@@ -363,6 +363,13 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3)
//
// Pointer types
//
+#if __has_builtin(__is_pointer)
+ template<typename _Tp>
+ struct __is_ptr : __truth_type<__is_pointer(_Tp)>
+ {
+ enum { __value = __is_pointer(_Tp) };
+ };
+#else
template<typename _Tp>
struct __is_ptr
{
@@ -376,6 +383,7 @@ __INT_N(__GLIBCXX_TYPE_INT_N_3)
enum { __value = 1 };
typedef __true_type __type;
};
+#endif
//
// An arithmetic type is an integer type or a floating point type
@@ -515,6 +515,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
struct is_array<_Tp[]>
: public true_type { };
+ /// is_pointer
+#if __has_builtin(__is_pointer)
+ template<typename _Tp>
+ struct is_pointer
+ : public __bool_constant<__is_pointer(_Tp)>
+ { };
+#else
template<typename>
struct __is_pointer_helper
: public false_type { };
@@ -523,11 +530,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
struct __is_pointer_helper<_Tp*>
: public true_type { };
- /// is_pointer
template<typename _Tp>
struct is_pointer
: public __is_pointer_helper<__remove_cv_t<_Tp>>::type
{ };
+#endif
/// is_lvalue_reference
template<typename>
@@ -3168,8 +3175,22 @@ template <typename _Tp>
template <typename _Tp, size_t _Num>
inline constexpr bool is_array_v<_Tp[_Num]> = true;
+#if __has_builtin(__is_pointer)
template <typename _Tp>
- inline constexpr bool is_pointer_v = is_pointer<_Tp>::value;
+ inline constexpr bool is_pointer_v = __is_pointer(_Tp);
+#else
+template <typename _Tp>
+ inline constexpr bool is_pointer_v = false;
+template <typename _Tp>
+ inline constexpr bool is_pointer_v<_Tp*> = true;
+template <typename _Tp>
+ inline constexpr bool is_pointer_v<_Tp* const> = true;
+template <typename _Tp>
+ inline constexpr bool is_pointer_v<_Tp* volatile> = true;
+template <typename _Tp>
+ inline constexpr bool is_pointer_v<_Tp* const volatile> = true;
+#endif
+
template <typename _Tp>
inline constexpr bool is_lvalue_reference_v = false;
template <typename _Tp>
This patch lets libstdc++ use new built-in trait __is_pointer. libstdc++-v3/ChangeLog: * include/bits/cpp_type_traits.h (__is_ptr): Use __is_pointer built-in trait. * include/std/type_traits (is_pointer): Likewise. (is_pointer_v): Likewise. Optimize its implementation. Signed-off-by: Ken Matsui <kmatsui@gcc.gnu.org> --- libstdc++-v3/include/bits/cpp_type_traits.h | 8 +++++++ libstdc++-v3/include/std/type_traits | 25 +++++++++++++++++++-- 2 files changed, 31 insertions(+), 2 deletions(-)