[v2,2/2] libstdc++: Use new built-in trait __is_signed
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Commit Message
This patch lets libstdc++ use new built-in trait __is_signed.
libstdc++-v3/ChangeLog:
* include/std/type_traits (is_signed): Use __is_signed built-in trait.
(is_signed_v): Likewise.
Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
---
libstdc++-v3/include/std/type_traits | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
@@ -865,6 +865,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
: public __bool_constant<__is_abstract(_Tp)>
{ };
+ /// is_signed
+#if __has_builtin(__is_signed)
+ template<typename _Tp>
+ struct is_signed
+ : public __bool_constant<__is_signed(_Tp)>
+ { };
+#else
/// @cond undocumented
template<typename _Tp,
bool = is_arithmetic<_Tp>::value>
@@ -877,11 +884,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{ };
/// @endcond
- /// is_signed
template<typename _Tp>
struct is_signed
: public __is_signed_helper<_Tp>::type
{ };
+#endif
/// is_unsigned
template<typename _Tp>
@@ -3240,8 +3247,14 @@ template <typename _Tp>
template <typename _Tp>
inline constexpr bool is_final_v = __is_final(_Tp);
+#if __has_builtin(__is_signed)
+template <typename _Tp>
+ inline constexpr bool is_signed_v = __is_signed(_Tp);
+#else
template <typename _Tp>
inline constexpr bool is_signed_v = is_signed<_Tp>::value;
+#endif
+
template <typename _Tp>
inline constexpr bool is_unsigned_v = is_unsigned<_Tp>::value;