This patch finalizes the std::ranges::range_adaptor_closure
class template from https://wg21.link/P2387R3.
// [range.adaptor.object], range adaptor objects
template<class D>
requires is_class_v<D> && same_as<D, remove_cv_t<D>>
class range_adaptor_closure { };
The current implementation of __range_adaptor_closure was introduced
in ee44dd8062a26541808fc0d3fd5c6703e19f6016 and has served as the
foundation for the range adaptors in libc++ for a while. This patch
keeps its implementation, with the exception of the following changes:
- __range_adaptor_closure now includes the missing constraints
`is_class_v<D> && same_as<D, remove_cv_t<D>>` to restrict the
type of class that can inherit from it. (https://eel.is/c++draft/ranges.syn)
- The operator| of __range_adaptor_closure no longer requires its
first argument to model viewable_range. (https://eel.is/c++draft/range.adaptor.object#1)
- The _RangeAdaptorClosure concept is refined to exclude cases where
T models range or where T has base classes of type range_adaptor_closure<U>
for another type U. (https://eel.is/c++draft/range.adaptor.object#2)
The paper
- P2286R8 Formatting ranges
is fully implemented modulo its feature test macro. This macro has been
revised by
- LWG3750 Too many papers bump __cpp_lib_format
The new macro depends on
- P2585R0 Improving default container formatting
This paper revises parts of P2286R8 and adds new formatter
specializations. The specialization for debug strings has some wording
issues, which is addresses in this paper
- P2733R0 Fix handling of empty specifiers in std::format
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D142153
Focus on the not-yet-implemented features: remove most details about the
already-implemented C++20 stuff, list out the major C++23 additions.
Differential Revision: https://reviews.llvm.org/D136657
