@@ -739,11 +739,21 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#endif
/// is_fundamental
+#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_arithmetic)
+ template<typename _Tp>
+ struct is_fundamental
+ : public __bool_constant<__is_arithmetic(_Tp)
+ || is_void<_Tp>::value
+ || is_null_pointer<_Tp>::value>
+ { };
+#else
template<typename _Tp>
struct is_fundamental
- : public __or_<is_arithmetic<_Tp>, is_void<_Tp>,
- is_null_pointer<_Tp>>::type
+ : public __bool_constant<is_arithmetic<_Tp>::value
+ || is_void<_Tp>::value
+ || is_null_pointer<_Tp>::value>
{ };
+#endif
/// is_object
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_function) \
@@ -3354,13 +3364,15 @@ template <typename _Tp>
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_arithmetic)
template <typename _Tp>
inline constexpr bool is_arithmetic_v = __is_arithmetic(_Tp);
+template <typename _Tp>
+ inline constexpr bool is_fundamental_v
+ = __is_arithmetic(_Tp) || is_void_v<_Tp> || is_null_pointer_v<_Tp>;
#else
template <typename _Tp>
inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
-#endif
-
template <typename _Tp>
inline constexpr bool is_fundamental_v = is_fundamental<_Tp>::value;
+#endif
#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_function) \
&& _GLIBCXX_USE_BUILTIN_TRAIT(__is_reference)
This patch optimizes the performance of the is_fundamental trait by dispatching to the new __is_arithmetic built-in trait. libstdc++-v3/ChangeLog: * include/std/type_traits (is_fundamental_v): Use __is_arithmetic built-in trait. (is_fundamental): Likewise. Optimize the original implementation. Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org> --- libstdc++-v3/include/std/type_traits | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-)