C++20 design is complete

The C++ Committee held an official ISO meeting in Kona, Hawaii last week to determine the feature set for the next international standard, C++20. According to the conference report, the functional design of C++20 is now complete. It is planned to complete the C++20 specification at the meeting in Cologne in July 2019 and send a draft committee for review.

• Modules!

• Coroutines!

• static, thread_local, and lambda capture for structured bindings.

• std::polymorphic_allocator<>.

• std::midpoint and std::lerp.

• std::execution::unseq execution policy.

• std::ssize() free function that returns a sized size.

• std::span usability enhancements.

• Precalculated hash values in lookup.

The following features have been approved by C++20 at this or previous meeting, but have not been added to C++20 because the specification is still being completed. They are expected to be added at the Cologne conference in July 2019, but due to time constraints, it may not be possible to complete all the work.

• Expansion statements.

• The C++20 synchronization library.

• std::format.

• constexprstd::vector.

• Allow constexpr allocation, but disallow allocations that are not deleted at compile time.

• constexprstd::type_info::operator==.

• New conceptification of iterators.

• Monadic operations for std::optional.

• std::source_location.

• std::flatmap.

• std::flatset.

• std::ostream_joiner.

• Stack trace library.

• std::byteswap.

• constinit.

• Deprecating some uses of volatile.

• Implicit creation of objects for low-level object manipulation.

• using enum.

You can read more 2019-02 Kona ISO C++ Committee Trip Report here.