[v14,26/40] libstdc++: Optimize is_object trait performance
Commit Message
This patch optimizes the performance of the is_object trait by dispatching to
the new __is_function and __is_reference built-in traits.
libstdc++-v3/ChangeLog:
* include/std/type_traits (is_object): Use __is_function and
__is_reference built-in traits.
(is_object_v): Likewise.
Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org>
---
libstdc++-v3/include/std/type_traits | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
@@ -725,11 +725,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{ };
/// is_object
+#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_function) \
+ && _GLIBCXX_USE_BUILTIN_TRAIT(__is_reference)
+ template<typename _Tp>
+ struct is_object
+ : public __bool_constant<!(__is_function(_Tp) || __is_reference(_Tp)
+ || is_void<_Tp>::value)>
+ { };
+#else
template<typename _Tp>
struct is_object
: public __not_<__or_<is_function<_Tp>, is_reference<_Tp>,
is_void<_Tp>>>::type
{ };
+#endif
template<typename>
struct is_member_pointer;
@@ -3305,8 +3314,17 @@ template <typename _Tp>
inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
template <typename _Tp>
inline constexpr bool is_fundamental_v = is_fundamental<_Tp>::value;
+
+#if _GLIBCXX_USE_BUILTIN_TRAIT(__is_function) \
+ && _GLIBCXX_USE_BUILTIN_TRAIT(__is_reference)
+template <typename _Tp>
+ inline constexpr bool is_object_v
+ = !(__is_function(_Tp) || __is_reference(_Tp) || is_void<_Tp>::value);
+#else
template <typename _Tp>
inline constexpr bool is_object_v = is_object<_Tp>::value;
+#endif
+
template <typename _Tp>
inline constexpr bool is_scalar_v = is_scalar<_Tp>::value;
template <typename _Tp>