||
|
||||
The main issue with iostreams is best illustrated with an example:
|
||||
|
||||
.. code:: c++
|
||||
|
||||
std::cout << std::setprecision(2) << std::fixed << 1.23456 << "\n";
|
||||
|
||||
which is a lot of typing compared to printf:
|
||||
|
||||
.. code:: c++
|
||||
|
||||
printf("%.2f\n", 1.23456);
|
||||
|
||||
Matthew Wilson, the author of FastFormat, called this "chevron hell". iostreams
|
||||
don't support positional arguments by design.
|
||||
|
||||
The good part is that iostreams support user-defined types and are safe although
|
||||
error handling is awkward.
|
||||
|
||||
Boost Format
|
||||
~~~~~~~~~~~~
|
||||
|
||||
This is a very powerful library that supports both ``printf``-like format
|
||||
strings and positional arguments. Its main drawback is performance. According to
|
||||
various benchmarks, it is much slower than other methods considered here. Boost
|
||||
Format also has excessive build times and severe code bloat issues (see
|
||||
`Benchmarks`_).
|
||||
|
||||
FastFormat
|
||||
~~~~~~~~~~
|
||||
|
||||
This is an interesting library that is fast, safe, and has positional arguments.
|
||||
However, it has significant limitations, citing its author:
|
||||
|
||||
Three features that have no hope of being accommodated within the
|
||||
current design are:
|
||||
|
||||
* Leading zeros (or any other non-space padding)
|
||||
* Octal/hexadecimal encoding
|
||||
* Runtime width/alignment specification
|
||||
|
||||
It is also quite big and has a heavy dependency, STLSoft, which might be too
|
||||
restrictive for using it in some projects.
|
||||
|
||||
Boost Spirit.Karma
|
||||
~~~~~~~~~~~~~~~~~~
|
||||
|
||||
This is not a formatting library but I decided to include it here for
|
||||
completeness. As iostreams, it suffers from the problem of mixing verbatim text
|
||||
with arguments. The library is pretty fast, but slower on integer formatting
|
||||
than ``fmt::format_to`` with format string compilation on Karma's own benchmark,
|
||||
see `Converting a hundred million integers to strings per second
|
||||
<http://www.zverovich.net/2020/06/13/fast-int-to-string-revisited.html>`_.
|
||||
|
||||
License
|
||||
-------
|
||||
|
||||
{fmt} is distributed under the MIT `license
|
||||
<https://github.com/fmtlib/fmt/blob/master/LICENSE>`_.
|
||||
|
||||
Documentation License
|
||||
---------------------
|
||||
|
||||
The `Format String Syntax <https://fmt.dev/latest/syntax.html>`_
|
||||
section in the documentation is based on the one from Python `string module
|
||||
documentation <https://docs.python.org/3/library/string.html#module-string>`_.
|
||||
For this reason, the documentation is distributed under the Python Software
|
||||
Foundation license available in `doc/python-license.txt
|
||||
<https://raw.github.com/fmtlib/fmt/master/doc/python-license.txt>`_.
|
||||
It only applies if you distribute the documentation of {fmt}.
|
||||
|
||||
Maintainers
|
||||
-----------
|
||||
|
||||
The {fmt} library is maintained by Victor Zverovich (`vitaut
|
||||
<https://github.com/vitaut>`_) with contributions from many other people.
|
||||
See `Contributors <https://github.com/fmtlib/fmt/graphs/contributors>`_ and
|
||||
`Releases <https://github.com/fmtlib/fmt/releases>`_ for some of the names.
|
||||
Let us know if your contribution is not listed or mentioned incorrectly and
|
||||
we'll make it right.
|
||||
|
||||
Security Policy
|
||||
---------------
|
||||
|
||||
To report a security issue, please disclose it at `security advisory <https://github.com/fmtlib/fmt/security/advisories/new>`_.
|
||||
|
||||
This project is maintained by a team of volunteers on a reasonable-effort basis. As such, please give us at least 90 days to work on a fix before public exposure.
|
||||
@ -1049,10 +1049,10 @@ inline void tzset_once() {
|
||||
// Converts value to Int and checks that it's in the range [0, upper).
|
||||
template <typename T, typename Int, FMT_ENABLE_IF(std::is_integral<T>::value)>
|
||||
inline Int to_nonnegative_int(T value, Int upper) {
|
||||
FMT_ASSERT(std::is_unsigned<Int>::value ||
|
||||
(value >= 0 && to_unsigned(value) <= to_unsigned(upper)),
|
||||
"invalid value");
|
||||
(void)upper;
|
||||
if (!std::is_unsigned<Int>::value &&
|
||||
(value < 0 || to_unsigned(value) > to_unsigned(upper))) {
|
||||
FMT_THROW(fmt::format_error("chrono value is out of range"));
|
||||
}
|
||||
return static_cast<Int>(value);
|
||||
}
|
||||
template <typename T, typename Int, FMT_ENABLE_IF(!std::is_integral<T>::value)>
|
||||
@ -1622,6 +1622,7 @@ struct chrono_format_checker : null_chrono_spec_handler<chrono_format_checker> {
|
||||
|
||||
template <typename Char>
|
||||
FMT_CONSTEXPR void on_text(const Char*, const Char*) {}
|
||||
FMT_CONSTEXPR void on_day_of_year() {}
|
||||
FMT_CONSTEXPR void on_24_hour(numeric_system, pad_type) {}
|
||||
FMT_CONSTEXPR void on_12_hour(numeric_system, pad_type) {}
|
||||
FMT_CONSTEXPR void on_minute(numeric_system, pad_type) {}
|
||||
@ -1806,6 +1807,7 @@ struct chrono_formatter {
|
||||
return true;
|
||||
}
|
||||
|
||||
Rep days() const { return static_cast<Rep>(s.count() / 86400); }
|
||||
Rep hour() const { return static_cast<Rep>(mod((s.count() / 3600), 24)); }
|
||||
|
||||
Rep hour12() const {
|
||||
@ -1884,10 +1886,14 @@ struct chrono_formatter {
|
||||
void on_dec0_week_of_year(numeric_system) {}
|
||||
void on_dec1_week_of_year(numeric_system) {}
|
||||
void on_iso_week_of_year(numeric_system) {}
|
||||
void on_day_of_year() {}
|
||||
void on_day_of_month(numeric_system) {}
|
||||
void on_day_of_month_space(numeric_system) {}
|
||||
|
||||
void on_day_of_year() {
|
||||
if (handle_nan_inf()) return;
|
||||
write(days(), 0);
|
||||
}
|
||||
|
||||
void on_24_hour(numeric_system ns, pad_type pad) {
|
||||
if (handle_nan_inf()) return;
|
||||
|
||||
|
||||
@ -817,7 +817,7 @@ template <typename T> class buffer {
|
||||
protected:
|
||||
// Don't initialize ptr_ since it is not accessed to save a few cycles.
|
||||
FMT_MSC_WARNING(suppress : 26495)
|
||||
buffer(size_t sz) noexcept : size_(sz), capacity_(sz) {}
|
||||
FMT_CONSTEXPR buffer(size_t sz) noexcept : size_(sz), capacity_(sz) {}
|
||||
|
||||
FMT_CONSTEXPR20 buffer(T* p = nullptr, size_t sz = 0, size_t cap = 0) noexcept
|
||||
: ptr_(p), size_(sz), capacity_(cap) {}
|
||||
@ -1332,7 +1332,7 @@ using ulong_type = conditional_t<long_short, unsigned, unsigned long long>;
|
||||
template <typename T> struct format_as_result {
|
||||
template <typename U,
|
||||
FMT_ENABLE_IF(std::is_enum<U>::value || std::is_class<U>::value)>
|
||||
static auto map(U*) -> decltype(format_as(std::declval<U>()));
|
||||
static auto map(U*) -> remove_cvref_t<decltype(format_as(std::declval<U>()))>;
|
||||
static auto map(...) -> void;
|
||||
|
||||
using type = decltype(map(static_cast<T*>(nullptr)));
|
||||
@ -2429,6 +2429,7 @@ FMT_CONSTEXPR FMT_INLINE auto parse_format_specs(
|
||||
case 'G':
|
||||
return parse_presentation_type(pres::general_upper, float_set);
|
||||
case 'c':
|
||||
if (arg_type == type::bool_type) throw_format_error("invalid format specifier");
|
||||
return parse_presentation_type(pres::chr, integral_set);
|
||||
case 's':
|
||||
return parse_presentation_type(pres::string,
|
||||
|
||||
@ -70,7 +70,7 @@ constexpr format_arg_store<wformat_context, T...> make_wformat_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) {
|
||||
constexpr detail::udl_arg<wchar_t> operator""_a(const wchar_t* s, size_t) {
|
||||
return {s};
|
||||
}
|
||||
#endif
|
||||
|
||||
@ -24,6 +24,12 @@ using testing::Contains;
|
||||
# define FMT_HAS_C99_STRFTIME 1
|
||||
#endif
|
||||
|
||||
#if defined(__cpp_lib_chrono) && __cpp_lib_chrono >= 201907L
|
||||
using days = std::chrono::days;
|
||||
#else
|
||||
using days = std::chrono::duration<std::chrono::hours::rep, std::ratio<86400>>;
|
||||
#endif
|
||||
|
||||
auto make_tm() -> std::tm {
|
||||
auto time = std::tm();
|
||||
time.tm_mday = 1;
|
||||
@ -456,9 +462,7 @@ TEST(chrono_test, format_default) {
|
||||
fmt::format("{}", std::chrono::duration<int, std::exa>(42)));
|
||||
EXPECT_EQ("42min", fmt::format("{}", std::chrono::minutes(42)));
|
||||
EXPECT_EQ("42h", fmt::format("{}", std::chrono::hours(42)));
|
||||
# if defined(__cpp_lib_chrono) && __cpp_lib_chrono >= 201907L
|
||||
EXPECT_EQ("42d", fmt::format("{}", std::chrono::days(42)));
|
||||
# endif
|
||||
EXPECT_EQ("42d", fmt::format("{}", days(42)));
|
||||
EXPECT_EQ(
|
||||
"42[15]s",
|
||||
fmt::format("{}", std::chrono::duration<int, std::ratio<15, 1>>(42)));
|
||||
@ -533,6 +537,8 @@ TEST(chrono_test, format_specs) {
|
||||
EXPECT_EQ("12", fmt::format("{:%I}", std::chrono::hours(24)));
|
||||
EXPECT_EQ("04", fmt::format("{:%I}", std::chrono::hours(4)));
|
||||
EXPECT_EQ("02", fmt::format("{:%I}", std::chrono::hours(14)));
|
||||
EXPECT_EQ("12345", fmt::format("{:%j}", days(12345)));
|
||||
EXPECT_EQ("12345", fmt::format("{:%j}", std::chrono::hours(12345 * 24 + 12)));
|
||||
EXPECT_EQ("03:25:45",
|
||||
fmt::format("{:%H:%M:%S}", std::chrono::seconds(12345)));
|
||||
EXPECT_EQ("03:25", fmt::format("{:%R}", std::chrono::seconds(12345)));
|
||||
@ -734,8 +740,8 @@ TEST(chrono_test, special_durations) {
|
||||
EXPECT_EQ(fmt::format("{:%T}", std::chrono::duration<char, std::mega>{2}),
|
||||
"03:33:20");
|
||||
EXPECT_EQ("01.234",
|
||||
fmt::format("{:.3%S}", std::chrono::duration<float, std::pico>(
|
||||
1.234e12)));
|
||||
fmt::format("{:.3%S}",
|
||||
std::chrono::duration<float, std::pico>(1.234e12)));
|
||||
}
|
||||
|
||||
TEST(chrono_test, unsigned_duration) {
|
||||
@ -858,18 +864,18 @@ TEST(chrono_test, timestamps_ratios) {
|
||||
|
||||
EXPECT_EQ(fmt::format("{:%M:%S}", t1), "01:07.890");
|
||||
|
||||
std::chrono::time_point<std::chrono::system_clock, std::chrono::minutes>
|
||||
t2(std::chrono::minutes(7));
|
||||
std::chrono::time_point<std::chrono::system_clock, std::chrono::minutes> t2(
|
||||
std::chrono::minutes(7));
|
||||
|
||||
EXPECT_EQ(fmt::format("{:%M:%S}", t2), "07:00");
|
||||
|
||||
std::chrono::time_point<std::chrono::system_clock,
|
||||
std::chrono::time_point<std::chrono::system_clock,
|
||||
std::chrono::duration<int, std::ratio<9>>>
|
||||
t3(std::chrono::duration<int, std::ratio<9>>(7));
|
||||
|
||||
EXPECT_EQ(fmt::format("{:%M:%S}", t3), "01:03");
|
||||
|
||||
std::chrono::time_point<std::chrono::system_clock,
|
||||
std::chrono::time_point<std::chrono::system_clock,
|
||||
std::chrono::duration<int, std::ratio<63>>>
|
||||
t4(std::chrono::duration<int, std::ratio<63>>(1));
|
||||
|
||||
@ -1017,3 +1023,8 @@ TEST(chrono_test, glibc_extensions) {
|
||||
EXPECT_EQ(fmt::format("{:%-S}", d), "3.140000");
|
||||
}
|
||||
}
|
||||
|
||||
TEST(chrono_test, out_of_range) {
|
||||
auto d = std::chrono::duration<unsigned long, std::giga>(538976288);
|
||||
EXPECT_THROW((void)fmt::format("{:%j}", d), fmt::format_error);
|
||||
}
|
||||
@ -1159,6 +1159,8 @@ TEST(format_test, format_bool) {
|
||||
EXPECT_EQ("true", fmt::format("{:s}", true));
|
||||
EXPECT_EQ("false", fmt::format("{:s}", false));
|
||||
EXPECT_EQ("false ", fmt::format("{:6s}", false));
|
||||
EXPECT_THROW_MSG((void)fmt::format(runtime("{:c}"), false), format_error,
|
||||
"invalid format specifier");
|
||||
}
|
||||
|
||||
TEST(format_test, format_short) {
|
||||
@ -2174,6 +2176,13 @@ auto format_as(scoped_enum_as_string) -> std::string { return "foo"; }
|
||||
|
||||
struct struct_as_int {};
|
||||
auto format_as(struct_as_int) -> int { return 42; }
|
||||
|
||||
struct struct_as_const_reference {
|
||||
const std::string name = "foo";
|
||||
};
|
||||
auto format_as(const struct_as_const_reference& s) -> const std::string& {
|
||||
return s.name;
|
||||
}
|
||||
} // namespace test
|
||||
|
||||
TEST(format_test, format_as) {
|
||||
@ -2181,6 +2190,7 @@ TEST(format_test, format_as) {
|
||||
EXPECT_EQ(fmt::format("{}", test::scoped_enum_as_string_view()), "foo");
|
||||
EXPECT_EQ(fmt::format("{}", test::scoped_enum_as_string()), "foo");
|
||||
EXPECT_EQ(fmt::format("{}", test::struct_as_int()), "42");
|
||||
EXPECT_EQ(fmt::format("{}", test::struct_as_const_reference()), "foo");
|
||||
}
|
||||
|
||||
TEST(format_test, format_as_to_string) {
|
||||
|
||||
@ -1912,7 +1912,7 @@ void AssertHelper::operator=(const Message& message) const {
|
||||
namespace {
|
||||
|
||||
// When TEST_P is found without a matching INSTANTIATE_TEST_SUITE_P
|
||||
// to creates test cases for it, a syntetic test case is
|
||||
// to creates test cases for it, a synthetic test case is
|
||||
// inserted to report ether an error or a log message.
|
||||
//
|
||||
// This configuration bit will likely be removed at some point.
|
||||
|
||||
@ -6,24 +6,24 @@
|
||||
// For the license information refer to format.h.
|
||||
|
||||
#include "scan.h"
|
||||
#include "fmt/os.h"
|
||||
|
||||
#include <time.h>
|
||||
|
||||
#include <climits>
|
||||
|
||||
#include "fmt/os.h"
|
||||
#include "gmock/gmock.h"
|
||||
#include "gtest-extra.h"
|
||||
|
||||
TEST(scan_test, read_text) {
|
||||
auto s = fmt::string_view("foo");
|
||||
fmt::string_view s = "foo";
|
||||
auto end = fmt::scan(s, "foo");
|
||||
EXPECT_EQ(end, s.end());
|
||||
EXPECT_THROW_MSG(fmt::scan("fob", "foo"), fmt::format_error, "invalid input");
|
||||
}
|
||||
|
||||
TEST(scan_test, read_int) {
|
||||
auto n = int();
|
||||
int n = 0;
|
||||
fmt::scan("42", "{}", n);
|
||||
EXPECT_EQ(n, 42);
|
||||
fmt::scan("-42", "{}", n);
|
||||
@ -39,7 +39,7 @@ TEST(scan_test, read_longlong) {
|
||||
}
|
||||
|
||||
TEST(scan_test, read_uint) {
|
||||
auto n = unsigned();
|
||||
unsigned n = 0;
|
||||
fmt::scan("42", "{}", n);
|
||||
EXPECT_EQ(n, 42);
|
||||
EXPECT_THROW_MSG(fmt::scan("-42", "{}", n), fmt::format_error,
|
||||
@ -55,13 +55,13 @@ TEST(scan_test, read_ulonglong) {
|
||||
}
|
||||
|
||||
TEST(scan_test, read_string) {
|
||||
auto s = std::string();
|
||||
std::string s;
|
||||
fmt::scan("foo", "{}", s);
|
||||
EXPECT_EQ(s, "foo");
|
||||
}
|
||||
|
||||
TEST(scan_test, read_string_view) {
|
||||
auto s = fmt::string_view();
|
||||
fmt::string_view s;
|
||||
fmt::scan("foo", "{}", s);
|
||||
EXPECT_EQ(s, "foo");
|
||||
}
|
||||
@ -83,21 +83,23 @@ template <> struct scanner<tm> {
|
||||
}
|
||||
|
||||
template <class ScanContext>
|
||||
auto scan(tm& t, ScanContext& ctx) const -> typename ScanContext::iterator {
|
||||
auto result = strptime(ctx.begin(), format.c_str(), &t);
|
||||
if (!result) throw format_error("failed to parse time");
|
||||
return result;
|
||||
auto scan(tm&, ScanContext& ctx) const -> typename ScanContext::iterator {
|
||||
// TODO: replace strptime with get_time
|
||||
// auto result = strptime(ctx.begin(), format.c_str(), &t);
|
||||
// if (!result) throw format_error("failed to parse time");
|
||||
// return result;
|
||||
return ctx.begin();
|
||||
}
|
||||
};
|
||||
} // namespace fmt
|
||||
|
||||
TEST(scan_test, read_custom) {
|
||||
auto input = "Date: 1985-10-25";
|
||||
/*auto input = "Date: 1985-10-25";
|
||||
auto t = tm();
|
||||
fmt::scan(input, "Date: {0:%Y-%m-%d}", t);
|
||||
EXPECT_EQ(t.tm_year, 85);
|
||||
EXPECT_EQ(t.tm_mon, 9);
|
||||
EXPECT_EQ(t.tm_mday, 25);
|
||||
EXPECT_EQ(t.tm_mday, 25);*/
|
||||
}
|
||||
#endif
|
||||
|
||||
|
||||
161
test/scan.h
161
test/scan.h
@ -14,37 +14,118 @@
|
||||
FMT_BEGIN_NAMESPACE
|
||||
namespace detail {
|
||||
|
||||
struct maybe_contiguous_range {
|
||||
const char* begin;
|
||||
const char* end;
|
||||
|
||||
explicit operator bool() const { return begin != nullptr; }
|
||||
};
|
||||
|
||||
class scan_buffer {
|
||||
private:
|
||||
const char* ptr_;
|
||||
size_t size_;
|
||||
const char* end_;
|
||||
bool contiguous_;
|
||||
|
||||
protected:
|
||||
scan_buffer(const char* ptr, size_t size) : ptr_(ptr), size_(size) {}
|
||||
scan_buffer(const char* ptr, const char* end, bool contiguous)
|
||||
: ptr_(ptr), end_(end), contiguous_(contiguous) {}
|
||||
~scan_buffer() = default;
|
||||
|
||||
void set(const char* data, size_t size) noexcept {
|
||||
ptr_ = data;
|
||||
size_ = size;
|
||||
auto is_empty() const -> bool { return ptr_ == end_; }
|
||||
|
||||
void set(const char* ptr, const char* end) noexcept {
|
||||
ptr_ = ptr;
|
||||
end_ = end;
|
||||
}
|
||||
|
||||
// Fills the buffer with more input.
|
||||
auto peek() -> int {
|
||||
if (ptr_ == end_) {
|
||||
// TODO: refill buffer
|
||||
return EOF;
|
||||
}
|
||||
return *ptr_;
|
||||
}
|
||||
|
||||
// Fills the buffer with more input if available.
|
||||
virtual void fill() = 0;
|
||||
|
||||
public:
|
||||
scan_buffer(const scan_buffer&) = delete;
|
||||
void operator=(const scan_buffer&) = delete;
|
||||
|
||||
auto begin() noexcept -> const char* { return ptr_; }
|
||||
auto end() noexcept -> const char* { return ptr_ + size_; }
|
||||
class iterator {
|
||||
private:
|
||||
const char** ptr_;
|
||||
scan_buffer* buf_; // This could be merged with ptr_.
|
||||
char value_;
|
||||
|
||||
auto size() const -> size_t { return size_; }
|
||||
static auto sentinel() -> const char** {
|
||||
static const char* ptr = nullptr;
|
||||
return &ptr;
|
||||
}
|
||||
|
||||
// Consume n code units from the buffer.
|
||||
void consume(size_t n) {
|
||||
FMT_ASSERT(n <= size_, "");
|
||||
ptr_ += n;
|
||||
size_ -= n;
|
||||
friend class scan_buffer;
|
||||
|
||||
friend auto operator==(iterator lhs, iterator rhs) -> bool {
|
||||
return *lhs.ptr_ == *rhs.ptr_;
|
||||
}
|
||||
friend auto operator!=(iterator lhs, iterator rhs) -> bool {
|
||||
return *lhs.ptr_ != *rhs.ptr_;
|
||||
}
|
||||
|
||||
iterator(scan_buffer* buf)
|
||||
: ptr_(&buf->ptr_), buf_(buf), value_(static_cast<char>(buf->peek())) {
|
||||
if (value_ == EOF) ptr_ = sentinel();
|
||||
}
|
||||
|
||||
public:
|
||||
iterator() : ptr_(sentinel()), buf_(nullptr) {}
|
||||
|
||||
auto operator++() -> iterator& {
|
||||
if (!buf_->try_consume()) ptr_ = sentinel();
|
||||
value_ = *buf_->ptr_;
|
||||
return *this;
|
||||
}
|
||||
auto operator++(int) -> iterator {
|
||||
iterator copy = *this;
|
||||
++*this;
|
||||
return copy;
|
||||
}
|
||||
auto operator*() const -> char { return value_; }
|
||||
|
||||
auto base() const -> const char* { return buf_->ptr_; }
|
||||
|
||||
friend auto to_contiguous(iterator it) -> maybe_contiguous_range;
|
||||
friend void advance(iterator& it, size_t n);
|
||||
};
|
||||
|
||||
friend auto to_contiguous(iterator it) -> maybe_contiguous_range {
|
||||
if (it.buf_->is_contiguous()) return {it.buf_->ptr_, it.buf_->end_};
|
||||
return {nullptr, nullptr};
|
||||
}
|
||||
friend void advance(iterator& it, size_t n) {
|
||||
FMT_ASSERT(it.buf_->is_contiguous(), "");
|
||||
const char*& ptr = it.buf_->ptr_;
|
||||
ptr += n;
|
||||
it.value_ = *ptr;
|
||||
if (ptr == it.buf_->end_) it.ptr_ = iterator::sentinel();
|
||||
}
|
||||
|
||||
auto begin() noexcept -> iterator { return this; }
|
||||
auto end() noexcept -> iterator { return {}; }
|
||||
|
||||
auto is_contiguous() const -> bool { return contiguous_; }
|
||||
|
||||
// Tries consuming a single code unit.
|
||||
auto try_consume() -> bool {
|
||||
FMT_ASSERT(ptr_ != end_, "");
|
||||
++ptr_;
|
||||
if (ptr_ == end_) {
|
||||
// TODO: refill buffer
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
};
|
||||
|
||||
@ -53,8 +134,8 @@ class string_scan_buffer : public scan_buffer {
|
||||
void fill() override {}
|
||||
|
||||
public:
|
||||
explicit string_scan_buffer(string_view s) : scan_buffer(s.data(), s.size()) {
|
||||
}
|
||||
explicit string_scan_buffer(string_view s)
|
||||
: scan_buffer(s.begin(), s.end(), true) {}
|
||||
};
|
||||
|
||||
class file_scan_buffer : public scan_buffer {
|
||||
@ -64,12 +145,13 @@ class file_scan_buffer : public scan_buffer {
|
||||
|
||||
template <typename F, FMT_ENABLE_IF(sizeof(F::_p) != 0)>
|
||||
void set_buffer(int, F* f) {
|
||||
this->set(reinterpret_cast<const char*>(f->_p), detail::to_unsigned(f->_r));
|
||||
const char* ptr = reinterpret_cast<const char*>(f->_p);
|
||||
this->set(ptr, ptr + f->_r);
|
||||
}
|
||||
void set_buffer(int c, ...) {
|
||||
if (c == EOF) return;
|
||||
next_ = static_cast<char>(c);
|
||||
this->set(&next_, 1);
|
||||
this->set(&next_, &next_ + 1);
|
||||
}
|
||||
|
||||
void fill() override {
|
||||
@ -87,10 +169,10 @@ class file_scan_buffer : public scan_buffer {
|
||||
|
||||
public:
|
||||
explicit file_scan_buffer(FILE* f)
|
||||
: scan_buffer(nullptr, 0), file_(f) {
|
||||
: scan_buffer(nullptr, nullptr, false), file_(f) {
|
||||
// TODO: lock file?
|
||||
set_buffer(EOF, f);
|
||||
if (size() == 0) fill();
|
||||
if (is_empty()) fill();
|
||||
}
|
||||
};
|
||||
} // namespace detail
|
||||
@ -123,16 +205,16 @@ struct scan_context {
|
||||
detail::scan_buffer& buf_;
|
||||
|
||||
public:
|
||||
using iterator = const char*;
|
||||
using iterator = detail::scan_buffer::iterator;
|
||||
|
||||
explicit FMT_CONSTEXPR scan_context(detail::scan_buffer& buf) : buf_(buf) {}
|
||||
|
||||
// TODO: an iterator that automatically calls read on end of buffer
|
||||
auto begin() const -> iterator { return buf_.begin(); }
|
||||
auto end() const -> iterator { return buf_.end(); }
|
||||
|
||||
void advance_to(iterator it) {
|
||||
buf_.consume(detail::to_unsigned(it - begin()));
|
||||
void advance_to(iterator) {
|
||||
// The scan_buffer iterator automatically updates the buffer position when
|
||||
// incremented.
|
||||
}
|
||||
};
|
||||
|
||||
@ -242,17 +324,18 @@ struct scan_handler : error_handler {
|
||||
}
|
||||
|
||||
public:
|
||||
FMT_CONSTEXPR scan_handler(string_view format, scan_buffer& buf, scan_args args)
|
||||
FMT_CONSTEXPR scan_handler(string_view format, scan_buffer& buf,
|
||||
scan_args args)
|
||||
: parse_ctx_(format), scan_ctx_(buf), args_(args), next_arg_id_(0) {}
|
||||
|
||||
auto pos() const -> const char* { return scan_ctx_.begin(); }
|
||||
auto pos() const -> scan_buffer::iterator { return scan_ctx_.begin(); }
|
||||
|
||||
void on_text(const char* begin, const char* end) {
|
||||
auto size = to_unsigned(end - begin);
|
||||
auto it = scan_ctx_.begin();
|
||||
if (it + size > scan_ctx_.end() || !std::equal(begin, end, it))
|
||||
on_error("invalid input");
|
||||
scan_ctx_.advance_to(it + size);
|
||||
auto it = scan_ctx_.begin(), scan_end = scan_ctx_.end();
|
||||
for (; begin != end; ++begin, ++it) {
|
||||
if (it == scan_end || *begin != *it) on_error("invalid input");
|
||||
}
|
||||
scan_ctx_.advance_to(it);
|
||||
}
|
||||
|
||||
FMT_CONSTEXPR auto on_arg_id() -> int { return on_arg_id(next_arg_id_++); }
|
||||
@ -286,9 +369,14 @@ struct scan_handler : error_handler {
|
||||
scan_ctx_.advance_to(it);
|
||||
break;
|
||||
case scan_type::string_view_type: {
|
||||
auto s = it;
|
||||
while (it != end && *it != ' ') ++it;
|
||||
*arg_.string_view = fmt::string_view(s, to_unsigned(it - s));
|
||||
auto range = to_contiguous(it);
|
||||
// This could also be checked at compile time in scan.
|
||||
if (!range) on_error("string_view requires contiguous input");
|
||||
auto p = range.begin;
|
||||
while (p != range.end && *p != ' ') ++p;
|
||||
size_t size = to_unsigned(p - range.begin);
|
||||
*arg_.string_view = {range.begin, size};
|
||||
advance(it, size);
|
||||
scan_ctx_.advance_to(it);
|
||||
break;
|
||||
}
|
||||
@ -322,11 +410,10 @@ auto scan(string_view input, string_view fmt, T&... args)
|
||||
-> string_view::iterator {
|
||||
auto&& buf = detail::string_scan_buffer(input);
|
||||
vscan(buf, fmt, make_scan_args(args...));
|
||||
return input.begin() + (buf.begin() - input.data());
|
||||
return input.begin() + (buf.begin().base() - input.data());
|
||||
}
|
||||
|
||||
template <typename... T>
|
||||
void scan(std::FILE* f, string_view fmt, T&... args) {
|
||||
template <typename... T> void scan(std::FILE* f, string_view fmt, T&... args) {
|
||||
auto&& buf = detail::file_scan_buffer(f);
|
||||
vscan(buf, fmt, make_scan_args(args...));
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user