Known Issues

These are patches from library authors which were found too late to be fixed in the release. Be careful as they have not been through the normal testing process.

• Fix moved-from executor in idle ping timeout (#1599)

  • Beast patch

New Libraries

• Outcome: A set of tools for reporting and handling function failures in contexts where directly using C++ exception handling is unsuitable, from Niall Douglas.
• Histogram: Fast and extensible multi-dimensional histograms with convenient interface for C++14, from Hans Dembinski.

Updated Libraries

• Asio:

  • This release includes a number of new features, bug fixes, performance enhancements, and documentation improvements. Notable changes include:

    • Added the ability to use custom I/O executors with I/O objects (such as sockets).
    • Added a new async_result form with an initiate static member function.
    • Updated the Coroutines TS support and promoted it to the asio namespace.
    • Added a new DynamicBuffer_v2 concept which is CopyConstructible.
    • Added a new async_compose function that simplifies the implementation of user-defined asynchronous operations.
    • Added a make_strand helper function.
    • Relaxed the completion condition type requirements to only require move-constructibility rather than copy-constructibility.
    • Added a constructor for local::basic_endpoint that takes a string_view.
    • Added the noexcept qualifier to various functions.
    • Added a new BOOST_ASIO_DISABLE_VISIBILITY configuration #define.
    • Enabled recycling of the memory used to type-erase a function object with the polymorphic executor.
    • Changed receive operations to return the correct number of bytes transferred when truncation (error::message_size) occurs on a datagram-oriented socket.
    • Fixed calculation of absolute timeout when the backend uses pthread_cond_timedwait.
    • Changed the range-based asynchronous connect operation to deduce the EndpointSequence iterator type.
    • Fixed buffer_sequence_begin and buffer_sequence_end to prevent implicit conversion.
    • Ensured SSL handshake errors are propagated to the peer before the local operation completes.
    • Suppressed the eof error on SSL shutdown as it actually indicates success.
    • Added a fallback error code for when we OpenSSL produces an SSL_ERROR_SYSCALL result without an associated error.
    • Changed composed asynchronous read and write operations to move buffer sequence objects.
    • Fixed a macOS-specific warning about the deprecation of OSMemoryBarrier.
    • Fixed compile errors that occur when using the composed read and write operations with MSVC 11.0.
    • Improved dispatch, post and defer documentation.
    • Fixed a Windows-specific memory leak that may occur when system_executor is used.
  • Consult the Revision History for further details.
• Beast: BIG Update!!!

  • Some APIs have changed.
  • The reference shows a star ★ next to each new item.
  • Beast needs your help!

    • Tell Us how you or your company use Beast
    • Please report any bugs, feature requests, or general feedback
    • Join the C++ Slack Workspace for free and chat with us in the #beast and #boost channels
    • Don't forget to star the repository ⭐!
  • More tutorials, code like the pros!

    • Networking Refresher teaches you from the ground up.
    • Updated Asynchronous Echo example
    • Updated Detect SSL composed operation tutorial
    • websocket-chat-multi threaded chat server with a JavaScript browser client
  • basic_stream and tcp_stream offer:

    • Timeouts: async_read_some, async_write_some complete with error::timeout on expiration!
    • Traffic-shaping policies simple and unlimited, or a user-defined RatePolicy!
    • Put the strand directly on the socket using P1322R0, no more bind_executor at call sites!
  • Base classes async_base and stable_async_base and handle all composed operation boilerplate for you.
  • ssl_stream provides a movable, assignable SSL stream with a flat write optimization.
  • All asynchronous operations use Asio's async_initiate for efficient integration with Coroutines TS.
  • ⚡ faster compilation, define BOOST_BEAST_SEPARATE_COMPILATION and #include <boost/beast/src.hpp> in one of your .cpp files!
  • See the full Release Notes for a complete list of changes.
• Context:

  • #91: cleanup of stack if creating ucontext fails
  • #97: add missing BOST_CONTEXT_DECL in stack_context
  • #98: fix jump_i386_sysv_macho writing garbage to the x87 control word
• Coroutine2:

  • #28: don't crash on pthread_cancel
• DLL:

  • New macro BOOST_DLL_USE_STD_FS. Define it to 1 to make the Boost.DLL use C++17's std::filesystem::path, std::system_error and std::error_code (#21). Note that exception types change from boost::system::system_error to std::system_error, so make sure to update catches.
  • Significant rewrite of the dynamic loadable detection and decoration logic. More precise errors are now reported in case of loading failures. Added shared_library::decorate() function that returns a decorated path to the library without doing any platform related queries and detections. Prefer using shared_library::load and shared_library constructors for better results (many thanks to Loïc Touraine for the work PR#23).
  • CI hardening, docs updates, typos fixes, cleanups and many portability fixes.
• Dynamic Bitset:

  • Disabled hardware-assisted popcount (added in 1.69.0) on MSVC due to undefined behavior on older CPUs. (#33 PR#35)
• Fiber:

  • #191: ignore unused argument warning
  • #196: fix high contention on remote_ready_splk_
• Filesystem:

  • Fixed a few instances of dereferencing std::string::end() in path implementation.
  • Fixed program termination in case of out of memory condition in directory iterators constructors and operations accepting a reference to error_code. (#58)
  • Fixed possible linking errors caused by missing definitions of static members of path. (#12759)
  • Fixed possible use of uninitialized data in directory iterator increment operation on Linux.
  • Added support for movability to directory iterators.
  • Added file status query overloads for directory_entry. This avoids a relatively expensive OS query when file status is requested for a result of dereferencing a directory iterator. (PR#55)
  • Reworked current_path and read_symlink implementation to avoid possible memory exhaustion on broken or tampered with filesystems. The functions now have an internal limit of the path size they will accept from the OS, which is currently 16 MiB.
  • Increased the size of the internal buffer used by copy_file.
• Integer:

  • Added Extended Euclidean Algorithm and Modular Multiplicative Inverse function. (Nick Thompson, PR#11)
• Log:

  • New features:

    • Added support for generating another log file name before collecting the file in the text file sink backend. This allows to combine appending to an existing log file with timestamps and file counters in log filenames, and, consequently, file collection in general.
  • See changelog for more details.
• Math:

  • New features:

    • Add Lanczos smoothing derivatives
    • Move numerical_differentiation.hpp from boost/math/tools/ to boost/math/differentiation/finite_difference.hpp.
    • Add mean, variance, skewness, kurtosis, median, Gini coefficient, and median absolute deviation to tools/univariate_statistics.hpp.
    • Add correlation coefficients and covariance to tools/bivariate_statistics.hpp
    • Add absolute Gini coefficient, Hoyer sparsity, oracle SNR, and the M[sub 2]M[sub 4] SNR estimator to tools/signal_statistics.hpp.
    • Add total variation, l0, l1, l2, and sup norms, as well as corresponding distance functions to tools/norms.hpp.
    • Add move constructors for polynomials, support complex coefficients, add .prime() and .integrate() methods.
    • Add quadratic_roots to tools/roots.hpp.
    • Add support for complex-valued functions to Newton's method in roots.hpp.
    • Add Catmull-Rom interpolator.
• Mp11:

  • Renamed mp_invoke to mp_invoke_q
  • Added mp_similar
  • Added mp_set_union, mp_set_intersection, mp_set_difference
  • Added mp_not_fn
  • Added mp_transform_first, mp_transform_second, mp_transform_third
  • Added mp_filter
  • Added mp_eval_if_not, mp_eval_or, mp_valid_q
  • Added mp_back, mp_pop_back
• Multi-index Containers:

  • size_type and difference_type are now defined as the allocator's same-named types. This will not make any difference in the vast majority of cases, but allows for some degree of control of resulting internal structures via user-defined allocator types (see issue #17 for motivation). For the moment being, this change is not documented in the reference section (i.e., it has semi-official status).
  • Maintenance work.
• Multiprecision:

  • Fix various conversion issues in the traits classes, check for compatibility with Boost.Optional.
  • Prevent instantiation of std::numeric_limits on any old type when checking for convertibility. See #98.
  • Update variable precision code to account for arbitrary precision integers. See #103.
  • Add support for XML serialization archives.
  • Fix bug in fixed precision iostream formatting in mpf_float and mpfr_float. See #113.
  • Add more overloads for special functions which are better handled natively by MPFR.
  • Fixed bug in generic exp implementation which could cause invariant failure.
  • Fixed generic conversion from float to integer to avoid undefined behaviour. See #110.
• PolyCollection:

  • Improved handling of stateful allocators and allocator propagation traits, after an error reported by Billy O'Neal (PR#9).
  • Fixed a potentially serious bug with an internal cache structure.
• Spirit:

  • Removed use of deprecated boost/detail/iterator.hpp header. PR#432
  • X3

    • Integer parsers should now handle user defined types. PR#429
    • Note: The check_overflow trait default implementation now relies on std::numeric_limits<T>::is_bounded instead of boost::integer_traits<T>::is_integral.
    • Removed sequence into plain parsing. Now it triggers a compile time error instead of silently parsing the the sequence and taking the last value as a result. PR#439
    • Fixed parse_rule instantiation with BOOST_SPIRIT_INSTANTIATE when:

      • A rule has no attribute. PR#455
      • An actual attribute is not of type a rule was declared with. PR#456 #457
    • A huge thanks goes out to Xeverous for reporting a regression in #453.
    • Fixed unneded attribute synthesization and no-transformation attribute reference pass-through in rules. #444 PR#449 PR#452
    • Removed broken 1.0#INF parser. It was poorly documented and never worked. #415 PR#458 #8699
    • The undocumented make_attribute trait was removed due to bugs PR#449 and to simplify attribute transformation. PR#460
    • If you were using it to workaround bugs in attribute transformation - they should not be needed anymore as of this release.
    • The integer value parser now respects std::numeric_limits<T>::digits10 value. PR#469
    • Fixed underflow check for a (Min % Base) == 0 corner case. PR#469
    • Fixed an output value on overflow of IgnoreOverflowDigits=true integer parser. PR#470
    • Container attribute elements were copyied, but not moved. PR#472
    • Special handling of references in transform_attribute was removed. PR#480
  • V2

    • Macro name collisions and namespace conflicts with Boost.Endian were fixed. PR#349 PR#482
    • utree

      • Fixed UB in tag getter due to left shift of negative value. PR#423
      • Fixed double-conversion (spirit::string -> std::string -> spirit::string). PR#462
    • Qi

      • Added static asserts for rule skipper type problems. PR#427
      • The check_overflow trait default implementation now relies on std::numeric_limits<T>::is_bounded instead of boost::integer_traits<T>::is_integral PR#429
      • Integer parsers should now handle user defined types. PR#429
      • Note: The check_overflow trait default implementation now relies on std::numeric_limits<T>::is_bounded instead of boost::integer_traits<T>::is_integral.
      • Removed broken 1.0#INF parser. It was poorly documented and never worked. #415 PR#458 #8699
      • The undocumented make_attribute trait was merged into transform_attribute trait. PR#471
      • The pre_transform, post_transform, and fail_transform utility functions were removed in favor of directly using pre/post/fail of the transform trait. PR#467
      • The integer value parser now respects std::numeric_limits<T>::digits10 value. PR#469
      • Fixed underflow check for a (Min % Base) == 0 corner case. PR#469
      • Fixed an output value on overflow of IgnoreOverflowDigits=true integer parser. PR#470
      • Special handling of references in transform_attribute was removed. PR#480
    • Lex

      • Fixed UB in default constructor of lexer with user specified token type. PR#420
  • Classic:

    • Fixed position_iterator forming reference to local when the underlying iterator dereference operator returns a non-reference type. PR#422 #9737
• Stacktrace:

  • Build fix for iOS 32-bit ARM (many thanks to Ivan Ponomarev for providing the fix PR#70)
  • Fixed multiple typos, warnings and updated the docs.
• Test:

  • Boost.test v3.10 see the Changes log for more details.
  • Breaking changes:

    • Boost.Test minimal.hpp is now showing a deprecation warning,
    • Change in floating point comparison may fail tests that were silently not using the floating point comparison logic prior to this release,
    • Internal API change to unit_test_log_formatter, see detailed change log,
  • New feature:

    • Floating point comparison has been extended to capture non-floating point and arithmetic operands: expressions like BOOST_TEST(3.0001 == 3) now use floating point support of Boost.Test,
    • Custom datasets are not required to declare the sample type field anymore,
    • Extending template test cases from std::tuple to any variadic definition,
    • Windows support for timed tests,
    • Timed test on test-suites,
    • Removed dependency to Boost.Timer,
    • New macro BOOST_TEST_INFO_SCOPE for scoped context declaration,
    • Improved BOOST_TEST_CONTEXT syntax
  • Bug fixes and pull requests:

    • Trac tickets: #7397, #9434, #13106, #13418
    • GitHub Issues: #133, #138, #141, #157, #160, #174, #176, #177, #180, #181, #194, #196, #198, #199, #202, #203, #204
    • GitHub Pull Requests: PR#171, PR#172, PR#182, PR#183, PR#184, PR#190, PR#195, PR#195, PR#197, PR#205
• TypeIndex:

  • Support for the GHS C++ compiler added (many thanks to Brandon Castellano for providing the patch PR#28)
  • Optimized string and type comparisons (many thanks to Andrey Semashev for providing the patch PR#23)
  • Fixed clang-win compilation (many thanks to Peter Dimov for providing the patch PR#25)
  • CI hardening.
• TypeTraits:

  • Added is_bounded_array and is_unbounded_array (Glen Fernandes).
  • Added copy_reference and copy_cv_ref (Glen Fernandes).
  • Improved support for msvc with /clr option.
  • Misc compiler compatibility fixes.
• Variant:

  • Many cleanups and internal improvements, many thanks to Nikita Kniazev (PR#55, PR#56, PR#57) and Louis Dionne (PR#51)
  • CI hardening.
• uBlas:

  • Addition of tensor framework (many thanks to Cem Bassoy PR#65)
  • Addition of basic OpenCL support (many thanks to Fady Essam PR#59)
  • Integration of basic benchmark suite (many thanks to Stefan Seefeld PR#57)
  • CI integration and hardening

Compilers Tested

Boost's primary test compilers are:

• Linux:

  • Clang: 3.0, 4.0.1, 6.0.1
  • Clang, C++0x: 3.0
  • Clang, C++11: 3.0, 3.1, 3.2, 3.3, 3.4, 4.0.1, 6.0.1, 7.0.0, 8.0.0
  • Clang, C++14: 3.5.0, 3.6.0, 3.7.1, 3.8.0, 3.9.1, 4.0.0, 4.0.1, 5.0.2, 6.0.1, 7.0.0, 8.0.0
  • Clang, C++17: 5.0.2, 6.0.1, 7.0.0, 8.0.0
  • GCC: 4.4.7, 4.5.3, 4.6.3, 5.4.0, 8.0.1
  • GCC, C++0x: 4.4.7
  • GCC, C++11: 4.7.3, 4.8.5, 4.9.4, 5.4.0, 6.4.0, 7.1.0, 8.0.1
  • GCC, C++14: 5.4.0, 5.5.0, 6.4.0, 7.1.0, 7.3.0, 8.0.1
  • GCC, C++17: 7.3.0, 8.0.1
  • Intel, C++14: 18.0
• OS X:

  • Apple Clang: 9.0.0, 9.1.0, 10.0.0
  • Apple Clang, C++11: 9.0.0, 9.1.0, 10.0.0
  • Apple Clang, C++14: 9.0.0, 9.1.0, 10.0.0
  • Apple Clang, C++17: 9.1.0, 10.0.0
  • Apple Clang, C++1z: 9.0.0
  • Apple Clang, C++2a: 10.0.0
• Windows:

  • GCC: 3.4.5, 4.1.2, 4.2.4, 4.3.3, 4.4.0, 4.5.4
  • GCC, C++0x: 4.6.4
  • GCC, C++11: 4.7.3, 4.8.1, 4.9.3
  • GCC, C++14: 5.1.0, 5.2.0, 5.3.0, 6.1.0, 6.2.0, 6.3.0, 6.4.0
  • GCC, C++17: 7.1.0, 7.2.0, 7.3.0
  • Visual C++: 7.1, 8.0, 9.0, 10.0, 11.0, 12.0, 14.0, 14.1
• FreeBSD:

  • Clang: 4.0.0
  • Clang, C++11: 4.0.0
  • Clang, C++14: 4.0.0
  • Clang, C++1z: 4.0.0

Boost's additional test compilers include:

• Linux:

  • Clang: 3.0, 3.8.1, 3.9.1, 4.0.1, 5.0.2, 6.0.1
  • Clang, C++0x: 3.0
  • Clang, C++11: 3.0, 3.1, 3.2, 3.3, 3.4, 4.0.1, 6.0.1, 7.0.0, 8.0.0
  • Clang, C++14: 3.5.0, 3.6.0, 3.7.1, 3.8.0, 3.9.1, 4.0.0, 4.0.1, 5.0.2, 6.0.1, 7.0.0, 8.0.0
  • Clang, C++17: 5.0.2, 6.0.1, 7.0.0, 8.0.0
  • GCC: 4.4.7, 4.5.3, 4.6.3, 4.9.4, 5.4.0, 5.5.0, 8.0.1
  • GCC, C++0x: 4.4.7
  • GCC, C++11: 4.7.3, 4.8.5, 4.9.4, 5.4.0, 6.4.0, 7.1.0, 8.0.1
  • GCC, C++14: 5.4.0, 5.5.0, 6.3.0, 6.4.0, 7.1.0, 7.3.0, 8.0.1, 8.1.0
  • GCC, C++17: 7.3.0, 8.0.1
  • Intel, C++14: 18.0
• OS X:

  • Apple Clang: 9.0.0, 9.1.0, 10.0.0
  • Apple Clang, C++11: 9.0.0, 9.1.0, 10.0.0
  • Apple Clang, C++14: 9.0.0, 9.1.0, 10.0.0
  • Apple Clang, C++17: 9.1.0, 10.0.0
  • Apple Clang, C++1z: 9.0.0
  • Apple Clang, C++2a: 10.0.0
• Windows:

  • GCC: 3.4.5, 4.1.2, 4.2.4, 4.3.3, 4.4.0, 4.5.4
  • GCC, C++0x: 4.6.4
  • GCC, C++11: 4.7.3, 4.8.1, 4.9.3
  • GCC, C++14: 5.1.0, 5.2.0, 5.3.0, 6.1.0, 6.2.0, 6.3.0, 6.4.0
  • GCC, C++17: 7.1.0, 7.2.0, 7.3.0
  • Visual C++: 7.1, 8.0, 9.0, 10.0, 11.0, 12.0, 14.0, 14.1
• FreeBSD:

  • Clang: 4.0.0
  • Clang, C++11: 4.0.0
  • Clang, C++14: 4.0.0
  • Clang, C++1z: 4.0.0

Acknowledgements

Daniel James, Vladimir Prus, Marshall Clow and Michael Caisse managed this release.