6.1.0

• {fmt} now formats IEEE 754 float and double using the shortest decimal representation with correct rounding by default:

  #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:

  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 (#1336, #1353, #1360, #1361):

  fmt::print("{}", 0.1f);

  prints 0.1 instead of 0.10000000149011612. Thanks @orivej (Orivej Desh).

• Made floating-point formatting output consistent with printf/iostreams (#1376, #1417).

• Added support for 128-bit integers (#1287):

  fmt::print("{}", std::numeric_limits<__int128_t>::max());

  prints 170141183460469231731687303715884105727. Thanks @denizevrenci (Deniz Evrenci).

• The overload of print that takes text_style is now atomic, i.e. the output from different threads doesn't interleave (#1351). Thanks @tankiJong (Tanki Zhang).

• 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 (#1322, #1330):

  #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 (Jeremy Ong).

• Changed formatting of octal zero with prefix from "00" to "0":

  fmt::print("{:#o}", 0);

  prints 0.

• The locale is now passed to ostream insertion (<<) operators (#1406):

  #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 (Daniel Laügt).

• Locale-specific number formatting now uses grouping (#1393 #1394). Thanks @skrdaniel.

• Fixed handling of types with deleted implicit rvalue conversion to const char** (#1421):

  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 (#1286). Thanks @agmt (Egor Seredin).

• Enum classes are no longer implicitly converted to int (#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 (#1389, #1390). Thanks @tajtiattila (Attila Tajti).

• {fmt} can now be installed on Linux, macOS and Windows with Conda using its conda-forge package (#1410):

  conda install -c conda-forge fmt
  

  Thanks @tdegeus (Tom de Geus).

• Added a CUDA test (#1285, #1317). Thanks @luncliff (Park DongHa) and @risa2000.

• Improved documentation (#1276, #1291, #1296, #1315, #1332, #1337, #1395 #1418). Thanks @waywardmonkeys (Bruce Mitchener), @pauldreik (Paul Dreik), @jackoalan (Jack Andersen).

• Various code improvements (#1358, #1407). Thanks @orivej (Orivej Desh), @dpacbach (David P. Sicilia),

• Fixed compile-time format string checks for user-defined types (#1292).

• Worked around a false positive in unsigned-integer-overflow sanitizer (#1377).

• Fixed various warnings and compilation issues (#1273, #1278, #1280, #1281, #1288, #1290, #1301, #1305, #1306, #1309, #1312, #1313, #1316, #1319, #1320, #1326, #1328, #1344, #1345, #1347, #1349, #1354, #1362, #1366, #1364, #1370, #1371, #1385, #1388, #1397, #1414, #1416, #1422 #1427, #1431, #1433). Thanks @hhb, @gsjaardema (Greg Sjaardema), @gabime (Gabi Melman), @neheb (Rosen Penev), @vedranmiletic (Vedran Miletić), @dkavolis (Daumantas Kavolis), @mwinterb, @orivej (Orivej Desh), @denizevrenci (Deniz Evrenci) @leonklingele, @chronoxor (Ivan Shynkarenka), @kent-tri, @0x8000-0000 (Florin Iucha), @marti4d (Chris Martin).