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| author | Jonathan Wakely <jwakely@redhat.com> | 2019-10-11 16:53:44 +0100 |
|---|---|---|
| committer | Jonathan Wakely <redi@gcc.gnu.org> | 2019-10-11 16:53:44 +0100 |
| commit | 02f6fdff65671ccfaf2f79092ccdfccdef1bcebf (patch) | |
| tree | 508378686454dfbed782d893175443b4b2a061cb /libstdc++-v3/include | |
| parent | 07758d90c7bc6b80b10a83bac52f9ab9e394131d (diff) | |
| download | gcc-02f6fdff65671ccfaf2f79092ccdfccdef1bcebf.tar.gz | |
Use __is_same_as for std::is_same and std::is_same_v
By using the built-in we don't need to match a partial specialization
for std::is_same and don't need to instantiate std::is_same at all for
uses of std::is_same_v.
* include/std/type_traits (is_same): Replace partial specialization
by using __is_same_as built-in in primary template.
(is_same_v): Use __is_same_as built-in instead of instantiating the
is_same trait.
From-SVN: r276891
Diffstat (limited to 'libstdc++-v3/include')
| -rw-r--r-- | libstdc++-v3/include/std/type_traits | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits index dc8a019324d..4de5daa9f06 100644 --- a/libstdc++-v3/include/std/type_traits +++ b/libstdc++-v3/include/std/type_traits @@ -1388,13 +1388,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION // Type relations. /// is_same - template<typename, typename> + template<typename _Tp, typename _Up> struct is_same - : public false_type { }; - - template<typename _Tp> - struct is_same<_Tp, _Tp> - : public true_type { }; + : public integral_constant<bool, __is_same_as(_Tp, _Up)> + { }; /// is_base_of template<typename _Base, typename _Derived> @@ -3158,7 +3155,7 @@ template <typename _Tp> template <typename _Tp, unsigned _Idx = 0> inline constexpr size_t extent_v = extent<_Tp, _Idx>::value; template <typename _Tp, typename _Up> - inline constexpr bool is_same_v = is_same<_Tp, _Up>::value; + inline constexpr bool is_same_v = __is_same_as(_Tp, _Up); template <typename _Base, typename _Derived> inline constexpr bool is_base_of_v = is_base_of<_Base, _Derived>::value; template <typename _From, typename _To> |