libc++ C++2a Status

In July 2017, the C++ standard committee created a draft for the next version of the C++ standard, known here as "C++2a" (probably to be C++20).

This page shows the status of libc++; the status of clang's support of the language features is here.

Reminder: Features in unreleased drafts of the standard are subject to change.

The groups that have contributed papers:

Paper Status

Paper #GroupPaper NameMeetingStatusFirst released version
P0463R1LWGEndian just EndianTorontoIn progress
P0674R1LWGExtending make_shared to Support ArraysToronto
P0020R6LWGFloating Point AtomicAlbuquerque
P0053R7LWGC++ Synchronized Buffered OstreamAlbuquerque
P0202R3LWGAdd constexpr modifiers to functions in <algorithm> and <utility> HeadersAlbuquerqueIn Progress7.0
P0415R1LWGConstexpr for std::complexAlbuquerque
P0439R0LWGMake std::memory_order a scoped enumerationAlbuquerque
P0457R2LWGString Prefix and Suffix CheckingAlbuquerqueComplete6.0
P0550R2LWGTransformation Trait remove_cvrefAlbuquerqueComplete6.0
P0600R1LWGnodiscard in the LibraryAlbuquerqueIn Progress7.0
P0616R0LWGde-pessimize legacy algorithms with std::moveAlbuquerque
P0653R2LWGUtility to convert a pointer to a raw pointerAlbuquerqueComplete6.0
P0718R2LWGAtomic shared_ptrAlbuquerque
P0767R1CWGDeprecate PODAlbuquerque
P0768R1CWGLibrary Support for the Spaceship (Comparison) OperatorAlbuquerque
P0777R1LWGTreating Unnecessary decayAlbuquerque

[ Note: "Nothing to do" means that no library changes were needed to implement this change -- end note]

The missing bits in P0600 are in [mem.res.class], [mem.poly.allocator.class], and [container.node.overview]

Library Working group Issues Status

Issue #Issue NameMeetingStatus
2070allocate_shared should use allocator_traits<A>::constructTorontoResolved by P0674R1
2444Inconsistent complexity for std::sort_heapToronto
2593Moved-from state of AllocatorsToronto
2597std::log misspecified for complex numbersToronto
2783stack::emplace() and queue::emplace() should return decltype(auto)Toronto
2932Constraints on parallel algorithm implementations are underspecifiedToronto
2937Is equivalent("existing_thing", "not_existing_thing") an errorTorontoComplete
2940result_of specification also needs a little cleanupToronto
2942LWG 2873's resolution missed weak_ptr::owner_beforeTorontoComplete
2954Specialization of the convenience variable templates should be prohibitedTorontoComplete
2961Bad postcondition for set_default_resourceToronto
2966Incomplete resolution of US 74TorontoNothing to do
2974Diagnose out of bounds tuple_element/variant_alternativeTorontoComplete
2779[networking.ts] Relax requirements on buffer sequence iteratorsAlbuquerque
2870Default value of parameter theta of polar should be dependentAlbuquerque
2935What should create_directories do when p already exists but is not a directory?Albuquerque
2941[thread.req.timing] wording should apply to both member and namespace-level functionsAlbuquerqueNothing to do
2944LWG 2905 accidentally removed requirement that construction of the deleter doesn't throw an exceptionAlbuquerqueNothing to do
2945Order of template parameters in optional comparisonsAlbuquerqueComplete
2948unique_ptr does not define operator<< for stream outputAlbuquerqueComplete
2950std::byte operations are misspecifiedAlbuquerqueComplete
2952iterator_traits should work for pointers to cv TAlbuquerqueComplete
2953LWG 2853 should apply to deque::erase tooAlbuquerque
2958Moves improperly defined as deletedAlbuquerque
2964Apparently redundant requirement for dynamic_pointer_castAlbuquerque
2965Non-existing path::native_string() in filesystem_error::what() specificationAlbuquerque
2972What is is_trivially_destructible_v?AlbuquerqueComplete
2976Dangling uses_allocator specialization for packaged_taskAlbuquerqueComplete
2977unordered_meow::merge() has incorrect Throws: clauseAlbuquerque
2978Hash support for pmr::string and friendsAlbuquerque
2979aligned_union should require complete object typesAlbuquerqueComplete
2980Cannot compare_exchange empty pointersAlbuquerque
2981Remove redundant deduction guides from standard libraryAlbuquerque
2982Making size_type consistent in associative container deduction guidesAlbuquerque
2988Clause 32 cleanup missed one typenameAlbuquerque
2993reference_wrapper conversion from T&&Albuquerque
2998Requirements on function objects passed to {forward_,}list-specific algorithmsAlbuquerqueNothing to do
3001weak_ptr::element_type needs remove_extent_tAlbuquerque
3024variant's copies must be deleted instead of disabled via SFINAEAlbuquerque

Last Updated: 15-Jan-2018