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Releases: fmtlib/fmt

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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2.0.1

13 Mar 17:20
@vitaut vitaut
2.0.1
8c16747

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2.0.0

01 Dec 15:36
@vitaut vitaut
2.0.0
5f8af5e

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2.0.0

General

  • [Breaking] Named arguments (#169, #173, #174):

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

    Thanks to @jamboree.

  • [Experimental] User-defined literals for format and named arguments (#204, #206, #207):

    using namespace fmt::literals;
fmt::print("The answer is {answer}.", "answer"_a=42);

    Thanks to @dean0x7d (Dean Moldovan).

  • [Breaking] Formatting of more than 16 arguments is now supported when using variadic templates (#141). Thanks to @Shauren.

  • Runtime width specification (#168):

    fmt::format("{0:{1}}", 42, 5); // gives "   42"

    Thanks to @jamboree.

  • [Breaking] Enums are now formatted with an overloaded std::ostream insertion operator (operator<<) if available (#232).

  • [Breaking] Changed default bool format to textual, "true" or "false" (#170):

    fmt::print("{}", true); // prints "true"

    To print bool as a number use numeric format specifier such as d:

    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" (#223):

    fmt::printf("%s", true); // prints "true"

    Thanks to @LarsGullik.

  • [Breaking] signed char and unsigned char are now formatted as integers by default (#217).

  • [Breaking] Pointers to C strings can now be formatted with the p specifier (#223):

    fmt::print("{:p}", "test"); // prints pointer value

    Thanks to @LarsGullik.

  • [Breaking] fmt::printf and fmt::sprintf now print null pointers as (nil) and null strings as (null) for consistency with glibc (#226). Thanks to @LarsGullik.

  • [Breaking] fmt::(s)printf now supports formatting of objects of user-defined types that provide an overloaded std::ostream insertion operator (operator<<) (#201):

    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 (#140). Thanks to @polyvertex (Jean-Charles Lefebvre).

  • [Breaking] Improved compatibility between BasicStringRef and std::experimental::basic_string_view (#100, #159, #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 (#185).

  • New CMake options FMT_DOC, FMT_INSTALL and FMT_TEST to control generation of doc, install and test targets respectively, on by default (#197, #198, #200). Thanks to @maddinat0r (Alex Martin).

  • noexcept is now used when compiling with MSVC2015 (#215). Thanks to @dmkrepo (Dmitriy).

  • Added an option to disable use of windows.h when FMT_USE_WINDOWS_H is defined as 0 before including format.h (#171). Thanks to @alfps (Alf P. Steinbach).

  • [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 (#152, #153, #154). Thanks to @DevO2012.

  • Improved support for custom character types (#171). Thanks to @alfps (Alf P. Steinbach).

  • Added an option to disable use of IOStreams when FMT_USE_IOSTREAMS is defined as 0 before including format.h (#205, #208). Thanks to @JodiTheTigger.

  • Improved detection of isnan, isinf and signbit.

Optimization

  • Made formatting of user-defined types more efficient with a custom stream buffer (#92, #230). Thanks to @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 (#186).
  • [Breaking] Reduced compiled code size (#143, #149).

Distribution

Documentation

Fixes

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