[02/10] libstdc++: use new built-in trait __is_reference for std::is_reference
Commit Message
This patch gets std::is_reference to dispatch to new built-in trait
__is_reference.
libstdc++-v3/ChangeLog:
* include/std/type_traits (is_reference): Use __is_reference built-in
trait.
Signed-off-by: Ken Matsui <kmatsui@cs.washington.edu>
---
libstdc++-v3/include/std/type_traits | 7 +++++++
1 file changed, 7 insertions(+)
@@ -639,6 +639,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Composite type categories.
/// is_reference
+#if __has_builtin(__is_reference)
+ template<typename _Tp>
+ struct is_reference
+ : public __bool_constant<__is_reference(_Tp)>
+ { };
+#else
template<typename _Tp>
struct is_reference
: public false_type
@@ -653,6 +659,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
struct is_reference<_Tp&&>
: public true_type
{ };
+#endif
/// is_arithmetic
template<typename _Tp>