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Releases: fmtlib/fmt

2.0.1

13 Mar 17:20
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2.0.0

01 Dec 15:36
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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

1.1.0

06 Mar 16:33
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  • Added BasicArrayWriter, a class template that provides operations for formatting and writing data into a fixed-size array (#105 and #122):
char buffer[100];
fmt::ArrayWriter w(buffer);
w.write("The answer is {}", 42);

You can now install C++ Format with make install command.

The android-ndk-example repository provides and example of using C++ Format with Android NDK:

image

  • Improved documentation of SystemError and WindowsError (#54).
  • Various code improvements (#110, #111 #112). Thanks to @CarterLi.
  • Improved compile-time errors when formatting wide into narrow strings (#117).
  • Fixed BasicWriter::write without formatting arguments when C++11 support is disabled (#109).
  • Fixed header-only build on OS X with GCC 4.9 (#124).
  • Fixed packaging issues (#94).
  • Fixed warnings in GCC, MSVC and Xcode/Clang (#95, #96 and #114).
  • Added changelog (#103).

1.0.0

05 Feb 16:45
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  • Add support for a header-only configuration when FMT_HEADER_ONLY is defined before including format.h:

    #define FMT_HEADER_ONLY
    #include "format.h"
    
  • Compute string length in the constructor of BasicStringRef instead of the size method (#79). This eliminates size computation for string literals on reasonable optimizing compilers.

  • Fix formatting of types with overloaded operator << for std::wostream (#86):

    fmt::format(L"The date is {0}", Date(2012, 12, 9));
    
  • Fix linkage of tests on Arch Linux (#89).

  • Allow precision specifier for non-float arguments (#90):

    fmt::print("{:.3}\n", "Carpet"); // prints "Car"
    
  • Fix build on Android NDK (#93)

  • Improvements to documentation build procedure.

  • Remove FMT_SHARED CMake variable in favor of standard BUILD_SHARED_LIBS.

  • Fix error handling in fmt::fprintf.

  • Fix a number of warnings.

0.12.0

27 Oct 15:36
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  • [Breaking] Improved separation between formatting and buffer management. Writer is now a base class that cannot be instantiated directly. The new MemoryWriter class implements the default buffer management with small allocations done on stack. So fmt::Writer should be replaced with fmt::MemoryWriter in variable declarations.
    Old code:

    fmt::Writer w;
    

    New code:

    fmt::MemoryWriter w;
    

    If you pass fmt::Writer by reference, you can continue to do so:

    void f(fmt::Writer &w);
    

    This doesn't affect the formatting API.

  • Support for custom memory allocators (#69)

  • Formatting functions now accept signed char and unsigned char strings as arguments (#73):

    auto s = format("GLSL version: {}", glGetString(GL_VERSION)); 
    
  • Reduced code bloat. According to the new benchmark results, cppformat is close to printf and by the order of magnitude better than Boost Format in terms of compiled code size.

  • Improved appearance of the documentation on mobile by using the Sphinx Bootstrap theme:

Old New
screenshot_2014-10-20-09-00-17 screenshot_2014-10-20-09-01-12

0.11.0

21 Aug 16:03
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  • Safe printf implementation with a POSIX extension for positional arguments:

    fmt::printf("Elapsed time: %.2f seconds", 1.23);
    fmt::printf("%1$s, %3$d %2$s", weekday, month, day);
    
  • Arguments of char type can now be formatted as integers (#55):

    fmt::format("0x{0:02X}", 'a');
    
  • Deprecated parts of the API removed.

  • The library is now built and tested on MinGW with Appveyor in addition to existing test platforms Linux/GCC, OS X/Clang, Windows/MSVC.

0.10.0

01 Jul 14:23
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Improved API

  • All formatting methods are now implemented as variadic functions instead of using operator<< for feeding arbitrary arguments into a temporary formatter object. This works both with C++11 where variadic templates are used and with older standards where variadic functions are emulated by providing lightweight wrapper functions defined with the FMT_VARIADIC macro. You can use this macro for defining your own portable variadic functions:

    void report_error(const char *format, const fmt::ArgList &args) {
      fmt::print("Error: {}");
      fmt::print(format, args);
    }
    FMT_VARIADIC(void, report_error, const char *)
    
    report_error("file not found: {}", path);

    Apart from a more natural syntax, this also improves performance as there is no need to construct temporary formatter objects and control arguments' lifetimes. Because the wrapper functions are very ligthweight, this doesn't cause code bloat even in pre-C++11 mode.

  • Simplified common case of formatting an std::string. Now it requires a single function call:

    std::string s = format("The answer is {}.", 42);

    Previously it required 2 function calls:

    std::string s = str(Format("The answer is {}.") << 42);

    Instead of unsafe c_str function, fmt::Writer should be used directly to bypass creation of std::string:

    fmt::Writer w;
    w.write("The answer is {}.", 42);
    w.c_str();  // returns a C string

    This doesn't do dynamic memory allocation for small strings and is less error prone as the lifetime of the string is the same as for std::string::c_str which is well understood (hopefully).

  • Improved consistency in naming functions that are a part of the public API. Now all public functions are lowercase following the standard library conventions. Previously it was a combination of lowercase and CapitalizedWords. Issue #50.

  • Old functions are marked as deprecated and will be removed in the next release.

Other Changes

  • Experimental support for printf format specifications (work in progress):

    fmt::printf("The answer is %d.", 42);
    std::string s = fmt::sprintf("Look, a %s!", "string");
  • Support for hexadecimal floating point format specifiers a and A:

    print("{:a}", -42.0); // Prints -0x1.5p+5
    print("{:A}", -42.0); // Prints -0X1.5P+5
  • CMake option FMT_SHARED that specifies whether to build format as a shared library (off by default).

0.9.0

13 May 16:30
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  • More efficient implementation of variadic formatting functions.

  • Writer::Format now has a variadic overload:

    Writer out;
    out.Format("Look, I'm {}!", "variadic");
    
  • For efficiency and consistency with other overloads, variadic overload of the Format function now returns Writer instead of std::string. Use the str function to convert it to std::string:

    std::string s = str(Format("Look, I'm {}!", "variadic"));
    
  • Replaced formatter actions with output sinks: NoAction -> NullSink, Write -> FileSink, ColorWriter -> ANSITerminalSink. This improves naming consistency and shouldn't affect client code unless these classes are used directly which should be rarely needed.

  • Added ThrowSystemError function that formats a message and throws SystemError containing the formatted message and system-specific error description. For example, the following code

    FILE *f = fopen(filename, "r");
    if (!f)
        ThrowSystemError(errno, "Failed to open file '{}'") << filename;
    

    will throw SystemError exception with description "Failed to open file '<filename>': No such file or directory" if file doesn't exist.

  • Support for AppVeyor continuous integration platform.

  • Format now throws SystemError in case of I/O errors.

  • Improve test infrastructure. Print functions are now tested by redirecting the output to a pipe.

0.8.0

07 Feb 15:13
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Initial release