Boost C++ Libraries of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Version 1.82.0

Version 1.82.0 beta 1

March 15th, 2023 15:05 GMT


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Notice of Dropping C++03 Support

The following libraries will be dropping C++03 support in release 1.84, two releases from now:

  • Align
  • Any
  • Bind
  • Chrono
  • ContainerHash
  • Conversion
  • DLL
  • Endian
  • Function
  • Functional
  • Io
  • LexicalCast
  • Random
  • Ratio
  • SmartPtr
  • System
  • Stacktrace
  • Thread
  • Timer
  • TypeIndex
  • Typeof
  • Unordered
  • Variant

This release (1.82) and the next (1.83) will be the last releases offering C++03 support for the above libraries and most of their dependencies.

The new baseline requirement for the above libraries, and for most of Boost, will be C++11. Since old compiler versions often implement C++11 only partially, due to missing support or bugs, what compilers are considered to meet the C++11 requirement may vary by library.

However, a general rule is that if a compiler does not recognize a C++11 keyword or syntax at all (e.g. use of noexcept, use of constexpr, or defining a =deleted function results in an immediate compile error), or if a compiler does not provide a required C++11 header at all (e.g. trying to include <atomic> or <chrono> fails), or the compiler provides a C++11 feature or a header that is completely unusable, this compiler is not considered a C++11 compiler.

This rules out, for instance, Microsoft Visual C++ before 14.0, or GCC before 4.8.

New Libraries

  • Mysql: a C++11 client for the MySQL database server, based on Boost.Asio, from Reuben Perez.

Updated Libraries

  • Any:
    • Now uses core/enable_if instead of the deprecated utility/enable_if. Thanks to Michael Ford for the PR PR#25.
  • ContainerHash:
    • Added an overload of hash_value for std::nullptr_t.
    • Added is_tuple_like and an overload of hash_value for tuple-like types.
    • Changed string hashing to use mulxp1_hash. This improves both quality and speed.
  • DLL:
    • Avoid implicit cast from size_t to uint32_t, thanks to Travers Biddle for the PR PR#57.
  • Math:
    • Deprecated C++11 support: We now require C++14 as a minimum standard. Our minimum tested compiler versions are now Clang-5, GCC-5 or MSVC-14.1.
    • Added Estrin's method for polynomial evaluation.
    • Fix various issues in non-central distributions to allow for larger non-centralities see 939.
    • Added CMake install target.
    • Fix special_functions.hpp to disable anything which can't be used in an exception-free environment.
    • Get condition number calculation working in C++14.
    • Fix constexpr table driven functions to avoid massive slowdown when the code is not actually constexpr, see 923.
    • Improve tanh_sinh boundary handling, see 894.
    • Add Linux arm64, s390x and Apple M1 testing, fix up test cases to handle 128-bit long doubles.
    • Improve constexpr math functions to better handle infinities and NaN's.
    • Make the integrators const-correct.
    • Fix tanh_sinh integrator in case the function underflows, see 898.
    • Don't use std::cbrt as some platforms still don't support it.
    • Stop non-central T from raising spurious FE_INVALID exceptions, see 892.
    • Fix binomial distribution edge case.
    • Improve ibeta handling of very small arguments, see 884.
    • Improve ibeta handling of infinities and NaN's, see 878.
    • Improve error handling in powm1, see 781.
    • Improve root-finder bracketing to bracket faster when the exponent is super-large or small.
    • Fix root finding edge cases, see 873.
    • Lots of miscellaneous warning fixes.
    • Add assertions when using features which require C++17 for better error messages when invoking the compiler in a lower std version.
  • Multi-index Containers:
    • Serialization now uses unsigned long instead of collection_size_type, and multi_index_container serialization class version has been bumped from 2 to 3 to reflect this change. Reading old archives may fail for custom archive types giving special treatment to collection_size_type values: if this is the case, globally define the macro BOOST_MULTI_INDEX_ENABLE_SERIALIZATION_COMPATIBILITY_V2 to ensure backwards compatibility in reading operations.
    • Maintenance work.
  • Multiprecision:
    • Deprecated C++11 support: We now require C++14 as a minimum standard. Our minimum tested compiler versions are now Clang-5, GCC-5 or MSVC-14.1.
    • Added a new forward declaration header.
    • Update Eigen interoperability so we no longer rely on Eigen's details, see 479.
    • Add Cmake install target.
    • Fix cpp_dec_float construction from string in standalone case for better error handling, see 499.
    • Remove redundent definitions when in C++17 mode, see 530.
    • Fix the error handling in standalone itrunc and ltrunc.
    • Fix potentially uninitialized storage when parsing octal strings.
    • Add arm64 and s390x CI testing.
    • Add some missing expression template unpacking code for powm, see 506.
  • PFR:
    • Implemented the boost::pfr::is_implicitly_reflectable and the machinery for specializing aggregates as reflectable or not, thanks to Denis Mikhailov for the PR PR#111.
    • Implemented the BOOST_PFR_ENABLED to macro to detect library support, thanks to Denis Mikhailov for the PR PR#86.
    • Fixed missing terminating character, thanks to Denis Mikhailov for the PR PR#114.
    • Fixed for the boost/pfr/config.hpp on older compilers, thanks to Denis Mikhailov for the PR PR#118.
    • Workaround for broken C++17 stuctured binding in old compilers, thanks to Denis Mikhailov for the PR PR#119.
    • Avoid -Wzero-as-null-pointer-constant warnings, thanks to Markus F.X.J. Oberhumer for the PR PR#117.
    • Fixed multiple typos, thanks to Denis Mikhailov for the fixes.
    • Added missing #pragma once, thanks to caozhanhao for the PR PR#121.
    • Implemented boost::pfr::get by type of an element in the aggregate.
    • Multiple fixes and improvements for the docs.
  • StaticString:
    • Boost.Core string_view and std::string_view interoperability
  • Test:
    • Fixed several unused variable warnings
    • Fixed sprintf deprecation warnings
    • Fixed undefined behavior in basic_cstring::rfind
    • Added CI through Github Actions
  • Unordered:
    • Major update.
    • Added node-based, open-addressing containers boost::unordered_node_map and boost::unordered_node_set.
    • Extended heterogeneous lookup to more member functions as specified in P2363.
    • Replaced the previous post-mixing process for open-addressing containers with a new algorithm based on extended multiplication by a constant.
    • Fixed bug in internal emplace impl where stack-local types were not properly constructed using the allocator of the container which breaks uses-allocator construction.
  • URL:
    • Add url::format with automatic percent-encoding
    • URL router example
    • set_params convenience function
    • Support implicit conversions to string_view
    • Parsing constructors are implicit
    • string_token::arg has virtual destructor and slice protection
    • Improvements and Bug fixes:
      • WIN32_LEAN_AND_MEAN macro redefinition warning
      • Comparison differentiates absent and empty components
      • Detect hier_part_rule with empty-port-like segments
      • Segments comparison as if normalized works above root
      • hier-part path-rootless considers invalid segments
      • port as number is set to 0 when it overflows
      • ipv4 to string overflow detection algorithm
  • Variant:
    • Now uses core/enable_if instead of the deprecated utility/enable_if. Thanks to Michael Ford for the PR PR#105.

Updated Tools

Compilers Tested

Boost's primary test compilers are:

  • Linux:
    • Clang, C++03: 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 12.0.0, 13.0.0, 14.0.0, 15.0.0
    • Clang, C++11: 3.4, 11.0.0, 13.0.0, 14.0.0, 15.0.0
    • Clang, C++14: 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 5.0, 12.0.0, 13.0.0, 14.0.0, 15.0.0
    • Clang, C++17: 6.0.1, 7.0.0, 8.0.0, 9.0.0, 10.0.0, 11.0.0, 12.0.0, 13.0.0, 14.0.0, 15.0.0
    • Clang, C++20: 11.0.0, 12.0.0, 13.0.0, 14.0.0, 15.0.0
    • GCC, C++03: 4.6.3, 11, 12
    • GCC, C++11: 4.7.3, 4.8.5, 11, 12
    • GCC, C++14: 5.4.0, 6.4.0, 7.3.0, 8.0.1, 9.1.0, 11, 12
    • GCC, C++17: 7.3.0, 8.0.1, 9.1.0, 11, 12
    • GCC, C++20: 8.0.1, 9.1.0, 10, 11, 12
  • OS X:
    • Apple Clang, C++03: 11.0.3
    • Apple Clang, C++11: 11.0.3
    • Apple Clang, C++14: 11.0.3
    • Apple Clang, C++17: 11.0.3
    • Apple Clang, C++20: 11.0.3
  • Windows:
    • Visual C++: 10.0, 11.0, 12.0, 14.0, 14.1, 14.2, 14.3


Marshall Clow and Glen Fernandes managed this release.