6.0.0

• Switched to the MIT license with an optional exception that allows distributing binary code without attribution.

• Floating-point formatting is now locale-independent by default:

  #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:

  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:

  #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 (full results):

• Separated formatting and parsing contexts for consistency with C++20 std::format, removing the undocumented basic_format_context::parse_context() function.

• Added oss-fuzz support (#1199). Thanks @pauldreik (Paul Dreik).

• formatter specializations now always take precedence over operator<< (#952):

  #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 (#618, #1169, #1171):

  #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 (Mateusz Janek).

• Added experimental support for the % format specifier that formats floating-point values as percentages (#1060, #1069, #1071):

  auto s = fmt::format("{:.1%}", 0.42); // s == "42.0%"

  Thanks @gawain-bolton (Gawain Bolton).

• Implemented precision for floating-point durations (#1004, #1012):

  auto s = fmt::format("{:.1}", std::chrono::duration<double>(1.234));
  // s == 1.2s

  Thanks @DanielaE (Daniela Engert).

• Implemented chrono format specifiers %Q and %q that give the value and the unit respectively (#1019):

  auto value = fmt::format("{:%Q}", 42s); // value == "42"
  auto unit  = fmt::format("{:%q}", 42s); // unit == "s"

  Thanks @DanielaE (Daniela Engert).

• Fixed handling of dynamic width in chrono formatter:

  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 (#993, #994):

  #include <fmt/color.h>
  
  std::string message = fmt::format(fmt::emphasis::bold | fg(fmt::color::red),
                                    "The answer is {}.", 42);

  Thanks @Naios (Denis Blank).

• 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 (#1121):

  std::unique_ptr<int> p = ...;
  fmt::print("{}", fmt::ptr(p)); // prints p as a pointer

  Thanks @sighingnow (Tao He).

• Made print and vprint report I/O errors (#1098, #1099). Thanks @BillyDonahue (Billy Donahue).

• Marked deprecated APIs with the [[deprecated]] attribute and removed internal uses of deprecated APIs (#1022). Thanks @eliaskosunen (Elias Kosunen).

• 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 (#1229, #1243). Thanks @jackoalan (Jack Andersen).

• Improved literal-based API (#1254). Thanks @sylveon (Charles Milette).

• Added support for exotic platforms without uintptr_t such as IBM i (AS/400) which has 128-bit pointers and only 64-bit integers (#1059).

• Added Sublime Text syntax highlighting config (#1037). Thanks @Kronuz (Germán Méndez Bravo).

• Added the FMT_ENFORCE_COMPILE_STRING macro to enforce the use of compile-time format strings (#1231). Thanks @jackoalan (Jack Andersen).

• Stopped setting CMAKE_BUILD_TYPE if {fmt} is a subproject (#1081).

• Various build improvements (#1039, #1078, #1091, #1103, #1177). Thanks @luncliff (Park DongHa), @jasonszang (Jason Shuo Zang), @olafhering (Olaf Hering), @Lecetem, @pauldreik (Paul Dreik).

• Improved documentation (#1049, #1051, #1083, #1113, #1114, #1146, #1180, #1250, #1252, #1265). Thanks @mikelui (Michael Lui), @foonathan (Jonathan Müller), @BillyDonahue (Billy Donahue), @jwakely (Jonathan Wakely), @kaisbe (Kais Ben Salah), @sdebionne (Samuel Debionne).

• Fixed ambiguous formatter specialization in fmt/ranges.h (#1123).

• Fixed formatting of a non-empty std::filesystem::path which is an infinitely deep range of its components (#1268).

• Fixed handling of general output iterators when formatting characters (#1056, #1058). Thanks @abolz (Alexander Bolz).

• Fixed handling of output iterators in formatter specialization for ranges (#1064).

• Fixed handling of exotic character types (#1188).

• Made chrono formatting work with exceptions disabled (#1062).

• Fixed DLL visibility issues (#1134, #1147). Thanks @denchat.

• Disabled the use of UDL template extension on GCC 9 (#1148).

• Removed misplaced format compile-time checks from printf (#1173).

• Fixed issues in the experimental floating-point formatter (#1072, #1129, #1153, #1155, #1210, #1222). Thanks @alabuzhev (Alex Alabuzhev).

• Fixed bugs discovered by fuzzing or during fuzzing integration (#1124, #1127, #1132, #1135, #1136, #1141, #1142, #1178, #1179, #1194). Thanks @pauldreik (Paul Dreik).

• Fixed building tests on FreeBSD and Hurd (#1043). Thanks @jackyf (Eugene V. Lyubimkin).

• Fixed various warnings and compilation issues (#998, #1006, #1008, #1011, #1025, #1027, #1028, #1029, #1030, #1031, #1054, #1063, #1068, #1074, #1075, #1079, #1086, #1088, #1089, #1094, #1101, #1102, #1105, #1107, #1115, #1117, #1118, #1120, #1123, #1139, #1140, #1143, #1144, #1150, #1151, #1152, #1154, #1156, #1159, #1175, #1181, #1186, #1187, #1191, #1197, #1200, #1203, #1205, #1206, #1213, #1214, #1217, #1228, #1230, #1232, #1235, #1236, #1240). Thanks @DanielaE (Daniela Engert), @mwinterb, @eliaskosunen (Elias Kosunen), @morinmorin, @ricco19 (Brian Ricciardelli), @waywardmonkeys (Bruce Mitchener), @chronoxor (Ivan Shynkarenka), @remyabel, @pauldreik (Paul Dreik), @gsjaardema (Greg Sjaardema), @rcane (Ronny Krüger), @mocabe, @denchat, @cjdb (Christopher Di Bella), @HazardyKnusperkeks (Björn Schäpers), @vedranmiletic (Vedran Miletić), @jackoalan (Jack Andersen), @DaanDeMeyer (Daan De Meyer), @starkmapper (Mark Stapper).