https://gcc.gnu.org/g:92b554a8412624a0aa3ca9b502976ebec7eff34e
commit r15-1258-g92b554a8412624a0aa3ca9b502976ebec7eff34e Author: Jonathan Wakely <jwak...@redhat.com> Date: Wed Jun 12 15:02:14 2024 +0100 libstdc++: Add ranges::range_common_reference_t for C++20 (LWG 3860) LWG 3860 added this alias template. Both libc++ and MSVC treat this as a DR for C++20, so this change does so too. libstdc++-v3/ChangeLog: * include/bits/ranges_base.h (range_common_reference_t): New alias template, as per LWG 3860. * testsuite/std/ranges/range.cc: Check it. Diff: --- libstdc++-v3/include/bits/ranges_base.h | 6 ++++++ libstdc++-v3/testsuite/std/ranges/range.cc | 6 ++++++ 2 files changed, 12 insertions(+) diff --git a/libstdc++-v3/include/bits/ranges_base.h b/libstdc++-v3/include/bits/ranges_base.h index 23c0b56ff225..63eb552b48bb 100644 --- a/libstdc++-v3/include/bits/ranges_base.h +++ b/libstdc++-v3/include/bits/ranges_base.h @@ -537,6 +537,12 @@ namespace ranges using range_rvalue_reference_t = iter_rvalue_reference_t<iterator_t<_Range>>; + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 3860. range_common_reference_t is missing + template<range _Range> + using range_common_reference_t + = iter_common_reference_t<iterator_t<_Range>>; + /// [range.sized] The sized_range concept. template<typename _Tp> concept sized_range = range<_Tp> diff --git a/libstdc++-v3/testsuite/std/ranges/range.cc b/libstdc++-v3/testsuite/std/ranges/range.cc index 184356591375..760f6ffacfdb 100644 --- a/libstdc++-v3/testsuite/std/ranges/range.cc +++ b/libstdc++-v3/testsuite/std/ranges/range.cc @@ -83,3 +83,9 @@ static_assert( same_as<std::ranges::range_rvalue_reference_t<I>, char&&> ); static_assert( same_as<std::ranges::range_rvalue_reference_t<O>, WritableObject<char>> ); + +// LWG 3860. range_common_reference_t is missing +static_assert( same_as<std::ranges::range_common_reference_t<C>, + char&> ); +static_assert( same_as<std::ranges::range_common_reference_t<I>, + char&> );