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| author | Jonathan Wakely <jwakely@redhat.com> | 2022-01-10 17:28:19 +0000 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2022-01-11 13:22:35 +0000 |
| commit | 5b417b35824fb5c15e3ee958cb86436b3409ebea (patch) | |
| tree | 200cfb1337a68b8be3cc6c976272aece4f0ec425 /libstdc++-v3/include/std/version | |
| parent | 11d3e8f4364b05e2746689c6d0f573594f6ddb74 (diff) | |
| download | gcc-5b417b35824fb5c15e3ee958cb86436b3409ebea.zip gcc-5b417b35824fb5c15e3ee958cb86436b3409ebea.tar.gz gcc-5b417b35824fb5c15e3ee958cb86436b3409ebea.tar.bz2 | |
libstdc++: Make std::variant work with Clang in C++20 mode [PR103891]
Clang has some bugs with destructors that use constraints to be
conditionally trivial, so disable the P2231R1 constexpr changes to
std::variant unless the compiler is GCC 12 or later.
If/when P2493R0 gets accepted and implemented by G++ we can remove the
__GNUC__ check and use __cpp_concepts >= 202002 instead.
libstdc++-v3/ChangeLog:
PR libstdc++/103891
* include/bits/c++config (_GLIBCXX_HAVE_COND_TRIVIAL_SPECIAL_MEMBERS):
Define.
* include/std/variant (__cpp_lib_variant): Only define C++20
value when the compiler is known to support conditionally
trivial destructors.
* include/std/version (__cpp_lib_variant): Likewise.
Diffstat (limited to 'libstdc++-v3/include/std/version')
| -rw-r--r-- | libstdc++-v3/include/std/version | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version index f421056..012d78e 100644 --- a/libstdc++-v3/include/std/version +++ b/libstdc++-v3/include/std/version @@ -173,7 +173,8 @@ # define __cpp_lib_to_chars 201611L #endif #define __cpp_lib_unordered_map_try_emplace 201411 -#if __cplusplus == 201703L || ! __cpp_concepts // N.B. updated value in C++20 +#ifndef _GLIBCXX_HAVE_COND_TRIVIAL_SPECIAL_MEMBERS +// N.B. updated value in C++20 # define __cpp_lib_variant 202102L #endif #endif @@ -286,7 +287,7 @@ # endif #define __cpp_lib_to_address 201711L #define __cpp_lib_to_array 201907L -#if __cpp_concepts +#ifdef _GLIBCXX_HAVE_COND_TRIVIAL_SPECIAL_MEMBERS # define __cpp_lib_variant 202106L #endif #endif |