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| author | Stefan Boberg <[email protected]> | 2025-11-07 14:49:13 +0100 |
|---|---|---|
| committer | GitHub Enterprise <[email protected]> | 2025-11-07 14:49:13 +0100 |
| commit | 24e43a913f29ac3b314354e8ce5175f135bcc64f (patch) | |
| tree | ca442937ceeb63461012b33a4576e9835099f106 /thirdparty/fmt/doc | |
| parent | get oplog attachments (#622) (diff) | |
| download | zen-24e43a913f29ac3b314354e8ce5175f135bcc64f.tar.xz zen-24e43a913f29ac3b314354e8ce5175f135bcc64f.zip | |
switch to xmake for package management (#611)
This change removes our dependency on vcpkg for package management, in favour of bringing some code in-tree in the `thirdparty` folder as well as using the xmake build-in package management feature. For the latter, all the package definitions are maintained in the zen repo itself, in the `repo` folder.
It should now also be easier to build the project as it will no longer depend on having the right version of vcpkg installed, which has been a common problem for new people coming in to the codebase. Now you should only need xmake to build.
* Bumps xmake requirement on github runners to 2.9.9 to resolve an issue where xmake on Windows invokes cmake with `v144` toolchain which does not exist
* BLAKE3 is now in-tree at `thirdparty/blake3`
* cpr is now in-tree at `thirdparty/cpr`
* cxxopts is now in-tree at `thirdparty/cxxopts`
* fmt is now in-tree at `thirdparty/fmt`
* robin-map is now in-tree at `thirdparty/robin-map`
* ryml is now in-tree at `thirdparty/ryml`
* sol2 is now in-tree at `thirdparty/sol2`
* spdlog is now in-tree at `thirdparty/spdlog`
* utfcpp is now in-tree at `thirdparty/utfcpp`
* xmake package repo definitions is in `repo`
* implemented support for sanitizers. ASAN is supported on windows, TSAN, UBSAN, MSAN etc are supported on Linux/MacOS though I have not yet tested it extensively on MacOS
* the zencore encryption implementation also now supports using mbedTLS which is used on MacOS, though for now we still use openssl on Linux
* crashpad
* bumps libcurl to 8.11.0 (from 8.8.0) which should address a rare build upload bug
Diffstat (limited to 'thirdparty/fmt/doc')
| -rw-r--r-- | thirdparty/fmt/doc/ChangeLog-old.md | 3290 | ||||
| -rw-r--r-- | thirdparty/fmt/doc/api.md | 710 | ||||
| -rw-r--r-- | thirdparty/fmt/doc/fmt.css | 61 | ||||
| -rw-r--r-- | thirdparty/fmt/doc/fmt.js | 4 | ||||
| -rw-r--r-- | thirdparty/fmt/doc/get-started.md | 233 | ||||
| -rw-r--r-- | thirdparty/fmt/doc/index.md | 151 | ||||
| -rw-r--r-- | thirdparty/fmt/doc/perf.svg | 1 | ||||
| -rw-r--r-- | thirdparty/fmt/doc/python-license.txt | 290 | ||||
| -rw-r--r-- | thirdparty/fmt/doc/syntax.md | 886 |
9 files changed, 5626 insertions, 0 deletions
diff --git a/thirdparty/fmt/doc/ChangeLog-old.md b/thirdparty/fmt/doc/ChangeLog-old.md new file mode 100644 index 000000000..e8f993c42 --- /dev/null +++ b/thirdparty/fmt/doc/ChangeLog-old.md @@ -0,0 +1,3290 @@ +# 7.1.3 - 2020-11-24 + +- Fixed handling of buffer boundaries in `format_to_n` + (https://github.com/fmtlib/fmt/issues/1996, + https://github.com/fmtlib/fmt/issues/2029). +- Fixed linkage errors when linking with a shared library + (https://github.com/fmtlib/fmt/issues/2011). +- Reintroduced ostream support to range formatters + (https://github.com/fmtlib/fmt/issues/2014). +- Worked around an issue with mixing std versions in gcc + (https://github.com/fmtlib/fmt/issues/2017). + +# 7.1.2 - 2020-11-04 + +- Fixed floating point formatting with large precision + (https://github.com/fmtlib/fmt/issues/1976). + +# 7.1.1 - 2020-11-01 + +- Fixed ABI compatibility with 7.0.x + (https://github.com/fmtlib/fmt/issues/1961). +- Added the `FMT_ARM_ABI_COMPATIBILITY` macro to work around ABI + incompatibility between GCC and Clang on ARM + (https://github.com/fmtlib/fmt/issues/1919). +- Worked around a SFINAE bug in GCC 8 + (https://github.com/fmtlib/fmt/issues/1957). +- Fixed linkage errors when building with GCC\'s LTO + (https://github.com/fmtlib/fmt/issues/1955). +- Fixed a compilation error when building without `__builtin_clz` or + equivalent (https://github.com/fmtlib/fmt/pull/1968). + Thanks @tohammer. +- Fixed a sign conversion warning + (https://github.com/fmtlib/fmt/pull/1964). Thanks @OptoCloud. + +# 7.1.0 - 2020-10-25 + +- Switched from + [Grisu3](https://www.cs.tufts.edu/~nr/cs257/archive/florian-loitsch/printf.pdf) + to [Dragonbox](https://github.com/jk-jeon/dragonbox) for the default + floating-point formatting which gives the shortest decimal + representation with round-trip guarantee and correct rounding + (https://github.com/fmtlib/fmt/pull/1882, + https://github.com/fmtlib/fmt/pull/1887, + https://github.com/fmtlib/fmt/pull/1894). This makes {fmt} + up to 20-30x faster than common implementations of + `std::ostringstream` and `sprintf` on + [dtoa-benchmark](https://github.com/fmtlib/dtoa-benchmark) and + faster than double-conversion and Ryū: + +  + + It is possible to get even better performance at the cost of larger + binary size by compiling with the `FMT_USE_FULL_CACHE_DRAGONBOX` + macro set to 1. + + Thanks @jk-jeon. + +- Added an experimental unsynchronized file output API which, together + with [format string + compilation](https://fmt.dev/latest/api.html#compile-api), can give + [5-9 times speed up compared to + fprintf](https://www.zverovich.net/2020/08/04/optimal-file-buffer-size.html) + on common platforms ([godbolt](https://godbolt.org/z/nsTcG8)): + + ```c++ + #include <fmt/os.h> + + int main() { + auto f = fmt::output_file("guide"); + f.print("The answer is {}.", 42); + } + ``` + +- Added a formatter for `std::chrono::time_point<system_clock>` + (https://github.com/fmtlib/fmt/issues/1819, + https://github.com/fmtlib/fmt/pull/1837). For example + ([godbolt](https://godbolt.org/z/c4M6fh)): + + ```c++ + #include <fmt/chrono.h> + + int main() { + auto now = std::chrono::system_clock::now(); + fmt::print("The time is {:%H:%M:%S}.\n", now); + } + ``` + + Thanks @adamburgess. + +- Added support for ranges with non-const `begin`/`end` to `fmt::join` + (https://github.com/fmtlib/fmt/issues/1784, + https://github.com/fmtlib/fmt/pull/1786). For example + ([godbolt](https://godbolt.org/z/jP63Tv)): + + ```c++ + #include <fmt/ranges.h> + #include <range/v3/view/filter.hpp> + + int main() { + using std::literals::string_literals::operator""s; + auto strs = std::array{"a"s, "bb"s, "ccc"s}; + auto range = strs | ranges::views::filter( + [] (const std::string &x) { return x.size() != 2; } + ); + fmt::print("{}\n", fmt::join(range, "")); + } + ``` + + prints \"accc\". + + Thanks @tonyelewis. + +- Added a `memory_buffer::append` overload that takes a range + (https://github.com/fmtlib/fmt/pull/1806). Thanks @BRevzin. + +- Improved handling of single code units in `FMT_COMPILE`. For + example: + + ```c++ + #include <fmt/compile.h> + + char* f(char* buf) { + return fmt::format_to(buf, FMT_COMPILE("x{}"), 42); + } + ``` + + compiles to just ([godbolt](https://godbolt.org/z/5vncz3)): + + ```asm + _Z1fPc: + movb $120, (%rdi) + xorl %edx, %edx + cmpl $42, _ZN3fmt2v76detail10basic_dataIvE23zero_or_powers_of_10_32E+8(%rip) + movl $3, %eax + seta %dl + subl %edx, %eax + movzwl _ZN3fmt2v76detail10basic_dataIvE6digitsE+84(%rip), %edx + cltq + addq %rdi, %rax + movw %dx, -2(%rax) + ret + ``` + + Here a single `mov` instruction writes `'x'` (`$120`) to the output + buffer. + +- Added dynamic width support to format string compilation + (https://github.com/fmtlib/fmt/issues/1809). + +- Improved error reporting for unformattable types: now you\'ll get + the type name directly in the error message instead of the note: + + ```c++ + #include <fmt/core.h> + + struct how_about_no {}; + + int main() { + fmt::print("{}", how_about_no()); + } + ``` + + Error ([godbolt](https://godbolt.org/z/GoxM4e)): + + `fmt/core.h:1438:3: error: static_assert failed due to requirement 'fmt::v7::formattable<how_about_no>()' "Cannot format an argument. To make type T formattable provide a formatter<T> specialization: https://fmt.dev/latest/api.html#udt" ...` + +- Added the + [make_args_checked](https://fmt.dev/7.1.0/api.html#argument-lists) + function template that allows you to write formatting functions with + compile-time format string checks and avoid binary code bloat + ([godbolt](https://godbolt.org/z/PEf9qr)): + + ```c++ + void vlog(const char* file, int line, fmt::string_view format, + fmt::format_args args) { + fmt::print("{}: {}: ", file, line); + fmt::vprint(format, args); + } + + template <typename S, typename... Args> + void log(const char* file, int line, const S& format, Args&&... args) { + vlog(file, line, format, + fmt::make_args_checked<Args...>(format, args...)); + } + + #define MY_LOG(format, ...) \ + log(__FILE__, __LINE__, FMT_STRING(format), __VA_ARGS__) + + MY_LOG("invalid squishiness: {}", 42); + ``` + +- Replaced `snprintf` fallback with a faster internal IEEE 754 `float` + and `double` formatter for arbitrary precision. For example + ([godbolt](https://godbolt.org/z/dPhWvj)): + + ```c++ + #include <fmt/core.h> + + int main() { + fmt::print("{:.500}\n", 4.9406564584124654E-324); + } + ``` + + prints + + `4.9406564584124654417656879286822137236505980261432476442558568250067550727020875186529983636163599237979656469544571773092665671035593979639877479601078187812630071319031140452784581716784898210368871863605699873072305000638740915356498438731247339727316961514003171538539807412623856559117102665855668676818703956031062493194527159149245532930545654440112748012970999954193198940908041656332452475714786901472678015935523861155013480352649347201937902681071074917033322268447533357208324319360923829e-324`. + +- Made `format_to_n` and `formatted_size` part of the [core + API](https://fmt.dev/latest/api.html#core-api) + ([godbolt](https://godbolt.org/z/sPjY1K)): + + ```c++ + #include <fmt/core.h> + + int main() { + char buffer[10]; + auto result = fmt::format_to_n(buffer, sizeof(buffer), "{}", 42); + } + ``` + +- Added `fmt::format_to_n` overload with format string compilation + (https://github.com/fmtlib/fmt/issues/1764, + https://github.com/fmtlib/fmt/pull/1767, + https://github.com/fmtlib/fmt/pull/1869). For example + ([godbolt](https://godbolt.org/z/93h86q)): + + ```c++ + #include <fmt/compile.h> + + int main() { + char buffer[8]; + fmt::format_to_n(buffer, sizeof(buffer), FMT_COMPILE("{}"), 42); + } + ``` + + Thanks @Kurkin and @alexezeder. + +- Added `fmt::format_to` overload that take `text_style` + (https://github.com/fmtlib/fmt/issues/1593, + https://github.com/fmtlib/fmt/issues/1842, + https://github.com/fmtlib/fmt/pull/1843). For example + ([godbolt](https://godbolt.org/z/91153r)): + + ```c++ + #include <fmt/color.h> + + int main() { + std::string out; + fmt::format_to(std::back_inserter(out), + fmt::emphasis::bold | fg(fmt::color::red), + "The answer is {}.", 42); + } + ``` + + Thanks @Naios. + +- Made the `'#'` specifier emit trailing zeros in addition to the + decimal point (https://github.com/fmtlib/fmt/issues/1797). + For example ([godbolt](https://godbolt.org/z/bhdcW9)): + + ```c++ + #include <fmt/core.h> + + int main() { + fmt::print("{:#.2g}", 0.5); + } + ``` + + prints `0.50`. + +- Changed the default floating point format to not include `.0` for + consistency with `std::format` and `std::to_chars` + (https://github.com/fmtlib/fmt/issues/1893, + https://github.com/fmtlib/fmt/issues/1943). It is possible + to get the decimal point and trailing zero with the `#` specifier. + +- Fixed an issue with floating-point formatting that could result in + addition of a non-significant trailing zero in rare cases e.g. + `1.00e-34` instead of `1.0e-34` + (https://github.com/fmtlib/fmt/issues/1873, + https://github.com/fmtlib/fmt/issues/1917). + +- Made `fmt::to_string` fallback on `ostream` insertion operator if + the `formatter` specialization is not provided + (https://github.com/fmtlib/fmt/issues/1815, + https://github.com/fmtlib/fmt/pull/1829). Thanks @alexezeder. + +- Added support for the append mode to the experimental file API and + improved `fcntl.h` detection. + (https://github.com/fmtlib/fmt/pull/1847, + https://github.com/fmtlib/fmt/pull/1848). Thanks @t-wiser. + +- Fixed handling of types that have both an implicit conversion + operator and an overloaded `ostream` insertion operator + (https://github.com/fmtlib/fmt/issues/1766). + +- Fixed a slicing issue in an internal iterator type + (https://github.com/fmtlib/fmt/pull/1822). Thanks @BRevzin. + +- Fixed an issue in locale-specific integer formatting + (https://github.com/fmtlib/fmt/issues/1927). + +- Fixed handling of exotic code unit types + (https://github.com/fmtlib/fmt/issues/1870, + https://github.com/fmtlib/fmt/issues/1932). + +- Improved `FMT_ALWAYS_INLINE` + (https://github.com/fmtlib/fmt/pull/1878). Thanks @jk-jeon. + +- Removed dependency on `windows.h` + (https://github.com/fmtlib/fmt/pull/1900). Thanks @bernd5. + +- Optimized counting of decimal digits on MSVC + (https://github.com/fmtlib/fmt/pull/1890). Thanks @mwinterb. + +- Improved documentation + (https://github.com/fmtlib/fmt/issues/1772, + https://github.com/fmtlib/fmt/pull/1775, + https://github.com/fmtlib/fmt/pull/1792, + https://github.com/fmtlib/fmt/pull/1838, + https://github.com/fmtlib/fmt/pull/1888, + https://github.com/fmtlib/fmt/pull/1918, + https://github.com/fmtlib/fmt/pull/1939). + Thanks @leolchat, @pepsiman, @Klaim, @ravijanjam, @francesco-st and @udnaan. + +- Added the `FMT_REDUCE_INT_INSTANTIATIONS` CMake option that reduces + the binary code size at the cost of some integer formatting + performance. This can be useful for extremely memory-constrained + embedded systems + (https://github.com/fmtlib/fmt/issues/1778, + https://github.com/fmtlib/fmt/pull/1781). Thanks @kammce. + +- Added the `FMT_USE_INLINE_NAMESPACES` macro to control usage of + inline namespaces + (https://github.com/fmtlib/fmt/pull/1945). Thanks @darklukee. + +- Improved build configuration + (https://github.com/fmtlib/fmt/pull/1760, + https://github.com/fmtlib/fmt/pull/1770, + https://github.com/fmtlib/fmt/issues/1779, + https://github.com/fmtlib/fmt/pull/1783, + https://github.com/fmtlib/fmt/pull/1823). + Thanks @dvetutnev, @xvitaly, @tambry, @medithe and @martinwuehrer. + +- Fixed various warnings and compilation issues + (https://github.com/fmtlib/fmt/pull/1790, + https://github.com/fmtlib/fmt/pull/1802, + https://github.com/fmtlib/fmt/pull/1808, + https://github.com/fmtlib/fmt/issues/1810, + https://github.com/fmtlib/fmt/issues/1811, + https://github.com/fmtlib/fmt/pull/1812, + https://github.com/fmtlib/fmt/pull/1814, + https://github.com/fmtlib/fmt/pull/1816, + https://github.com/fmtlib/fmt/pull/1817, + https://github.com/fmtlib/fmt/pull/1818, + https://github.com/fmtlib/fmt/issues/1825, + https://github.com/fmtlib/fmt/pull/1836, + https://github.com/fmtlib/fmt/pull/1855, + https://github.com/fmtlib/fmt/pull/1856, + https://github.com/fmtlib/fmt/pull/1860, + https://github.com/fmtlib/fmt/pull/1877, + https://github.com/fmtlib/fmt/pull/1879, + https://github.com/fmtlib/fmt/pull/1880, + https://github.com/fmtlib/fmt/issues/1896, + https://github.com/fmtlib/fmt/pull/1897, + https://github.com/fmtlib/fmt/pull/1898, + https://github.com/fmtlib/fmt/issues/1904, + https://github.com/fmtlib/fmt/pull/1908, + https://github.com/fmtlib/fmt/issues/1911, + https://github.com/fmtlib/fmt/issues/1912, + https://github.com/fmtlib/fmt/issues/1928, + https://github.com/fmtlib/fmt/pull/1929, + https://github.com/fmtlib/fmt/issues/1935, + https://github.com/fmtlib/fmt/pull/1937, + https://github.com/fmtlib/fmt/pull/1942, + https://github.com/fmtlib/fmt/issues/1949). + Thanks @TheQwertiest, @medithe, @martinwuehrer, @n16h7hunt3r, @Othereum, + @gsjaardema, @AlexanderLanin, @gcerretani, @chronoxor, @noizefloor, + @akohlmey, @jk-jeon, @rimathia, @rglarix, @moiwi, @heckad, @MarcDirven. + @BartSiwek and @darklukee. + +# 7.0.3 - 2020-08-06 + +- Worked around broken `numeric_limits` for 128-bit integers + (https://github.com/fmtlib/fmt/issues/1787). +- Added error reporting on missing named arguments + (https://github.com/fmtlib/fmt/issues/1796). +- Stopped using 128-bit integers with clang-cl + (https://github.com/fmtlib/fmt/pull/1800). Thanks @Kingcom. +- Fixed issues in locale-specific integer formatting + (https://github.com/fmtlib/fmt/issues/1782, + https://github.com/fmtlib/fmt/issues/1801). + +# 7.0.2 - 2020-07-29 + +- Worked around broken `numeric_limits` for 128-bit integers + (https://github.com/fmtlib/fmt/issues/1725). +- Fixed compatibility with CMake 3.4 + (https://github.com/fmtlib/fmt/issues/1779). +- Fixed handling of digit separators in locale-specific formatting + (https://github.com/fmtlib/fmt/issues/1782). + +# 7.0.1 - 2020-07-07 + +- Updated the inline version namespace name. +- Worked around a gcc bug in mangling of alias templates + (https://github.com/fmtlib/fmt/issues/1753). +- Fixed a linkage error on Windows + (https://github.com/fmtlib/fmt/issues/1757). Thanks @Kurkin. +- Fixed minor issues with the documentation. + +# 7.0.0 - 2020-07-05 + +- Reduced the library size. For example, on macOS a stripped test + binary statically linked with {fmt} [shrank from \~368k to less than + 100k](http://www.zverovich.net/2020/05/21/reducing-library-size.html). + +- Added a simpler and more efficient [format string compilation + API](https://fmt.dev/7.0.0/api.html#compile-api): + + ```c++ + #include <fmt/compile.h> + + // Converts 42 into std::string using the most efficient method and no + // runtime format string processing. + std::string s = fmt::format(FMT_COMPILE("{}"), 42); + ``` + + The old `fmt::compile` API is now deprecated. + +- Optimized integer formatting: `format_to` with format string + compilation and a stack-allocated buffer is now [faster than + to_chars on both libc++ and + libstdc++](http://www.zverovich.net/2020/06/13/fast-int-to-string-revisited.html). + +- Optimized handling of small format strings. For example, + + ```c++ + fmt::format("Result: {}: ({},{},{},{})", str1, str2, str3, str4, str5) + ``` + + is now \~40% faster + (https://github.com/fmtlib/fmt/issues/1685). + +- Applied extern templates to improve compile times when using the + core API and `fmt/format.h` + (https://github.com/fmtlib/fmt/issues/1452). For example, + on macOS with clang the compile time of a test translation unit + dropped from 2.3s to 0.3s with `-O2` and from 0.6s to 0.3s with the + default settings (`-O0`). + + Before (`-O2`): + + % time c++ -c test.cc -I include -std=c++17 -O2 + c++ -c test.cc -I include -std=c++17 -O2 2.22s user 0.08s system 99% cpu 2.311 total + + After (`-O2`): + + % time c++ -c test.cc -I include -std=c++17 -O2 + c++ -c test.cc -I include -std=c++17 -O2 0.26s user 0.04s system 98% cpu 0.303 total + + Before (default): + + % time c++ -c test.cc -I include -std=c++17 + c++ -c test.cc -I include -std=c++17 0.53s user 0.06s system 98% cpu 0.601 total + + After (default): + + % time c++ -c test.cc -I include -std=c++17 + c++ -c test.cc -I include -std=c++17 0.24s user 0.06s system 98% cpu 0.301 total + + It is still recommended to use `fmt/core.h` instead of + `fmt/format.h` but the compile time difference is now smaller. + Thanks @alex3d for the suggestion. + +- Named arguments are now stored on stack (no dynamic memory + allocations) and the compiled code is more compact and efficient. + For example + + ```c++ + #include <fmt/core.h> + + int main() { + fmt::print("The answer is {answer}\n", fmt::arg("answer", 42)); + } + ``` + + compiles to just ([godbolt](https://godbolt.org/z/NcfEp_)) + + ```asm + .LC0: + .string "answer" + .LC1: + .string "The answer is {answer}\n" + main: + sub rsp, 56 + mov edi, OFFSET FLAT:.LC1 + mov esi, 23 + movabs rdx, 4611686018427387905 + lea rax, [rsp+32] + lea rcx, [rsp+16] + mov QWORD PTR [rsp+8], 1 + mov QWORD PTR [rsp], rax + mov DWORD PTR [rsp+16], 42 + mov QWORD PTR [rsp+32], OFFSET FLAT:.LC0 + mov DWORD PTR [rsp+40], 0 + call fmt::v6::vprint(fmt::v6::basic_string_view<char>, + fmt::v6::format_args) + xor eax, eax + add rsp, 56 + ret + + .L.str.1: + .asciz "answer" + ``` + +- Implemented compile-time checks for dynamic width and precision + (https://github.com/fmtlib/fmt/issues/1614): + + ```c++ + #include <fmt/format.h> + + int main() { + fmt::print(FMT_STRING("{0:{1}}"), 42); + } + ``` + + now gives a compilation error because argument 1 doesn\'t exist: + + In file included from test.cc:1: + include/fmt/format.h:2726:27: error: constexpr variable 'invalid_format' must be + initialized by a constant expression + FMT_CONSTEXPR_DECL bool invalid_format = + ^ + ... + include/fmt/core.h:569:26: note: in call to + '&checker(s, {}).context_->on_error(&"argument not found"[0])' + if (id >= num_args_) on_error("argument not found"); + ^ + +- Added sentinel support to `fmt::join` + (https://github.com/fmtlib/fmt/pull/1689) + + ```c++ + struct zstring_sentinel {}; + bool operator==(const char* p, zstring_sentinel) { return *p == '\0'; } + bool operator!=(const char* p, zstring_sentinel) { return *p != '\0'; } + + struct zstring { + const char* p; + const char* begin() const { return p; } + zstring_sentinel end() const { return {}; } + }; + + auto s = fmt::format("{}", fmt::join(zstring{"hello"}, "_")); + // s == "h_e_l_l_o" + ``` + + Thanks @BRevzin. + +- Added support for named arguments, `clear` and `reserve` to + `dynamic_format_arg_store` + (https://github.com/fmtlib/fmt/issues/1655, + https://github.com/fmtlib/fmt/pull/1663, + https://github.com/fmtlib/fmt/pull/1674, + https://github.com/fmtlib/fmt/pull/1677). Thanks @vsolontsov-ll. + +- Added support for the `'c'` format specifier to integral types for + compatibility with `std::format` + (https://github.com/fmtlib/fmt/issues/1652). + +- Replaced the `'n'` format specifier with `'L'` for compatibility + with `std::format` + (https://github.com/fmtlib/fmt/issues/1624). The `'n'` + specifier can be enabled via the `FMT_DEPRECATED_N_SPECIFIER` macro. + +- The `'='` format specifier is now disabled by default for + compatibility with `std::format`. It can be enabled via the + `FMT_DEPRECATED_NUMERIC_ALIGN` macro. + +- Removed the following deprecated APIs: + + - `FMT_STRING_ALIAS` and `fmt` macros - replaced by `FMT_STRING` + - `fmt::basic_string_view::char_type` - replaced by + `fmt::basic_string_view::value_type` + - `convert_to_int` + - `format_arg_store::types` + - `*parse_context` - replaced by `*format_parse_context` + - `FMT_DEPRECATED_INCLUDE_OS` + - `FMT_DEPRECATED_PERCENT` - incompatible with `std::format` + - `*writer` - replaced by compiled format API + +- Renamed the `internal` namespace to `detail` + (https://github.com/fmtlib/fmt/issues/1538). The former is + still provided as an alias if the `FMT_USE_INTERNAL` macro is + defined. + +- Improved compatibility between `fmt::printf` with the standard specs + (https://github.com/fmtlib/fmt/issues/1595, + https://github.com/fmtlib/fmt/pull/1682, + https://github.com/fmtlib/fmt/pull/1683, + https://github.com/fmtlib/fmt/pull/1687, + https://github.com/fmtlib/fmt/pull/1699). Thanks @rimathia. + +- Fixed handling of `operator<<` overloads that use `copyfmt` + (https://github.com/fmtlib/fmt/issues/1666). + +- Added the `FMT_OS` CMake option to control inclusion of OS-specific + APIs in the fmt target. This can be useful for embedded platforms + (https://github.com/fmtlib/fmt/issues/1654, + https://github.com/fmtlib/fmt/pull/1656). Thanks @kwesolowski. + +- Replaced `FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION` with the + `FMT_FUZZ` macro to prevent interfering with fuzzing of projects + using {fmt} (https://github.com/fmtlib/fmt/pull/1650). + Thanks @asraa. + +- Fixed compatibility with emscripten + (https://github.com/fmtlib/fmt/issues/1636, + https://github.com/fmtlib/fmt/pull/1637). Thanks @ArthurSonzogni. + +- Improved documentation + (https://github.com/fmtlib/fmt/issues/704, + https://github.com/fmtlib/fmt/pull/1643, + https://github.com/fmtlib/fmt/pull/1660, + https://github.com/fmtlib/fmt/pull/1681, + https://github.com/fmtlib/fmt/pull/1691, + https://github.com/fmtlib/fmt/pull/1706, + https://github.com/fmtlib/fmt/pull/1714, + https://github.com/fmtlib/fmt/pull/1721, + https://github.com/fmtlib/fmt/pull/1739, + https://github.com/fmtlib/fmt/pull/1740, + https://github.com/fmtlib/fmt/pull/1741, + https://github.com/fmtlib/fmt/pull/1751). + Thanks @senior7515, @lsr0, @puetzk, @fpelliccioni, Alexey Kuzmenko, @jelly, + @claremacrae, @jiapengwen, @gsjaardema and @alexey-milovidov. + +- Implemented various build configuration fixes and improvements + (https://github.com/fmtlib/fmt/pull/1603, + https://github.com/fmtlib/fmt/pull/1657, + https://github.com/fmtlib/fmt/pull/1702, + https://github.com/fmtlib/fmt/pull/1728). + Thanks @scramsby, @jtojnar, @orivej and @flagarde. + +- Fixed various warnings and compilation issues + (https://github.com/fmtlib/fmt/pull/1616, + https://github.com/fmtlib/fmt/issues/1620, + https://github.com/fmtlib/fmt/issues/1622, + https://github.com/fmtlib/fmt/issues/1625, + https://github.com/fmtlib/fmt/pull/1627, + https://github.com/fmtlib/fmt/issues/1628, + https://github.com/fmtlib/fmt/pull/1629, + https://github.com/fmtlib/fmt/issues/1631, + https://github.com/fmtlib/fmt/pull/1633, + https://github.com/fmtlib/fmt/pull/1649, + https://github.com/fmtlib/fmt/issues/1658, + https://github.com/fmtlib/fmt/pull/1661, + https://github.com/fmtlib/fmt/pull/1667, + https://github.com/fmtlib/fmt/issues/1668, + https://github.com/fmtlib/fmt/pull/1669, + https://github.com/fmtlib/fmt/issues/1692, + https://github.com/fmtlib/fmt/pull/1696, + https://github.com/fmtlib/fmt/pull/1697, + https://github.com/fmtlib/fmt/issues/1707, + https://github.com/fmtlib/fmt/pull/1712, + https://github.com/fmtlib/fmt/pull/1716, + https://github.com/fmtlib/fmt/pull/1722, + https://github.com/fmtlib/fmt/issues/1724, + https://github.com/fmtlib/fmt/pull/1729, + https://github.com/fmtlib/fmt/pull/1738, + https://github.com/fmtlib/fmt/issues/1742, + https://github.com/fmtlib/fmt/issues/1743, + https://github.com/fmtlib/fmt/pull/1744, + https://github.com/fmtlib/fmt/issues/1747, + https://github.com/fmtlib/fmt/pull/1750). + Thanks @gsjaardema, @gabime, @johnor, @Kurkin, @invexed, @peterbell10, + @daixtrose, @petrutlucian94, @Neargye, @ambitslix, @gabime, + @tohammer and @0x8000-0000. + +# 6.2.1 - 2020-05-09 + +- Fixed ostream support in `sprintf` + (https://github.com/fmtlib/fmt/issues/1631). +- Fixed type detection when using implicit conversion to `string_view` + and ostream `operator<<` inconsistently + (https://github.com/fmtlib/fmt/issues/1662). + +# 6.2.0 - 2020-04-05 + +- Improved error reporting when trying to format an object of a + non-formattable type: + + ```c++ + fmt::format("{}", S()); + ``` + + now gives: + + include/fmt/core.h:1015:5: error: static_assert failed due to requirement + 'formattable' "Cannot format argument. To make type T formattable provide a + formatter<T> specialization: + https://fmt.dev/latest/api.html#formatting-user-defined-types" + static_assert( + ^ + ... + note: in instantiation of function template specialization + 'fmt::v6::format<char [3], S, char>' requested here + fmt::format("{}", S()); + ^ + + if `S` is not formattable. + +- Reduced the library size by \~10%. + +- Always print decimal point if `#` is specified + (https://github.com/fmtlib/fmt/issues/1476, + https://github.com/fmtlib/fmt/issues/1498): + + ```c++ + fmt::print("{:#.0f}", 42.0); + ``` + + now prints `42.` + +- Implemented the `'L'` specifier for locale-specific numeric + formatting to improve compatibility with `std::format`. The `'n'` + specifier is now deprecated and will be removed in the next major + release. + +- Moved OS-specific APIs such as `windows_error` from `fmt/format.h` + to `fmt/os.h`. You can define `FMT_DEPRECATED_INCLUDE_OS` to + automatically include `fmt/os.h` from `fmt/format.h` for + compatibility but this will be disabled in the next major release. + +- Added precision overflow detection in floating-point formatting. + +- Implemented detection of invalid use of `fmt::arg`. + +- Used `type_identity` to block unnecessary template argument + deduction. Thanks Tim Song. + +- Improved UTF-8 handling + (https://github.com/fmtlib/fmt/issues/1109): + + ```c++ + fmt::print("┌{0:─^{2}}┐\n" + "│{1: ^{2}}│\n" + "└{0:─^{2}}┘\n", "", "Прывітанне, свет!", 21); + ``` + + now prints: + + ┌─────────────────────┐ + │ Прывітанне, свет! │ + └─────────────────────┘ + + on systems that support Unicode. + +- Added experimental dynamic argument storage + (https://github.com/fmtlib/fmt/issues/1170, + https://github.com/fmtlib/fmt/pull/1584): + + ```c++ + fmt::dynamic_format_arg_store<fmt::format_context> store; + store.push_back("answer"); + store.push_back(42); + fmt::vprint("The {} is {}.\n", store); + ``` + + prints: + + The answer is 42. + + Thanks @vsolontsov-ll. + +- Made `fmt::join` accept `initializer_list` + (https://github.com/fmtlib/fmt/pull/1591). Thanks @Rapotkinnik. + +- Fixed handling of empty tuples + (https://github.com/fmtlib/fmt/issues/1588). + +- Fixed handling of output iterators in `format_to_n` + (https://github.com/fmtlib/fmt/issues/1506). + +- Fixed formatting of `std::chrono::duration` types to wide output + (https://github.com/fmtlib/fmt/pull/1533). Thanks @zeffy. + +- Added const `begin` and `end` overload to buffers + (https://github.com/fmtlib/fmt/pull/1553). Thanks @dominicpoeschko. + +- Added the ability to disable floating-point formatting via + `FMT_USE_FLOAT`, `FMT_USE_DOUBLE` and `FMT_USE_LONG_DOUBLE` macros + for extremely memory-constrained embedded system + (https://github.com/fmtlib/fmt/pull/1590). Thanks @albaguirre. + +- Made `FMT_STRING` work with `constexpr` `string_view` + (https://github.com/fmtlib/fmt/pull/1589). Thanks @scramsby. + +- Implemented a minor optimization in the format string parser + (https://github.com/fmtlib/fmt/pull/1560). Thanks @IkarusDeveloper. + +- Improved attribute detection + (https://github.com/fmtlib/fmt/pull/1469, + https://github.com/fmtlib/fmt/pull/1475, + https://github.com/fmtlib/fmt/pull/1576). + Thanks @federico-busato, @chronoxor and @refnum. + +- Improved documentation + (https://github.com/fmtlib/fmt/pull/1481, + https://github.com/fmtlib/fmt/pull/1523). + Thanks @JackBoosY and @imba-tjd. + +- Fixed symbol visibility on Linux when compiling with + `-fvisibility=hidden` + (https://github.com/fmtlib/fmt/pull/1535). Thanks @milianw. + +- Implemented various build configuration fixes and improvements + (https://github.com/fmtlib/fmt/issues/1264, + https://github.com/fmtlib/fmt/issues/1460, + https://github.com/fmtlib/fmt/pull/1534, + https://github.com/fmtlib/fmt/issues/1536, + https://github.com/fmtlib/fmt/issues/1545, + https://github.com/fmtlib/fmt/pull/1546, + https://github.com/fmtlib/fmt/issues/1566, + https://github.com/fmtlib/fmt/pull/1582, + https://github.com/fmtlib/fmt/issues/1597, + https://github.com/fmtlib/fmt/pull/1598). + Thanks @ambitslix, @jwillikers and @stac47. + +- Fixed various warnings and compilation issues + (https://github.com/fmtlib/fmt/pull/1433, + https://github.com/fmtlib/fmt/issues/1461, + https://github.com/fmtlib/fmt/pull/1470, + https://github.com/fmtlib/fmt/pull/1480, + https://github.com/fmtlib/fmt/pull/1485, + https://github.com/fmtlib/fmt/pull/1492, + https://github.com/fmtlib/fmt/issues/1493, + https://github.com/fmtlib/fmt/issues/1504, + https://github.com/fmtlib/fmt/pull/1505, + https://github.com/fmtlib/fmt/pull/1512, + https://github.com/fmtlib/fmt/issues/1515, + https://github.com/fmtlib/fmt/pull/1516, + https://github.com/fmtlib/fmt/pull/1518, + https://github.com/fmtlib/fmt/pull/1519, + https://github.com/fmtlib/fmt/pull/1520, + https://github.com/fmtlib/fmt/pull/1521, + https://github.com/fmtlib/fmt/pull/1522, + https://github.com/fmtlib/fmt/issues/1524, + https://github.com/fmtlib/fmt/pull/1530, + https://github.com/fmtlib/fmt/issues/1531, + https://github.com/fmtlib/fmt/pull/1532, + https://github.com/fmtlib/fmt/issues/1539, + https://github.com/fmtlib/fmt/issues/1547, + https://github.com/fmtlib/fmt/issues/1548, + https://github.com/fmtlib/fmt/pull/1554, + https://github.com/fmtlib/fmt/issues/1567, + https://github.com/fmtlib/fmt/pull/1568, + https://github.com/fmtlib/fmt/pull/1569, + https://github.com/fmtlib/fmt/pull/1571, + https://github.com/fmtlib/fmt/pull/1573, + https://github.com/fmtlib/fmt/pull/1575, + https://github.com/fmtlib/fmt/pull/1581, + https://github.com/fmtlib/fmt/issues/1583, + https://github.com/fmtlib/fmt/issues/1586, + https://github.com/fmtlib/fmt/issues/1587, + https://github.com/fmtlib/fmt/issues/1594, + https://github.com/fmtlib/fmt/pull/1596, + https://github.com/fmtlib/fmt/issues/1604, + https://github.com/fmtlib/fmt/pull/1606, + https://github.com/fmtlib/fmt/issues/1607, + https://github.com/fmtlib/fmt/issues/1609). + Thanks @marti4d, @iPherian, @parkertomatoes, @gsjaardema, @chronoxor, + @DanielaE, @torsten48, @tohammer, @lefticus, @ryusakki, @adnsv, @fghzxm, + @refnum, @pramodk, @Spirrwell and @scramsby. + +# 6.1.2 - 2019-12-11 + +- Fixed ABI compatibility with `libfmt.so.6.0.0` + (https://github.com/fmtlib/fmt/issues/1471). +- Fixed handling types convertible to `std::string_view` + (https://github.com/fmtlib/fmt/pull/1451). Thanks @denizevrenci. +- Made CUDA test an opt-in enabled via the `FMT_CUDA_TEST` CMake + option. +- Fixed sign conversion warnings + (https://github.com/fmtlib/fmt/pull/1440). Thanks @0x8000-0000. + +# 6.1.1 - 2019-12-04 + +- Fixed shared library build on Windows + (https://github.com/fmtlib/fmt/pull/1443, + https://github.com/fmtlib/fmt/issues/1445, + https://github.com/fmtlib/fmt/pull/1446, + https://github.com/fmtlib/fmt/issues/1450). + Thanks @egorpugin and @bbolli. +- Added a missing decimal point in exponent notation with trailing + zeros. +- Removed deprecated `format_arg_store::TYPES`. + +# 6.1.0 - 2019-12-01 + +- {fmt} now formats IEEE 754 `float` and `double` using the shortest + decimal representation with correct rounding by default: + + ```c++ + #include <cmath> + #include <fmt/core.h> + + int main() { + fmt::print("{}", M_PI); + } + ``` + + prints `3.141592653589793`. + +- Made the fast binary to decimal floating-point formatter the + default, simplified it and improved performance. {fmt} is now 15 + times faster than libc++\'s `std::ostringstream`, 11 times faster + than `printf` and 10% faster than double-conversion on + [dtoa-benchmark](https://github.com/fmtlib/dtoa-benchmark): + + | Function | Time (ns) | Speedup | + | ------------- | --------: | ------: | + | ostringstream | 1,346.30 | 1.00x | + | ostrstream | 1,195.74 | 1.13x | + | sprintf | 995.08 | 1.35x | + | doubleconv | 99.10 | 13.59x | + | fmt | 88.34 | 15.24x | + +  + +- {fmt} no longer converts `float` arguments to `double`. In + particular this improves the default (shortest) representation of + floats and makes `fmt::format` consistent with `std::format` specs + (https://github.com/fmtlib/fmt/issues/1336, + https://github.com/fmtlib/fmt/issues/1353, + https://github.com/fmtlib/fmt/pull/1360, + https://github.com/fmtlib/fmt/pull/1361): + + ```c++ + fmt::print("{}", 0.1f); + ``` + + prints `0.1` instead of `0.10000000149011612`. + + Thanks @orivej. + +- Made floating-point formatting output consistent with + `printf`/iostreams + (https://github.com/fmtlib/fmt/issues/1376, + https://github.com/fmtlib/fmt/issues/1417). + +- Added support for 128-bit integers + (https://github.com/fmtlib/fmt/pull/1287): + + ```c++ + fmt::print("{}", std::numeric_limits<__int128_t>::max()); + ``` + + prints `170141183460469231731687303715884105727`. + + Thanks @denizevrenci. + +- The overload of `print` that takes `text_style` is now atomic, i.e. + the output from different threads doesn\'t interleave + (https://github.com/fmtlib/fmt/pull/1351). Thanks @tankiJong. + +- Made compile time in the header-only mode \~20% faster by reducing + the number of template instantiations. `wchar_t` overload of + `vprint` was moved from `fmt/core.h` to `fmt/format.h`. + +- Added an overload of `fmt::join` that works with tuples + (https://github.com/fmtlib/fmt/issues/1322, + https://github.com/fmtlib/fmt/pull/1330): + + ```c++ + #include <tuple> + #include <fmt/ranges.h> + + int main() { + std::tuple<char, int, float> t{'a', 1, 2.0f}; + fmt::print("{}", t); + } + ``` + + prints `('a', 1, 2.0)`. + + Thanks @jeremyong. + +- Changed formatting of octal zero with prefix from \"00\" to \"0\": + + ```c++ + fmt::print("{:#o}", 0); + ``` + + prints `0`. + +- The locale is now passed to ostream insertion (`<<`) operators + (https://github.com/fmtlib/fmt/pull/1406): + + ```c++ + #include <fmt/locale.h> + #include <fmt/ostream.h> + + struct S { + double value; + }; + + std::ostream& operator<<(std::ostream& os, S s) { + return os << s.value; + } + + int main() { + auto s = fmt::format(std::locale("fr_FR.UTF-8"), "{}", S{0.42}); + // s == "0,42" + } + ``` + + Thanks @dlaugt. + +- Locale-specific number formatting now uses grouping + (https://github.com/fmtlib/fmt/issues/1393, + https://github.com/fmtlib/fmt/pull/1394). Thanks @skrdaniel. + +- Fixed handling of types with deleted implicit rvalue conversion to + `const char**` (https://github.com/fmtlib/fmt/issues/1421): + + ```c++ + struct mystring { + operator const char*() const&; + operator const char*() &; + operator const char*() const&& = delete; + operator const char*() && = delete; + }; + mystring str; + fmt::print("{}", str); // now compiles + ``` + +- Enums are now mapped to correct underlying types instead of `int` + (https://github.com/fmtlib/fmt/pull/1286). Thanks @agmt. + +- Enum classes are no longer implicitly converted to `int` + (https://github.com/fmtlib/fmt/issues/1424). + +- Added `basic_format_parse_context` for consistency with C++20 + `std::format` and deprecated `basic_parse_context`. + +- Fixed handling of UTF-8 in precision + (https://github.com/fmtlib/fmt/issues/1389, + https://github.com/fmtlib/fmt/pull/1390). Thanks @tajtiattila. + +- {fmt} can now be installed on Linux, macOS and Windows with + [Conda](https://docs.conda.io/en/latest/) using its + [conda-forge](https://conda-forge.org) + [package](https://github.com/conda-forge/fmt-feedstock) + (https://github.com/fmtlib/fmt/pull/1410): + + conda install -c conda-forge fmt + + Thanks @tdegeus. + +- Added a CUDA test (https://github.com/fmtlib/fmt/pull/1285, + https://github.com/fmtlib/fmt/pull/1317). + Thanks @luncliff and @risa2000. + +- Improved documentation + (https://github.com/fmtlib/fmt/pull/1276, + https://github.com/fmtlib/fmt/issues/1291, + https://github.com/fmtlib/fmt/issues/1296, + https://github.com/fmtlib/fmt/pull/1315, + https://github.com/fmtlib/fmt/pull/1332, + https://github.com/fmtlib/fmt/pull/1337, + https://github.com/fmtlib/fmt/issues/1395 + https://github.com/fmtlib/fmt/pull/1418). + Thanks @waywardmonkeys, @pauldreik and @jackoalan. + +- Various code improvements + (https://github.com/fmtlib/fmt/pull/1358, + https://github.com/fmtlib/fmt/pull/1407). + Thanks @orivej and @dpacbach. + +- Fixed compile-time format string checks for user-defined types + (https://github.com/fmtlib/fmt/issues/1292). + +- Worked around a false positive in `unsigned-integer-overflow` sanitizer + (https://github.com/fmtlib/fmt/issues/1377). + +- Fixed various warnings and compilation issues + (https://github.com/fmtlib/fmt/issues/1273, + https://github.com/fmtlib/fmt/pull/1278, + https://github.com/fmtlib/fmt/pull/1280, + https://github.com/fmtlib/fmt/issues/1281, + https://github.com/fmtlib/fmt/issues/1288, + https://github.com/fmtlib/fmt/pull/1290, + https://github.com/fmtlib/fmt/pull/1301, + https://github.com/fmtlib/fmt/issues/1305, + https://github.com/fmtlib/fmt/issues/1306, + https://github.com/fmtlib/fmt/issues/1309, + https://github.com/fmtlib/fmt/pull/1312, + https://github.com/fmtlib/fmt/issues/1313, + https://github.com/fmtlib/fmt/issues/1316, + https://github.com/fmtlib/fmt/issues/1319, + https://github.com/fmtlib/fmt/pull/1320, + https://github.com/fmtlib/fmt/pull/1326, + https://github.com/fmtlib/fmt/pull/1328, + https://github.com/fmtlib/fmt/issues/1344, + https://github.com/fmtlib/fmt/pull/1345, + https://github.com/fmtlib/fmt/pull/1347, + https://github.com/fmtlib/fmt/pull/1349, + https://github.com/fmtlib/fmt/issues/1354, + https://github.com/fmtlib/fmt/issues/1362, + https://github.com/fmtlib/fmt/issues/1366, + https://github.com/fmtlib/fmt/pull/1364, + https://github.com/fmtlib/fmt/pull/1370, + https://github.com/fmtlib/fmt/pull/1371, + https://github.com/fmtlib/fmt/issues/1385, + https://github.com/fmtlib/fmt/issues/1388, + https://github.com/fmtlib/fmt/pull/1397, + https://github.com/fmtlib/fmt/pull/1414, + https://github.com/fmtlib/fmt/pull/1416, + https://github.com/fmtlib/fmt/issues/1422 + https://github.com/fmtlib/fmt/pull/1427, + https://github.com/fmtlib/fmt/issues/1431, + https://github.com/fmtlib/fmt/pull/1433). + Thanks @hhb, @gsjaardema, @gabime, @neheb, @vedranmiletic, @dkavolis, + @mwinterb, @orivej, @denizevrenci, @leonklingele, @chronoxor, @kent-tri, + @0x8000-0000 and @marti4d. + +# 6.0.0 - 2019-08-26 + +- Switched to the [MIT license]( + https://github.com/fmtlib/fmt/blob/5a4b24613ba16cc689977c3b5bd8274a3ba1dd1f/LICENSE.rst) + with an optional exception that allows distributing binary code + without attribution. + +- Floating-point formatting is now locale-independent by default: + + ```c++ + #include <locale> + #include <fmt/core.h> + + int main() { + std::locale::global(std::locale("ru_RU.UTF-8")); + fmt::print("value = {}", 4.2); + } + ``` + + prints \"value = 4.2\" regardless of the locale. + + For locale-specific formatting use the `n` specifier: + + ```c++ + std::locale::global(std::locale("ru_RU.UTF-8")); + fmt::print("value = {:n}", 4.2); + ``` + + prints \"value = 4,2\". + +- Added an experimental Grisu floating-point formatting algorithm + implementation (disabled by default). To enable it compile with the + `FMT_USE_GRISU` macro defined to 1: + + ```c++ + #define FMT_USE_GRISU 1 + #include <fmt/format.h> + + auto s = fmt::format("{}", 4.2); // formats 4.2 using Grisu + ``` + + With Grisu enabled, {fmt} is 13x faster than `std::ostringstream` + (libc++) and 10x faster than `sprintf` on + [dtoa-benchmark](https://github.com/fmtlib/dtoa-benchmark) ([full + results](https://fmt.dev/unknown_mac64_clang10.0.html)): + +  + +- Separated formatting and parsing contexts for consistency with + [C++20 std::format](http://eel.is/c++draft/format), removing the + undocumented `basic_format_context::parse_context()` function. + +- Added [oss-fuzz](https://github.com/google/oss-fuzz) support + (https://github.com/fmtlib/fmt/pull/1199). Thanks @pauldreik. + +- `formatter` specializations now always take precedence over + `operator<<` (https://github.com/fmtlib/fmt/issues/952): + + ```c++ + #include <iostream> + #include <fmt/ostream.h> + + struct S {}; + + std::ostream& operator<<(std::ostream& os, S) { + return os << 1; + } + + template <> + struct fmt::formatter<S> : fmt::formatter<int> { + auto format(S, format_context& ctx) { + return formatter<int>::format(2, ctx); + } + }; + + int main() { + std::cout << S() << "\n"; // prints 1 using operator<< + fmt::print("{}\n", S()); // prints 2 using formatter + } + ``` + +- Introduced the experimental `fmt::compile` function that does format + string compilation + (https://github.com/fmtlib/fmt/issues/618, + https://github.com/fmtlib/fmt/issues/1169, + https://github.com/fmtlib/fmt/pull/1171): + + ```c++ + #include <fmt/compile.h> + + auto f = fmt::compile<int>("{}"); + std::string s = fmt::format(f, 42); // can be called multiple times to + // format different values + // s == "42" + ``` + + It moves the cost of parsing a format string outside of the format + function which can be beneficial when identically formatting many + objects of the same types. Thanks @stryku. + +- Added experimental `%` format specifier that formats floating-point + values as percentages + (https://github.com/fmtlib/fmt/pull/1060, + https://github.com/fmtlib/fmt/pull/1069, + https://github.com/fmtlib/fmt/pull/1071): + + ```c++ + auto s = fmt::format("{:.1%}", 0.42); // s == "42.0%" + ``` + + Thanks @gawain-bolton. + +- Implemented precision for floating-point durations + (https://github.com/fmtlib/fmt/issues/1004, + https://github.com/fmtlib/fmt/pull/1012): + + ```c++ + auto s = fmt::format("{:.1}", std::chrono::duration<double>(1.234)); + // s == 1.2s + ``` + + Thanks @DanielaE. + +- Implemented `chrono` format specifiers `%Q` and `%q` that give the + value and the unit respectively + (https://github.com/fmtlib/fmt/pull/1019): + + ```c++ + auto value = fmt::format("{:%Q}", 42s); // value == "42" + auto unit = fmt::format("{:%q}", 42s); // unit == "s" + ``` + + Thanks @DanielaE. + +- Fixed handling of dynamic width in chrono formatter: + + ```c++ + auto s = fmt::format("{0:{1}%H:%M:%S}", std::chrono::seconds(12345), 12); + // ^ width argument index ^ width + // s == "03:25:45 " + ``` + + Thanks Howard Hinnant. + +- Removed deprecated `fmt/time.h`. Use `fmt/chrono.h` instead. + +- Added `fmt::format` and `fmt::vformat` overloads that take + `text_style` (https://github.com/fmtlib/fmt/issues/993, + https://github.com/fmtlib/fmt/pull/994): + + ```c++ + #include <fmt/color.h> + + std::string message = fmt::format(fmt::emphasis::bold | fg(fmt::color::red), + "The answer is {}.", 42); + ``` + + Thanks @Naios. + +- Removed the deprecated color API (`print_colored`). Use the new API, + namely `print` overloads that take `text_style` instead. + +- Made `std::unique_ptr` and `std::shared_ptr` formattable as pointers + via `fmt::ptr` (https://github.com/fmtlib/fmt/pull/1121): + + ```c++ + std::unique_ptr<int> p = ...; + fmt::print("{}", fmt::ptr(p)); // prints p as a pointer + ``` + + Thanks @sighingnow. + +- Made `print` and `vprint` report I/O errors + (https://github.com/fmtlib/fmt/issues/1098, + https://github.com/fmtlib/fmt/pull/1099). Thanks @BillyDonahue. + +- Marked deprecated APIs with the `[[deprecated]]` attribute and + removed internal uses of deprecated APIs + (https://github.com/fmtlib/fmt/pull/1022). Thanks @eliaskosunen. + +- Modernized the codebase using more C++11 features and removing + workarounds. Most importantly, `buffer_context` is now an alias + template, so use `buffer_context<T>` instead of + `buffer_context<T>::type`. These features require GCC 4.8 or later. + +- `formatter` specializations now always take precedence over implicit + conversions to `int` and the undocumented `convert_to_int` trait is + now deprecated. + +- Moved the undocumented `basic_writer`, `writer`, and `wwriter` types + to the `internal` namespace. + +- Removed deprecated `basic_format_context::begin()`. Use `out()` + instead. + +- Disallowed passing the result of `join` as an lvalue to prevent + misuse. + +- Refactored the undocumented structs that represent parsed format + specifiers to simplify the API and allow multibyte fill. + +- Moved SFINAE to template parameters to reduce symbol sizes. + +- Switched to `fputws` for writing wide strings so that it\'s no + longer required to call `_setmode` on Windows + (https://github.com/fmtlib/fmt/issues/1229, + https://github.com/fmtlib/fmt/pull/1243). Thanks @jackoalan. + +- Improved literal-based API + (https://github.com/fmtlib/fmt/pull/1254). Thanks @sylveon. + +- Added support for exotic platforms without `uintptr_t` such as IBM i + (AS/400) which has 128-bit pointers and only 64-bit integers + (https://github.com/fmtlib/fmt/issues/1059). + +- Added [Sublime Text syntax highlighting config]( + https://github.com/fmtlib/fmt/blob/master/support/C%2B%2B.sublime-syntax) + (https://github.com/fmtlib/fmt/issues/1037). Thanks @Kronuz. + +- Added the `FMT_ENFORCE_COMPILE_STRING` macro to enforce the use of + compile-time format strings + (https://github.com/fmtlib/fmt/pull/1231). Thanks @jackoalan. + +- Stopped setting `CMAKE_BUILD_TYPE` if {fmt} is a subproject + (https://github.com/fmtlib/fmt/issues/1081). + +- Various build improvements + (https://github.com/fmtlib/fmt/pull/1039, + https://github.com/fmtlib/fmt/pull/1078, + https://github.com/fmtlib/fmt/pull/1091, + https://github.com/fmtlib/fmt/pull/1103, + https://github.com/fmtlib/fmt/pull/1177). + Thanks @luncliff, @jasonszang, @olafhering, @Lecetem and @pauldreik. + +- Improved documentation + (https://github.com/fmtlib/fmt/issues/1049, + https://github.com/fmtlib/fmt/pull/1051, + https://github.com/fmtlib/fmt/pull/1083, + https://github.com/fmtlib/fmt/pull/1113, + https://github.com/fmtlib/fmt/pull/1114, + https://github.com/fmtlib/fmt/issues/1146, + https://github.com/fmtlib/fmt/issues/1180, + https://github.com/fmtlib/fmt/pull/1250, + https://github.com/fmtlib/fmt/pull/1252, + https://github.com/fmtlib/fmt/pull/1265). + Thanks @mikelui, @foonathan, @BillyDonahue, @jwakely, @kaisbe and + @sdebionne. + +- Fixed ambiguous formatter specialization in `fmt/ranges.h` + (https://github.com/fmtlib/fmt/issues/1123). + +- Fixed formatting of a non-empty `std::filesystem::path` which is an + infinitely deep range of its components + (https://github.com/fmtlib/fmt/issues/1268). + +- Fixed handling of general output iterators when formatting + characters (https://github.com/fmtlib/fmt/issues/1056, + https://github.com/fmtlib/fmt/pull/1058). Thanks @abolz. + +- Fixed handling of output iterators in `formatter` specialization for + ranges (https://github.com/fmtlib/fmt/issues/1064). + +- Fixed handling of exotic character types + (https://github.com/fmtlib/fmt/issues/1188). + +- Made chrono formatting work with exceptions disabled + (https://github.com/fmtlib/fmt/issues/1062). + +- Fixed DLL visibility issues + (https://github.com/fmtlib/fmt/pull/1134, + https://github.com/fmtlib/fmt/pull/1147). Thanks @denchat. + +- Disabled the use of UDL template extension on GCC 9 + (https://github.com/fmtlib/fmt/issues/1148). + +- Removed misplaced `format` compile-time checks from `printf` + (https://github.com/fmtlib/fmt/issues/1173). + +- Fixed issues in the experimental floating-point formatter + (https://github.com/fmtlib/fmt/issues/1072, + https://github.com/fmtlib/fmt/issues/1129, + https://github.com/fmtlib/fmt/issues/1153, + https://github.com/fmtlib/fmt/pull/1155, + https://github.com/fmtlib/fmt/issues/1210, + https://github.com/fmtlib/fmt/issues/1222). Thanks @alabuzhev. + +- Fixed bugs discovered by fuzzing or during fuzzing integration + (https://github.com/fmtlib/fmt/issues/1124, + https://github.com/fmtlib/fmt/issues/1127, + https://github.com/fmtlib/fmt/issues/1132, + https://github.com/fmtlib/fmt/pull/1135, + https://github.com/fmtlib/fmt/issues/1136, + https://github.com/fmtlib/fmt/issues/1141, + https://github.com/fmtlib/fmt/issues/1142, + https://github.com/fmtlib/fmt/issues/1178, + https://github.com/fmtlib/fmt/issues/1179, + https://github.com/fmtlib/fmt/issues/1194). Thanks @pauldreik. + +- Fixed building tests on FreeBSD and Hurd + (https://github.com/fmtlib/fmt/issues/1043). Thanks @jackyf. + +- Fixed various warnings and compilation issues + (https://github.com/fmtlib/fmt/pull/998, + https://github.com/fmtlib/fmt/pull/1006, + https://github.com/fmtlib/fmt/issues/1008, + https://github.com/fmtlib/fmt/issues/1011, + https://github.com/fmtlib/fmt/issues/1025, + https://github.com/fmtlib/fmt/pull/1027, + https://github.com/fmtlib/fmt/pull/1028, + https://github.com/fmtlib/fmt/pull/1029, + https://github.com/fmtlib/fmt/pull/1030, + https://github.com/fmtlib/fmt/pull/1031, + https://github.com/fmtlib/fmt/pull/1054, + https://github.com/fmtlib/fmt/issues/1063, + https://github.com/fmtlib/fmt/pull/1068, + https://github.com/fmtlib/fmt/pull/1074, + https://github.com/fmtlib/fmt/pull/1075, + https://github.com/fmtlib/fmt/pull/1079, + https://github.com/fmtlib/fmt/pull/1086, + https://github.com/fmtlib/fmt/issues/1088, + https://github.com/fmtlib/fmt/pull/1089, + https://github.com/fmtlib/fmt/pull/1094, + https://github.com/fmtlib/fmt/issues/1101, + https://github.com/fmtlib/fmt/pull/1102, + https://github.com/fmtlib/fmt/issues/1105, + https://github.com/fmtlib/fmt/pull/1107, + https://github.com/fmtlib/fmt/issues/1115, + https://github.com/fmtlib/fmt/issues/1117, + https://github.com/fmtlib/fmt/issues/1118, + https://github.com/fmtlib/fmt/issues/1120, + https://github.com/fmtlib/fmt/issues/1123, + https://github.com/fmtlib/fmt/pull/1139, + https://github.com/fmtlib/fmt/issues/1140, + https://github.com/fmtlib/fmt/issues/1143, + https://github.com/fmtlib/fmt/pull/1144, + https://github.com/fmtlib/fmt/pull/1150, + https://github.com/fmtlib/fmt/pull/1151, + https://github.com/fmtlib/fmt/issues/1152, + https://github.com/fmtlib/fmt/issues/1154, + https://github.com/fmtlib/fmt/issues/1156, + https://github.com/fmtlib/fmt/pull/1159, + https://github.com/fmtlib/fmt/issues/1175, + https://github.com/fmtlib/fmt/issues/1181, + https://github.com/fmtlib/fmt/issues/1186, + https://github.com/fmtlib/fmt/pull/1187, + https://github.com/fmtlib/fmt/pull/1191, + https://github.com/fmtlib/fmt/issues/1197, + https://github.com/fmtlib/fmt/issues/1200, + https://github.com/fmtlib/fmt/issues/1203, + https://github.com/fmtlib/fmt/issues/1205, + https://github.com/fmtlib/fmt/pull/1206, + https://github.com/fmtlib/fmt/issues/1213, + https://github.com/fmtlib/fmt/issues/1214, + https://github.com/fmtlib/fmt/pull/1217, + https://github.com/fmtlib/fmt/issues/1228, + https://github.com/fmtlib/fmt/pull/1230, + https://github.com/fmtlib/fmt/issues/1232, + https://github.com/fmtlib/fmt/pull/1235, + https://github.com/fmtlib/fmt/pull/1236, + https://github.com/fmtlib/fmt/issues/1240). + Thanks @DanielaE, @mwinterb, @eliaskosunen, @morinmorin, @ricco19, + @waywardmonkeys, @chronoxor, @remyabel, @pauldreik, @gsjaardema, @rcane, + @mocabe, @denchat, @cjdb, @HazardyKnusperkeks, @vedranmiletic, @jackoalan, + @DaanDeMeyer and @starkmapper. + +# 5.3.0 - 2018-12-28 + +- Introduced experimental chrono formatting support: + + ```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); + } + ``` + + prints: + + Default format: 42s 100ms + strftime-like format: 03:15:30 + +- Added experimental support for emphasis (bold, italic, underline, + strikethrough), colored output to a file stream, and improved + colored formatting API + (https://github.com/fmtlib/fmt/pull/961, + https://github.com/fmtlib/fmt/pull/967, + https://github.com/fmtlib/fmt/pull/973): + + ```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"); + } + ``` + + prints the following on modern terminals with RGB color support: + +  + + Thanks @Rakete1111. + +- Added support for 4-bit terminal colors + (https://github.com/fmtlib/fmt/issues/968, + https://github.com/fmtlib/fmt/pull/974) + + ```c++ + #include <fmt/color.h> + + int main() { + print(fg(fmt::terminal_color::red), "stop\n"); + } + ``` + + Note that these colors vary by terminal: + +  + + Thanks @Rakete1111. + +- Parameterized formatting functions on the type of the format string + (https://github.com/fmtlib/fmt/issues/880, + https://github.com/fmtlib/fmt/pull/881, + https://github.com/fmtlib/fmt/pull/883, + https://github.com/fmtlib/fmt/pull/885, + https://github.com/fmtlib/fmt/pull/897, + https://github.com/fmtlib/fmt/issues/920). Any object of + type `S` that has an overloaded `to_string_view(const S&)` returning + `fmt::string_view` can be used as a format string: + + ```c++ + namespace my_ns { + inline string_view to_string_view(const my_string& s) { + return {s.data(), s.length()}; + } + } + + std::string message = fmt::format(my_string("The answer is {}."), 42); + ``` + + Thanks @DanielaE. + +- Made `std::string_view` work as a format string + (https://github.com/fmtlib/fmt/pull/898): + + ```c++ + auto message = fmt::format(std::string_view("The answer is {}."), 42); + ``` + + Thanks @DanielaE. + +- Added wide string support to compile-time format string checks + (https://github.com/fmtlib/fmt/pull/924): + + ```c++ + print(fmt(L"{:f}"), 42); // compile-time error: invalid type specifier + ``` + + Thanks @XZiar. + +- Made colored print functions work with wide strings + (https://github.com/fmtlib/fmt/pull/867): + + ```c++ + #include <fmt/color.h> + + int main() { + print(fg(fmt::color::red), L"{}\n", 42); + } + ``` + + Thanks @DanielaE. + +- Introduced experimental Unicode support + (https://github.com/fmtlib/fmt/issues/628, + https://github.com/fmtlib/fmt/pull/891): + + ```c++ + using namespace fmt::literals; + auto s = fmt::format("{:*^5}"_u, "🤡"_u); // s == "**🤡**"_u + ``` + +- Improved locale support: + + ```c++ + #include <fmt/locale.h> + + struct numpunct : std::numpunct<char> { + protected: + char do_thousands_sep() const override { return '~'; } + }; + + std::locale loc; + auto s = fmt::format(std::locale(loc, new numpunct()), "{:n}", 1234567); + // s == "1~234~567" + ``` + +- Constrained formatting functions on proper iterator types + (https://github.com/fmtlib/fmt/pull/921). Thanks @DanielaE. + +- Added `make_printf_args` and `make_wprintf_args` functions + (https://github.com/fmtlib/fmt/pull/934). Thanks @tnovotny. + +- Deprecated `fmt::visit`, `parse_context`, and `wparse_context`. Use + `fmt::visit_format_arg`, `format_parse_context`, and + `wformat_parse_context` instead. + +- Removed undocumented `basic_fixed_buffer` which has been superseded + by the iterator-based API + (https://github.com/fmtlib/fmt/issues/873, + https://github.com/fmtlib/fmt/pull/902). Thanks @superfunc. + +- Disallowed repeated leading zeros in an argument ID: + + ```c++ + fmt::print("{000}", 42); // error + ``` + +- Reintroduced support for gcc 4.4. + +- Fixed compilation on platforms with exotic `double` + (https://github.com/fmtlib/fmt/issues/878). + +- Improved documentation + (https://github.com/fmtlib/fmt/issues/164, + https://github.com/fmtlib/fmt/issues/877, + https://github.com/fmtlib/fmt/pull/901, + https://github.com/fmtlib/fmt/pull/906, + https://github.com/fmtlib/fmt/pull/979). + Thanks @kookjr, @DarkDimius and @HecticSerenity. + +- Added pkgconfig support which makes it easier to consume the library + from meson and other build systems + (https://github.com/fmtlib/fmt/pull/916). Thanks @colemickens. + +- Various build improvements + (https://github.com/fmtlib/fmt/pull/909, + https://github.com/fmtlib/fmt/pull/926, + https://github.com/fmtlib/fmt/pull/937, + https://github.com/fmtlib/fmt/pull/953, + https://github.com/fmtlib/fmt/pull/959). + Thanks @tchaikov, @luncliff, @AndreasSchoenle, @hotwatermorning and @Zefz. + +- Improved `string_view` construction performance + (https://github.com/fmtlib/fmt/pull/914). Thanks @gabime. + +- Fixed non-matching char types + (https://github.com/fmtlib/fmt/pull/895). Thanks @DanielaE. + +- Fixed `format_to_n` with `std::back_insert_iterator` + (https://github.com/fmtlib/fmt/pull/913). Thanks @DanielaE. + +- Fixed locale-dependent formatting + (https://github.com/fmtlib/fmt/issues/905). + +- Fixed various compiler warnings and errors + (https://github.com/fmtlib/fmt/pull/882, + https://github.com/fmtlib/fmt/pull/886, + https://github.com/fmtlib/fmt/pull/933, + https://github.com/fmtlib/fmt/pull/941, + https://github.com/fmtlib/fmt/issues/931, + https://github.com/fmtlib/fmt/pull/943, + https://github.com/fmtlib/fmt/pull/954, + https://github.com/fmtlib/fmt/pull/956, + https://github.com/fmtlib/fmt/pull/962, + https://github.com/fmtlib/fmt/issues/965, + https://github.com/fmtlib/fmt/issues/977, + https://github.com/fmtlib/fmt/pull/983, + https://github.com/fmtlib/fmt/pull/989). + Thanks @Luthaf, @stevenhoving, @christinaa, @lgritz, @DanielaE, + @0x8000-0000 and @liuping1997. + +# 5.2.1 - 2018-09-21 + +- Fixed `visit` lookup issues on gcc 7 & 8 + (https://github.com/fmtlib/fmt/pull/870). Thanks @medithe. +- Fixed linkage errors on older gcc. +- Prevented `fmt/range.h` from specializing `fmt::basic_string_view` + (https://github.com/fmtlib/fmt/issues/865, + https://github.com/fmtlib/fmt/pull/868). Thanks @hhggit. +- Improved error message when formatting unknown types + (https://github.com/fmtlib/fmt/pull/872). Thanks @foonathan. +- Disabled templated user-defined literals when compiled under nvcc + (https://github.com/fmtlib/fmt/pull/875). Thanks @CandyGumdrop. +- Fixed `format_to` formatting to `wmemory_buffer` + (https://github.com/fmtlib/fmt/issues/874). + +# 5.2.0 - 2018-09-13 + +- Optimized format string parsing and argument processing which + resulted in up to 5x speed up on long format strings and significant + performance boost on various benchmarks. For example, version 5.2 is + 2.22x faster than 5.1 on decimal integer formatting with `format_to` + (macOS, clang-902.0.39.2): + + | Method | Time, s | Speedup | + | -------------------------- | --------------: | ------: | + | fmt::format 5.1 | 0.58 | | + | fmt::format 5.2 | 0.35 | 1.66x | + | fmt::format_to 5.1 | 0.51 | | + | fmt::format_to 5.2 | 0.23 | 2.22x | + | sprintf | 0.71 | | + | std::to_string | 1.01 | | + | std::stringstream | 1.73 | | + +- Changed the `fmt` macro from opt-out to opt-in to prevent name + collisions. To enable it define the `FMT_STRING_ALIAS` macro to 1 + before including `fmt/format.h`: + + ```c++ + #define FMT_STRING_ALIAS 1 + #include <fmt/format.h> + std::string answer = format(fmt("{}"), 42); + ``` + +- Added compile-time format string checks to `format_to` overload that + takes `fmt::memory_buffer` + (https://github.com/fmtlib/fmt/issues/783): + + ```c++ + fmt::memory_buffer buf; + // Compile-time error: invalid type specifier. + fmt::format_to(buf, fmt("{:d}"), "foo"); + ``` + +- Moved experimental color support to `fmt/color.h` and enabled the + new API by default. The old API can be enabled by defining the + `FMT_DEPRECATED_COLORS` macro. + +- Added formatting support for types explicitly convertible to + `fmt::string_view`: + + ```c++ + struct foo { + explicit operator fmt::string_view() const { return "foo"; } + }; + auto s = format("{}", foo()); + ``` + + In particular, this makes formatting function work with + `folly::StringPiece`. + +- Implemented preliminary support for `char*_t` by replacing the + `format` function overloads with a single function template + parameterized on the string type. + +- Added support for dynamic argument lists + (https://github.com/fmtlib/fmt/issues/814, + https://github.com/fmtlib/fmt/pull/819). Thanks @MikePopoloski. + +- Reduced executable size overhead for embedded targets using newlib + nano by making locale dependency optional + (https://github.com/fmtlib/fmt/pull/839). Thanks @teajay-fr. + +- Keep `noexcept` specifier when exceptions are disabled + (https://github.com/fmtlib/fmt/issues/801, + https://github.com/fmtlib/fmt/pull/810). Thanks @qis. + +- Fixed formatting of user-defined types providing `operator<<` with + `format_to_n` (https://github.com/fmtlib/fmt/pull/806). + Thanks @mkurdej. + +- Fixed dynamic linkage of new symbols + (https://github.com/fmtlib/fmt/issues/808). + +- Fixed global initialization issue + (https://github.com/fmtlib/fmt/issues/807): + + ```c++ + // This works on compilers with constexpr support. + static const std::string answer = fmt::format("{}", 42); + ``` + +- Fixed various compiler warnings and errors + (https://github.com/fmtlib/fmt/pull/804, + https://github.com/fmtlib/fmt/issues/809, + https://github.com/fmtlib/fmt/pull/811, + https://github.com/fmtlib/fmt/issues/822, + https://github.com/fmtlib/fmt/pull/827, + https://github.com/fmtlib/fmt/issues/830, + https://github.com/fmtlib/fmt/pull/838, + https://github.com/fmtlib/fmt/issues/843, + https://github.com/fmtlib/fmt/pull/844, + https://github.com/fmtlib/fmt/issues/851, + https://github.com/fmtlib/fmt/pull/852, + https://github.com/fmtlib/fmt/pull/854). + Thanks @henryiii, @medithe, and @eliasdaler. + +# 5.1.0 - 2018-07-05 + +- Added experimental support for RGB color output enabled with the + `FMT_EXTENDED_COLORS` macro: + + ```c++ + #define FMT_EXTENDED_COLORS + #define FMT_HEADER_ONLY // or compile fmt with FMT_EXTENDED_COLORS defined + #include <fmt/format.h> + + fmt::print(fmt::color::steel_blue, "Some beautiful text"); + ``` + + The old API (the `print_colored` and `vprint_colored` functions and + the `color` enum) is now deprecated. + (https://github.com/fmtlib/fmt/issues/762 + https://github.com/fmtlib/fmt/pull/767). thanks @Remotion. + +- Added quotes to strings in ranges and tuples + (https://github.com/fmtlib/fmt/pull/766). Thanks @Remotion. + +- Made `format_to` work with `basic_memory_buffer` + (https://github.com/fmtlib/fmt/issues/776). + +- Added `vformat_to_n` and `wchar_t` overload of `format_to_n` + (https://github.com/fmtlib/fmt/issues/764, + https://github.com/fmtlib/fmt/issues/769). + +- Made `is_range` and `is_tuple_like` part of public (experimental) + API to allow specialization for user-defined types + (https://github.com/fmtlib/fmt/issues/751, + https://github.com/fmtlib/fmt/pull/759). Thanks @drrlvn. + +- Added more compilers to continuous integration and increased + `FMT_PEDANTIC` warning levels + (https://github.com/fmtlib/fmt/pull/736). Thanks @eliaskosunen. + +- Fixed compilation with MSVC 2013. + +- Fixed handling of user-defined types in `format_to` + (https://github.com/fmtlib/fmt/issues/793). + +- Forced linking of inline `vformat` functions into the library + (https://github.com/fmtlib/fmt/issues/795). + +- Fixed incorrect call to on_align in `'{:}='` + (https://github.com/fmtlib/fmt/issues/750). + +- Fixed floating-point formatting to a non-back_insert_iterator with + sign & numeric alignment specified + (https://github.com/fmtlib/fmt/issues/756). + +- Fixed formatting to an array with `format_to_n` + (https://github.com/fmtlib/fmt/issues/778). + +- Fixed formatting of more than 15 named arguments + (https://github.com/fmtlib/fmt/issues/754). + +- Fixed handling of compile-time strings when including + `fmt/ostream.h`. (https://github.com/fmtlib/fmt/issues/768). + +- Fixed various compiler warnings and errors + (https://github.com/fmtlib/fmt/issues/742, + https://github.com/fmtlib/fmt/issues/748, + https://github.com/fmtlib/fmt/issues/752, + https://github.com/fmtlib/fmt/issues/770, + https://github.com/fmtlib/fmt/pull/775, + https://github.com/fmtlib/fmt/issues/779, + https://github.com/fmtlib/fmt/pull/780, + https://github.com/fmtlib/fmt/pull/790, + https://github.com/fmtlib/fmt/pull/792, + https://github.com/fmtlib/fmt/pull/800). + Thanks @Remotion, @gabime, @foonathan, @Dark-Passenger and @0x8000-0000. + +# 5.0.0 - 2018-05-21 + +- Added a requirement for partial C++11 support, most importantly + variadic templates and type traits, and dropped `FMT_VARIADIC_*` + emulation macros. Variadic templates are available since GCC 4.4, + Clang 2.9 and MSVC 18.0 (2013). For older compilers use {fmt} + [version 4.x](https://github.com/fmtlib/fmt/releases/tag/4.1.0) + which continues to be maintained and works with C++98 compilers. + +- Renamed symbols to follow standard C++ naming conventions and + proposed a subset of the library for standardization in [P0645R2 + Text Formatting](https://wg21.link/P0645). + +- Implemented `constexpr` parsing of format strings and [compile-time + format string + checks](https://fmt.dev/latest/api.html#compile-time-format-string-checks). + For example + + ```c++ + #include <fmt/format.h> + + std::string s = format(fmt("{:d}"), "foo"); + ``` + + gives a compile-time error because `d` is an invalid specifier for + strings ([godbolt](https://godbolt.org/g/rnCy9Q)): + + ... + <source>:4:19: note: in instantiation of function template specialization 'fmt::v5::format<S, char [4]>' requested here + std::string s = format(fmt("{:d}"), "foo"); + ^ + format.h:1337:13: note: non-constexpr function 'on_error' cannot be used in a constant expression + handler.on_error("invalid type specifier"); + + Compile-time checks require relaxed `constexpr` (C++14 feature) + support. If the latter is not available, checks will be performed at + runtime. + +- Separated format string parsing and formatting in the extension API + to enable compile-time format string processing. For example + + ```c++ + struct Answer {}; + + namespace fmt { + template <> + struct formatter<Answer> { + constexpr auto parse(parse_context& ctx) { + auto it = ctx.begin(); + spec = *it; + if (spec != 'd' && spec != 's') + throw format_error("invalid specifier"); + return ++it; + } + + template <typename FormatContext> + auto format(Answer, FormatContext& ctx) { + return spec == 's' ? + format_to(ctx.begin(), "{}", "fourty-two") : + format_to(ctx.begin(), "{}", 42); + } + + char spec = 0; + }; + } + + std::string s = format(fmt("{:x}"), Answer()); + ``` + + gives a compile-time error due to invalid format specifier + ([godbolt](https://godbolt.org/g/2jQ1Dv)): + + ... + <source>:12:45: error: expression '<throw-expression>' is not a constant expression + throw format_error("invalid specifier"); + +- Added [iterator + support](https://fmt.dev/latest/api.html#output-iterator-support): + + ```c++ + #include <vector> + #include <fmt/format.h> + + std::vector<char> out; + fmt::format_to(std::back_inserter(out), "{}", 42); + ``` + +- Added the + [format_to_n](https://fmt.dev/latest/api.html#_CPPv2N3fmt11format_to_nE8OutputItNSt6size_tE11string_viewDpRK4Args) + function that restricts the output to the specified number of + characters (https://github.com/fmtlib/fmt/issues/298): + + ```c++ + char out[4]; + fmt::format_to_n(out, sizeof(out), "{}", 12345); + // out == "1234" (without terminating '\0') + ``` + +- Added the [formatted_size]( + https://fmt.dev/latest/api.html#_CPPv2N3fmt14formatted_sizeE11string_viewDpRK4Args) + function for computing the output size: + + ```c++ + #include <fmt/format.h> + + auto size = fmt::formatted_size("{}", 12345); // size == 5 + ``` + +- Improved compile times by reducing dependencies on standard headers + and providing a lightweight [core + API](https://fmt.dev/latest/api.html#core-api): + + ```c++ + #include <fmt/core.h> + + fmt::print("The answer is {}.", 42); + ``` + + See [Compile time and code + bloat](https://github.com/fmtlib/fmt#compile-time-and-code-bloat). + +- Added the [make_format_args]( + https://fmt.dev/latest/api.html#_CPPv2N3fmt16make_format_argsEDpRK4Args) + function for capturing formatting arguments: + + ```c++ + // Prints formatted error message. + void vreport_error(const char *format, fmt::format_args args) { + fmt::print("Error: "); + fmt::vprint(format, args); + } + template <typename... Args> + void report_error(const char *format, const Args & ... args) { + vreport_error(format, fmt::make_format_args(args...)); + } + ``` + +- Added the `make_printf_args` function for capturing `printf` + arguments (https://github.com/fmtlib/fmt/issues/687, + https://github.com/fmtlib/fmt/pull/694). Thanks @Kronuz. + +- Added prefix `v` to non-variadic functions taking `format_args` to + distinguish them from variadic ones: + + ```c++ + std::string vformat(string_view format_str, format_args args); + + template <typename... Args> + std::string format(string_view format_str, const Args & ... args); + ``` + +- Added experimental support for formatting ranges, containers and + tuple-like types in `fmt/ranges.h` + (https://github.com/fmtlib/fmt/pull/735): + + ```c++ + #include <fmt/ranges.h> + + std::vector<int> v = {1, 2, 3}; + fmt::print("{}", v); // prints {1, 2, 3} + ``` + + Thanks @Remotion. + +- Implemented `wchar_t` date and time formatting + (https://github.com/fmtlib/fmt/pull/712): + + ```c++ + #include <fmt/time.h> + + std::time_t t = std::time(nullptr); + auto s = fmt::format(L"The date is {:%Y-%m-%d}.", *std::localtime(&t)); + ``` + + Thanks @DanielaE. + +- Provided more wide string overloads + (https://github.com/fmtlib/fmt/pull/724). Thanks @DanielaE. + +- Switched from a custom null-terminated string view class to + `string_view` in the format API and provided `fmt::string_view` + which implements a subset of `std::string_view` API for pre-C++17 + systems. + +- Added support for `std::experimental::string_view` + (https://github.com/fmtlib/fmt/pull/607): + + ```c++ + #include <fmt/core.h> + #include <experimental/string_view> + + fmt::print("{}", std::experimental::string_view("foo")); + ``` + + Thanks @virgiliofornazin. + +- Allowed mixing named and automatic arguments: + + ```c++ + fmt::format("{} {two}", 1, fmt::arg("two", 2)); + ``` + +- Removed the write API in favor of the [format + API](https://fmt.dev/latest/api.html#format-api) with compile-time + handling of format strings. + +- Disallowed formatting of multibyte strings into a wide character + target (https://github.com/fmtlib/fmt/pull/606). + +- Improved documentation + (https://github.com/fmtlib/fmt/pull/515, + https://github.com/fmtlib/fmt/issues/614, + https://github.com/fmtlib/fmt/pull/617, + https://github.com/fmtlib/fmt/pull/661, + https://github.com/fmtlib/fmt/pull/680). + Thanks @ibell, @mihaitodor and @johnthagen. + +- Implemented more efficient handling of large number of format + arguments. + +- Introduced an inline namespace for symbol versioning. + +- Added debug postfix `d` to the `fmt` library name + (https://github.com/fmtlib/fmt/issues/636). + +- Removed unnecessary `fmt/` prefix in includes + (https://github.com/fmtlib/fmt/pull/397). Thanks @chronoxor. + +- Moved `fmt/*.h` to `include/fmt/*.h` to prevent irrelevant files and + directories appearing on the include search paths when fmt is used + as a subproject and moved source files to the `src` directory. + +- Added qmake project file `support/fmt.pro` + (https://github.com/fmtlib/fmt/pull/641). Thanks @cowo78. + +- Added Gradle build file `support/build.gradle` + (https://github.com/fmtlib/fmt/pull/649). Thanks @luncliff. + +- Removed `FMT_CPPFORMAT` CMake option. + +- Fixed a name conflict with the macro `CHAR_WIDTH` in glibc + (https://github.com/fmtlib/fmt/pull/616). Thanks @aroig. + +- Fixed handling of nested braces in `fmt::join` + (https://github.com/fmtlib/fmt/issues/638). + +- Added `SOURCELINK_SUFFIX` for compatibility with Sphinx 1.5 + (https://github.com/fmtlib/fmt/pull/497). Thanks @ginggs. + +- Added a missing `inline` in the header-only mode + (https://github.com/fmtlib/fmt/pull/626). Thanks @aroig. + +- Fixed various compiler warnings + (https://github.com/fmtlib/fmt/pull/640, + https://github.com/fmtlib/fmt/pull/656, + https://github.com/fmtlib/fmt/pull/679, + https://github.com/fmtlib/fmt/pull/681, + https://github.com/fmtlib/fmt/pull/705, + https://github.com/fmtlib/fmt/issues/715, + https://github.com/fmtlib/fmt/pull/717, + https://github.com/fmtlib/fmt/pull/720, + https://github.com/fmtlib/fmt/pull/723, + https://github.com/fmtlib/fmt/pull/726, + https://github.com/fmtlib/fmt/pull/730, + https://github.com/fmtlib/fmt/pull/739). + Thanks @peterbell10, @LarsGullik, @foonathan, @eliaskosunen, + @christianparpart, @DanielaE and @mwinterb. + +- Worked around an MSVC bug and fixed several warnings + (https://github.com/fmtlib/fmt/pull/653). Thanks @alabuzhev. + +- Worked around GCC bug 67371 + (https://github.com/fmtlib/fmt/issues/682). + +- Fixed compilation with `-fno-exceptions` + (https://github.com/fmtlib/fmt/pull/655). Thanks @chenxiaolong. + +- Made `constexpr remove_prefix` gcc version check tighter + (https://github.com/fmtlib/fmt/issues/648). + +- Renamed internal type enum constants to prevent collision with + poorly written C libraries + (https://github.com/fmtlib/fmt/issues/644). + +- Added detection of `wostream operator<<` + (https://github.com/fmtlib/fmt/issues/650). + +- Fixed compilation on OpenBSD + (https://github.com/fmtlib/fmt/pull/660). Thanks @hubslave. + +- Fixed compilation on FreeBSD 12 + (https://github.com/fmtlib/fmt/pull/732). Thanks @dankm. + +- Fixed compilation when there is a mismatch between `-std` options + between the library and user code + (https://github.com/fmtlib/fmt/issues/664). + +- Fixed compilation with GCC 7 and `-std=c++11` + (https://github.com/fmtlib/fmt/issues/734). + +- Improved generated binary code on GCC 7 and older + (https://github.com/fmtlib/fmt/issues/668). + +- Fixed handling of numeric alignment with no width + (https://github.com/fmtlib/fmt/issues/675). + +- Fixed handling of empty strings in UTF8/16 converters + (https://github.com/fmtlib/fmt/pull/676). Thanks @vgalka-sl. + +- Fixed formatting of an empty `string_view` + (https://github.com/fmtlib/fmt/issues/689). + +- Fixed detection of `string_view` on libc++ + (https://github.com/fmtlib/fmt/issues/686). + +- Fixed DLL issues (https://github.com/fmtlib/fmt/pull/696). + Thanks @sebkoenig. + +- Fixed compile checks for mixing narrow and wide strings + (https://github.com/fmtlib/fmt/issues/690). + +- Disabled unsafe implicit conversion to `std::string` + (https://github.com/fmtlib/fmt/issues/729). + +- Fixed handling of reused format specs (as in `fmt::join`) for + pointers (https://github.com/fmtlib/fmt/pull/725). Thanks @mwinterb. + +- Fixed installation of `fmt/ranges.h` + (https://github.com/fmtlib/fmt/pull/738). Thanks @sv1990. + +# 4.1.0 - 2017-12-20 + +- Added `fmt::to_wstring()` in addition to `fmt::to_string()` + (https://github.com/fmtlib/fmt/pull/559). Thanks @alabuzhev. +- Added support for C++17 `std::string_view` + (https://github.com/fmtlib/fmt/pull/571 and + https://github.com/fmtlib/fmt/pull/578). + Thanks @thelostt and @mwinterb. +- Enabled stream exceptions to catch errors + (https://github.com/fmtlib/fmt/issues/581). Thanks @crusader-mike. +- Allowed formatting of class hierarchies with `fmt::format_arg()` + (https://github.com/fmtlib/fmt/pull/547). Thanks @rollbear. +- Removed limitations on character types + (https://github.com/fmtlib/fmt/pull/563). Thanks @Yelnats321. +- Conditionally enabled use of `std::allocator_traits` + (https://github.com/fmtlib/fmt/pull/583). Thanks @mwinterb. +- Added support for `const` variadic member function emulation with + `FMT_VARIADIC_CONST` + (https://github.com/fmtlib/fmt/pull/591). Thanks @ludekvodicka. +- Various bugfixes: bad overflow check, unsupported implicit type + conversion when determining formatting function, test segfaults + (https://github.com/fmtlib/fmt/issues/551), ill-formed + macros (https://github.com/fmtlib/fmt/pull/542) and + ambiguous overloads + (https://github.com/fmtlib/fmt/issues/580). Thanks @xylosper. +- Prevented warnings on MSVC + (https://github.com/fmtlib/fmt/pull/605, + https://github.com/fmtlib/fmt/pull/602, and + https://github.com/fmtlib/fmt/pull/545), clang + (https://github.com/fmtlib/fmt/pull/582), GCC + (https://github.com/fmtlib/fmt/issues/573), various + conversion warnings (https://github.com/fmtlib/fmt/pull/609, + https://github.com/fmtlib/fmt/pull/567, + https://github.com/fmtlib/fmt/pull/553 and + https://github.com/fmtlib/fmt/pull/553), and added + `override` and `[[noreturn]]` + (https://github.com/fmtlib/fmt/pull/549 and + https://github.com/fmtlib/fmt/issues/555). + Thanks @alabuzhev, @virgiliofornazin, @alexanderbock, @yumetodo, @VaderY, + @jpcima, @thelostt and @Manu343726. +- Improved CMake: Used `GNUInstallDirs` to set installation location + (https://github.com/fmtlib/fmt/pull/610) and fixed warnings + (https://github.com/fmtlib/fmt/pull/536 and + https://github.com/fmtlib/fmt/pull/556). + Thanks @mikecrowe, @evgen231 and @henryiii. + +# 4.0.0 - 2017-06-27 + +- Removed old compatibility headers `cppformat/*.h` and CMake options + (https://github.com/fmtlib/fmt/pull/527). Thanks @maddinat0r. + +- Added `string.h` containing `fmt::to_string()` as alternative to + `std::to_string()` as well as other string writer functionality + (https://github.com/fmtlib/fmt/issues/326 and + https://github.com/fmtlib/fmt/pull/441): + + ```c++ + #include "fmt/string.h" + + std::string answer = fmt::to_string(42); + ``` + + Thanks @glebov-andrey. + +- Moved `fmt::printf()` to new `printf.h` header and allowed `%s` as + generic specifier (https://github.com/fmtlib/fmt/pull/453), + made `%.f` more conformant to regular `printf()` + (https://github.com/fmtlib/fmt/pull/490), added custom + writer support (https://github.com/fmtlib/fmt/issues/476) + and implemented missing custom argument formatting + (https://github.com/fmtlib/fmt/pull/339 and + https://github.com/fmtlib/fmt/pull/340): + + ```c++ + #include "fmt/printf.h" + + // %s format specifier can be used with any argument type. + fmt::printf("%s", 42); + ``` + + Thanks @mojoBrendan, @manylegged and @spacemoose. + See also https://github.com/fmtlib/fmt/issues/360, + https://github.com/fmtlib/fmt/issues/335 and + https://github.com/fmtlib/fmt/issues/331. + +- Added `container.h` containing a `BasicContainerWriter` to write to + containers like `std::vector` + (https://github.com/fmtlib/fmt/pull/450). Thanks @polyvertex. + +- Added `fmt::join()` function that takes a range and formats its + elements separated by a given string + (https://github.com/fmtlib/fmt/pull/466): + + ```c++ + #include "fmt/format.h" + + std::vector<double> v = {1.2, 3.4, 5.6}; + // Prints "(+01.20, +03.40, +05.60)". + fmt::print("({:+06.2f})", fmt::join(v.begin(), v.end(), ", ")); + ``` + + Thanks @olivier80. + +- Added support for custom formatting specifications to simplify + customization of built-in formatting + (https://github.com/fmtlib/fmt/pull/444). Thanks @polyvertex. + See also https://github.com/fmtlib/fmt/issues/439. + +- Added `fmt::format_system_error()` for error code formatting + (https://github.com/fmtlib/fmt/issues/323 and + https://github.com/fmtlib/fmt/pull/526). Thanks @maddinat0r. + +- Added thread-safe `fmt::localtime()` and `fmt::gmtime()` as + replacement for the standard version to `time.h` + (https://github.com/fmtlib/fmt/pull/396). Thanks @codicodi. + +- Internal improvements to `NamedArg` and `ArgLists` + (https://github.com/fmtlib/fmt/pull/389 and + https://github.com/fmtlib/fmt/pull/390). Thanks @chronoxor. + +- Fixed crash due to bug in `FormatBuf` + (https://github.com/fmtlib/fmt/pull/493). Thanks @effzeh. See also + https://github.com/fmtlib/fmt/issues/480 and + https://github.com/fmtlib/fmt/issues/491. + +- Fixed handling of wide strings in `fmt::StringWriter`. + +- Improved compiler error messages + (https://github.com/fmtlib/fmt/issues/357). + +- Fixed various warnings and issues with various compilers + (https://github.com/fmtlib/fmt/pull/494, + https://github.com/fmtlib/fmt/pull/499, + https://github.com/fmtlib/fmt/pull/483, + https://github.com/fmtlib/fmt/pull/485, + https://github.com/fmtlib/fmt/pull/482, + https://github.com/fmtlib/fmt/pull/475, + https://github.com/fmtlib/fmt/pull/473 and + https://github.com/fmtlib/fmt/pull/414). + Thanks @chronoxor, @zhaohuaxishi, @pkestene, @dschmidt and @0x414c. + +- Improved CMake: targets are now namespaced + (https://github.com/fmtlib/fmt/pull/511 and + https://github.com/fmtlib/fmt/pull/513), supported + header-only `printf.h` + (https://github.com/fmtlib/fmt/pull/354), fixed issue with + minimal supported library subset + (https://github.com/fmtlib/fmt/issues/418, + https://github.com/fmtlib/fmt/pull/419 and + https://github.com/fmtlib/fmt/pull/420). + Thanks @bjoernthiel, @niosHD, @LogicalKnight and @alabuzhev. + +- Improved documentation (https://github.com/fmtlib/fmt/pull/393). + Thanks @pwm1234. + +# 3.0.2 - 2017-06-14 + +- Added `FMT_VERSION` macro + (https://github.com/fmtlib/fmt/issues/411). +- Used `FMT_NULL` instead of literal `0` + (https://github.com/fmtlib/fmt/pull/409). Thanks @alabuzhev. +- Added extern templates for `format_float` + (https://github.com/fmtlib/fmt/issues/413). +- Fixed implicit conversion issue + (https://github.com/fmtlib/fmt/issues/507). +- Fixed signbit detection + (https://github.com/fmtlib/fmt/issues/423). +- Fixed naming collision + (https://github.com/fmtlib/fmt/issues/425). +- Fixed missing intrinsic for C++/CLI + (https://github.com/fmtlib/fmt/pull/457). Thanks @calumr. +- Fixed Android detection + (https://github.com/fmtlib/fmt/pull/458). Thanks @Gachapen. +- Use lean `windows.h` if not in header-only mode + (https://github.com/fmtlib/fmt/pull/503). Thanks @Quentin01. +- Fixed issue with CMake exporting C++11 flag + (https://github.com/fmtlib/fmt/pull/455). Thanks @EricWF. +- Fixed issue with nvcc and MSVC compiler bug and MinGW + (https://github.com/fmtlib/fmt/issues/505). +- Fixed DLL issues (https://github.com/fmtlib/fmt/pull/469 and + https://github.com/fmtlib/fmt/pull/502). + Thanks @richardeakin and @AndreasSchoenle. +- Fixed test compilation under FreeBSD + (https://github.com/fmtlib/fmt/issues/433). +- Fixed various warnings + (https://github.com/fmtlib/fmt/pull/403, + https://github.com/fmtlib/fmt/pull/410 and + https://github.com/fmtlib/fmt/pull/510). + Thanks @Lecetem, @chenhayat and @trozen. +- Worked around a broken `__builtin_clz` in clang with MS codegen + (https://github.com/fmtlib/fmt/issues/519). +- Removed redundant include + (https://github.com/fmtlib/fmt/issues/479). +- Fixed documentation issues. + +# 3.0.1 - 2016-11-01 + +- Fixed handling of thousands separator + (https://github.com/fmtlib/fmt/issues/353). +- Fixed handling of `unsigned char` strings + (https://github.com/fmtlib/fmt/issues/373). +- Corrected buffer growth when formatting time + (https://github.com/fmtlib/fmt/issues/367). +- Removed warnings under MSVC and clang + (https://github.com/fmtlib/fmt/issues/318, + https://github.com/fmtlib/fmt/issues/250, also merged + https://github.com/fmtlib/fmt/pull/385 and + https://github.com/fmtlib/fmt/pull/361). + Thanks @jcelerier and @nmoehrle. +- Fixed compilation issues under Android + (https://github.com/fmtlib/fmt/pull/327, + https://github.com/fmtlib/fmt/issues/345 and + https://github.com/fmtlib/fmt/pull/381), FreeBSD + (https://github.com/fmtlib/fmt/pull/358), Cygwin + (https://github.com/fmtlib/fmt/issues/388), MinGW + (https://github.com/fmtlib/fmt/issues/355) as well as other + issues (https://github.com/fmtlib/fmt/issues/350, + https://github.com/fmtlib/fmt/issues/355, + https://github.com/fmtlib/fmt/pull/348, + https://github.com/fmtlib/fmt/pull/402, + https://github.com/fmtlib/fmt/pull/405). + Thanks @dpantele, @hghwng, @arvedarved, @LogicalKnight and @JanHellwig. +- Fixed some documentation issues and extended specification + (https://github.com/fmtlib/fmt/issues/320, + https://github.com/fmtlib/fmt/pull/333, + https://github.com/fmtlib/fmt/issues/347, + https://github.com/fmtlib/fmt/pull/362). Thanks @smellman. + +# 3.0.0 - 2016-05-07 + +- The project has been renamed from C++ Format (cppformat) to fmt for + consistency with the used namespace and macro prefix + (https://github.com/fmtlib/fmt/issues/307). Library headers + are now located in the `fmt` directory: + + ```c++ + #include "fmt/format.h" + ``` + + Including `format.h` from the `cppformat` directory is deprecated + but works via a proxy header which will be removed in the next major + version. + + The documentation is now available at <https://fmt.dev>. + +- Added support for + [strftime](http://en.cppreference.com/w/cpp/chrono/c/strftime)-like + [date and time + formatting](https://fmt.dev/3.0.0/api.html#date-and-time-formatting) + (https://github.com/fmtlib/fmt/issues/283): + + ```c++ + #include "fmt/time.h" + + std::time_t t = std::time(nullptr); + // Prints "The date is 2016-04-29." (with the current date) + fmt::print("The date is {:%Y-%m-%d}.", *std::localtime(&t)); + ``` + +- `std::ostream` support including formatting of user-defined types + that provide overloaded `operator<<` has been moved to + `fmt/ostream.h`: + + ```c++ + #include "fmt/ostream.h" + + class Date { + int year_, month_, day_; + public: + Date(int year, int month, int day) : year_(year), month_(month), day_(day) {} + + friend std::ostream &operator<<(std::ostream &os, const Date &d) { + return os << d.year_ << '-' << d.month_ << '-' << d.day_; + } + }; + + std::string s = fmt::format("The date is {}", Date(2012, 12, 9)); + // s == "The date is 2012-12-9" + ``` + +- Added support for [custom argument + formatters](https://fmt.dev/3.0.0/api.html#argument-formatters) + (https://github.com/fmtlib/fmt/issues/235). + +- Added support for locale-specific integer formatting with the `n` + specifier (https://github.com/fmtlib/fmt/issues/305): + + ```c++ + std::setlocale(LC_ALL, "en_US.utf8"); + fmt::print("cppformat: {:n}\n", 1234567); // prints 1,234,567 + ``` + +- Sign is now preserved when formatting an integer with an incorrect + `printf` format specifier + (https://github.com/fmtlib/fmt/issues/265): + + ```c++ + fmt::printf("%lld", -42); // prints -42 + ``` + + Note that it would be an undefined behavior in `std::printf`. + +- Length modifiers such as `ll` are now optional in printf formatting + functions and the correct type is determined automatically + (https://github.com/fmtlib/fmt/issues/255): + + ```c++ + fmt::printf("%d", std::numeric_limits<long long>::max()); + ``` + + Note that it would be an undefined behavior in `std::printf`. + +- Added initial support for custom formatters + (https://github.com/fmtlib/fmt/issues/231). + +- Fixed detection of user-defined literal support on Intel C++ + compiler (https://github.com/fmtlib/fmt/issues/311, + https://github.com/fmtlib/fmt/pull/312). + Thanks @dean0x7d and @speth. + +- Reduced compile time + (https://github.com/fmtlib/fmt/pull/243, + https://github.com/fmtlib/fmt/pull/249, + https://github.com/fmtlib/fmt/issues/317): + +  + +  + + Thanks @dean0x7d. + +- Compile test fixes (https://github.com/fmtlib/fmt/pull/313). + Thanks @dean0x7d. + +- Documentation fixes (https://github.com/fmtlib/fmt/pull/239, + https://github.com/fmtlib/fmt/issues/248, + https://github.com/fmtlib/fmt/issues/252, + https://github.com/fmtlib/fmt/pull/258, + https://github.com/fmtlib/fmt/issues/260, + https://github.com/fmtlib/fmt/issues/301, + https://github.com/fmtlib/fmt/pull/309). + Thanks @ReadmeCritic @Gachapen and @jwilk. + +- Fixed compiler and sanitizer warnings + (https://github.com/fmtlib/fmt/issues/244, + https://github.com/fmtlib/fmt/pull/256, + https://github.com/fmtlib/fmt/pull/259, + https://github.com/fmtlib/fmt/issues/263, + https://github.com/fmtlib/fmt/issues/274, + https://github.com/fmtlib/fmt/pull/277, + https://github.com/fmtlib/fmt/pull/286, + https://github.com/fmtlib/fmt/issues/291, + https://github.com/fmtlib/fmt/issues/296, + https://github.com/fmtlib/fmt/issues/308). + Thanks @mwinterb, @pweiskircher and @Naios. + +- Improved compatibility with Windows Store apps + (https://github.com/fmtlib/fmt/issues/280, + https://github.com/fmtlib/fmt/pull/285) Thanks @mwinterb. + +- Added tests of compatibility with older C++ standards + (https://github.com/fmtlib/fmt/pull/273). Thanks @niosHD. + +- Fixed Android build + (https://github.com/fmtlib/fmt/pull/271). Thanks @newnon. + +- Changed `ArgMap` to be backed by a vector instead of a map. + (https://github.com/fmtlib/fmt/issues/261, + https://github.com/fmtlib/fmt/pull/262). Thanks @mwinterb. + +- Added `fprintf` overload that writes to a `std::ostream` + (https://github.com/fmtlib/fmt/pull/251). + Thanks @nickhutchinson. + +- Export symbols when building a Windows DLL + (https://github.com/fmtlib/fmt/pull/245). + Thanks @macdems. + +- Fixed compilation on Cygwin + (https://github.com/fmtlib/fmt/issues/304). + +- Implemented a workaround for a bug in Apple LLVM version 4.2 of + clang (https://github.com/fmtlib/fmt/issues/276). + +- Implemented a workaround for Google Test bug + https://github.com/google/googletest/issues/705 on gcc 6 + (https://github.com/fmtlib/fmt/issues/268). Thanks @octoploid. + +- Removed Biicode support because the latter has been discontinued. + +# 2.1.1 - 2016-04-11 + +- The install location for generated CMake files is now configurable + via the `FMT_CMAKE_DIR` CMake variable + (https://github.com/fmtlib/fmt/pull/299). Thanks @niosHD. +- Documentation fixes + (https://github.com/fmtlib/fmt/issues/252). + +# 2.1.0 - 2016-03-21 + +- Project layout and build system improvements + (https://github.com/fmtlib/fmt/pull/267): + + - The code have been moved to the `cppformat` directory. Including + `format.h` from the top-level directory is deprecated but works + via a proxy header which will be removed in the next major + version. + - C++ Format CMake targets now have proper interface definitions. + - Installed version of the library now supports the header-only + configuration. + - Targets `doc`, `install`, and `test` are now disabled if C++ + Format is included as a CMake subproject. They can be enabled by + setting `FMT_DOC`, `FMT_INSTALL`, and `FMT_TEST` in the parent + project. + + Thanks @niosHD. + +# 2.0.1 - 2016-03-13 + +- Improved CMake find and package support + (https://github.com/fmtlib/fmt/issues/264). Thanks @niosHD. +- Fix compile error with Android NDK and mingw32 + (https://github.com/fmtlib/fmt/issues/241). Thanks @Gachapen. +- Documentation fixes + (https://github.com/fmtlib/fmt/issues/248, + https://github.com/fmtlib/fmt/issues/260). + +# 2.0.0 - 2015-12-01 + +## General + +- \[Breaking\] Named arguments + (https://github.com/fmtlib/fmt/pull/169, + https://github.com/fmtlib/fmt/pull/173, + https://github.com/fmtlib/fmt/pull/174): + + ```c++ + fmt::print("The answer is {answer}.", fmt::arg("answer", 42)); + ``` + + Thanks @jamboree. + +- \[Experimental\] User-defined literals for format and named + arguments (https://github.com/fmtlib/fmt/pull/204, + https://github.com/fmtlib/fmt/pull/206, + https://github.com/fmtlib/fmt/pull/207): + + ```c++ + using namespace fmt::literals; + fmt::print("The answer is {answer}.", "answer"_a=42); + ``` + + Thanks @dean0x7d. + +- \[Breaking\] Formatting of more than 16 arguments is now supported + when using variadic templates + (https://github.com/fmtlib/fmt/issues/141). Thanks @Shauren. + +- Runtime width specification + (https://github.com/fmtlib/fmt/pull/168): + + ```c++ + fmt::format("{0:{1}}", 42, 5); // gives " 42" + ``` + + Thanks @jamboree. + +- \[Breaking\] Enums are now formatted with an overloaded + `std::ostream` insertion operator (`operator<<`) if available + (https://github.com/fmtlib/fmt/issues/232). + +- \[Breaking\] Changed default `bool` format to textual, \"true\" or + \"false\" (https://github.com/fmtlib/fmt/issues/170): + + ```c++ + fmt::print("{}", true); // prints "true" + ``` + + To print `bool` as a number use numeric format specifier such as + `d`: + + ```c++ + fmt::print("{:d}", true); // prints "1" + ``` + +- `fmt::printf` and `fmt::sprintf` now support formatting of `bool` + with the `%s` specifier giving textual output, \"true\" or \"false\" + (https://github.com/fmtlib/fmt/pull/223): + + ```c++ + fmt::printf("%s", true); // prints "true" + ``` + + Thanks @LarsGullik. + +- \[Breaking\] `signed char` and `unsigned char` are now formatted as + integers by default + (https://github.com/fmtlib/fmt/pull/217). + +- \[Breaking\] Pointers to C strings can now be formatted with the `p` + specifier (https://github.com/fmtlib/fmt/pull/223): + + ```c++ + fmt::print("{:p}", "test"); // prints pointer value + ``` + + Thanks @LarsGullik. + +- \[Breaking\] `fmt::printf` and `fmt::sprintf` now print null + pointers as `(nil)` and null strings as `(null)` for consistency + with glibc (https://github.com/fmtlib/fmt/pull/226). + Thanks @LarsGullik. + +- \[Breaking\] `fmt::(s)printf` now supports formatting of objects of + user-defined types that provide an overloaded `std::ostream` + insertion operator (`operator<<`) + (https://github.com/fmtlib/fmt/issues/201): + + ```c++ + fmt::printf("The date is %s", Date(2012, 12, 9)); + ``` + +- \[Breaking\] The `Buffer` template is now part of the public API and + can be used to implement custom memory buffers + (https://github.com/fmtlib/fmt/issues/140). Thanks @polyvertex. + +- \[Breaking\] Improved compatibility between `BasicStringRef` and + [std::experimental::basic_string_view]( + http://en.cppreference.com/w/cpp/experimental/basic_string_view) + (https://github.com/fmtlib/fmt/issues/100, + https://github.com/fmtlib/fmt/issues/159, + https://github.com/fmtlib/fmt/issues/183): + + - Comparison operators now compare string content, not pointers + - `BasicStringRef::c_str` replaced by `BasicStringRef::data` + - `BasicStringRef` is no longer assumed to be null-terminated + + References to null-terminated strings are now represented by a new + class, `BasicCStringRef`. + +- Dependency on pthreads introduced by Google Test is now optional + (https://github.com/fmtlib/fmt/issues/185). + +- New CMake options `FMT_DOC`, `FMT_INSTALL` and `FMT_TEST` to control + generation of `doc`, `install` and `test` targets respectively, on + by default (https://github.com/fmtlib/fmt/issues/197, + https://github.com/fmtlib/fmt/issues/198, + https://github.com/fmtlib/fmt/issues/200). Thanks @maddinat0r. + +- `noexcept` is now used when compiling with MSVC2015 + (https://github.com/fmtlib/fmt/pull/215). Thanks @dmkrepo. + +- Added an option to disable use of `windows.h` when + `FMT_USE_WINDOWS_H` is defined as 0 before including `format.h` + (https://github.com/fmtlib/fmt/issues/171). Thanks @alfps. + +- \[Breaking\] `windows.h` is now included with `NOMINMAX` unless + `FMT_WIN_MINMAX` is defined. This is done to prevent breaking code + using `std::min` and `std::max` and only affects the header-only + configuration (https://github.com/fmtlib/fmt/issues/152, + https://github.com/fmtlib/fmt/pull/153, + https://github.com/fmtlib/fmt/pull/154). Thanks @DevO2012. + +- Improved support for custom character types + (https://github.com/fmtlib/fmt/issues/171). Thanks @alfps. + +- Added an option to disable use of IOStreams when `FMT_USE_IOSTREAMS` + is defined as 0 before including `format.h` + (https://github.com/fmtlib/fmt/issues/205, + https://github.com/fmtlib/fmt/pull/208). Thanks @JodiTheTigger. + +- Improved detection of `isnan`, `isinf` and `signbit`. + +## Optimization + +- Made formatting of user-defined types more efficient with a custom + stream buffer (https://github.com/fmtlib/fmt/issues/92, + https://github.com/fmtlib/fmt/pull/230). Thanks @NotImplemented. +- Further improved performance of `fmt::Writer` on integer formatting + and fixed a minor regression. Now it is \~7% faster than + `karma::generate` on Karma\'s benchmark + (https://github.com/fmtlib/fmt/issues/186). +- \[Breaking\] Reduced [compiled code + size](https://github.com/fmtlib/fmt#compile-time-and-code-bloat) + (https://github.com/fmtlib/fmt/issues/143, + https://github.com/fmtlib/fmt/pull/149). + +## Distribution + +- \[Breaking\] Headers are now installed in + `${CMAKE_INSTALL_PREFIX}/include/cppformat` + (https://github.com/fmtlib/fmt/issues/178). Thanks @jackyf. + +- \[Breaking\] Changed the library name from `format` to `cppformat` + for consistency with the project name and to avoid potential + conflicts (https://github.com/fmtlib/fmt/issues/178). + Thanks @jackyf. + +- C++ Format is now available in [Debian](https://www.debian.org/) + GNU/Linux + ([stretch](https://packages.debian.org/source/stretch/cppformat), + [sid](https://packages.debian.org/source/sid/cppformat)) and derived + distributions such as + [Ubuntu](https://launchpad.net/ubuntu/+source/cppformat) 15.10 and + later (https://github.com/fmtlib/fmt/issues/155): + + $ sudo apt-get install libcppformat1-dev + + Thanks @jackyf. + +- [Packages for Fedora and + RHEL](https://admin.fedoraproject.org/pkgdb/package/cppformat/) are + now available. Thanks Dave Johansen. + +- C++ Format can now be installed via [Homebrew](http://brew.sh/) on + OS X (https://github.com/fmtlib/fmt/issues/157): + + $ brew install cppformat + + Thanks @ortho and Anatoliy Bulukin. + +## Documentation + +- Migrated from ReadTheDocs to GitHub Pages for better responsiveness + and reliability (https://github.com/fmtlib/fmt/issues/128). + New documentation address is <http://cppformat.github.io/>. +- Added [Building thedocumentation]( + https://fmt.dev/2.0.0/usage.html#building-the-documentation) + section to the documentation. +- Documentation build script is now compatible with Python 3 and newer + pip versions. (https://github.com/fmtlib/fmt/pull/189, + https://github.com/fmtlib/fmt/issues/209). + Thanks @JodiTheTigger and @xentec. +- Documentation fixes and improvements + (https://github.com/fmtlib/fmt/issues/36, + https://github.com/fmtlib/fmt/issues/75, + https://github.com/fmtlib/fmt/issues/125, + https://github.com/fmtlib/fmt/pull/160, + https://github.com/fmtlib/fmt/pull/161, + https://github.com/fmtlib/fmt/issues/162, + https://github.com/fmtlib/fmt/issues/165, + https://github.com/fmtlib/fmt/issues/210). + Thanks @syohex. +- Fixed out-of-tree documentation build + (https://github.com/fmtlib/fmt/issues/177). Thanks @jackyf. + +## Fixes + +- Fixed `initializer_list` detection + (https://github.com/fmtlib/fmt/issues/136). Thanks @Gachapen. + +- \[Breaking\] Fixed formatting of enums with numeric format + specifiers in `fmt::(s)printf` + (https://github.com/fmtlib/fmt/issues/131, + https://github.com/fmtlib/fmt/issues/139): + + ```c++ + enum { ANSWER = 42 }; + fmt::printf("%d", ANSWER); + ``` + + Thanks @Naios. + +- Improved compatibility with old versions of MinGW + (https://github.com/fmtlib/fmt/issues/129, + https://github.com/fmtlib/fmt/pull/130, + https://github.com/fmtlib/fmt/issues/132). Thanks @cstamford. + +- Fixed a compile error on MSVC with disabled exceptions + (https://github.com/fmtlib/fmt/issues/144). + +- Added a workaround for broken implementation of variadic templates + in MSVC2012 (https://github.com/fmtlib/fmt/issues/148). + +- Placed the anonymous namespace within `fmt` namespace for the + header-only configuration (https://github.com/fmtlib/fmt/issues/171). + Thanks @alfps. + +- Fixed issues reported by Coverity Scan + (https://github.com/fmtlib/fmt/issues/187, + https://github.com/fmtlib/fmt/issues/192). + +- Implemented a workaround for a name lookup bug in MSVC2010 + (https://github.com/fmtlib/fmt/issues/188). + +- Fixed compiler warnings + (https://github.com/fmtlib/fmt/issues/95, + https://github.com/fmtlib/fmt/issues/96, + https://github.com/fmtlib/fmt/pull/114, + https://github.com/fmtlib/fmt/issues/135, + https://github.com/fmtlib/fmt/issues/142, + https://github.com/fmtlib/fmt/issues/145, + https://github.com/fmtlib/fmt/issues/146, + https://github.com/fmtlib/fmt/issues/158, + https://github.com/fmtlib/fmt/issues/163, + https://github.com/fmtlib/fmt/issues/175, + https://github.com/fmtlib/fmt/issues/190, + https://github.com/fmtlib/fmt/pull/191, + https://github.com/fmtlib/fmt/issues/194, + https://github.com/fmtlib/fmt/pull/196, + https://github.com/fmtlib/fmt/issues/216, + https://github.com/fmtlib/fmt/pull/218, + https://github.com/fmtlib/fmt/pull/220, + https://github.com/fmtlib/fmt/pull/229, + https://github.com/fmtlib/fmt/issues/233, + https://github.com/fmtlib/fmt/issues/234, + https://github.com/fmtlib/fmt/pull/236, + https://github.com/fmtlib/fmt/issues/281, + https://github.com/fmtlib/fmt/issues/289). + Thanks @seanmiddleditch, @dixlorenz, @CarterLi, @Naios, @fmatthew5876, + @LevskiWeng, @rpopescu, @gabime, @cubicool, @jkflying, @LogicalKnight, + @inguin and @Jopie64. + +- Fixed portability issues (mostly causing test failures) on ARM, + ppc64, ppc64le, s390x and SunOS 5.11 i386 + (https://github.com/fmtlib/fmt/issues/138, + https://github.com/fmtlib/fmt/issues/179, + https://github.com/fmtlib/fmt/issues/180, + https://github.com/fmtlib/fmt/issues/202, + https://github.com/fmtlib/fmt/issues/225, [Red Hat Bugzilla + Bug 1260297](https://bugzilla.redhat.com/show_bug.cgi?id=1260297)). + Thanks @Naios, @jackyf and Dave Johansen. + +- Fixed a name conflict with macro `free` defined in `crtdbg.h` when + `_CRTDBG_MAP_ALLOC` is set (https://github.com/fmtlib/fmt/issues/211). + +- Fixed shared library build on OS X + (https://github.com/fmtlib/fmt/pull/212). Thanks @dean0x7d. + +- Fixed an overload conflict on MSVC when `/Zc:wchar_t-` option is + specified (https://github.com/fmtlib/fmt/pull/214). + Thanks @slavanap. + +- Improved compatibility with MSVC 2008 + (https://github.com/fmtlib/fmt/pull/236). Thanks @Jopie64. + +- Improved compatibility with bcc32 + (https://github.com/fmtlib/fmt/issues/227). + +- Fixed `static_assert` detection on Clang + (https://github.com/fmtlib/fmt/pull/228). Thanks @dean0x7d. + +# 1.1.0 - 2015-03-06 + +- Added `BasicArrayWriter`, a class template that provides operations + for formatting and writing data into a fixed-size array + (https://github.com/fmtlib/fmt/issues/105 and + https://github.com/fmtlib/fmt/issues/122): + + ```c++ + char buffer[100]; + fmt::ArrayWriter w(buffer); + w.write("The answer is {}", 42); + ``` + +- Added [0 A.D.](http://play0ad.com/) and [PenUltima Online + (POL)](http://www.polserver.com/) to the list of notable projects + using C++ Format. + +- C++ Format now uses MSVC intrinsics for better formatting performance + (https://github.com/fmtlib/fmt/pull/115, + https://github.com/fmtlib/fmt/pull/116, + https://github.com/fmtlib/fmt/pull/118 and + https://github.com/fmtlib/fmt/pull/121). Previously these + optimizations where only used on GCC and Clang. + Thanks @CarterLi and @objectx. + +- CMake install target + (https://github.com/fmtlib/fmt/pull/119). Thanks @TrentHouliston. + + You can now install C++ Format with `make install` command. + +- Improved [Biicode](http://www.biicode.com/) support + (https://github.com/fmtlib/fmt/pull/98 and + https://github.com/fmtlib/fmt/pull/104). + Thanks @MariadeAnton and @franramirez688. + +- Improved support for building with [Android NDK]( + https://developer.android.com/tools/sdk/ndk/index.html) + (https://github.com/fmtlib/fmt/pull/107). Thanks @newnon. + + The [android-ndk-example](https://github.com/fmtlib/android-ndk-example) + repository provides and example of using C++ Format with Android NDK: + +  + +- Improved documentation of `SystemError` and `WindowsError` + (https://github.com/fmtlib/fmt/issues/54). + +- Various code improvements + (https://github.com/fmtlib/fmt/pull/110, + https://github.com/fmtlib/fmt/pull/111 + https://github.com/fmtlib/fmt/pull/112). Thanks @CarterLi. + +- Improved compile-time errors when formatting wide into narrow + strings (https://github.com/fmtlib/fmt/issues/117). + +- Fixed `BasicWriter::write` without formatting arguments when C++11 + support is disabled + (https://github.com/fmtlib/fmt/issues/109). + +- Fixed header-only build on OS X with GCC 4.9 + (https://github.com/fmtlib/fmt/issues/124). + +- Fixed packaging issues (https://github.com/fmtlib/fmt/issues/94). + +- Added [changelog](https://github.com/fmtlib/fmt/blob/master/ChangeLog.md) + (https://github.com/fmtlib/fmt/issues/103). + +# 1.0.0 - 2015-02-05 + +- Add support for a header-only configuration when `FMT_HEADER_ONLY` + is defined before including `format.h`: + + ```c++ + #define FMT_HEADER_ONLY + #include "format.h" + ``` + +- Compute string length in the constructor of `BasicStringRef` instead + of the `size` method + (https://github.com/fmtlib/fmt/issues/79). This eliminates + size computation for string literals on reasonable optimizing + compilers. + +- Fix formatting of types with overloaded `operator <<` for + `std::wostream` (https://github.com/fmtlib/fmt/issues/86): + + ```c++ + fmt::format(L"The date is {0}", Date(2012, 12, 9)); + ``` + +- Fix linkage of tests on Arch Linux + (https://github.com/fmtlib/fmt/issues/89). + +- Allow precision specifier for non-float arguments + (https://github.com/fmtlib/fmt/issues/90): + + ```c++ + fmt::print("{:.3}\n", "Carpet"); // prints "Car" + ``` + +- Fix build on Android NDK (https://github.com/fmtlib/fmt/issues/93). + +- Improvements to documentation build procedure. + +- Remove `FMT_SHARED` CMake variable in favor of standard [BUILD_SHARED_LIBS]( + http://www.cmake.org/cmake/help/v3.0/variable/BUILD_SHARED_LIBS.html). + +- Fix error handling in `fmt::fprintf`. + +- Fix a number of warnings. + +# 0.12.0 - 2014-10-25 + +- \[Breaking\] Improved separation between formatting and buffer + management. `Writer` is now a base class that cannot be instantiated + directly. The new `MemoryWriter` class implements the default buffer + management with small allocations done on stack. So `fmt::Writer` + should be replaced with `fmt::MemoryWriter` in variable + declarations. + + Old code: + + ```c++ + fmt::Writer w; + ``` + + New code: + + ```c++ + fmt::MemoryWriter w; + ``` + + If you pass `fmt::Writer` by reference, you can continue to do so: + + ```c++ + void f(fmt::Writer &w); + ``` + + This doesn\'t affect the formatting API. + +- Support for custom memory allocators + (https://github.com/fmtlib/fmt/issues/69) + +- Formatting functions now accept [signed char]{.title-ref} and + [unsigned char]{.title-ref} strings as arguments + (https://github.com/fmtlib/fmt/issues/73): + + ```c++ + auto s = format("GLSL version: {}", glGetString(GL_VERSION)); + ``` + +- Reduced code bloat. According to the new [benchmark + results](https://github.com/fmtlib/fmt#compile-time-and-code-bloat), + cppformat is close to `printf` and by the order of magnitude better + than Boost Format in terms of compiled code size. + +- Improved appearance of the documentation on mobile by using the + [Sphinx Bootstrap + theme](http://ryan-roemer.github.io/sphinx-bootstrap-theme/): + + | Old | New | + | --- | --- | + |  |  | + +# 0.11.0 - 2014-08-21 + +- Safe printf implementation with a POSIX extension for positional + arguments: + + ```c++ + fmt::printf("Elapsed time: %.2f seconds", 1.23); + fmt::printf("%1$s, %3$d %2$s", weekday, month, day); + ``` + +- Arguments of `char` type can now be formatted as integers (Issue + https://github.com/fmtlib/fmt/issues/55): + + ```c++ + fmt::format("0x{0:02X}", 'a'); + ``` + +- Deprecated parts of the API removed. + +- The library is now built and tested on MinGW with Appveyor in + addition to existing test platforms Linux/GCC, OS X/Clang, + Windows/MSVC. + +# 0.10.0 - 2014-07-01 + +**Improved API** + +- All formatting methods are now implemented as variadic functions + instead of using `operator<<` for feeding arbitrary arguments into a + temporary formatter object. This works both with C++11 where + variadic templates are used and with older standards where variadic + functions are emulated by providing lightweight wrapper functions + defined with the `FMT_VARIADIC` macro. You can use this macro for + defining your own portable variadic functions: + + ```c++ + void report_error(const char *format, const fmt::ArgList &args) { + fmt::print("Error: {}"); + fmt::print(format, args); + } + FMT_VARIADIC(void, report_error, const char *) + + report_error("file not found: {}", path); + ``` + + Apart from a more natural syntax, this also improves performance as + there is no need to construct temporary formatter objects and + control arguments\' lifetimes. Because the wrapper functions are + very lightweight, this doesn\'t cause code bloat even in pre-C++11 + mode. + +- Simplified common case of formatting an `std::string`. Now it + requires a single function call: + + ```c++ + std::string s = format("The answer is {}.", 42); + ``` + + Previously it required 2 function calls: + + ```c++ + std::string s = str(Format("The answer is {}.") << 42); + ``` + + Instead of unsafe `c_str` function, `fmt::Writer` should be used + directly to bypass creation of `std::string`: + + ```c++ + fmt::Writer w; + w.write("The answer is {}.", 42); + w.c_str(); // returns a C string + ``` + + This doesn\'t do dynamic memory allocation for small strings and is + less error prone as the lifetime of the string is the same as for + `std::string::c_str` which is well understood (hopefully). + +- Improved consistency in naming functions that are a part of the + public API. Now all public functions are lowercase following the + standard library conventions. Previously it was a combination of + lowercase and CapitalizedWords. Issue + https://github.com/fmtlib/fmt/issues/50. + +- Old functions are marked as deprecated and will be removed in the + next release. + +**Other Changes** + +- Experimental support for printf format specifications (work in + progress): + + ```c++ + fmt::printf("The answer is %d.", 42); + std::string s = fmt::sprintf("Look, a %s!", "string"); + ``` + +- Support for hexadecimal floating point format specifiers `a` and + `A`: + + ```c++ + print("{:a}", -42.0); // Prints -0x1.5p+5 + print("{:A}", -42.0); // Prints -0X1.5P+5 + ``` + +- CMake option `FMT_SHARED` that specifies whether to build format as + a shared library (off by default). + +# 0.9.0 - 2014-05-13 + +- More efficient implementation of variadic formatting functions. + +- `Writer::Format` now has a variadic overload: + + ```c++ + Writer out; + out.Format("Look, I'm {}!", "variadic"); + ``` + +- For efficiency and consistency with other overloads, variadic + overload of the `Format` function now returns `Writer` instead of + `std::string`. Use the `str` function to convert it to + `std::string`: + + ```c++ + std::string s = str(Format("Look, I'm {}!", "variadic")); + ``` + +- Replaced formatter actions with output sinks: `NoAction` -\> + `NullSink`, `Write` -\> `FileSink`, `ColorWriter` -\> + `ANSITerminalSink`. This improves naming consistency and shouldn\'t + affect client code unless these classes are used directly which + should be rarely needed. + +- Added `ThrowSystemError` function that formats a message and throws + `SystemError` containing the formatted message and system-specific + error description. For example, the following code + + ```c++ + FILE *f = fopen(filename, "r"); + if (!f) + ThrowSystemError(errno, "Failed to open file '{}'") << filename; + ``` + + will throw `SystemError` exception with description \"Failed to open + file \'\<filename\>\': No such file or directory\" if file doesn\'t + exist. + +- Support for AppVeyor continuous integration platform. + +- `Format` now throws `SystemError` in case of I/O errors. + +- Improve test infrastructure. Print functions are now tested by + redirecting the output to a pipe. + +# 0.8.0 - 2014-04-14 + +- Initial release diff --git a/thirdparty/fmt/doc/api.md b/thirdparty/fmt/doc/api.md new file mode 100644 index 000000000..2c584abc0 --- /dev/null +++ b/thirdparty/fmt/doc/api.md @@ -0,0 +1,710 @@ +# API Reference + +The {fmt} library API consists of the following components: + +- [`fmt/base.h`](#base-api): the base API providing main formatting functions + for `char`/UTF-8 with C++20 compile-time checks and minimal dependencies +- [`fmt/format.h`](#format-api): `fmt::format` and other formatting functions + as well as locale support +- [`fmt/ranges.h`](#ranges-api): formatting of ranges and tuples +- [`fmt/chrono.h`](#chrono-api): date and time formatting +- [`fmt/std.h`](#std-api): formatters for standard library types +- [`fmt/compile.h`](#compile-api): format string compilation +- [`fmt/color.h`](#color-api): terminal colors and text styles +- [`fmt/os.h`](#os-api): system APIs +- [`fmt/ostream.h`](#ostream-api): `std::ostream` support +- [`fmt/args.h`](#args-api): dynamic argument lists +- [`fmt/printf.h`](#printf-api): safe `printf` +- [`fmt/xchar.h`](#xchar-api): optional `wchar_t` support + +All functions and types provided by the library reside in namespace `fmt` +and macros have prefix `FMT_`. + +## Base API + +`fmt/base.h` defines the base API which provides main formatting functions +for `char`/UTF-8 with C++20 compile-time checks. It has minimal include +dependencies for better compile times. This header is only beneficial when +using {fmt} as a library (the default) and not in the header-only mode. +It also provides `formatter` specializations for the following types: + +- `int`, `long long`, +- `unsigned`, `unsigned long long` +- `float`, `double`, `long double` +- `bool` +- `char` +- `const char*`, [`fmt::string_view`](#basic_string_view) +- `const void*` + +The following functions use [format string syntax](syntax.md) similar to that +of [str.format](https://docs.python.org/3/library/stdtypes.html#str.format) +in Python. They take *fmt* and *args* as arguments. + +*fmt* is a format string that contains literal text and replacement fields +surrounded by braces `{}`. The fields are replaced with formatted arguments +in the resulting string. [`fmt::format_string`](#format_string) is a format +string which can be implicitly constructed from a string literal or a +`constexpr` string and is checked at compile time in C++20. To pass a runtime +format string wrap it in [`fmt::runtime`](#runtime). + +*args* is an argument list representing objects to be formatted. + +I/O errors are reported as [`std::system_error`]( +https://en.cppreference.com/w/cpp/error/system_error) exceptions unless +specified otherwise. + +::: print(format_string<T...>, T&&...) + +::: print(FILE*, format_string<T...>, T&&...) + +::: println(format_string<T...>, T&&...) + +::: println(FILE*, format_string<T...>, T&&...) + +::: format_to(OutputIt&&, format_string<T...>, T&&...) + +::: format_to_n(OutputIt, size_t, format_string<T...>, T&&...) + +::: format_to_n_result + +::: formatted_size(format_string<T...>, T&&...) + +<a id="udt"></a> +### Formatting User-Defined Types + +The {fmt} library provides formatters for many standard C++ types. +See [`fmt/ranges.h`](#ranges-api) for ranges and tuples including standard +containers such as `std::vector`, [`fmt/chrono.h`](#chrono-api) for date and +time formatting and [`fmt/std.h`](#std-api) for other standard library types. + +There are two ways to make a user-defined type formattable: providing a +`format_as` function or specializing the `formatter` struct template. +Formatting of non-void pointer types is intentionally disallowed and they +cannot be made formattable via either extension API. + +Use `format_as` if you want to make your type formattable as some other +type with the same format specifiers. The `format_as` function should +take an object of your type and return an object of a formattable type. +It should be defined in the same namespace as your type. + +Example ([run](https://godbolt.org/z/nvME4arz8)): + + #include <fmt/format.h> + + namespace kevin_namespacy { + + enum class film { + house_of_cards, american_beauty, se7en = 7 + }; + + auto format_as(film f) { return fmt::underlying(f); } + + } + + int main() { + fmt::print("{}\n", kevin_namespacy::film::se7en); // Output: 7 + } + +Using specialization is more complex but gives you full control over +parsing and formatting. To use this method specialize the `formatter` +struct template for your type and implement `parse` and `format` +methods. + +The recommended way of defining a formatter is by reusing an existing +one via inheritance or composition. This way you can support standard +format specifiers without implementing them yourself. For example: + +```c++ +// color.h: +#include <fmt/base.h> + +enum class color {red, green, blue}; + +template <> struct fmt::formatter<color>: formatter<string_view> { + // parse is inherited from formatter<string_view>. + + auto format(color c, format_context& ctx) const + -> format_context::iterator; +}; +``` + +```c++ +// color.cc: +#include "color.h" +#include <fmt/format.h> + +auto fmt::formatter<color>::format(color c, format_context& ctx) const + -> format_context::iterator { + string_view name = "unknown"; + switch (c) { + case color::red: name = "red"; break; + case color::green: name = "green"; break; + case color::blue: name = "blue"; break; + } + return formatter<string_view>::format(name, ctx); +} +``` + +Note that `formatter<string_view>::format` is defined in `fmt/format.h` +so it has to be included in the source file. Since `parse` is inherited +from `formatter<string_view>` it will recognize all string format +specifications, for example + +```c++ +fmt::format("{:>10}", color::blue) +``` + +will return `" blue"`. + +<!-- The experimental `nested_formatter` provides an easy way of applying a +formatter to one or more subobjects. + +For example: + + #include <fmt/format.h> + + struct point { + double x, y; + }; + + template <> + struct fmt::formatter<point> : nested_formatter<double> { + auto format(point p, format_context& ctx) const { + return write_padded(ctx, [=](auto out) { + return format_to(out, "({}, {})", this->nested(p.x), + this->nested(p.y)); + }); + } + }; + + int main() { + fmt::print("[{:>20.2f}]", point{1, 2}); + } + +prints: + + [ (1.00, 2.00)] + +Notice that fill, align and width are applied to the whole object which +is the recommended behavior while the remaining specifiers apply to +elements. --> + +In general the formatter has the following form: + + template <> struct fmt::formatter<T> { + // Parses format specifiers and stores them in the formatter. + // + // [ctx.begin(), ctx.end()) is a, possibly empty, character range that + // contains a part of the format string starting from the format + // specifications to be parsed, e.g. in + // + // fmt::format("{:f} continued", ...); + // + // the range will contain "f} continued". The formatter should parse + // specifiers until '}' or the end of the range. In this example the + // formatter should parse the 'f' specifier and return an iterator + // pointing to '}'. + constexpr auto parse(format_parse_context& ctx) + -> format_parse_context::iterator; + + // Formats value using the parsed format specification stored in this + // formatter and writes the output to ctx.out(). + auto format(const T& value, format_context& ctx) const + -> format_context::iterator; + }; + +It is recommended to at least support fill, align and width that apply +to the whole object and have the same semantics as in standard +formatters. + +You can also write a formatter for a hierarchy of classes: + +```c++ +// demo.h: +#include <type_traits> +#include <fmt/format.h> + +struct A { + virtual ~A() {} + virtual std::string name() const { return "A"; } +}; + +struct B : A { + virtual std::string name() const { return "B"; } +}; + +template <typename T> +struct fmt::formatter<T, std::enable_if_t<std::is_base_of_v<A, T>, char>> : + fmt::formatter<std::string> { + auto format(const A& a, format_context& ctx) const { + return formatter<std::string>::format(a.name(), ctx); + } +}; +``` + +```c++ +// demo.cc: +#include "demo.h" +#include <fmt/format.h> + +int main() { + B b; + A& a = b; + fmt::print("{}", a); // Output: B +} +``` + +Providing both a `formatter` specialization and a `format_as` overload is +disallowed. + +::: basic_format_parse_context + +::: context + +::: format_context + +### Compile-Time Checks + +Compile-time format string checks are enabled by default on compilers +that support C++20 `consteval`. On older compilers you can use the +[FMT_STRING](#legacy-checks) macro defined in `fmt/format.h` instead. + +Unused arguments are allowed as in Python's `str.format` and ordinary functions. + +See [Type Erasure](#type-erasure) for an example of how to enable compile-time +checks in your own functions with `fmt::format_string` while avoiding template +bloat. + +::: fstring + +::: format_string + +::: runtime(string_view) + +### Type Erasure + +You can create your own formatting function with compile-time checks and +small binary footprint, for example ([run](https://godbolt.org/z/b9Pbasvzc)): + +```c++ +#include <fmt/format.h> + +void vlog(const char* file, int line, + fmt::string_view fmt, fmt::format_args args) { + fmt::print("{}: {}: {}", file, line, fmt::vformat(fmt, args)); +} + +template <typename... T> +void log(const char* file, int line, + fmt::format_string<T...> fmt, T&&... args) { + vlog(file, line, fmt, fmt::make_format_args(args...)); +} + +#define MY_LOG(fmt, ...) log(__FILE__, __LINE__, fmt, __VA_ARGS__) + +MY_LOG("invalid squishiness: {}", 42); +``` + +Note that `vlog` is not parameterized on argument types which improves +compile times and reduces binary code size compared to a fully +parameterized version. + +::: make_format_args(T&...) + +::: basic_format_args + +::: format_args + +::: basic_format_arg + +### Named Arguments + +::: arg(const Char*, const T&) + +Named arguments are not supported in compile-time checks at the moment. + +### Compatibility + +::: basic_string_view + +::: string_view + +## Format API + +`fmt/format.h` defines the full format API providing additional +formatting functions and locale support. + +<a id="format"></a> +::: format(format_string<T...>, T&&...) + +::: vformat(string_view, format_args) + +::: operator""_a() + +### Utilities + +::: ptr(T) + +::: underlying(Enum) + +::: to_string(const T&) + +::: group_digits(T) + +::: detail::buffer + +::: basic_memory_buffer + +### System Errors + +{fmt} does not use `errno` to communicate errors to the user, but it may +call system functions which set `errno`. Users should not make any +assumptions about the value of `errno` being preserved by library +functions. + +::: system_error + +::: format_system_error + +### Custom Allocators + +The {fmt} library supports custom dynamic memory allocators. A custom +allocator class can be specified as a template argument to +[`fmt::basic_memory_buffer`](#basic_memory_buffer): + + using custom_memory_buffer = + fmt::basic_memory_buffer<char, fmt::inline_buffer_size, custom_allocator>; + +It is also possible to write a formatting function that uses a custom +allocator: + + using custom_string = + std::basic_string<char, std::char_traits<char>, custom_allocator>; + + auto vformat(custom_allocator alloc, fmt::string_view fmt, + fmt::format_args args) -> custom_string { + auto buf = custom_memory_buffer(alloc); + fmt::vformat_to(std::back_inserter(buf), fmt, args); + return custom_string(buf.data(), buf.size(), alloc); + } + + template <typename ...Args> + auto format(custom_allocator alloc, fmt::string_view fmt, + const Args& ... args) -> custom_string { + return vformat(alloc, fmt, fmt::make_format_args(args...)); + } + +The allocator will be used for the output container only. Formatting +functions normally don't do any allocations for built-in and string +types except for non-default floating-point formatting that occasionally +falls back on `sprintf`. + +### Locale + +All formatting is locale-independent by default. Use the `'L'` format +specifier to insert the appropriate number separator characters from the +locale: + + #include <fmt/format.h> + #include <locale> + + std::locale::global(std::locale("en_US.UTF-8")); + auto s = fmt::format("{:L}", 1000000); // s == "1,000,000" + +`fmt/format.h` provides the following overloads of formatting functions +that take `std::locale` as a parameter. The locale type is a template +parameter to avoid the expensive `<locale>` include. + +::: format(locale_ref, format_string<T...>, T&&...) + +::: format_to(OutputIt, locale_ref, format_string<T...>, T&&...) + +::: formatted_size(locale_ref, format_string<T...>, T&&...) + +<a id="legacy-checks"></a> +### Legacy Compile-Time Checks + +`FMT_STRING` enables compile-time checks on older compilers. It requires +C++14 or later and is a no-op in C++11. + +::: FMT_STRING + +To force the use of legacy compile-time checks, define the preprocessor +variable `FMT_ENFORCE_COMPILE_STRING`. When set, functions accepting +`FMT_STRING` will fail to compile with regular strings. + +<a id="ranges-api"></a> +## Range and Tuple Formatting + +`fmt/ranges.h` provides formatting support for ranges and tuples: + + #include <fmt/ranges.h> + + fmt::print("{}", std::tuple<char, int>{'a', 42}); + // Output: ('a', 42) + +Using `fmt::join`, you can separate tuple elements with a custom separator: + + #include <fmt/ranges.h> + + auto t = std::tuple<int, char>{1, 'a'}; + fmt::print("{}", fmt::join(t, ", ")); + // Output: 1, a + +::: join(Range&&, string_view) + +::: join(It, Sentinel, string_view) + +::: join(std::initializer_list<T>, string_view) + +<a id="chrono-api"></a> +## Date and Time Formatting + +`fmt/chrono.h` provides formatters for + +- [`std::chrono::duration`](https://en.cppreference.com/w/cpp/chrono/duration) +- [`std::chrono::time_point`]( + https://en.cppreference.com/w/cpp/chrono/time_point) +- [`std::tm`](https://en.cppreference.com/w/cpp/chrono/c/tm) + +The format syntax is described in [Chrono Format Specifications](syntax.md# +chrono-format-specifications). + +**Example**: + + #include <fmt/chrono.h> + + int main() { + auto now = std::chrono::system_clock::now(); + + fmt::print("The date is {:%Y-%m-%d}.\n", now); + // Output: The date is 2020-11-07. + // (with 2020-11-07 replaced by the current date) + + using namespace std::literals::chrono_literals; + + fmt::print("Default format: {} {}\n", 42s, 100ms); + // Output: Default format: 42s 100ms + + fmt::print("strftime-like format: {:%H:%M:%S}\n", 3h + 15min + 30s); + // Output: strftime-like format: 03:15:30 + } + +::: gmtime(std::time_t) + +<a id="std-api"></a> +## Standard Library Types Formatting + +`fmt/std.h` provides formatters for: + +- [`std::atomic`](https://en.cppreference.com/w/cpp/atomic/atomic) +- [`std::atomic_flag`](https://en.cppreference.com/w/cpp/atomic/atomic_flag) +- [`std::bitset`](https://en.cppreference.com/w/cpp/utility/bitset) +- [`std::error_code`](https://en.cppreference.com/w/cpp/error/error_code) +- [`std::exception`](https://en.cppreference.com/w/cpp/error/exception) +- [`std::filesystem::path`](https://en.cppreference.com/w/cpp/filesystem/path) +- [`std::monostate`]( + https://en.cppreference.com/w/cpp/utility/variant/monostate) +- [`std::optional`](https://en.cppreference.com/w/cpp/utility/optional) +- [`std::source_location`]( + https://en.cppreference.com/w/cpp/utility/source_location) +- [`std::thread::id`](https://en.cppreference.com/w/cpp/thread/thread/id) +- [`std::variant`](https://en.cppreference.com/w/cpp/utility/variant/variant) + +::: ptr(const std::unique_ptr<T, Deleter>&) + +::: ptr(const std::shared_ptr<T>&) + +### Variants + +A `std::variant` is only formattable if every variant alternative is +formattable, and requires the `__cpp_lib_variant` [library +feature](https://en.cppreference.com/w/cpp/feature_test). + +**Example**: + + #include <fmt/std.h> + + fmt::print("{}", std::variant<char, float>('x')); + // Output: variant('x') + + fmt::print("{}", std::variant<std::monostate, char>()); + // Output: variant(monostate) + +## Bit-Fields and Packed Structs + +To format a bit-field or a field of a struct with `__attribute__((packed))` +applied to it, you need to convert it to the underlying or compatible type via +a cast or a unary `+` ([godbolt](https://www.godbolt.org/z/3qKKs6T5Y)): + +```c++ +struct smol { + int bit : 1; +}; + +auto s = smol(); +fmt::print("{}", +s.bit); +``` + +This is a known limitation of "perfect" forwarding in C++. + +<a id="compile-api"></a> +## Compile-Time Support + +`fmt/compile.h` provides format string compilation and compile-time +(`constexpr`) formatting enabled via the `FMT_COMPILE` macro or the `_cf` +user-defined literal defined in namespace `fmt::literals`. Format strings +marked with `FMT_COMPILE` or `_cf` are parsed, checked and converted into +efficient formatting code at compile-time. This supports arguments of built-in +and string types as well as user-defined types with `format` methods taking +the format context type as a template parameter in their `formatter` +specializations. For example ([run](https://www.godbolt.org/z/3c13erEoq)): + + struct point { + double x; + double y; + }; + + template <> struct fmt::formatter<point> { + constexpr auto parse(format_parse_context& ctx) { return ctx.begin(); } + + template <typename FormatContext> + auto format(const point& p, FormatContext& ctx) const { + return format_to(ctx.out(), "({}, {})"_cf, p.x, p.y); + } + }; + + using namespace fmt::literals; + std::string s = fmt::format("{}"_cf, point(4, 2)); + +Format string compilation can generate more binary code compared to the +default API and is only recommended in places where formatting is a +performance bottleneck. + +The same APIs support formatting at compile time e.g. in `constexpr` +and `consteval` functions. Additionally there is an experimental +`FMT_STATIC_FORMAT` that allows formatting into a string of the exact +required size at compile time. Compile-time formatting works with built-in +and user-defined formatters that have `constexpr` `format` methods. +Example: + + template <> struct fmt::formatter<point> { + constexpr auto parse(format_parse_context& ctx) { return ctx.begin(); } + + template <typename FormatContext> + constexpr auto format(const point& p, FormatContext& ctx) const { + return format_to(ctx.out(), "({}, {})"_cf, p.x, p.y); + } + }; + + constexpr auto s = FMT_STATIC_FORMAT("{}", point(4, 2)); + const char* cstr = s.c_str(); // Points the static string "(4, 2)". + +::: operator""_cf + +::: FMT_COMPILE + +::: FMT_STATIC_FORMAT + +<a id="color-api"></a> +## Terminal Colors and Text Styles + +`fmt/color.h` provides support for terminal color and text style output. + +::: print(text_style, format_string<T...>, T&&...) + +::: fg(detail::color_type) + +::: bg(detail::color_type) + +::: styled(const T&, text_style) + +<a id="os-api"></a> +## System APIs + +::: ostream + +::: windows_error + +<a id="ostream-api"></a> +## `std::ostream` Support + +`fmt/ostream.h` provides `std::ostream` support including formatting of +user-defined types that have an overloaded insertion operator +(`operator<<`). In order to make a type formattable via `std::ostream` +you should provide a `formatter` specialization inherited from +`ostream_formatter`: + + #include <fmt/ostream.h> + + struct date { + int year, month, day; + + friend std::ostream& operator<<(std::ostream& os, const date& d) { + return os << d.year << '-' << d.month << '-' << d.day; + } + }; + + template <> struct fmt::formatter<date> : ostream_formatter {}; + + std::string s = fmt::format("The date is {}", date{2012, 12, 9}); + // s == "The date is 2012-12-9" + +::: streamed(const T&) + +::: print(std::ostream&, format_string<T...>, T&&...) + +<a id="args-api"></a> +## Dynamic Argument Lists + +The header `fmt/args.h` provides `dynamic_format_arg_store`, a builder-like API +that can be used to construct format argument lists dynamically. + +::: dynamic_format_arg_store + +<a id="printf-api"></a> +## Safe `printf` + +The header `fmt/printf.h` provides `printf`-like formatting +functionality. The following functions use [printf format string +syntax](https://pubs.opengroup.org/onlinepubs/009695399/functions/fprintf.html) +with the POSIX extension for positional arguments. Unlike their standard +counterparts, the `fmt` functions are type-safe and throw an exception +if an argument type doesn't match its format specification. + +::: printf(string_view, const T&...) + +::: fprintf(std::FILE*, string_view, const T&...) + +::: sprintf(string_view, const T&...) + +<a id="xchar-api"></a> +## Wide Strings + +The optional header `fmt/xchar.h` provides support for `wchar_t` and +exotic character types. + +::: wstring_view + +::: wformat_context + +::: to_wstring(const T&) + +## Compatibility with C++20 `std::format` + +{fmt} implements nearly all of the [C++20 formatting +library](https://en.cppreference.com/w/cpp/utility/format) with the +following differences: + +- Names are defined in the `fmt` namespace instead of `std` to avoid + collisions with standard library implementations. + +- Width calculation doesn't use grapheme clusterization. The latter has + been implemented in a separate branch but hasn't been integrated yet. + +- The default floating-point representation in {fmt} uses the smallest + precision that provides round-trip guarantees similarly to other languages + like Java and Python. `std::format` is currently specified in terms of + `std::to_chars` which tries to generate the smallest number of characters + (ignoring redundant digits and sign in exponent) and may procude more + decimal digits than necessary. diff --git a/thirdparty/fmt/doc/fmt.css b/thirdparty/fmt/doc/fmt.css new file mode 100644 index 000000000..994d6e2e9 --- /dev/null +++ b/thirdparty/fmt/doc/fmt.css @@ -0,0 +1,61 @@ +:root { + --md-primary-fg-color: #0050D0; +} + +.md-grid { + max-width: 960px; +} + +@media (min-width: 400px) { + .md-tabs { + display: block; + } +} + +.docblock { + border-left: .05rem solid var(--md-primary-fg-color); +} + +.docblock-desc { + margin-left: 1em; +} + +pre > code.decl { + white-space: pre-wrap; +} + + +code.decl > div { + text-indent: -2ch; /* Negative indent to counteract the indent on the first line */ + padding-left: 2ch; /* Add padding to the left to create an indent */ +} + +.features-container { + display: flex; + flex-wrap: wrap; + gap: 20px; + justify-content: center; /* Center the items horizontally */ +} + +.feature { + flex: 1 1 calc(50% - 20px); /* Two columns with space between */ + max-width: 600px; /* Set the maximum width for the feature boxes */ + box-sizing: border-box; + padding: 10px; + overflow: hidden; /* Hide overflow content */ + text-overflow: ellipsis; /* Handle text overflow */ + white-space: normal; /* Allow text wrapping */ +} + +.feature h2 { + margin-top: 0px; + font-weight: bold; +} + +@media (max-width: 768px) { + .feature { + flex: 1 1 100%; /* Stack columns on smaller screens */ + max-width: 100%; /* Allow full width on smaller screens */ + white-space: normal; /* Allow text wrapping on smaller screens */ + } +} diff --git a/thirdparty/fmt/doc/fmt.js b/thirdparty/fmt/doc/fmt.js new file mode 100644 index 000000000..da7e95b77 --- /dev/null +++ b/thirdparty/fmt/doc/fmt.js @@ -0,0 +1,4 @@ +document$.subscribe(() => { + hljs.highlightAll(), + { language: 'c++' } +}) diff --git a/thirdparty/fmt/doc/get-started.md b/thirdparty/fmt/doc/get-started.md new file mode 100644 index 000000000..6bcefe7d0 --- /dev/null +++ b/thirdparty/fmt/doc/get-started.md @@ -0,0 +1,233 @@ +# Get Started + +Compile and run {fmt} examples online with [Compiler Explorer]( +https://godbolt.org/z/P7h6cd6o3). + +{fmt} is compatible with any build system. The next section describes its usage +with CMake, while the [Build Systems](#build-systems) section covers the rest. + +## CMake + +{fmt} provides two CMake targets: `fmt::fmt` for the compiled library and +`fmt::fmt-header-only` for the header-only library. It is recommended to use +the compiled library for improved build times. + +There are three primary ways to use {fmt} with CMake: + +* **FetchContent**: Starting from CMake 3.11, you can use [`FetchContent`]( + https://cmake.org/cmake/help/v3.30/module/FetchContent.html) to automatically + download {fmt} as a dependency at configure time: + + include(FetchContent) + + FetchContent_Declare( + fmt + GIT_REPOSITORY https://github.com/fmtlib/fmt + GIT_TAG e69e5f977d458f2650bb346dadf2ad30c5320281) # 10.2.1 + FetchContent_MakeAvailable(fmt) + + target_link_libraries(<your-target> fmt::fmt) + +* **Installed**: You can find and use an [installed](#installation) version of + {fmt} in your `CMakeLists.txt` file as follows: + + find_package(fmt) + target_link_libraries(<your-target> fmt::fmt) + +* **Embedded**: You can add the {fmt} source tree to your project and include it + in your `CMakeLists.txt` file: + + add_subdirectory(fmt) + target_link_libraries(<your-target> fmt::fmt) + +## Installation + +### Debian/Ubuntu + +To install {fmt} on Debian, Ubuntu, or any other Debian-based Linux +distribution, use the following command: + + apt install libfmt-dev + +### Homebrew + +Install {fmt} on macOS using [Homebrew](https://brew.sh/): + + brew install fmt + +### Conda + +Install {fmt} on Linux, macOS, and Windows with [Conda]( +https://docs.conda.io/en/latest/), using its [conda-forge package]( +https://github.com/conda-forge/fmt-feedstock): + + conda install -c conda-forge fmt + +### vcpkg + +Download and install {fmt} using the vcpkg package manager: + + git clone https://github.com/Microsoft/vcpkg.git + cd vcpkg + ./bootstrap-vcpkg.sh + ./vcpkg integrate install + ./vcpkg install fmt + +<!-- The fmt package in vcpkg is kept up to date by Microsoft team members and +community contributors. If the version is out of date, please [create an +issue or pull request](https://github.com/Microsoft/vcpkg) on the vcpkg +repository. --> + +### Conan + +You can download and install {fmt} using the [Conan](https://conan.io/) package manager: + + conan install -r conancenter --requires="fmt/[*]" --build=missing + +<!-- The {fmt} package in Conan Center is maintained by +[ConanCenterIndex](https://github.com/conan-io/conan-center-index) community. +If the version is out of date or the package does not work, +please create an issue or pull request on the Conan Center Index repository. --> + +## Building from Source + +CMake works by generating native makefiles or project files that can be +used in the compiler environment of your choice. The typical workflow +starts with: + + mkdir build # Create a directory to hold the build output. + cd build + cmake .. # Generate native build scripts. + +run in the `fmt` repository. + +If you are on a Unix-like system, you should now see a Makefile in the +current directory. Now you can build the library by running `make`. + +Once the library has been built you can invoke `make test` to run the tests. + +You can control generation of the make `test` target with the `FMT_TEST` +CMake option. This can be useful if you include fmt as a subdirectory in +your project but don't want to add fmt's tests to your `test` target. + +To build a shared library set the `BUILD_SHARED_LIBS` CMake variable to `TRUE`: + + cmake -DBUILD_SHARED_LIBS=TRUE .. + +To build a static library with position-independent code (e.g. for +linking it into another shared library such as a Python extension), set the +`CMAKE_POSITION_INDEPENDENT_CODE` CMake variable to `TRUE`: + + cmake -DCMAKE_POSITION_INDEPENDENT_CODE=TRUE .. + +After building the library you can install it on a Unix-like system by +running `sudo make install`. + +### Building the Docs + +To build the documentation you need the following software installed on +your system: + +- [Python](https://www.python.org/) +- [Doxygen](http://www.stack.nl/~dimitri/doxygen/) +- [MkDocs](https://www.mkdocs.org/) with `mkdocs-material`, `mkdocstrings`, + `pymdown-extensions` and `mike` + +First generate makefiles or project files using CMake as described in +the previous section. Then compile the `doc` target/project, for example: + + make doc + +This will generate the HTML documentation in `doc/html`. + +## Build Systems + +### build2 + +You can use [build2](https://build2.org), a dependency manager and a build +system, to use {fmt}. + +Currently this package is available in these package repositories: + +- <https://cppget.org/fmt/> for released and published versions. +- <https://github.com/build2-packaging/fmt> for unreleased or custom versions. + +**Usage:** + +- `build2` package name: `fmt` +- Library target name: `lib{fmt}` + +To make your `build2` project depend on `fmt`: + +- Add one of the repositories to your configurations, or in your + `repositories.manifest`, if not already there: + + : + role: prerequisite + location: https://pkg.cppget.org/1/stable + +- Add this package as a dependency to your `manifest` file (example + for version 10): + + depends: fmt ~10.0.0 + +- Import the target and use it as a prerequisite to your own target + using `fmt` in the appropriate `buildfile`: + + import fmt = fmt%lib{fmt} + lib{mylib} : cxx{**} ... $fmt + +Then build your project as usual with `b` or `bdep update`. + +### Meson + +[Meson WrapDB](https://mesonbuild.com/Wrapdb-projects.html) includes an `fmt` +package. + +**Usage:** + +- Install the `fmt` subproject from the WrapDB by running: + + meson wrap install fmt + + from the root of your project. + +- In your project's `meson.build` file, add an entry for the new subproject: + + fmt = subproject('fmt') + fmt_dep = fmt.get_variable('fmt_dep') + +- Include the new dependency object to link with fmt: + + my_build_target = executable( + 'name', 'src/main.cc', dependencies: [fmt_dep]) + +**Options:** + +If desired, {fmt} can be built as a static library, or as a header-only library. + +For a static build, use the following subproject definition: + + fmt = subproject('fmt', default_options: 'default_library=static') + fmt_dep = fmt.get_variable('fmt_dep') + +For the header-only version, use: + + fmt = subproject('fmt', default_options: ['header-only=true']) + fmt_dep = fmt.get_variable('fmt_header_only_dep') + +### Android NDK + +{fmt} provides [Android.mk file]( +https://github.com/fmtlib/fmt/blob/master/support/Android.mk) that can be used +to build the library with [Android NDK]( +https://developer.android.com/tools/sdk/ndk/index.html). + +### Other + +To use the {fmt} library with any other build system, add +`include/fmt/base.h`, `include/fmt/format.h`, `include/fmt/format-inl.h`, +`src/format.cc` and optionally other headers from a [release archive]( +https://github.com/fmtlib/fmt/releases) or the [git repository]( +https://github.com/fmtlib/fmt) to your project, add `include` to include +directories and make sure `src/format.cc` is compiled and linked with your code. diff --git a/thirdparty/fmt/doc/index.md b/thirdparty/fmt/doc/index.md new file mode 100644 index 000000000..a26947364 --- /dev/null +++ b/thirdparty/fmt/doc/index.md @@ -0,0 +1,151 @@ +--- +hide: + - navigation + - toc +--- + +# A modern formatting library + +<div class="features-container"> + +<div class="feature"> +<h2>Safety</h2> +<p> + Inspired by Python's formatting facility, {fmt} provides a safe replacement + for the <code>printf</code> family of functions. Errors in format strings, + which are a common source of vulnerabilities in C, are <b>reported at + compile time</b>. For example: + + <pre><code class="language-cpp" + >fmt::format("{:d}", "I am not a number");</code></pre> + + will give a compile-time error because <code>d</code> is not a valid + format specifier for strings. APIs like <a href="api/#format"> + <code>fmt::format</code></a> <b>prevent buffer overflow errors</b> via + automatic memory management. +</p> +<a href="api#compile-time-checks">→ Learn more</a> +</div> + +<div class="feature"> +<h2>Extensibility</h2> +<p> + Formatting of most <b>standard types</b>, including all containers, dates, + and times is <b>supported out-of-the-box</b>. For example: + + <pre><code class="language-cpp" + >fmt::print("{}", std::vector{1, 2, 3});</code></pre> + + prints the vector in a JSON-like format: + + <pre><code>[1, 2, 3]</code></pre> + + You can <b>make your own types formattable</b> and even make compile-time + checks work for them. +</p> +<a href="api#udt">→ Learn more</a> +</div> + +<div class="feature"> +<h2>Performance</h2> +<p> + {fmt} can be anywhere from <b>tens of percent to 20-30 times faster</b> than + iostreams and <code>sprintf</code>, especially for numeric formatting. + +<a href="https://github.com/fmtlib/fmt?tab=readme-ov-file#benchmarks"> +<img src="perf.svg"> +</a> + + The library <b>minimizes dynamic memory allocations</b> and can optionally + <a href="api#compile-api">compile format strings</a> to optimal code. +</p> +</div> + +<div class="feature"> +<h2>Unicode support</h2> +<p> + {fmt} provides <b>portable Unicode support</b> on major operating systems + with UTF-8 and <code>char</code> strings. For example: + + <pre><code class="language-cpp" + >fmt::print("Слава Україні!");</code></pre> + + will be printed correctly on Linux, macOS, and even Windows console, + irrespective of the codepages. +</p> +<p> + The default is <b>locale-independent</b>, but you can opt into localized + formatting and {fmt} makes it work with Unicode, addressing issues in the + standard libary. +</p> +</div> + +<div class="feature"> +<h2>Fast compilation</h2> +<p> + The library makes extensive use of <b>type erasure</b> to achieve fast + compilation. <code>fmt/base.h</code> provides a subset of the API with + <b>minimal include dependencies</b> and enough functionality to replace + all uses of <code>*printf</code>. +</p> +<p> + Code using {fmt} is usually several times faster to compile than the + equivalent iostreams code, and while <code>printf</code> compiles faster + still, the gap is narrowing. +</p> +<a href= +"https://github.com/fmtlib/fmt?tab=readme-ov-file#compile-time-and-code-bloat"> +→ Learn more</a> +</div> + +<div class="feature"> +<h2>Small binary footprint</h2> +<p> + Type erasure is also used to prevent template bloat, resulting in <b>compact + per-call binary code</b>. For example, a call to <code>fmt::print</code> with + a single argument is just <a href="https://godbolt.org/g/TZU4KF">a few + instructions</a>, comparable to <code>printf</code> despite adding + runtime safety, and much smaller than the equivalent iostreams code. +</p> +<p> + The library itself has small binary footprint and some components such as + floating-point formatting can be disabled to make it even smaller for + resource-constrained devices. +</p> +</div> + +<div class="feature"> +<h2>Portability</h2> +<p> + {fmt} has a <b>small self-contained codebase</b> with the core consisting of + just three headers and no external dependencies. +</p> +<p> + The library is highly portable and requires only a minimal <b>subset of + C++11</b> features which are available in GCC 4.9, Clang 3.6, MSVC 19.10 + (2017) and later. Newer compiler and standard library features are used + if available, and enable additional functionality. +</p> +<p> + Where possible, the output of formatting functions is <b>consistent across + platforms</b>. +</p> +</p> +</div> + +<div class="feature"> +<h2>Open source</h2> +<p> + {fmt} is in the top hundred open-source C++ libraries on GitHub and has + <a href="https://github.com/fmtlib/fmt/graphs/contributors">hundreds of + all-time contributors</a>. +</p> +<p> + The library is distributed under a permissive MIT + <a href="https://github.com/fmtlib/fmt#license">license</a> and is + <b>relied upon by many open-source projects</b>, including Blender, PyTorch, + Apple's FoundationDB, Windows Terminal, MongoDB, and others. +</p> +</div> + +</div> diff --git a/thirdparty/fmt/doc/perf.svg b/thirdparty/fmt/doc/perf.svg new file mode 100644 index 000000000..7867a1544 --- /dev/null +++ b/thirdparty/fmt/doc/perf.svg @@ -0,0 +1 @@ +<svg xmlns="http://www.w3.org/2000/svg" version="1.1" 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\ No newline at end of file diff --git a/thirdparty/fmt/doc/python-license.txt b/thirdparty/fmt/doc/python-license.txt new file mode 100644 index 000000000..88eed1f9c --- /dev/null +++ b/thirdparty/fmt/doc/python-license.txt @@ -0,0 +1,290 @@ +A. HISTORY OF THE SOFTWARE +========================== + +Python was created in the early 1990s by Guido van Rossum at Stichting +Mathematisch Centrum (CWI, see http://www.cwi.nl) in the Netherlands +as a successor of a language called ABC. Guido remains Python's +principal author, although it includes many contributions from others. + +In 1995, Guido continued his work on Python at the Corporation for +National Research Initiatives (CNRI, see http://www.cnri.reston.va.us) +in Reston, Virginia where he released several versions of the +software. + +In May 2000, Guido and the Python core development team moved to +BeOpen.com to form the BeOpen PythonLabs team. In October of the same +year, the PythonLabs team moved to Digital Creations (now Zope +Corporation, see http://www.zope.com). In 2001, the Python Software +Foundation (PSF, see http://www.python.org/psf/) was formed, a +non-profit organization created specifically to own Python-related +Intellectual Property. Zope Corporation is a sponsoring member of +the PSF. + +All Python releases are Open Source (see http://www.opensource.org for +the Open Source Definition). Historically, most, but not all, Python +releases have also been GPL-compatible; the table below summarizes +the various releases. + + Release Derived Year Owner GPL- + from compatible? (1) + + 0.9.0 thru 1.2 1991-1995 CWI yes + 1.3 thru 1.5.2 1.2 1995-1999 CNRI yes + 1.6 1.5.2 2000 CNRI no + 2.0 1.6 2000 BeOpen.com no + 1.6.1 1.6 2001 CNRI yes (2) + 2.1 2.0+1.6.1 2001 PSF no + 2.0.1 2.0+1.6.1 2001 PSF yes + 2.1.1 2.1+2.0.1 2001 PSF yes + 2.2 2.1.1 2001 PSF yes + 2.1.2 2.1.1 2002 PSF yes + 2.1.3 2.1.2 2002 PSF yes + 2.2.1 2.2 2002 PSF yes + 2.2.2 2.2.1 2002 PSF yes + 2.2.3 2.2.2 2003 PSF yes + 2.3 2.2.2 2002-2003 PSF yes + 2.3.1 2.3 2002-2003 PSF yes + 2.3.2 2.3.1 2002-2003 PSF yes + 2.3.3 2.3.2 2002-2003 PSF yes + 2.3.4 2.3.3 2004 PSF yes + 2.3.5 2.3.4 2005 PSF yes + 2.4 2.3 2004 PSF yes + 2.4.1 2.4 2005 PSF yes + 2.4.2 2.4.1 2005 PSF yes + 2.4.3 2.4.2 2006 PSF yes + 2.4.4 2.4.3 2006 PSF yes + 2.5 2.4 2006 PSF yes + 2.5.1 2.5 2007 PSF yes + 2.5.2 2.5.1 2008 PSF yes + 2.5.3 2.5.2 2008 PSF yes + 2.6 2.5 2008 PSF yes + 2.6.1 2.6 2008 PSF yes + 2.6.2 2.6.1 2009 PSF yes + 2.6.3 2.6.2 2009 PSF yes + 2.6.4 2.6.3 2009 PSF yes + 2.6.5 2.6.4 2010 PSF yes + 3.0 2.6 2008 PSF yes + 3.0.1 3.0 2009 PSF yes + 3.1 3.0.1 2009 PSF yes + 3.1.1 3.1 2009 PSF yes + 3.1.2 3.1.1 2010 PSF yes + 3.1.3 3.1.2 2010 PSF yes + 3.1.4 3.1.3 2011 PSF yes + 3.2 3.1 2011 PSF yes + 3.2.1 3.2 2011 PSF yes + 3.2.2 3.2.1 2011 PSF yes + 3.2.3 3.2.2 2012 PSF yes + 3.3.0 3.2 2012 PSF yes + +Footnotes: + +(1) GPL-compatible doesn't mean that we're distributing Python under + the GPL. All Python licenses, unlike the GPL, let you distribute + a modified version without making your changes open source. The + GPL-compatible licenses make it possible to combine Python with + other software that is released under the GPL; the others don't. + +(2) According to Richard Stallman, 1.6.1 is not GPL-compatible, + because its license has a choice of law clause. According to + CNRI, however, Stallman's lawyer has told CNRI's lawyer that 1.6.1 + is "not incompatible" with the GPL. + +Thanks to the many outside volunteers who have worked under Guido's +direction to make these releases possible. + + +B. TERMS AND CONDITIONS FOR ACCESSING OR OTHERWISE USING PYTHON +=============================================================== + +PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2 +-------------------------------------------- + +1. This LICENSE AGREEMENT is between the Python Software Foundation +("PSF"), and the Individual or Organization ("Licensee") accessing and +otherwise using this software ("Python") in source or binary form and +its associated documentation. + +2. Subject to the terms and conditions of this License Agreement, PSF hereby +grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce, +analyze, test, perform and/or display publicly, prepare derivative works, +distribute, and otherwise use Python alone or in any derivative version, +provided, however, that PSF's License Agreement and PSF's notice of copyright, +i.e., "Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, +2011, 2012 Python Software Foundation; All Rights Reserved" are retained in Python +alone or in any derivative version prepared by Licensee. + +3. In the event Licensee prepares a derivative work that is based on +or incorporates Python or any part thereof, and wants to make +the derivative work available to others as provided herein, then +Licensee hereby agrees to include in any such work a brief summary of +the changes made to Python. + +4. PSF is making Python available to Licensee on an "AS IS" +basis. PSF MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR +IMPLIED. BY WAY OF EXAMPLE, BUT NOT LIMITATION, PSF MAKES NO AND +DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS +FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON WILL NOT +INFRINGE ANY THIRD PARTY RIGHTS. + +5. PSF SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON +FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS +A RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON, +OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF. + +6. 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Subject to the terms and conditions of this License Agreement, CNRI +hereby grants Licensee a nonexclusive, royalty-free, world-wide +license to reproduce, analyze, test, perform and/or display publicly, +prepare derivative works, distribute, and otherwise use Python 1.6.1 +alone or in any derivative version, provided, however, that CNRI's +License Agreement and CNRI's notice of copyright, i.e., "Copyright (c) +1995-2001 Corporation for National Research Initiatives; All Rights +Reserved" are retained in Python 1.6.1 alone or in any derivative +version prepared by Licensee. Alternately, in lieu of CNRI's License +Agreement, Licensee may substitute the following text (omitting the +quotes): "Python 1.6.1 is made available subject to the terms and +conditions in CNRI's License Agreement. This Agreement together with +Python 1.6.1 may be located on the Internet using the following +unique, persistent identifier (known as a handle): 1895.22/1013. This +Agreement may also be obtained from a proxy server on the Internet +using the following URL: http://hdl.handle.net/1895.22/1013". + +3. In the event Licensee prepares a derivative work that is based on +or incorporates Python 1.6.1 or any part thereof, and wants to make +the derivative work available to others as provided herein, then +Licensee hereby agrees to include in any such work a brief summary of +the changes made to Python 1.6.1. + +4. CNRI is making Python 1.6.1 available to Licensee on an "AS IS" +basis. CNRI MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR +IMPLIED. BY WAY OF EXAMPLE, BUT NOT LIMITATION, CNRI MAKES NO AND +DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS +FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON 1.6.1 WILL NOT +INFRINGE ANY THIRD PARTY RIGHTS. + +5. CNRI SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON +1.6.1 FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS +A RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON 1.6.1, +OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF. + +6. This License Agreement will automatically terminate upon a material +breach of its terms and conditions. + +7. This License Agreement shall be governed by the federal +intellectual property law of the United States, including without +limitation the federal copyright law, and, to the extent such +U.S. federal law does not apply, by the law of the Commonwealth of +Virginia, excluding Virginia's conflict of law provisions. +Notwithstanding the foregoing, with regard to derivative works based +on Python 1.6.1 that incorporate non-separable material that was +previously distributed under the GNU General Public License (GPL), the +law of the Commonwealth of Virginia shall govern this License +Agreement only as to issues arising under or with respect to +Paragraphs 4, 5, and 7 of this License Agreement. Nothing in this +License Agreement shall be deemed to create any relationship of +agency, partnership, or joint venture between CNRI and Licensee. This +License Agreement does not grant permission to use CNRI trademarks or +trade name in a trademark sense to endorse or promote products or +services of Licensee, or any third party. + +8. By clicking on the "ACCEPT" button where indicated, or by copying, +installing or otherwise using Python 1.6.1, Licensee agrees to be +bound by the terms and conditions of this License Agreement. + + ACCEPT + + +CWI LICENSE AGREEMENT FOR PYTHON 0.9.0 THROUGH 1.2 +-------------------------------------------------- + +Copyright (c) 1991 - 1995, Stichting Mathematisch Centrum Amsterdam, +The Netherlands. All rights reserved. + +Permission to use, copy, modify, and distribute this software and its +documentation for any purpose and without fee is hereby granted, +provided that the above copyright notice appear in all copies and that +both that copyright notice and this permission notice appear in +supporting documentation, and that the name of Stichting Mathematisch +Centrum or CWI not be used in advertising or publicity pertaining to +distribution of the software without specific, written prior +permission. + +STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO +THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND +FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE +FOR ANY SPECIAL, 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. diff --git a/thirdparty/fmt/doc/syntax.md b/thirdparty/fmt/doc/syntax.md new file mode 100644 index 000000000..46d7d2fd2 --- /dev/null +++ b/thirdparty/fmt/doc/syntax.md @@ -0,0 +1,886 @@ +# Format String Syntax + +Formatting functions such as [`fmt::format`](api.md#format) and [`fmt::print`]( +api.md#print) use the same format string syntax described in this section. + +Format strings contain "replacement fields" surrounded by curly braces `{}`. +Anything that is not contained in braces is considered literal text, which is +copied unchanged to the output. If you need to include a brace character in +the literal text, it can be escaped by doubling: `{{` and `}}`. + +The grammar for a replacement field is as follows: + +<a id="replacement-field"></a> +<pre><code class="language-json" +>replacement_field ::= "{" [arg_id] [":" (<a href="#format-spec" + >format_spec</a> | <a href="#chrono-format-spec">chrono_format_spec</a>)] "}" +arg_id ::= integer | identifier +integer ::= digit+ +digit ::= "0"..."9" +identifier ::= id_start id_continue* +id_start ::= "a"..."z" | "A"..."Z" | "_" +id_continue ::= id_start | digit</code> +</pre> + +In less formal terms, the replacement field can start with an *arg_id* that +specifies the argument whose value is to be formatted and inserted into the +output instead of the replacement field. The *arg_id* is optionally followed +by a *format_spec*, which is preceded by a colon `':'`. These specify a +non-default format for the replacement value. + +See also the [Format Specification +Mini-Language](#format-specification-mini-language) section. + +If the numerical arg_ids in a format string are 0, 1, 2, ... in sequence, +they can all be omitted (not just some) and the numbers 0, 1, 2, ... will be +automatically inserted in that order. + +Named arguments can be referred to by their names or indices. + +Some simple format string examples: + +```c++ +"First, thou shalt count to {0}" // References the first argument +"Bring me a {}" // Implicitly references the first argument +"From {} to {}" // Same as "From {0} to {1}" +``` + +The *format_spec* field contains a specification of how the value should +be presented, including such details as field width, alignment, padding, +decimal precision and so on. Each value type can define its own +"formatting mini-language" or interpretation of the *format_spec*. + +Most built-in types support a common formatting mini-language, which is +described in the next section. + +A *format_spec* field can also include nested replacement fields in +certain positions within it. These nested replacement fields can contain +only an argument id; format specifications are not allowed. This allows +the formatting of a value to be dynamically specified. + +See the [Format Examples](#format-examples) section for some examples. + +## Format Specification Mini-Language + +"Format specifications" are used within replacement fields contained within a +format string to define how individual values are presented. Each formattable +type may define how the format specification is to be interpreted. + +Most built-in types implement the following options for format +specifications, although some of the formatting options are only +supported by the numeric types. + +The general form of a *standard format specifier* is: + +<a id="format-spec"></a> +<pre><code class="language-json" +>format_spec ::= [[fill]align][sign]["#"]["0"][width]["." precision]["L"][type] +fill ::= <a character other than '{' or '}'> +align ::= "<" | ">" | "^" +sign ::= "+" | "-" | " " +width ::= <a href="#replacement-field">integer</a> | "{" [<a + href="#replacement-field">arg_id</a>] "}" +precision ::= <a href="#replacement-field">integer</a> | "{" [<a + href="#replacement-field">arg_id</a>] "}" +type ::= "a" | "A" | "b" | "B" | "c" | "d" | "e" | "E" | "f" | "F" | + "g" | "G" | "o" | "p" | "s" | "x" | "X" | "?"</code> +</pre> + +The *fill* character can be any Unicode code point other than `'{'` or `'}'`. +The presence of a fill character is signaled by the character following it, +which must be one of the alignment options. If the second character of +*format_spec* is not a valid alignment option, then it is assumed that both +the fill character and the alignment option are absent. + +The meaning of the various alignment options is as follows: + +<table> +<tr> + <th>Option</th> + <th>Meaning</th> +</tr> +<tr> + <td><code>'<'</code></td> + <td> + Forces the field to be left-aligned within the available space (this is the + default for most objects). + </td> +</tr> +<tr> + <td><code>'>'</code></td> + <td> + Forces the field to be right-aligned within the available space (this is + the default for numbers). + </td> +</tr> +<tr> + <td><code>'^'</code></td> + <td>Forces the field to be centered within the available space.</td> +</tr> +</table> + +Note that unless a minimum field width is defined, the field width will +always be the same size as the data to fill it, so that the alignment +option has no meaning in this case. + +The *sign* option is only valid for floating point and signed integer types, +and can be one of the following: + +<table> +<tr> + <th>Option</th> + <th>Meaning</th> +</tr> +<tr> + <td><code>'+'</code></td> + <td> + Indicates that a sign should be used for both nonnegative as well as + negative numbers. + </td> +</tr> +<tr> + <td><code>'-'</code></td> + <td> + Indicates that a sign should be used only for negative numbers (this is the + default behavior). + </td> +</tr> +<tr> + <td>space</td> + <td> + Indicates that a leading space should be used on nonnegative numbers, and a + minus sign on negative numbers. + </td> +</tr> +</table> + +The `'#'` option causes the "alternate form" to be used for the +conversion. The alternate form is defined differently for different +types. This option is only valid for integer and floating-point types. +For integers, when binary, octal, or hexadecimal output is used, this +option adds the prefix respective `"0b"` (`"0B"`), `"0"`, or `"0x"` +(`"0X"`) to the output value. Whether the prefix is lower-case or +upper-case is determined by the case of the type specifier, for example, +the prefix `"0x"` is used for the type `'x'` and `"0X"` is used for +`'X'`. For floating-point numbers the alternate form causes the result +of the conversion to always contain a decimal-point character, even if +no digits follow it. Normally, a decimal-point character appears in the +result of these conversions only if a digit follows it. In addition, for +`'g'` and `'G'` conversions, trailing zeros are not removed from the +result. + +*width* is a decimal integer defining the minimum field width. If not +specified, then the field width will be determined by the content. + +Preceding the *width* field by a zero (`'0'`) character enables +sign-aware zero-padding for numeric types. It forces the padding to be +placed after the sign or base (if any) but before the digits. This is +used for printing fields in the form "+000000120". This option is only +valid for numeric types and it has no effect on formatting of infinity +and NaN. This option is ignored when any alignment specifier is present. + +The *precision* is a decimal number indicating how many digits should be +displayed after the decimal point for a floating-point value formatted +with `'f'` and `'F'`, or before and after the decimal point for a +floating-point value formatted with `'g'` or `'G'`. For non-number types +the field indicates the maximum field size - in other words, how many +characters will be used from the field content. The *precision* is not +allowed for integer, character, Boolean, and pointer values. Note that a +C string must be null-terminated even if precision is specified. + +The `'L'` option uses the current locale setting to insert the appropriate +number separator characters. This option is only valid for numeric types. + +Finally, the *type* determines how the data should be presented. + +The available string presentation types are: + +<table> +<tr> + <th>Type</th> + <th>Meaning</th> +</tr> +<tr> + <td><code>'s'</code></td> + <td> + String format. This is the default type for strings and may be omitted. + </td> +</tr> +<tr> + <td><code>'?'</code></td> + <td>Debug format. The string is quoted and special characters escaped.</td> +</tr> +<tr> + <td>none</td> + <td>The same as <code>'s'</code>.</td> +</tr> +</table> + +The available character presentation types are: + +<table> +<tr> + <th>Type</th> + <th>Meaning</th> +</tr> +<tr> + <td><code>'c'</code></td> + <td> + Character format. This is the default type for characters and may be + omitted. + </td> +</tr> +<tr> + <td><code>'?'</code></td> + <td>Debug format. The character is quoted and special characters escaped.</td> +</tr> +<tr> + <td>none</td> + <td>The same as <code>'c'</code>.</td> +</tr> +</table> + +The available integer presentation types are: + +<table> +<tr> + <th>Type</th> + <th>Meaning</th> +</tr> +<tr> + <td><code>'b'</code></td> + <td> + Binary format. Outputs the number in base 2. Using the <code>'#'</code> + option with this type adds the prefix <code>"0b"</code> to the output value. + </td> +</tr> +<tr> + <td><code>'B'</code></td> + <td> + Binary format. Outputs the number in base 2. Using the <code>'#'</code> + option with this type adds the prefix <code>"0B"</code> to the output value. + </td> +</tr> +<tr> + <td><code>'c'</code></td> + <td>Character format. Outputs the number as a character.</td> +</tr> +<tr> + <td><code>'d'</code></td> + <td>Decimal integer. Outputs the number in base 10.</td> +</tr> +<tr> + <td><code>'o'</code></td> + <td>Octal format. Outputs the number in base 8.</td> +</tr> +<tr> + <td><code>'x'</code></td> + <td> + Hex format. Outputs the number in base 16, using lower-case letters for the + digits above 9. Using the <code>'#'</code> option with this type adds the + prefix <code>"0x"</code> to the output value. + </td> +</tr> +<tr> + <td><code>'X'</code></td> + <td> + Hex format. Outputs the number in base 16, using upper-case letters for the + digits above 9. Using the <code>'#'</code> option with this type adds the + prefix <code>"0X"</code> to the output value. + </td> +</tr> +<tr> + <td>none</td> + <td>The same as <code>'d'</code>.</td> +</tr> +</table> + +Integer presentation types can also be used with character and Boolean values +with the only exception that `'c'` cannot be used with `bool`. Boolean values +are formatted using textual representation, either `true` or `false`, if the +presentation type is not specified. + +The available presentation types for floating-point values are: + +<table> +<tr> + <th>Type</th> + <th>Meaning</th> +</tr> +<tr> + <td><code>'a'</code></td> + <td> + Hexadecimal floating point format. Prints the number in base 16 with + prefix <code>"0x"</code> and lower-case letters for digits above 9. + Uses <code>'p'</code> to indicate the exponent. + </td> +</tr> +<tr> + <td><code>'A'</code></td> + <td> + Same as <code>'a'</code> except it uses upper-case letters for the + prefix, digits above 9 and to indicate the exponent. + </td> +</tr> +<tr> + <td><code>'e'</code></td> + <td> + Exponent notation. Prints the number in scientific notation using + the letter 'e' to indicate the exponent. + </td> +</tr> +<tr> + <td><code>'E'</code></td> + <td> + Exponent notation. Same as <code>'e'</code> except it uses an + upper-case <code>'E'</code> as the separator character. + </td> +</tr> +<tr> + <td><code>'f'</code></td> + <td>Fixed point. Displays the number as a fixed-point number.</td> +</tr> +<tr> + <td><code>'F'</code></td> + <td> + Fixed point. Same as <code>'f'</code>, but converts <code>nan</code> + to <code>NAN</code> and <code>inf</code> to <code>INF</code>. + </td> +</tr> +<tr> + <td><code>'g'</code></td> + <td> + <p>General format. For a given precision <code>p >= 1</code>, + this rounds the number to <code>p</code> significant digits and then + formats the result in either fixed-point format or in scientific + notation, depending on its magnitude.</p> + <p>A precision of <code>0</code> is treated as equivalent to a precision + of <code>1</code>.</p> + </td> +</tr> +<tr> + <td><code>'G'</code></td> + <td> + General format. Same as <code>'g'</code> except switches to + <code>'E'</code> if the number gets too large. The representations of + infinity and NaN are uppercased, too. + </td> +</tr> +<tr> + <td>none</td> + <td> + Similar to <code>'g'</code>, except that the default precision is as + high as needed to represent the particular value. + </td> +</tr> +</table> + +The available presentation types for pointers are: + +<table> +<tr> + <th>Type</th> + <th>Meaning</th> +</tr> +<tr> + <td><code>'p'</code></td> + <td> + Pointer format. This is the default type for pointers and may be omitted. + </td> +</tr> +<tr> + <td>none</td> + <td>The same as <code>'p'</code>.</td> +</tr> +</table> + +## Chrono Format Specifications + +Format specifications for chrono duration and time point types as well as +`std::tm` have the following syntax: + +<a id="chrono-format-spec"></a> +<pre><code class="language-json" +>chrono_format_spec ::= [[<a href="#format-spec">fill</a>]<a href="#format-spec" + >align</a>][<a href="#format-spec">width</a>]["." <a href="#format-spec" + >precision</a>][chrono_specs] +chrono_specs ::= conversion_spec | + chrono_specs (conversion_spec | literal_char) +conversion_spec ::= "%" [padding_modifier] [locale_modifier] chrono_type +literal_char ::= <a character other than '{', '}' or '%'> +padding_modifier ::= "-" | "_" | "0" +locale_modifier ::= "E" | "O" +chrono_type ::= "a" | "A" | "b" | "B" | "c" | "C" | "d" | "D" | "e" | + "F" | "g" | "G" | "h" | "H" | "I" | "j" | "m" | "M" | + "n" | "p" | "q" | "Q" | "r" | "R" | "S" | "t" | "T" | + "u" | "U" | "V" | "w" | "W" | "x" | "X" | "y" | "Y" | + "z" | "Z" | "%"</code> +</pre> + +Literal chars are copied unchanged to the output. Precision is valid only +for `std::chrono::duration` types with a floating-point representation type. + +The available presentation types (*chrono_type*) are: + +<table> +<tr> + <th>Type</th> + <th>Meaning</th> +</tr> +<tr> + <td><code>'a'</code></td> + <td> + The abbreviated weekday name, e.g. "Sat". If the value does not contain a + valid weekday, an exception of type <code>format_error</code> is thrown. + </td> +</tr> +<tr> + <td><code>'A'</code></td> + <td> + The full weekday name, e.g. "Saturday". If the value does not contain a + valid weekday, an exception of type <code>format_error</code> is thrown. + </td> +</tr> +<tr> + <td><code>'b'</code></td> + <td> + The abbreviated month name, e.g. "Nov". If the value does not contain a + valid month, an exception of type <code>format_error</code> is thrown. + </td> +</tr> +<tr> + <td><code>'B'</code></td> + <td> + The full month name, e.g. "November". If the value does not contain a valid + month, an exception of type <code>format_error</code> is thrown. + </td> +</tr> +<tr> + <td><code>'c'</code></td> + <td> + The date and time representation, e.g. "Sat Nov 12 22:04:00 1955". The + modified command <code>%Ec</code> produces the locale's alternate date and + time representation. + </td> +</tr> +<tr> + <td><code>'C'</code></td> + <td> + The year divided by 100 using floored division, e.g. "19". If the result + is a single decimal digit, it is prefixed with 0. The modified command + <code>%EC</code> produces the locale's alternative representation of the + century. + </td> +</tr> +<tr> + <td><code>'d'</code></td> + <td> + The day of month as a decimal number. If the result is a single decimal + digit, it is prefixed with 0. The modified command <code>%Od</code> + produces the locale's alternative representation. + </td> +</tr> +<tr> + <td><code>'D'</code></td> + <td>Equivalent to <code>%m/%d/%y</code>, e.g. "11/12/55".</td> +</tr> +<tr> + <td><code>'e'</code></td> + <td> + The day of month as a decimal number. If the result is a single decimal + digit, it is prefixed with a space. The modified command <code>%Oe</code> + produces the locale's alternative representation. + </td> +</tr> +<tr> + <td><code>'F'</code></td> + <td>Equivalent to <code>%Y-%m-%d</code>, e.g. "1955-11-12".</td> +</tr> +<tr> + <td><code>'g'</code></td> + <td> + The last two decimal digits of the ISO week-based year. If the result is a + single digit it is prefixed by 0. + </td> +</tr> +<tr> + <td><code>'G'</code></td> + <td> + The ISO week-based year as a decimal number. If the result is less than + four digits it is left-padded with 0 to four digits. + </td> +</tr> +<tr> + <td><code>'h'</code></td> + <td>Equivalent to <code>%b</code>, e.g. "Nov".</td> +</tr> +<tr> + <td><code>'H'</code></td> + <td> + The hour (24-hour clock) as a decimal number. If the result is a single + digit, it is prefixed with 0. The modified command <code>%OH</code> + produces the locale's alternative representation. + </td> +</tr> +<tr> + <td><code>'I'</code></td> + <td> + The hour (12-hour clock) as a decimal number. If the result is a single + digit, it is prefixed with 0. The modified command <code>%OI</code> + produces the locale's alternative representation. + </td> +</tr> +<tr> + <td><code>'j'</code></td> + <td> + If the type being formatted is a specialization of duration, the decimal + number of days without padding. Otherwise, the day of the year as a decimal + number. Jan 1 is 001. If the result is less than three digits, it is + left-padded with 0 to three digits. + </td> +</tr> +<tr> + <td><code>'m'</code></td> + <td> + The month as a decimal number. Jan is 01. If the result is a single digit, + it is prefixed with 0. The modified command <code>%Om</code> produces the + locale's alternative representation. + </td> +</tr> +<tr> + <td><code>'M'</code></td> + <td> + The minute as a decimal number. If the result is a single digit, it + is prefixed with 0. The modified command <code>%OM</code> produces the + locale's alternative representation. + </td> +</tr> +<tr> + <td><code>'n'</code></td> + <td>A new-line character.</td> +</tr> +<tr> + <td><code>'p'</code></td> + <td>The AM/PM designations associated with a 12-hour clock.</td> +</tr> +<tr> + <td><code>'q'</code></td> + <td>The duration's unit suffix.</td> +</tr> +<tr> + <td><code>'Q'</code></td> + <td> + The duration's numeric value (as if extracted via <code>.count()</code>). + </td> +</tr> +<tr> + <td><code>'r'</code></td> + <td>The 12-hour clock time, e.g. "10:04:00 PM".</td> +</tr> +<tr> + <td><code>'R'</code></td> + <td>Equivalent to <code>%H:%M</code>, e.g. "22:04".</td> +</tr> +<tr> + <td><code>'S'</code></td> + <td> + Seconds as a decimal number. If the number of seconds is less than 10, the + result is prefixed with 0. If the precision of the input cannot be exactly + represented with seconds, then the format is a decimal floating-point number + with a fixed format and a precision matching that of the precision of the + input (or to a microseconds precision if the conversion to floating-point + decimal seconds cannot be made within 18 fractional digits). The modified + command <code>%OS</code> produces the locale's alternative representation. + </td> +</tr> +<tr> + <td><code>'t'</code></td> + <td>A horizontal-tab character.</td> +</tr> +<tr> + <td><code>'T'</code></td> + <td>Equivalent to <code>%H:%M:%S</code>.</td> +</tr> +<tr> + <td><code>'u'</code></td> + <td> + The ISO weekday as a decimal number (1-7), where Monday is 1. The modified + command <code>%Ou</code> produces the locale's alternative representation. + </td> +</tr> +<tr> + <td><code>'U'</code></td> + <td> + The week number of the year as a decimal number. The first Sunday of the + year is the first day of week 01. Days of the same year prior to that are + in week 00. If the result is a single digit, it is prefixed with 0. + The modified command <code>%OU</code> produces the locale's alternative + representation. + </td> +</tr> +<tr> + <td><code>'V'</code></td> + <td> + The ISO week-based week number as a decimal number. If the result is a + single digit, it is prefixed with 0. The modified command <code>%OV</code> + produces the locale's alternative representation. + </td> +</tr> +<tr> + <td><code>'w'</code></td> + <td> + The weekday as a decimal number (0-6), where Sunday is 0. The modified + command <code>%Ow</code> produces the locale's alternative representation. + </td> +</tr> +<tr> + <td><code>'W'</code></td> + <td> + The week number of the year as a decimal number. The first Monday of the + year is the first day of week 01. Days of the same year prior to that are + in week 00. If the result is a single digit, it is prefixed with 0. + The modified command <code>%OW</code> produces the locale's alternative + representation. + </td> +</tr> +<tr> + <td><code>'x'</code></td> + <td> + The date representation, e.g. "11/12/55". The modified command + <code>%Ex</code> produces the locale's alternate date representation. + </td> +</tr> +<tr> + <td><code>'X'</code></td> + <td> + The time representation, e.g. "10:04:00". The modified command + <code>%EX</code> produces the locale's alternate time representation. + </td> +</tr> +<tr> + <td><code>'y'</code></td> + <td> + The last two decimal digits of the year. If the result is a single digit + it is prefixed by 0. The modified command <code>%Oy</code> produces the + locale's alternative representation. The modified command <code>%Ey</code> + produces the locale's alternative representation of offset from + <code>%EC</code> (year only). + </td> +</tr> +<tr> + <td><code>'Y'</code></td> + <td> + The year as a decimal number. If the result is less than four digits it is + left-padded with 0 to four digits. The modified command <code>%EY</code> + produces the locale's alternative full year representation. + </td> +</tr> +<tr> + <td><code>'z'</code></td> + <td> + The offset from UTC in the ISO 8601:2004 format. For example -0430 refers + to 4 hours 30 minutes behind UTC. If the offset is zero, +0000 is used. + The modified commands <code>%Ez</code> and <code>%Oz</code> insert a + <code>:</code> between the hours and minutes: -04:30. If the offset + information is not available, an exception of type + <code>format_error</code> is thrown. + </td> +</tr> +<tr> + <td><code>'Z'</code></td> + <td> + The time zone abbreviation. If the time zone abbreviation is not available, + an exception of type <code>format_error</code> is thrown. + </td> +</tr> +<tr> + <td><code>'%'</code></td> + <td>A % character.</td> +</tr> +</table> + +Specifiers that have a calendaric component such as `'d'` (the day of month) +are valid only for `std::tm` and time points but not durations. + +The available padding modifiers (*padding_modifier*) are: + +| Type | Meaning | +|-------|-----------------------------------------| +| `'_'` | Pad a numeric result with spaces. | +| `'-'` | Do not pad a numeric result string. | +| `'0'` | Pad a numeric result string with zeros. | + +These modifiers are only supported for the `'H'`, `'I'`, `'M'`, `'S'`, `'U'`, +`'V'`, `'W'`, `'Y'`, `'d'`, `'j'` and `'m'` presentation types. + +## Range Format Specifications + +Format specifications for range types have the following syntax: + +<pre><code class="language-json" +>range_format_spec ::= ["n"][range_type][range_underlying_spec]</code> +</pre> + +The `'n'` option formats the range without the opening and closing brackets. + +The available presentation types for `range_type` are: + +| Type | Meaning | +|--------|------------------------------------------------------------| +| none | Default format. | +| `'s'` | String format. The range is formatted as a string. | +| `'?s'` | Debug format. The range is formatted as an escaped string. | + +If `range_type` is `'s'` or `'?s'`, the range element type must be a character +type. The `'n'` option and `range_underlying_spec` are mutually exclusive with +`'s'` and `'?s'`. + +The `range_underlying_spec` is parsed based on the formatter of the range's +element type. + +By default, a range of characters or strings is printed escaped and quoted. +But if any `range_underlying_spec` is provided (even if it is empty), then the +characters or strings are printed according to the provided specification. + +Examples: + +```c++ +fmt::print("{}", std::vector{10, 20, 30}); +// Output: [10, 20, 30] +fmt::print("{::#x}", std::vector{10, 20, 30}); +// Output: [0xa, 0x14, 0x1e] +fmt::print("{}", std::vector{'h', 'e', 'l', 'l', 'o'}); +// Output: ['h', 'e', 'l', 'l', 'o'] +fmt::print("{:n}", std::vector{'h', 'e', 'l', 'l', 'o'}); +// Output: 'h', 'e', 'l', 'l', 'o' +fmt::print("{:s}", std::vector{'h', 'e', 'l', 'l', 'o'}); +// Output: "hello" +fmt::print("{:?s}", std::vector{'h', 'e', 'l', 'l', 'o', '\n'}); +// Output: "hello\n" +fmt::print("{::}", std::vector{'h', 'e', 'l', 'l', 'o'}); +// Output: [h, e, l, l, o] +fmt::print("{::d}", std::vector{'h', 'e', 'l', 'l', 'o'}); +// Output: [104, 101, 108, 108, 111] +``` + +## Format Examples + +This section contains examples of the format syntax and comparison with +the printf formatting. + +In most of the cases the syntax is similar to the printf formatting, +with the addition of the `{}` and with `:` used instead of `%`. For +example, `"%03.2f"` can be translated to `"{:03.2f}"`. + +The new format syntax also supports new and different options, shown in +the following examples. + +Accessing arguments by position: + +```c++ +fmt::format("{0}, {1}, {2}", 'a', 'b', 'c'); +// Result: "a, b, c" +fmt::format("{}, {}, {}", 'a', 'b', 'c'); +// Result: "a, b, c" +fmt::format("{2}, {1}, {0}", 'a', 'b', 'c'); +// Result: "c, b, a" +fmt::format("{0}{1}{0}", "abra", "cad"); // arguments' indices can be repeated +// Result: "abracadabra" +``` + +Aligning the text and specifying a width: + +```c++ +fmt::format("{:<30}", "left aligned"); +// Result: "left aligned " +fmt::format("{:>30}", "right aligned"); +// Result: " right aligned" +fmt::format("{:^30}", "centered"); +// Result: " centered " +fmt::format("{:*^30}", "centered"); // use '*' as a fill char +// Result: "***********centered***********" +``` + +Dynamic width: + +```c++ +fmt::format("{:<{}}", "left aligned", 30); +// Result: "left aligned " +``` + +Dynamic precision: + +```c++ +fmt::format("{:.{}f}", 3.14, 1); +// Result: "3.1" +``` + +Replacing `%+f`, `%-f`, and `% f` and specifying a sign: + +```c++ +fmt::format("{:+f}; {:+f}", 3.14, -3.14); // show it always +// Result: "+3.140000; -3.140000" +fmt::format("{: f}; {: f}", 3.14, -3.14); // show a space for positive numbers +// Result: " 3.140000; -3.140000" +fmt::format("{:-f}; {:-f}", 3.14, -3.14); // show only the minus -- same as '{:f}; {:f}' +// Result: "3.140000; -3.140000" +``` + +Replacing `%x` and `%o` and converting the value to different bases: + +```c++ +fmt::format("int: {0:d}; hex: {0:x}; oct: {0:o}; bin: {0:b}", 42); +// Result: "int: 42; hex: 2a; oct: 52; bin: 101010" +// with 0x or 0 or 0b as prefix: +fmt::format("int: {0:d}; hex: {0:#x}; oct: {0:#o}; bin: {0:#b}", 42); +// Result: "int: 42; hex: 0x2a; oct: 052; bin: 0b101010" +``` + +Padded hex byte with prefix and always prints both hex characters: + +```c++ +fmt::format("{:#04x}", 0); +// Result: "0x00" +``` + +Box drawing using Unicode fill: + +```c++ +fmt::print( + "┌{0:─^{2}}┐\n" + "│{1: ^{2}}│\n" + "└{0:─^{2}}┘\n", "", "Hello, world!", 20); +``` + +prints: + +``` +┌────────────────────┐ +│ Hello, world! │ +└────────────────────┘ +``` + +Using type-specific formatting: + +```c++ +#include <fmt/chrono.h> + +auto t = tm(); +t.tm_year = 2010 - 1900; +t.tm_mon = 7; +t.tm_mday = 4; +t.tm_hour = 12; +t.tm_min = 15; +t.tm_sec = 58; +fmt::print("{:%Y-%m-%d %H:%M:%S}", t); +// Prints: 2010-08-04 12:15:58 +``` + +Using the comma as a thousands separator: + +```c++ +#include <fmt/format.h> + +auto s = fmt::format(std::locale("en_US.UTF-8"), "{:L}", 1234567890); +// s == "1,234,567,890" +``` |
