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Releases: fmtlib/fmt

5.2.0

13 Sep 14:35
@vitaut vitaut
5.2.0
295a0d8
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5.2.0

  • 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:

    #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 (#783):

    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:

    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 (#814, #819). Thanks @MikePopoloski (Michael Popoloski).

  • Reduced executable size overhead for embedded targets using newlib nano by making locale dependency optional (#839). Thanks @teajay-fr (Thomas Benard).

  • Keep noexcept specifier when exceptions are disabled (#801, #810). Thanks @qis (Alexej Harm).

  • Fixed formatting of user-defined types providing operator<< with format_to_n (#806). Thanks @mkurdej (Marek Kurdej).

  • Fixed dynamic linkage of new symbols (#808).

  • Fixed global initialization issue (#807):

    // This works on compilers with constexpr support.
static const std::string answer = fmt::format("{}", 42);

  • Fixed various compiler warnings and errors (#804, #809, #811, #822, #827, #830, #838, #843, #844, #851, #852, #854). Thanks @henryiii (Henry Schreiner), @medithe, and @eliasdaler (Elias Daler).

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5.1.0

05 Jul 13:25
@vitaut vitaut
5.1.0
c2ce7e4
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5.1.0

  • Added experimental support for RGB color output enabled with the FMT_EXTENDED_COLORS macro:

    #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. (#762 #767). Thanks @Remotion (Remo).

  • Added quotes to strings in ranges and tuples (#766). Thanks @Remotion (Remo).

  • Made format_to work with basic_memory_buffer (#776).

  • Added vformat_to_n and wchar_t overload of format_to_n (#764, #769).

  • Made is_range and is_tuple_like part of public (experimental) API to allow specialization for user-defined types (#751, #759). Thanks @drrlvn (Dror Levin).

  • Added more compilers to continuous integration and increased FMT_PEDANTIC warning levels (#736). Thanks @eliaskosunen (Elias Kosunen).

  • Fixed compilation with MSVC 2013.

  • Fixed handling of user-defined types in format_to (#793).

  • Forced linking of inline vformat functions into the library (#795).

  • Fixed incorrect call to on_align in '{:}=' (#750).

  • Fixed floating-point formatting to a non-back_insert_iterator with sign & numeric alignment specified (#756).

  • Fixed formatting to an array with format_to_n (#778).

  • Fixed formatting of more than 15 named arguments (#754).

  • Fixed handling of compile-time strings when including fmt/ostream.h. (#768).

  • Fixed various compiler warnings and errors (#742, #748, #752, #770, #775, #779, #780, #790, #792, #800). Thanks @Remotion (Remo), @gabime (Gabi Melman), @foonathan (Jonathan Müller), @Dark-Passenger (Dhruv Paranjape), and @0x8000-0000 (Sign Bit).

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5.0.0

22 May 13:08
@vitaut vitaut
5.0.0
5386f1d
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5.0.0

  • 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 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.

  • Implemented constexpr parsing of format strings and compile-time format string checks. For example

    #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):

    ...
<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

    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):

    ...
<source>:12:45: error: expression '<throw-expression>' is not a constant expression
       throw format_error("invalid specifier");

  • Added iterator support:

    #include <vector>
#include <fmt/format.h>

std::vector<char> out;
fmt::format_to(std::back_inserter(out), "{}", 42);

  • Added the format_to_n function that restricts the output to the specified number of characters (#298):

    char out[4];
fmt::format_to_n(out, sizeof(out), "{}", 12345);
// out == "1234" (without terminating '\0')

  • Added the formatted_size function for computing the output size:

    #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:

    #include <fmt/core.h>

fmt::print("The answer is {}.", 42);

    See Compile time and code bloat.

  • Added the make_format_args function for capturing formatting arguments:

    // 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 ( #687, #694). Thanks @Kronuz (Germán Méndez Bravo).

  • Added prefix v to non-variadic functions taking format_args to distinguish them from variadic ones:

    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 (#735):

    #include <fmt/ranges.h>

std::vector<int> v = {1, 2, 3};
fmt::print("{}", v); // prints {1, 2, 3}

    Thanks @Remotion (Remo).

  • Implemented wchar_t date and time formatting (#712):

    #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 (Daniela Engert).

  • Provided more wide string overloads (#724). Thanks @DanielaE (Daniela Engert).

  • 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 (#607):

    #include <fmt/core.h>
#include <experimental/string_view>

fmt::print("{}", std::experimental::string_view("foo"));

    Thanks @virgiliofornazin (Virgilio Alexandre Fornazin).

  • Allowed mixing named and automatic arguments:

    fmt::format("{} {two}", 1, fmt::arg("two", 2));

  • Removed the write API in favor of the format API with compile-time handling of format strings.

  • Disallowed formatting of multibyte strings into a wide character target (#606).

  • Improved documentation ( #515, #614, #617, #661, #680). Thanks @ibell (Ian Bell), @mihaitodor (Mihai Todor), 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 (#636).

  • Removed unnecessary fmt/ prefix in includes (#397). Thanks @chronoxor (Ivan Shynkarenka).

  • 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 (#641). Thanks @cowo78 (Giuseppe Corbelli).

  • Added Gradle build file support/build.gradle (#649). Thanks @luncliff (Park DongHa).

  • Removed FMT_CPPFORMAT CMake option.

  • Fixed a name conflict with the macro CHAR_WIDTH in glibc (#616). Thanks @aroig (Abdó Roig-Maranges).

  • Fixed handling of nested braces in fmt::join (#638).

  • Added SOURCELINK_SUFFIX for compatibility with Sphinx 1.5 (#497). Thanks @ginggs (Graham Inggs).

  • Added a missing inline in the header-only mode (#626). Thanks @aroig (Abdó Roig-Maranges).

  • Fixed various compiler warnings ( #640, #656, #679, #681, #705, #715, #717, #720, #723, #726, #730, #739). Thanks @peterbell10, @LarsGullik, @foonathan (Jonathan Müller), @eliaskosunen (Elias Kosunen), @christianparpart (Christian Parpart), @DanielaE (Daniela Engert), and @mwinterb.

  • Worked around an MSVC bug and fixed several warnings (#653). Thanks @alabuzhev (Alex Alabuzhev).

  • Worked around GCC bug 67371 (#682).

  • Fixed compilation with -fno-exceptions (#655). Thanks @chenxiaolong (Andrew Gunnerson).

  • Made constexpr remove_prefix gcc version check tighter (#648).

  • Renamed internal type enum constants to prevent collision with poorly written C libraries (#644).

  • Added detection of wostream operator<< (#650).

  • Fixed compilation on OpenBSD (#660). Thanks @hubslave.

  • Fixed compilation on FreeBSD 12 (#732). Thanks @dankm.

  • Fixed compilation when there is a mismatch between -std options between the library and user code (#664).

  • Fixed compilation with GCC 7 and -std=c++11 (#734).

  • Improved generated binary code on GCC 7 and older (#668).

  • Fixed handling of numeric alignment with no width (#675).

  • Fixed handling of empty strings in UTF8/16 converters (#676). Thanks @vgalka-sl (Vasili Galka).

  • Fixed formatting of an empty string_view (#689).

  • Fixed detection of string_view on libc++ (#686).

  • Fixed DLL issues (#696). Thanks @sebkoenig.

  • Fixed compile checks for mixing narrow and wide strings (#690).

  • Disabled unsafe implicit conversion to std::string (#729).

  • Fixed handling of reused format specs (as in fmt::join) for pointers (#725). Thanks @mwinterb.

  • Fixed installation of fmt/ranges.h (#738). Thanks @sv1990....

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4.1.0

20 Dec 16:22
@vitaut vitaut
4.1.0
135ab5c
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4.1.0
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4.0.0

27 Jun 17:06
@foonathan foonathan
4.0.0
3983438
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4.0.0
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3.0.2

14 Jun 16:08
@foonathan foonathan
3.0.2
5708bf8
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3.0.2
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3.0.1

01 Nov 08:47
@foonathan foonathan
3.0.1
7fa8f8f
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3.0.1
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3.0.0

07 May 17:07
@vitaut vitaut
3.0.0
e5e4fb3
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3.0.0

  • The project has been renamed from C++ Format (cppformat) to fmt for consistency with the used namespace and macro prefix (#307). Library headers are now located in the fmt directory:

    #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 http://fmtlib.net.

  • Added support for strftime-like date and time formatting (#283):

    #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:

    #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 (#235).

  • Added support for locale-specific integer formatting with the n specifier (#305):

    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 (#265):

    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 (#255):

    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 (#231).

  • Fixed detection of user-defined literal support on Intel C++ compiler (#311, #312). Thanks to @dean0x7d (Dean Moldovan) and @speth (Ray Speth).

  • Reduced compile time (#243, #249, #317):Thanks to @dean0x7d (Dean Moldovan).

  • Compile test fixes (#313). Thanks to @dean0x7d (Dean Moldovan).

  • Documentation fixes (#239, #248, #252, #258, #260, #301, #309). Thanks to @ReadmeCritic @Gachapen (Magnus Bjerke Vik) and @jwilk (Jakub Wilk).

  • Fixed compiler and sanitizer warnings (#244, #256, #259, #263, #274, #277, #286, #291, #296, #308) Thanks to @mwinterb, @pweiskircher (Patrik Weiskircher), @Naios.

  • Improved compatibility with Windows Store apps (#280, #285) Thanks to @mwinterb.

  • Added tests of compatibility with older C++ standards (#273). Thanks to @niosHD.

  • Fixed Android build (#271). Thanks to @newnon.

  • Changed ArgMap to be backed by a vector instead of a map. (#261, #262). Thanks to @mwinterb.

  • Added fprintf overload that writes to a std::ostream (#251). Thanks to nickhutchinson (Nicholas Hutchinson).

  • Export symbols when building a Windows DLL (#245). Thanks to macdems (Maciek Dems).

  • Fixed compilation on Cygwin (#304).

  • Implemented a workaround for a bug in Apple LLVM version 4.2 of clang (#276).

  • Implemented a workaround for Google Test bug #705 on gcc 6 (#268). Thanks to octoploid.

  • Removed Biicode support because the latter has been discontinued.

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2.1.1

11 Apr 19:19
@vitaut vitaut
2.1.1
ed5a862
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2.1.1
  • The install location for generated CMake files is now configurable via the FMT_CMAKE_DIR CMake variable (#299). Thanks to @niosHD.
  • Documentation fixes (#252).
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2.1.0

21 Mar 15:00
@vitaut vitaut
2.1.0
ab77225
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2.1.0

  • Project layout and build system improvements (#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 to @niosHD.

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