Boost C++ Libraries

New Libraries Variant2: A never-valueless, strong guarantee implementation of std::variant, from Peter Dimov. Updated Libraries ... [More] Align: Support for any integral type in the integral versions of align_up and align_down. Revised the implementation of aligned_allocator to no longer require a specialization for void. Define propagate_on_container_move_assignment and is_always_equal in aligned_allocator. Asio: Improved performance slightly by eliminating a redundant move construction when completed handlers are dispatched. Eliminated a compiler warning by annotating a case fall-through in the free function connect() implementation. Fixed the is_*_buffer_sequence detection traits for user-defined sequence types. Fixed some Windows-specific warnings about an incompatible pointer cast when obtaining the CancelIoEx entry point. Changed to automatically set the defaults when opening a serial port on Windows. Changed the serial port get_option() member function to be const. Fixed a name hiding issue with the WinRT stream-oriented socket backend's shutdown function. Applied a minor fix to the documentation for is_dynamic_buffer. Added some support for Haiku OS. Added wolfSSL compatability. Changed to require C++17 or later for coroutines TS support with clang. Fixed a doxygen generation problem in the tutorial. Ensured example programs are correctly incorporated into the documentation. Any: Static initialization of the default constructed boost::any is now possible. Fixed performance regression in assignment on a compilers without move-semantics. Maintenance work. Beast: This version consists mostly of bug fixes and performance improvements. Substantial work included for the split compilation mode, to reduce compile time when defining BOOST_BEAST_SEPARATE_COMPILATION. We'd love to know how you or your company use Beast, consider adding an item to the Companies and Individuals Using Beast list. See the full Release Notes for a complete list of changes. Circular Buffer: Correct doxygen generated reference to no longer show internal members. (Glen Fernandes) Eliminate ubsan warning on add and sub. (Glen Fernandes) Fix incorrect check in is_uninitialized. (Niklas Fejes) Container: Fixed bugs: GitHub #47: "added alignment specification for small_vector". GitHub #88: "Implement C++17 MoveAssignable requirements for self-move assignments". GitHub #107: "Alignment ignored in resource_adaptor". GitHub #109: "Get rid of integer overflow in copy_move_algo.hpp (-fsanitize=integer)". GitHub #110: "Avoid gcc 9 deprecated copy warnings in new_allocator.hpp". GitHub #112: "vector::resize() compilation error with msvc-10..12: data is not a member of boost::detail::aligned_storage". GitHub #114: "Fix small_vector noexcept specification". GitHub #116: "MSVC + boost 1.70 compilation error when windows.h is already included (detail/thread_mutex.hpp)". GitHub #117: "flat_map/map::insert_or_assign with hint has wrong return types". GitHub #118: "Non-unique inplace_set_difference used in in flat_tree_merge_unique and iterator invalidation in insert_unique". GitHub #122: "Fix has_trivial_destructor_after_move". GitHub #123: "With heterogeneous lookup, equal_range can result in a range with length greater than 1". deque can now have options, using deque_options. The block size/bytes can be be specified. static_vector can now have options, using static_vector_options. Alignment and throwing behaviour can be be specified. small_vector can now have options, using small_vector_options. Alignment and growth factor can be be specified. Context: Add support for RISC-V LP64D #72: Fix ABI violation on ppc64 ELFv2 #99: cleanup of stack if creating ucontext fails Conversion: Maintenance work. Core: Added functions alloc_construct, alloc_construct_n, alloc_destroy, and alloc_destroy_n in <boost/core/alloc_construct.hpp> for allocator aware and exception safe construction and destruction of objects and arrays. (Glen Fernandes) Added constexpr functions first_scalar in <boost/core/first_scalar.hpp> for obtaining a pointer to the first scalar element of an array. Given a pointer of type T* they return a pointer of type remove_all_extents_t<T>*. (Glen Fernandes) Added class template noinit_adaptor in <boost/core/noinit_adaptor.hpp> which is an allocator adaptor that converts any allocator into one whose construct(ptr) performs default initialization via placement new, and whose destroy(ptr) invokes the value_type destructor directly. (Glen Fernandes) Added class template default_allocator in <boost/core/default_allocator.hpp>, which can serve as a minimal default allocator that has interface similar to C++20 std::allocator, supports configurations with disabled exceptions and does not have std as an associated namespace. The allocator uses operator new and operator delete for allocation. (Glen Fernandes) In <boost/core/uncaught_exceptions.hpp> header, added workarounds for better compatibility with QNX SDP 7.0 when libc++/libc++abi libraries are used. (Andrey Semashev, #59) The <boost/detail/sp_typeinfo.hpp> header is now marked as deprecated and will be removed in a future release. <boost/core/typeinfo.hpp> should be used instead. (Peter Dimov) Dynamic Bitset: Enabled hardware-assisted popcount on MSVC (PR#38). Added support for boost::hash and std::hash (PR#45). Support copy-initialization with default constructor (PR#48). Endian: Clarified requirements on the value type template parameter Added support for float and double Added endian_load, endian_store Updated endian_reverse to correctly support all non-bool integral types Moved deprecated names to the deprecated header endian.hpp Fiber: documentation for shared_work updated Filesystem: Fixed incorrect error_code returned from directory iterator increment when readdir_r is used. For path, fixed rvalue-aware operator/ return type to return an rvalue instead of rvalue reference. This fixes leaving a dangling reference in the user's code if the result of operator/ is bound to a const reference. (#110) Fixes for better compatibility with Windows CE. (PR#24) Added minimal support for CMake. (PR#106) Flyweight: Maintenance work. Histogram: New features: Support for thread-safe storages and new thread-safe accumulators Support for compiling without exceptions/RTTI (increases performance by 10-20 %) (with Glen Fernandes) Performance improvements for 1D and 2D histograms boost::histogram::indexed now returns forward iterator range instead of input iterator range boost::histogram::indexed_range::accessor is now non-copyable and acts like reference to cell value, making more algorithms from the C++ stdlib work boost::histogram::algorithm::reduce with new slice option and option fusion boost::histogram::algorithm::project accepts runtime indices for static histograms Bug Fixes: boost::histogram::algorithm::reduce also works on histograms that have some axis types without reduction support boost::histogram::axis::traits::update now works correctly for boost::histogram::axis::variant Other: 100 % test coverage Reduced internal Boost dependencies Improved documentation and examples Guaranteed no-throw moves for all builtin axis types Compile cleanly at higher warning levels See changelog for more details. IoStreams: Fixed processing of multi-stream files (PR#87). Added support for multi-threaded LZMA (PR#95). Interprocess: GitHub #85 ("warning: Implicit conversion loses integer precision"). GitHub #86 ("warning: Possible misuse of comma operator"). Intrusive: GitHub #42: Documentation does not describe treap priority_of_value changes GitHub #43: Fix tests with BOOST_INTRUSIVE_VARIADIC_TEMPLATES enabled GitHub #45: Disable variadic templates for MSVC-12 to avoid ICEs LexicalCast: Added tests for boost::filesystem::path conversions #25. Maintenance work, including #28. Log: New features: Improved support for C++17 std::string_view in basic_formatting_ostream. The string view can now participate in character code conversion on output. Added auto_newline formatter and stream manipulator. It can be used to ensure that formatted output always ends with a newline while avoiding duplicate newlines. In the output stream, text file and text multi-file sink backends added support for configuring behavior with regard to appending a trailing newline to every formatted log record. Use auto_newline_mode named parameter of the backend constructor or call the set_auto_newline_mode method on the sink backend. Note: The default behavior with regard to trailing newlines added by sink backends has changed slightly compared to the previous Boost.Log releases. The backends will now only add a trailing newline if there isn't one in the formatted log message string already. In previous releases a newline was added unconditionally. Added support for passing arbitrary function objects in the filter and format named parameters to sink constructors and convenience functions for initializing sinks. For example, it is now possible to specify C++11 lambda functions directly in these parameters. (#63) In the default filter and formatter factories used in filter and formatter parsers, added support for severity level attribute values of type boost::log::trivial::severity_level. For filters, the support is limited to attributes with "Severity" name. Bug fixes: Fixed incorrect parsing of components of the rotated file names while scanning for files in the text file sink backend. If the file name pattern ended with a placeholder (for example, a file counter), the scan_for_files method would not find files matching that pattern in the target storage, leaving them unmanaged. In particular, such files would not be deleted to free target storage. (#78) Updated basic_formatting_ostream and basic_record_ostream to make it possible to overload stream output operators for pointers to user-defined types. User-defined operator<< overloads taking std::basic_ostream and a pointer argument should now be picked up by the compiler when the pointer is being written to one of Boost.Log streams. (#84) See changelog for more details. Math: New features: Catmull-Rom interpolator now works in C++11 Cardinal quadratic B-spline interpolation Domain of elliptic integrals extended sin_pi and cos_pi performance improvements Forward-mode automatic differentiation Vector valued barycentric rational interpolation Ooura's method for evaluation of Fourier integrals Bug fixes: Multiple compatibility issues with Multiprecision fixed Lambert-W fixed on a rare architecture Metaparse: New features: In C++11 variadic template support for the following: sequence, one_of_c, one_of, repeated_one_of, repeated_one_of1, one_char_except_c, one_char_except. Bug fixes: BOOST_METAPARSE_STRING does not use out of range character values as template arguments. any_of_c<> does not create empty array in C++14. Move: Git Issue #26: "Invalid iterator increment/decrement in the last iteration of adaptive_sort_combine_blocks". Multi Array: Simplify allocator support by using new alloc_construct_n and alloc_destroy_n facilities from Core. (Glen Fernandes) Multi-index Containers: Added variants of const_mem_fun and mem_fun for differently qualified member functions (issue #24). Terse key specification syntax now correctly handles noexcept-specified member functions (issue #24). Outcome: Enhancements: #184 As per request from Boost release managers, relocated version.hpp and revision.hpp into detail, and added the Boost licence boilerplate to the top of every source file which was missing one (I think). Also took the opportunity to run the licence restamping script over all Outcome, so copyright dates are now up to date. #185 Add FAQ item explaining issue #185, and why we will do nothing to fix it right now. #189 Refactored the OUTCOME_TRY implementation to use more clarified customisation points capable of accepting very foreign inputs. Removed the std::experimental::expected<T, E> specialisations, as those are no longer necessary. Fixed the documentation for the customisation points which previously claimed that they are ADL discovered, which they are not. Added a recipe describing how to add in support for foreign input types. #183 Added a separate motivation/plug_error_code specifically for Boost. Bug fixes: OUTCOME_VERSION_MINOR hadn't been updated to 1. #181 Fix issue #181 where Outcome didn't actually implement the strong swap guarantee, despite being documented as doing so. #190 Fix issue #190 in Boost edition where unit test suite was not runnable from the Boost release distro. #182 Fix issue #182 where trait::is_exception_ptr_available<T> was always true, thus causing much weirdness, like not printing diagnostics and trying to feed everything to make_exception_ptr(). #192 Fix issue #192 where the std::basic_outcome_failure_exception_from_error() was being defined twice for translation units which combine standalone and Boost Outcome's. Parameter: Upgraded keyword generation macro BOOST_PARAMETER_TEMPLATE_KEYWORD (PR#15). Moved keyword generation macro BOOST_PARAMETER_NESTED_KEYWORD from Accumulators to this library (PR#28). Added support for std::reference_wrapper and std::ref() (PR#16). Moved boost::parameter::required, boost::parameter::optional, and boost::parameter::deduced metafunction definitions to their own header files in directory boost/parameter (PR#18). Added support for Boost.Parameter-enabled function call operators (PR#20). Added support for parameter category qualifiers "forward", "consume", and "move_from" (current qualifiers are "in", "out", and "in_out") (PR#21) (PR#23) based on http://www.modernescpp.com/index.php/c-core-guidelines-how-to-pass-function-parameters. Added new usage syntax BOOST_PARAMETER_NAME((object-name), namespace-name) qualifier(tag-name)) and BOOST_PARAMETER_NAME(qualifier(name)). (Existing code that uses qualifiers directly and correctly with BOOST_PARAMETER_FUNCTION and other code generation macros should remain unaffected for now, so no breaking changes.) The reason for the change in usage is to enable applying of parameter category constraints to Boost.Parameter-enabled functions and constructors invoked through argument composition. (Otherwise, it is currently possible to use argument composition to bypass parameter category constraints applied in BOOST_PARAMETER_FUNCTION et. al.) Added support for perfect forwarding (PR#23) (PR#26), so that parameter::parameters::operator() can accept non-const rvalues. As a positive side effect, Boost.Parameter-enabled functions and constructors are no longer bound by BOOST_PARAMETER_MAX_ARITY on compilers that support perfect forwarding. User code can now check for this support by detecting the configuration macro BOOST_PARAMETER_HAS_PERFECT_FORWARDING, or manually turn off this support by defining the configuration macro BOOST_PARAMETER_DISABLE_PERFECT_FORWARDING. Added metafunctions boost::parameter::is_argument_pack (PR#27), boost::parameter::are_tagged_arguments (PR#52), and boost::parameter::result_of::compose (PR#75). Added variadic function template boost::parameter::compose() which takes in named arguments and returns them in an argument pack (PR#52). For compilers that do not support perfect forwarding, the configuration macro BOOST_PARAMETER_COMPOSE_MAX_ARITY determines the maximum number of arguments that boost::parameter::compose() can take in (PR#61). Added code generation macros BOOST_PARAMETER_BASIC_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_BASIC_CONST_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_NO_SPEC_FUNCTION, BOOST_PARAMETER_NO_SPEC_MEMBER_FUNCTION, BOOST_PARAMETER_NO_SPEC_CONST_MEMBER_FUNCTION, BOOST_PARAMETER_NO_SPEC_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_NO_SPEC_CONST_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_NO_SPEC_CONSTRUCTOR, and BOOST_PARAMETER_NO_SPEC_NO_BASE_CONSTRUCTOR (PR#52). Added support for Boost.MP11 (PR#47) (PR#66) (PR#70). User code can now check for this support by detecting the configuration macro BOOST_PARAMETER_CAN_USE_MP11, or manually turn off this support by defining the configuration macro BOOST_PARAMETER_DISABLE_MP11_USAGE. Improved support for parameter-dependent return types via SFINAE (PR#73). PtrContainer: Fix a ptr_vector regression introduced in 1.66.0 (PR#24). PolyCollection: Maintenance work. SmartPtr: Added aliasing constructors to weak_ptr Added weak_ptr<T>::empty() Added enable_shared_from, shared_from, and weak_from Stacktrace: Fixed output of name(), source_location() and source_line() for the default constructed frame with thread sanitizer builds in C++98 mode. Fixed output of long strings from name() and source_location() on MSVC #78. Maintenance work. Test: Boost.test v3.11 see the Changes log for more details. Breaking changes: Boost.Test shows deprecation warnings if some very old headers as deprecated. If you encounter such warnings, please follow the indications: those headers will be removed in a future release. New feature: Now BOOST_TEST can be used to compare abstract types Bug fixes and pull requests: GitHub Issues: #209, #218 GitHub Pull Requests: PR#219, PR#224 Utility: Implemented function template ostream_string in <boost/utility/ostream_string.hpp> to optimally write any kind of string content to an output stream. It satisfies the requirements of [ostream.formatted.reqmts]. (Glen Fernandes) Optimized the stream output operators of basic_string_view and basic_string_ref to write directly to the rdbuf stream buffer. (Glen Fernandes) Uuid: Breaking change: MD5 name-based uuid generation was corrected to be identical on all endian systems. Define BOOST_UUID_COMPAT_PRE_1_71_MD5 to keep the result in a format compatible with 1.66 through 1.70. This does not affect the default name-based uuid generation which is based on SHA1. (PR#109) Variant: Fixed compilation of boost::apply_visitor with variants passed by non const reference in PR#68. Many thanks to Ed Catmur for providing the fix. Added support for std::hash (PR#49). Macro BOOST_VARIANT_DO_NOT_SPECIALIZE_STD_HASH could be defined to avoid those specializations. Added micro optimizations for binary size and performance by Nikita Kniazev in PR#63 and PR#66. Maintenance work, including PR#64 by Nikita Kniazev and PR#67 by Hans Dembinski. YAP: Added an example showing how to make self-evaluating YAP expressions (that is, expressions that don't need an explicit call to evaluate() or transform()). 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 Marshall Clow and Michael Caisse managed this release. 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New Libraries Variant2: A never-valueless, strong guarantee implementation of std::variant, from Peter Dimov. Updated Libraries ... [More] Align: Support for any integral type in the integral versions of align_up and align_down. Revised the implementation of aligned_allocator to no longer require a specialization for void. Define propagate_on_container_move_assignment and is_always_equal in aligned_allocator. Asio: Improved performance slightly by eliminating a redundant move construction when completed handlers are dispatched. Eliminated a compiler warning by annotating a case fall-through in the free function connect() implementation. Fixed the is_*_buffer_sequence detection traits for user-defined sequence types. Fixed some Windows-specific warnings about an incompatible pointer cast when obtaining the CancelIoEx entry point. Changed to automatically set the defaults when opening a serial port on Windows. Changed the serial port get_option() member function to be const. Fixed a name hiding issue with the WinRT stream-oriented socket backend's shutdown function. Applied a minor fix to the documentation for is_dynamic_buffer. Added some support for Haiku OS. Added wolfSSL compatability. Changed to require C++17 or later for coroutines TS support with clang. Fixed a doxygen generation problem in the tutorial. Ensured example programs are correctly incorporated into the documentation. Any: Static initialization of the default constructed boost::any is now possible. Fixed performance regression in assignment on a compilers without move-semantics. Maintenance work. Beast: This version consists mostly of bug fixes and performance improvements. Substantial work included for the split compilation mode, to reduce compile time when defining BOOST_BEAST_SEPARATE_COMPILATION. We'd love to know how you or your company use Beast, consider adding an item to the Companies and Individuals Using Beast list. See the full Release Notes for a complete list of changes. Circular Buffer: Correct doxygen generated reference to no longer show internal members. (Glen Fernandes) Eliminate ubsan warning on add and sub. (Glen Fernandes) Fix incorrect check in is_uninitialized. (Niklas Fejes) Container: Fixed bugs: GitHub #47: "added alignment specification for small_vector". GitHub #88: "Implement C++17 MoveAssignable requirements for self-move assignments". GitHub #107: "Alignment ignored in resource_adaptor". GitHub #109: "Get rid of integer overflow in copy_move_algo.hpp (-fsanitize=integer)". GitHub #110: "Avoid gcc 9 deprecated copy warnings in new_allocator.hpp". GitHub #112: "vector::resize() compilation error with msvc-10..12: data is not a member of boost::detail::aligned_storage". GitHub #114: "Fix small_vector noexcept specification". GitHub #116: "MSVC + boost 1.70 compilation error when windows.h is already included (detail/thread_mutex.hpp)". GitHub #117: "flat_map/map::insert_or_assign with hint has wrong return types". GitHub #118: "Non-unique inplace_set_difference used in in flat_tree_merge_unique and iterator invalidation in insert_unique". GitHub #122: "Fix has_trivial_destructor_after_move". GitHub #123: "With heterogeneous lookup, equal_range can result in a range with length greater than 1". deque can now have options, using deque_options. The block size/bytes can be be specified. static_vector can now have options, using static_vector_options. Alignment and throwing behaviour can be be specified. small_vector can now have options, using small_vector_options. Alignment and growth factor can be be specified. Context: Add support for RISC-V LP64D #72: Fix ABI violation on ppc64 ELFv2 #99: cleanup of stack if creating ucontext fails Conversion: Maintenance work. Core: Added functions alloc_construct, alloc_construct_n, alloc_destroy, and alloc_destroy_n in <boost/core/alloc_construct.hpp> for allocator aware and exception safe construction and destruction of objects and arrays. (Glen Fernandes) Added constexpr functions first_scalar in <boost/core/first_scalar.hpp> for obtaining a pointer to the first scalar element of an array. Given a pointer of type T* they return a pointer of type remove_all_extents_t<T>*. (Glen Fernandes) Added class template noinit_adaptor in <boost/core/noinit_adaptor.hpp> which is an allocator adaptor that converts any allocator into one whose construct(ptr) performs default initialization via placement new, and whose destroy(ptr) invokes the value_type destructor directly. (Glen Fernandes) Added class template default_allocator in <boost/core/default_allocator.hpp>, which can serve as a minimal default allocator that has interface similar to C++20 std::allocator, supports configurations with disabled exceptions and does not have std as an associated namespace. The allocator uses operator new and operator delete for allocation. (Glen Fernandes) In <boost/core/uncaught_exceptions.hpp> header, added workarounds for better compatibility with QNX SDP 7.0 when libc++/libc++abi libraries are used. (Andrey Semashev, #59) The <boost/detail/sp_typeinfo.hpp> header is now marked as deprecated and will be removed in a future release. <boost/core/typeinfo.hpp> should be used instead. (Peter Dimov) Dynamic Bitset: Enabled hardware-assisted popcount on MSVC (PR#38). Added support for boost::hash and std::hash (PR#45). Support copy-initialization with default constructor (PR#48). Endian: Clarified requirements on the value type template parameter Added support for float and double Added endian_load, endian_store Updated endian_reverse to correctly support all non-bool integral types Moved deprecated names to the deprecated header endian.hpp Fiber: documentation for shared_work updated Filesystem: Fixed incorrect error_code returned from directory iterator increment when readdir_r is used. For path, fixed rvalue-aware operator/ return type to return an rvalue instead of rvalue reference. This fixes leaving a dangling reference in the user's code if the result of operator/ is bound to a const reference. (#110) Fixes for better compatibility with Windows CE. (PR#24) Added minimal support for CMake. (PR#106) Flyweight: Maintenance work. Histogram: New features: Support for thread-safe storages and new thread-safe accumulators Support for compiling without exceptions/RTTI (increases performance by 10-20 %) (with Glen Fernandes) Performance improvements for 1D and 2D histograms boost::histogram::indexed now returns forward iterator range instead of input iterator range boost::histogram::indexed_range::accessor is now non-copyable and acts like reference to cell value, making more algorithms from the C++ stdlib work boost::histogram::algorithm::reduce with new slice option and option fusion boost::histogram::algorithm::project accepts runtime indices for static histograms Bug Fixes: boost::histogram::algorithm::reduce also works on histograms that have some axis types without reduction support boost::histogram::axis::traits::update now works correctly for boost::histogram::axis::variant Other: 100 % test coverage Reduced internal Boost dependencies Improved documentation and examples Guaranteed no-throw moves for all builtin axis types Compile cleanly at higher warning levels See changelog for more details. IoStreams: Fixed processing of multi-stream files (PR#87). Added support for multi-threaded LZMA (PR#95). Interprocess: GitHub #85 ("warning: Implicit conversion loses integer precision"). GitHub #86 ("warning: Possible misuse of comma operator"). Intrusive: GitHub #42: Documentation does not describe treap priority_of_value changes GitHub #43: Fix tests with BOOST_INTRUSIVE_VARIADIC_TEMPLATES enabled GitHub #45: Disable variadic templates for MSVC-12 to avoid ICEs LexicalCast: Added tests for boost::filesystem::path conversions #25. Maintenance work, including #28. Log: New features: Improved support for C++17 std::string_view in basic_formatting_ostream. The string view can now participate in character code conversion on output. Added auto_newline formatter and stream manipulator. It can be used to ensure that formatted output always ends with a newline while avoiding duplicate newlines. In the output stream, text file and text multi-file sink backends added support for configuring behavior with regard to appending a trailing newline to every formatted log record. Use auto_newline_mode named parameter of the backend constructor or call the set_auto_newline_mode method on the sink backend. Note: The default behavior with regard to trailing newlines added by sink backends has changed slightly compared to the previous Boost.Log releases. The backends will now only add a trailing newline if there isn't one in the formatted log message string already. In previous releases a newline was added unconditionally. Added support for passing arbitrary function objects in the filter and format named parameters to sink constructors and convenience functions for initializing sinks. For example, it is now possible to specify C++11 lambda functions directly in these parameters. (#63) In the default filter and formatter factories used in filter and formatter parsers, added support for severity level attribute values of type boost::log::trivial::severity_level. For filters, the support is limited to attributes with "Severity" name. Bug fixes: Fixed incorrect parsing of components of the rotated file names while scanning for files in the text file sink backend. If the file name pattern ended with a placeholder (for example, a file counter), the scan_for_files method would not find files matching that pattern in the target storage, leaving them unmanaged. In particular, such files would not be deleted to free target storage. (#78) Updated basic_formatting_ostream and basic_record_ostream to make it possible to overload stream output operators for pointers to user-defined types. User-defined operator<< overloads taking std::basic_ostream and a pointer argument should now be picked up by the compiler when the pointer is being written to one of Boost.Log streams. (#84) See changelog for more details. Math: New features: Catmull-Rom interpolator now works in C++11 Cardinal quadratic B-spline interpolation Domain of elliptic integrals extended sin_pi and cos_pi performance improvements Forward-mode automatic differentiation Vector valued barycentric rational interpolation Ooura's method for evaluation of Fourier integrals Bug fixes: Multiple compatibility issues with Multiprecision fixed Lambert-W fixed on a rare architecture Metaparse: New features: In C++11 variadic template support for the following: sequence, one_of_c, one_of, repeated_one_of, repeated_one_of1, one_char_except_c, one_char_except. Bug fixes: BOOST_METAPARSE_STRING does not use out of range character values as template arguments. any_of_c<> does not create empty array in C++14. Move: Git Issue #26: "Invalid iterator increment/decrement in the last iteration of adaptive_sort_combine_blocks". Multi Array: Simplify allocator support by using new alloc_construct_n and alloc_destroy_n facilities from Core. (Glen Fernandes) Multi-index Containers: Added variants of const_mem_fun and mem_fun for differently qualified member functions (issue #24). Terse key specification syntax now correctly handles noexcept-specified member functions (issue #24). Outcome: Enhancements: #184 As per request from Boost release managers, relocated version.hpp and revision.hpp into detail, and added the Boost licence boilerplate to the top of every source file which was missing one (I think). Also took the opportunity to run the licence restamping script over all Outcome, so copyright dates are now up to date. #185 Add FAQ item explaining issue #185, and why we will do nothing to fix it right now. #189 Refactored the OUTCOME_TRY implementation to use more clarified customisation points capable of accepting very foreign inputs. Removed the std::experimental::expected<T, E> specialisations, as those are no longer necessary. Fixed the documentation for the customisation points which previously claimed that they are ADL discovered, which they are not. Added a recipe describing how to add in support for foreign input types. #183 Added a separate motivation/plug_error_code specifically for Boost. Bug fixes: OUTCOME_VERSION_MINOR hadn't been updated to 1. #181 Fix issue #181 where Outcome didn't actually implement the strong swap guarantee, despite being documented as doing so. #190 Fix issue #190 in Boost edition where unit test suite was not runnable from the Boost release distro. #182 Fix issue #182 where trait::is_exception_ptr_available<T> was always true, thus causing much weirdness, like not printing diagnostics and trying to feed everything to make_exception_ptr(). #192 Fix issue #192 where the std::basic_outcome_failure_exception_from_error() was being defined twice for translation units which combine standalone and Boost Outcome's. Parameter: Upgraded keyword generation macro BOOST_PARAMETER_TEMPLATE_KEYWORD (PR#15). Moved keyword generation macro BOOST_PARAMETER_NESTED_KEYWORD from Accumulators to this library (PR#28). Added support for std::reference_wrapper and std::ref() (PR#16). Moved boost::parameter::required, boost::parameter::optional, and boost::parameter::deduced metafunction definitions to their own header files in directory boost/parameter (PR#18). Added support for Boost.Parameter-enabled function call operators (PR#20). Added support for parameter category qualifiers "forward", "consume", and "move_from" (current qualifiers are "in", "out", and "in_out") (PR#21) (PR#23) based on http://www.modernescpp.com/index.php/c-core-guidelines-how-to-pass-function-parameters. Added new usage syntax BOOST_PARAMETER_NAME((object-name), namespace-name) qualifier(tag-name)) and BOOST_PARAMETER_NAME(qualifier(name)). (Existing code that uses qualifiers directly and correctly with BOOST_PARAMETER_FUNCTION and other code generation macros should remain unaffected for now, so no breaking changes.) The reason for the change in usage is to enable applying of parameter category constraints to Boost.Parameter-enabled functions and constructors invoked through argument composition. (Otherwise, it is currently possible to use argument composition to bypass parameter category constraints applied in BOOST_PARAMETER_FUNCTION et. al.) Added support for perfect forwarding (PR#23) (PR#26), so that parameter::parameters::operator() can accept non-const rvalues. As a positive side effect, Boost.Parameter-enabled functions and constructors are no longer bound by BOOST_PARAMETER_MAX_ARITY on compilers that support perfect forwarding. User code can now check for this support by detecting the configuration macro BOOST_PARAMETER_HAS_PERFECT_FORWARDING, or manually turn off this support by defining the configuration macro BOOST_PARAMETER_DISABLE_PERFECT_FORWARDING. Added metafunctions boost::parameter::is_argument_pack (PR#27), boost::parameter::are_tagged_arguments (PR#52), and boost::parameter::result_of::compose (PR#75). Added variadic function template boost::parameter::compose() which takes in named arguments and returns them in an argument pack (PR#52). For compilers that do not support perfect forwarding, the configuration macro BOOST_PARAMETER_COMPOSE_MAX_ARITY determines the maximum number of arguments that boost::parameter::compose() can take in (PR#61). Added code generation macros BOOST_PARAMETER_BASIC_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_BASIC_CONST_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_NO_SPEC_FUNCTION, BOOST_PARAMETER_NO_SPEC_MEMBER_FUNCTION, BOOST_PARAMETER_NO_SPEC_CONST_MEMBER_FUNCTION, BOOST_PARAMETER_NO_SPEC_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_NO_SPEC_CONST_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_NO_SPEC_CONSTRUCTOR, and BOOST_PARAMETER_NO_SPEC_NO_BASE_CONSTRUCTOR (PR#52). Added support for Boost.MP11 (PR#47) (PR#66) (PR#70). User code can now check for this support by detecting the configuration macro BOOST_PARAMETER_CAN_USE_MP11, or manually turn off this support by defining the configuration macro BOOST_PARAMETER_DISABLE_MP11_USAGE. Improved support for parameter-dependent return types via SFINAE (PR#73). PtrContainer: Fix a ptr_vector regression introduced in 1.66.0 (PR#24). PolyCollection: Maintenance work. SmartPtr: Added aliasing constructors to weak_ptr Added weak_ptr<T>::empty() Added enable_shared_from, shared_from, and weak_from Stacktrace: Fixed output of name(), source_location() and source_line() for the default constructed frame with thread sanitizer builds in C++98 mode. Fixed output of long strings from name() and source_location() on MSVC #78. Maintenance work. Test: Boost.test v3.11 see the Changes log for more details. Breaking changes: Boost.Test shows deprecation warnings if some very old headers as deprecated. If you encounter such warnings, please follow the indications: those headers will be removed in a future release. New feature: Now BOOST_TEST can be used to compare abstract types Bug fixes and pull requests: GitHub Issues: #209, #218 GitHub Pull Requests: PR#219, PR#224 Utility: Implemented function template ostream_string in <boost/utility/ostream_string.hpp> to optimally write any kind of string content to an output stream. It satisfies the requirements of [ostream.formatted.reqmts]. (Glen Fernandes) Optimized the stream output operators of basic_string_view and basic_string_ref to write directly to the rdbuf stream buffer. (Glen Fernandes) Uuid: Breaking change: MD5 name-based uuid generation was corrected to be identical on all endian systems. Define BOOST_UUID_COMPAT_PRE_1_71_MD5 to keep the result in a format compatible with 1.66 through 1.70. This does not affect the default name-based uuid generation which is based on SHA1. (PR#109) Variant: Fixed compilation of boost::apply_visitor with variants passed by non const reference in PR#68. Many thanks to Ed Catmur for providing the fix. Added support for std::hash (PR#49). Macro BOOST_VARIANT_DO_NOT_SPECIALIZE_STD_HASH could be defined to avoid those specializations. Added micro optimizations for binary size and performance by Nikita Kniazev in PR#63 and PR#66. Maintenance work, including PR#64 by Nikita Kniazev and PR#67 by Hans Dembinski. YAP: Added an example showing how to make self-evaluating YAP expressions (that is, expressions that don't need an explicit call to evaluate() or transform()). 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 Marshall Clow and Michael Caisse managed this release. 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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 ... [More] 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. [Less]

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 ... [More] 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. [Less]

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 ... [More] 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. [Less]

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. ... [More] 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. 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) 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. 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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 ... [More] 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. 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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. ... [More] 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. 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) 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. 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Notes for non-Windows users Boost build system now supports visibilities and builds shared libraries with hidden visibility by default. As a result Boost shared libraries become smaller, load faster and have less ... [More] chances to get a symbol collision. See Boost.Build visibility and local-visibility for more info. To disable that feature use ./b2 visibility=global like command during build. New Libraries TODO Discontinued Libraries Signals (v1) was deprecated in 1.54, announced for removal in 1.68, and removed in 1.69. Use Signals2 instead. TODO Updated Libraries Any: Fixed issue with visibility. Now boost::any variables constructed in one shared library with hidden visibility could be used and destroyed in other shared library with hidden visibility. Maintenance: dropped some dependencies on other Boost libraries, fixes for docs. Assign: Add rvalue reference, perfect forwarding, and variadic template support (PR#6) (#10477) Avoid conversion to container's allocator (PR#29) (#5419) (#7364) Beast: This version fixes some issues in the examples, and provides a new experimental socket which supports built-in timeouts on asynchronous operations. New CppCon 2018 websocket chat example and presentation video. For a complete list of changes, please view the official Release Notes. CircularBuffer: Use the empty base optimization for storing allocators that are empty and not final (Glen Fernandes). Concept Check: Removed dependency on mpl. (PR#14) Context: #85: duplicate alias should be missing GCC alias #87: the clang-win toolset (clang-cl.exe) uses masm from the underlying msvc #90: remove useless lines in Jamfile.v2 #91: add .file section for *_elf_gas.S files Core: Implemented boost::empty_value, for library authors to conveniently leverage the Empty Base Optimization to store objects of potentially empty types (Glen Fernandes). This facility is now used in Boost.Beast, Boost.CircularBuffer, Boost.MultiArray, and more. Implemented boost::quick_exit to provide the C++11 standard library facility std::quick_exit functionality (Peter Dimov). Reduced the number of statics in Lightweight Test, and employ lighter abort behavior for MSVC compilers upon failure to call boost::report_errors (Glen Fernandes). DLL: Resolved link issues with the smart library #20. Maintenance: fixes for docs and tests. Dynamic Bitset: Performance improvements (over 2x in some cases). (PR#26) Added range-based set, reset, flip methods (PR#27) Fiber: #181: unbuffered_channel push not return #182: Remove UTF-8 BOM at begining of the file #183: Fix boost-install use; should only be issued once Filesystem: Don't use readdir_r on Linux and Android since the readdir function is already thread-safe. (PR#68, #72) Fixed crashes in boost::filesystem::copy due to undefined behavior in the implementation. (PR#71) Fixed undefined behavior in boost::filesystem::directory_iterator implementation. (PR#77) Fixed compilation errors when using directory iterators with BOOST_FOREACH. Removed workarounds for older PGI C++ compiler versions to fix compilation on the newer ones. (PR#49) Fixed MSVC warnings about narrowing conversions. (PR#44) Flyweight: Fixed some issues in GCC related to Boost.MPL placeholder expression handling. Maintenance fixes. Function: Removed dependencies on mpl, test (PR#20) (PR#22) Geometry: Improvements 486 Karney's solution of direct geodesic problem for internal use (thanks to Adeel Ahmad). 490 Discrete Frechet and Hausdorff distance algorithms (thanks to Yaghyavardhan Singh Khangarot). 496 New run-time and upgraded compile-time SRS transformation interfaces (undocumented for now due to potential interface changes). Solved issues 520 Missing documentation for dsv(). 521 Wrong documentation description for distance(). 524 Fixed 'enumeration values not handled in switch' warnings. 527 Workaround for VS 2017 (msvc-15). Bugfixes 505 Fixed overflow in overlay algorithms (thanks to Dane Springmeyer). 518 Fixed passing of temporaries in append() (thanks to xventura81). 522 Support python3 in building documentation. Integer: boost/pending/integer_log2.hpp header is deprecated and will be removed in future releases. Use boost/integer/integer_log2.hpp instead. Iostreams: Remove call to nonexistent member seekpos() of std::fpos (PR#58) Iterator: Fixed compilation problems with ambiguous unqualified calls to advance and distance on iterators whose types involve types in the namespace boost. (#43) LexicalCast: Fixed sign-conversion warnings #8991. Maintenance: dropped some dependencies on other Boost libraries, fixed build system warnings. Log: General changes: Updated syslog sink backend to avoid using deprecated Boost.ASIO interfaces. (#59) Bug fixes: Fixed a possible incorrect estimation of the total size of rotated files in the target directory of a text file sink in some cases. See changelog for more details. Logic: Breaking change: Use explicit operator bool when available (PR#5) Math: Add LambertW functions. Update integration routines to support complex valued integrands and contour integrals. Added the derivative of the Barycentric rational approximation. Minor fixes to better support variable precision floating point types. Removed use of deprecated Boost.Endian in favour of Predef. Updated continued fraction and series evaluation code to support complex types. Prevent logic error leading to infinite loop in toms748_solve. See #138. Fix mean and standard_deviation for extreme_value_distribution. See #139. Improve heuristics used in newton_raphson_iterate. See #145. Fix result of erf(NaN). See #141. Big push to reduce GCC warnings. See #136. Refactor polynomial addition. See PR132. Fix for vxWorks having a real function in the global namespace. See PR131. Improve sinc approximations and add better tests. Fix typo in Student's T hypothesis testing documentation, see #143. Mp11: Implemented the mp_starts_with facility (Glen Fernandes). MultiArray: Improve C++11 allocator model support including: Support for C++11 minimal allocators, support for stateful allocators, using the allocator for construction and destruction of the value type, and using the empty base optimization for storing empty or stateless allocators (Glen Fernandes). Multi-index Containers: Introduced an alternative terse key specification syntax for C++17 compliant environments. /libs/multiprecision/Multiprecision: Big update to better support variable precision types so that the precision of the result is always the largest of all the arguments. Add support for allocators that are final in __cpp_int. Removed use of deprecated Boost.Endian in favour of Predef. Add support for std::string_view. Fixed minor bug in constant initialization. See #67. Make assignment of non-finite value to cpp_int a runtime errors. See #58. Added typedefs for cpp_bin_float_oct and cpp_complex_oct. PolyCollection: Added Bost.PolyCollection-specific versions of algorithms std::for_each_n and std::sample. Pool: Replace boost::mutex use to avoid a dependency on Boost.Thread (PR#23) Preprocessor: Supports the new C++ standard conforming preprocessor in VC++ 14.1, which is currently enabled by using the /experimental:preprocessor switch, in Visual Studio 2017 15.8 on up. Rational: Add constexpr support (PR#28) (PR#32) Spirit: Spirit.X3: Drop own FP routines in favor of boost::math (#392) (#13531) Missing visibility mark on exception types (#409) to_utf8: Fixed wchar_t handling on Windows (#413) (#395) Spirit V2 Drop own FP routines in favor of boost::math (#392) (#13531) Missing visibility mark on exception types (#409) Fixed transform_attribute ambiguity (#407) (#396) to_utf8: Fixed wchar_t handling on Windows (#413) (#395) Spirit.Classic: Missing visibility mark on exception types (#409) Stacktrace: libbacktrace usage was significantly improved. BOOST_STACKTRACE_USE_BACKTRACE or boost_stacktrace_backtrace users are encouraged to update: Memory consumprion dropped down. Stack capturing became faster by an order of magnitude. syminfo fallback enabled to provide information for visible symbols even without debug information (thanks to github user driesdeschout!)#60, #61. Exact location of the backtrace.h header now can be specified via BOOST_STACKTRACE_BACKTRACE_INCLUDE_FILE, to allow backtrace.h header usage on platforms and compilers where that header is unreachable otherwise (for example Ubuntu Xenial + Clang) #59. Optimized stack capturing if max_depth is set (thanks to Jan Eisenhauer for the PR!) #67. Added to_string(const stacktrace& ) functions for fast conversion of stacktraces to std::string #57. Maintenance: updated docs #62, tests updated. System: Boost.System is now header-only. A stub library is still built for compatibility, but linking to it is no longer necessary. Even more functions have been marked constexpr. The destructor of error_category is now protected and no longer virtual. This is a potentially breaking change, but its impact is expected to be limited. error_category now has a constructor that accepts a 64 bit identifier, enabling distinct category objects to compare equal. The constructors of error_category are now protected. A non-allocating, nonthrowing overload of message has been added. A virtual function failed has been added, allowing categories for which success is not synonymous with 0. The deprecated boost::system::throws object has been removed. boost::throws() is now deprecated and its use is discouraged. The constructor of system_error taking a single error_code argument is now explicit. system_error::code() now returns by value. Test: Boost.test v3.9 see the Changes log for more details. New feature: Official support of header-only variant of Boost.Test with multiple translation units. Now possible to manually add a test case by specifying its name, with BOOST_TEST_CASE_NAME Better support of boost::exception in the logs Bug fixes and pull requests: Trac tickets: #13380, #13625, #13637 GitHub Issues: #149, #150, #156, #158, #163 GitHub Pull Requests: PR#147, PR#148, PR#151, PR#154, PR#161 TypeIndex: Fix the regression and speed up parsing of the boost/type_traits.hpp header by 30% (thanks to Nikita Kniazev for the PR!) #21. Utility: Added support for non-inheritable empty types to boost::compressed_pair by avoiding the empty base optimization for types which are declared as final (Glen Fernandes). Variant: Fixed issue with visibility. Now boost::bad_visit exception could cross the boundaries of shared library with hidden visibility and could be catched in other shared library with hidden visibility. YAP: Minor changes to support MSVC++ version 14.15 (Visual Studio 2017 version 15.8). Doc fixes. TODO Compilers Tested Boost's primary test compilers are: TODO Boost's additional test compilers include: TODO Acknowledgements TODO [Less]

Notes for non-Windows users The Boost build system now supports visibilities. If you are building shared libraries, they will use hidden visibility by default. As a result Boost shared libraries become smaller ... [More] , load faster and have less chances to get a symbol collision. See Boost.Build visibility and local-visibility for more info. To disable that feature you can use use a command line ./b2 visibility=global to build. New Libraries Safe Numerics: A library for guaranteed correct integer arithmetic for C++14 and later, from Robert Ramey. Updated Libraries Any: Fixed issue with visibility. Now boost::any variables constructed in one shared library with hidden visibility could be used and destroyed in other shared library with hidden visibility. Maintenance: dropped some dependencies on other Boost libraries, fixes for docs. Asio: Fixed a problem with the detection of std::future availability with libstdc++. Fixed compile error in regex overload of read_until. Fixed a timer heap corruption issue that can occur when moving a cancelled timer. Fixed detection of std::experimental::string_view and std::string_view with newer clang/libc++. Fixed MSVC version detection for availability of std::invoke_result. Fixed the buffer sequence traits to test the new requirements, if decltype is available. Fixed an MSVC issue when building with exceptions disabled. Added SSL context options for TLS v1.3. Added a compile-time test for TLS v1 support. Fixed the macro used to test for TLS v1.2 support. Prevented global objects from being created once per thread on Windows. Fixed a crash when using size(), max_size() or empty() on default-constructed resolver results. Changed to move the return value in basic_resolver_results::begin() to avoid copying. Enabled move support for the Intel Compiler. Fixed std::string_view detection issue when using clang-cl. Fixed the handler tracking operation name for io_context::executor_type::dispatch. Fixed a buffer overflow that could occur when parsing an address string with a 64-bit scope id. Added examples showing how to write composed operations. Added C++11 versions of the Timeouts, Timers, SOCKS4 and SSL examples. Fixed minor issues in documentation and examples. Assign: Add rvalue reference, perfect forwarding, and variadic template support (PR#6) (#10477) Avoid conversion to container's allocator (PR#29) (#5419) (#7364) Beast: This version fixes some issues in the examples, and provides a new experimental socket which supports built-in timeouts on asynchronous operations. New CppCon 2018 websocket chat example and presentation video. For a complete list of changes, please view the official Release Notes. CircularBuffer: Use the empty base optimization for storing allocators that are empty and not final (Glen Fernandes). Concept Check: Removed dependency on mpl. (PR#14) Context: #85: duplicate alias should be missing GCC alias #87: the clang-win toolset (clang-cl.exe) uses masm from the underlying msvc #90: remove useless lines in Jamfile.v2 #91: add .file section for *_elf_gas.S files Core: Implemented boost::empty_value, for library authors to conveniently leverage the Empty Base Optimization to store objects of potentially empty types (Glen Fernandes). This facility is now used in Boost.Beast, Boost.CircularBuffer, Boost.MultiArray, and more. Implemented boost::quick_exit to provide the C++11 standard library facility std::quick_exit functionality (Peter Dimov). Reduced the number of statics in Lightweight Test, and employ lighter abort behavior for MSVC compilers upon failure to call boost::report_errors (Glen Fernandes). DLL: Resolved link issues with the smart library #20. Maintenance: fixes for docs and tests. Dynamic Bitset: Performance improvements (over 2x in some cases). (PR#26) Added range-based set, reset, flip methods (PR#27) Fiber: #181: unbuffered_channel push not return #182: Remove UTF-8 BOM at begining of the file #183: Fix boost-install use; should only be issued once Filesystem: Don't use readdir_r on Linux and Android since the readdir function is already thread-safe. (PR#68, #72) Fixed crashes in boost::filesystem::copy due to undefined behavior in the implementation. (PR#71) Fixed undefined behavior in boost::filesystem::directory_iterator implementation. (PR#77) Fixed compilation errors when using directory iterators with BOOST_FOREACH. Removed workarounds for older PGI C++ compiler versions to fix compilation on the newer ones. (PR#49) Fixed MSVC warnings about narrowing conversions. (PR#44) Flyweight: Fixed some issues in GCC related to Boost.MPL placeholder expression handling. Maintenance fixes. Function: Removed dependencies on mpl, test (PR#20) (PR#22) Geometry: Improvements PR#486 Karney's solution of direct geodesic problem for internal use (thanks to Adeel Ahmad). PR#490 Discrete Frechet and Hausdorff distance algorithms (thanks to Yaghyavardhan Singh Khangarot). PR#496 New run-time and upgraded compile-time SRS transformation interfaces (undocumented for now due to potential interface changes). Solved issues #520 Missing documentation for dsv(). #521 Wrong documentation description for distance(). #524 Fixed 'enumeration values not handled in switch' warnings. #527 Workaround for VS 2017 (msvc-15). Bugfixes PR#505 Fixed overflow in overlay algorithms (thanks to Dane Springmeyer). PR#518 Fixed passing of temporaries in append() (thanks to xventura81). PR#522 Support python3 in building documentation. Integer: boost/pending/integer_log2.hpp header is deprecated and will be removed in future releases. Use boost/integer/integer_log2.hpp instead. Iostreams: Remove call to nonexistent member seekpos() of std::fpos (PR#58) Iterator: Fixed compilation problems with ambiguous unqualified calls to advance and distance on iterators whose types involve types in the namespace boost. (#43) LexicalCast: Fixed sign-conversion warnings #8991. Maintenance: dropped some dependencies on other Boost libraries, fixed build system warnings. Log: General changes: Updated syslog sink backend to avoid using deprecated Boost.ASIO interfaces. (#59) Bug fixes: Fixed a possible incorrect estimation of the total size of rotated files in the target directory of a text file sink in some cases. See changelog for more details. Logic: Breaking change: Use explicit operator bool when available (PR#5) Math: Add LambertW functions. Update integration routines to support complex valued integrands and contour integrals. Added the derivative of the Barycentric rational approximation. Minor fixes to better support variable precision floating point types. Removed use of deprecated Boost.Endian in favour of Predef. Updated continued fraction and series evaluation code to support complex types. Prevent logic error leading to infinite loop in toms748_solve. See #138. Fix mean and standard_deviation for extreme_value_distribution. See #139. Improve heuristics used in newton_raphson_iterate. See #145. Fix result of erf(NaN). See #141 #141. Big push to reduce GCC warnings. See #136 #136. Refactor polynomial addition. See PR#132. Fix for vxWorks having a real function in the global namespace. See PR#131. Improve sinc approximations and add better tests. Fix typo in Student's T hypothesis testing documentation, see #143. Mp11: Implemented the mp_starts_with facility (Glen Fernandes). MultiArray: Improve C++11 allocator model support including: Support for C++11 minimal allocators, support for stateful allocators, using the allocator for construction and destruction of the value type, and using the empty base optimization for storing empty or stateless allocators (Glen Fernandes). Multi-index Containers: Introduced an alternative terse key specification syntax for C++17 compliant environments. Multiprecision: Big update to better support variable precision types so that the precision of the result is always the largest of all the arguments. Add support for allocators that are final in __cpp_int (Glen Fernandes). Removed use of deprecated Boost.Endian in favour of Predef. Add support for std::string_view. Fixed minor bug in constant initialization. See #67. Make assignment of non-finite value to cpp_int a runtime errors. See #58. Added typedefs for cpp_bin_float_oct and cpp_complex_oct. PolyCollection: Added Boost.PolyCollection-specific versions of algorithms std::for_each_n and std::sample. Pool: Replace boost::mutex use to avoid a dependency on Boost.Thread (PR#23) Preprocessor: Supports the new C++ standard conforming preprocessor in VC++ 14.1, which is currently enabled by using the /experimental:preprocessor switch, in Visual Studio 2017 15.8 on up. Rational: Add constexpr support (PR#28) (PR#32) Spirit: Spirit.X3: Drop own FP routines in favor of boost::math (#392) (#13531) Missing visibility mark on exception types (#409) to_utf8: Fixed wchar_t handling on Windows (#413) (#395) Spirit V2 Drop own FP routines in favor of boost::math (#392) (#13531) Missing visibility mark on exception types (#409) Fixed transform_attribute ambiguity (#407) (#396) to_utf8: Fixed wchar_t handling on Windows (#413) (#395) Spirit.Classic: Missing visibility mark on exception types (#409) Stacktrace: libbacktrace usage was significantly improved. BOOST_STACKTRACE_USE_BACKTRACE or boost_stacktrace_backtrace users are encouraged to update: Memory consumprion dropped down. Stack capturing became faster by an order of magnitude. syminfo fallback enabled to provide information for visible symbols even without debug information (thanks to github user driesdeschout!)#60, #61. Exact location of the backtrace.h header now can be specified via BOOST_STACKTRACE_BACKTRACE_INCLUDE_FILE, to allow backtrace.h header usage on platforms and compilers where that header is unreachable otherwise (for example Ubuntu Xenial + Clang) #59. Optimized stack capturing if max_depth is set (thanks to Jan Eisenhauer for the PR!) #67. Added to_string(const stacktrace& ) functions for fast conversion of stacktraces to std::string #57. Maintenance: updated docs #62, tests updated. System: Boost.System is now header-only. A stub library is still built for compatibility, but linking to it is no longer necessary. Even more functions have been marked constexpr. The destructor of error_category is now protected and no longer virtual. This is a potentially breaking change, but its impact is expected to be limited. error_category now has a constructor that accepts a 64 bit identifier, enabling distinct category objects to compare equal. The constructors of error_category are now protected. A non-allocating, nonthrowing overload of message has been added. A virtual function failed has been added, allowing categories for which success is not synonymous with 0. The deprecated boost::system::throws object has been removed. boost::throws() is now deprecated and its use is discouraged. The constructor of system_error taking a single error_code argument is now explicit. system_error::code() now returns by value. Test: Boost.test v3.9 see the Changes log for more details. New feature: Official support of header-only variant of Boost.Test with multiple translation units. Now possible to manually add a test case by specifying its name, with BOOST_TEST_CASE_NAME Better support of boost::exception in the logs Bug fixes and pull requests: Trac tickets: #13380, #13625, #13637 GitHub Issues: #149, #150, #156, #158, #163 GitHub Pull Requests: PR#147, PR#148, PR#151, PR#154, PR#161 TypeIndex: Fix the regression and speed up parsing of the boost/type_traits.hpp header by 30% (thanks to Nikita Kniazev for the PR!) #21. Utility: Added support for non-inheritable empty types to boost::compressed_pair by avoiding the empty base optimization for types which are declared as final (Glen Fernandes). Variant: Fixed issue with visibility. Now boost::bad_visit exception could cross the boundaries of shared library with hidden visibility and could be catched in other shared library with hidden visibility. YAP: Minor changes to support MSVC++ version 14.15 (Visual Studio 2017 version 15.8). Doc fixes. Discontinued Libraries Signals (v1) is now removed. Its removal was announced in 1.68 and its deprecation was announced in 1.54. Boost 1.68 is the last release that provides this library. Users are encouraged to use Signals2 instead. The Boost community thanks Douglas Gregor for his work on Signals which served its users well and which also inspired Signals2. 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 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 Clang, C++17: 5.0.2, 6.0.1 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 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 Clang, C++17: 5.0.2, 6.0.1 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. 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