[v2,2/2] libstdc++: use new built-in trait __is_array
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Commit Message
This patch lets libstdc++ use new built-in trait __is_array.
libstdc++-v3/ChangeLog:
* include/std/type_traits (is_array): Use __is_array built-in trait.
(is_array_v): Likewise.
Signed-off-by: Ken Matsui <kmatsui@cs.washington.edu>
---
libstdc++-v3/include/std/type_traits | 12 ++++++++++++
1 file changed, 12 insertions(+)
@@ -503,6 +503,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{ };
/// is_array
+#if __has_builtin(__is_array)
+ template<typename _Tp>
+ struct is_array
+ : public __bool_constant<__is_array(_Tp)>
+ { };
+#else
template<typename>
struct is_array
: public false_type { };
@@ -514,6 +520,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Tp>
struct is_array<_Tp[]>
: public true_type { };
+#endif
template<typename>
struct __is_pointer_helper
@@ -3161,12 +3168,17 @@ template <typename _Tp>
template <typename _Tp>
inline constexpr bool is_floating_point_v = is_floating_point<_Tp>::value;
+#if __has_builtin(__is_array)
+template <typename _Tp>
+ inline constexpr bool is_array_v = __is_array(_Tp);
+#else
template <typename _Tp>
inline constexpr bool is_array_v = false;
template <typename _Tp>
inline constexpr bool is_array_v<_Tp[]> = true;
template <typename _Tp, size_t _Num>
inline constexpr bool is_array_v<_Tp[_Num]> = true;
+#endif
template <typename _Tp>
inline constexpr bool is_pointer_v = is_pointer<_Tp>::value;