Same remark for all your alike patches.
On 11/06/2023 04:43, Ken Matsui via Libstdc++ wrote:
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.
(is_reference_v): Likewise.
Signed-off-by: Ken Matsui <kmat...@cs.washington.edu>
---
libstdc++-v3/include/std/type_traits | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/libstdc++-v3/include/std/type_traits
b/libstdc++-v3/include/std/type_traits
index 0e7a9c9c7f3..b2eb4bd3e7f 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -639,6 +639,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
// Composite type categories.
/// is_reference
+#if __has_builtin(__is_reference)
Here you are checking __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>
@@ -3193,11 +3200,7 @@ template <typename _Tp>
template <typename _Tp>
inline constexpr bool is_function_v = is_function<_Tp>::value;
template <typename _Tp>
- inline constexpr bool is_reference_v = false;
-template <typename _Tp>
- inline constexpr bool is_reference_v<_Tp&> = true;
-template <typename _Tp>
- inline constexpr bool is_reference_v<_Tp&&> = true;
+ inline constexpr bool is_reference_v = __is_reference(_Tp);
...but not here, why ?
