10.1.0

• Optimized format string compilation resulting in up to 40% speed up in compiled format_to and ~4x speed up in compiled format_to_n on a concatenation benchmark (#3133, #3484).

  {fmt} 10.0:

  ---------------------------------------------------------
  Benchmark               Time             CPU   Iterations
  ---------------------------------------------------------
  BM_format_to         78.9 ns         78.9 ns      8881746
  BM_format_to_n        568 ns          568 ns      1232089
  

  {fmt} 10.1:

  ---------------------------------------------------------
  Benchmark               Time             CPU   Iterations
  ---------------------------------------------------------
  BM_format_to         54.9 ns         54.9 ns     12727944
  BM_format_to_n        133 ns          133 ns      5257795
  

• Optimized storage of an empty allocator in basic_memory_buffer (#3485). Thanks @Minty-Meeo.

• Added formatters for proxy references to elements of std::vector<bool> and std::bitset<N> (#3567, #3570). For example (godbolt):

  #include <vector>
  #include <fmt/std.h>
  
  int main() {
    auto v = std::vector<bool>{true};
    fmt::print("{}", v[0]);
  }

  Thanks @phprus (Vladislav Shchapov) and @felix642 (Félix-Antoine Constantin).

• Fixed an ambiguous formatter specialization for containers that look like container adaptors such as boost::flat_set (#3556, #3561). Thanks @5chmidti.

• Fixed compilation when formatting durations not convertible from std::chrono::seconds (#3430). Thanks @patlkli (Patrick Geltinger).

• Made the formatter specialization for char* const-correct (#3432). Thanks @timsong-cpp.

• Made {} and {:} handled consistently during compile-time checks (#3526).

• Disallowed passing temporaries to make_format_args to improve API safety by preventing dangling references.

• Improved the compile-time error for unformattable types (#3478). Thanks @BRevzin (Barry Revzin).

• Improved the floating-point formatter (#3448, #3450). Thanks @florimond-collette (Florimond Collette).

• Fixed handling of precision for long double larger than 64 bits. (#3539, #3564).

• Made floating-point and chrono tests less platform-dependent (#3337, #3433, #3434). Thanks @phprus (Vladislav Shchapov).

• Removed the remnants of the Grisu floating-point formatter that has been replaced by Dragonbox in earlier versions.

• Added throw_format_error to the public API (#3551). Thanks @mjerabek (Martin Jeřábek).

• Made FMT_THROW assert even if assertions are disabled when compiling with exceptions disabled (#3418, #3439). Thanks @BRevzin (Barry Revzin).

• Added support for the ? format specifier to std::filesystem::path and made the default unescaped for consistency with strings.

• Made format_as and std::filesystem::path formatter work with exotic code unit types. (#3457, #3476). Thanks @gix (Nico Rieck), @hmbj (Hans-Martin B. Jensen).

• Deprecated the wide stream overload of printf.

• Removed unused basic_printf_parse_context.

• Improved RTTI detection used when formatting exceptions (#3468). Thanks @danakj (Dana Jansens).

• Improved compatibility with VxWorks7 (#3467). Thanks @wenshan1 (Bin Lan).

• Improved documentation (#3174, #3423, #3454, #3458, #3461, #3487, #3515). Thanks @zencatalyst (Kasra Hashemi), @rlalik, @mikecrowe (Mike Crowe).

• Improved build and CI configurations (#3449, #3451, #3452, #3453, #3459, #3481, #3486, #3489, #3496, #3517, #3523, #3563). Thanks @joycebrum (Joyce), @glebm (Gleb Mazovetskiy), @phprus (Vladislav Shchapov), @petrmanek (Petr Mánek), @setoye (Alta), @abouvier (Alexandre Bouvier).

• Fixed various warnings and compilation issues (#3408, #3424, #3444, #3446, #3475, #3482, #3492, #3493, #3508, #3509, #3533, #3542, #3543, #3540, #3544, #3548, #3549, #3550, #3552). Thanks @adesitter (Arnaud Desitter), @hmbj (Hans-Martin B. Jensen), @Minty-Meeo, @phprus (Vladislav Shchapov), @TobiSchluter (Tobias Schlüter), @kieranclancy (Kieran Clancy), @alexeedm (Dmitry Alexeev), @jurihock (Jürgen Hock), @Ozomahtli, @razaqq.

Pull Requests

• Fix time_point formatting for durations with certain ratios by @patlkli in #3430
• Make hex float test more stable by @phprus in #3434
• Always assert in FMT_THROW by @brevzin in #3439
• format-inl.h: address implicit int to bool conversion by @adesitter in #3446
• remove code duplication by @florimond-collette in #3448
• replace mod_inv_25 by explicit value as a fix for VS warning C4307 by @florimond-collette in #3450
• Fix parameter type of formatter<char*> by @timsong-cpp in #3432
• Hash pin Github Workflows by @joycebrum in #3451
• Create dependabot.yml by @joycebrum in #3452
• Update README.rst by @zencatalyst in #3454
• CMake: Do not fail on unknown compiler features by @glebm in #3453
• Fix example for user-defined types in documentation for 10.0.0 by @rlalik in #3461
• Make constexpr ceil by @phprus in #3459
• Pass correct Char to base format_as formatter by @gix in #3457
• Add VxWorks7 user space and kernel space support by @wenshan1 in #3467
• Only use typeid() in std.h when it is available by @danakj in #3468
• Fix MSVC warning in std::chrono::time_point formatter by @hmbj in #3475
• Use correct Char type in std::filesystem::path formatter by @hmbj in #3476
• Use FMT_TRY and FMT_CATCH in std.h by @Minty-Meeo in #3482
• Bump actions/checkout from 3.5.2 to 3.5.3 by @dependabot in #3486
• Give basic_memory_buffer allocator [[no_unique_address]] by @Minty-Meeo in #3485
• Fix for issue #3492 by @phprus in #3493
• Revert ae25f79 to restore capability to cmake --install when included as a subproject by @petrmanek in #3496
• Fix typo in assert message. by @TobiSchluter in #3508
• README: Add link to merged clang-tidy check by @mikecrowe in #3515
• Trying to improve errors in the unformattable case. by @brevzin in #3478
• fix missing header files when using CMake install by @setoye in #3523
• Fix format_string_checker initialisation order by @kieranclancy in #3542
• Turn off error-producing NVCC workaround when using c++20 by @alexeedm in #3544
• Remove std::copy usage. by @Ozomahtli in #3550
• expose detail::throw_format_error by @mjerabek in #3551
• Use the U literal for unsigned integer constants. by @jurihock in #3549
• Add missing inline specifier by @razaqq in #3552
• cmake: fix FMT_PKGCONFIG_DIR path by @abouvier in #3563
• fix ambiguous formatter lookup for flat_set by @5chmidti in #3561
• Added formatter for bit_reference-like types by @phprus in #3570

New Contributors

• @adesitter made their first contribution in #3446
• @florimond-collette made their first contribution in #3448
• @zencatalyst made their first contribution in #3454
• @rlalik made their first contribution in #3461
• @gix made their first contribution in #3457
• @wenshan1 made their first contribution in #3467
• @danakj made their first contribution in #3468
• @Minty-Meeo made their first contribution in #3482
• @dependabot made their first contribution in #3486
• @petrmanek made their first contribution in #3496
• @TobiSchluter made their first contribution in #3508
• @kieranclancy made their first contribution in #3542
• @alexeedm made their first contribution in #3544
• @Ozomahtli made their first contribution in #3550
• @mjerabek made their first contribution in #3551
• @jurihock made their first contribution in #3549
• @razaqq made their first contribution in #3552
• @abouvier made their first contribution in #3563
• @5chmidti made their first contribution in #3561