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| author | Jonathan Wakely <jwakely@redhat.com> | 2022-09-01 12:32:09 +0100 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2022-09-01 20:31:00 +0100 |
| commit | 33005a4be49466880fe3f5a9317bccc8c1ed423b (patch) | |
| tree | cb0cda5fb50c540387592f44f49e3b7920191aa1 | |
| parent | cd20d9482a1f10ddf1c398c1a1d8421f97dfdefa (diff) | |
| download | gcc-33005a4be49466880fe3f5a9317bccc8c1ed423b.zip gcc-33005a4be49466880fe3f5a9317bccc8c1ed423b.tar.gz gcc-33005a4be49466880fe3f5a9317bccc8c1ed423b.tar.bz2 | |
libstdc++: Add specializations for some variable templates
This avoids having to instantiate a class template when we can detect
the true cases easily with a partial specialization.
libstdc++-v3/ChangeLog:
* include/std/type_traits (is_lvalue_reference_v)
(is_rvalue_reference_v, is_reference_v, is_const_v)
(is_volatile_v): Define using partial specializations instead
of instantiating class templates.
| -rw-r--r-- | libstdc++-v3/include/std/type_traits | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits index 52cca8b..e4b9b59 100644 --- a/libstdc++-v3/include/std/type_traits +++ b/libstdc++-v3/include/std/type_traits @@ -3153,11 +3153,13 @@ template <typename _Tp, size_t _Num> template <typename _Tp> inline constexpr bool is_pointer_v = is_pointer<_Tp>::value; template <typename _Tp> - inline constexpr bool is_lvalue_reference_v = - is_lvalue_reference<_Tp>::value; + inline constexpr bool is_lvalue_reference_v = false; template <typename _Tp> - inline constexpr bool is_rvalue_reference_v = - is_rvalue_reference<_Tp>::value; + inline constexpr bool is_lvalue_reference_v<_Tp&> = true; +template <typename _Tp> + inline constexpr bool is_rvalue_reference_v = false; +template <typename _Tp> + inline constexpr bool is_rvalue_reference_v<_Tp&&> = true; template <typename _Tp> inline constexpr bool is_member_object_pointer_v = is_member_object_pointer<_Tp>::value; @@ -3173,7 +3175,11 @@ template <typename _Tp> template <typename _Tp> inline constexpr bool is_function_v = is_function<_Tp>::value; template <typename _Tp> - inline constexpr bool is_reference_v = is_reference<_Tp>::value; + inline constexpr bool is_reference_v = false; +template <typename _Tp> + inline constexpr bool is_reference_v<_Tp&> = true; +template <typename _Tp> + inline constexpr bool is_reference_v<_Tp&&> = true; template <typename _Tp> inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value; template <typename _Tp> @@ -3187,9 +3193,13 @@ template <typename _Tp> template <typename _Tp> inline constexpr bool is_member_pointer_v = is_member_pointer<_Tp>::value; template <typename _Tp> - inline constexpr bool is_const_v = is_const<_Tp>::value; + inline constexpr bool is_const_v = false; +template <typename _Tp> + inline constexpr bool is_const_v<const _Tp> = true; +template <typename _Tp> + inline constexpr bool is_volatile_v = false; template <typename _Tp> - inline constexpr bool is_volatile_v = is_volatile<_Tp>::value; + inline constexpr bool is_volatile_v<volatile _Tp> = true; template <typename _Tp> inline constexpr bool is_trivial_v = is_trivial<_Tp>::value; template <typename _Tp> |