diff mbox series

[v7,2/6] libstdc++: use new built-in trait __is_reference for std::is_reference

Message ID 20230612224909.21188-3-kmatsui@cs.washington.edu
State Superseded
Headers
Series c++, libstdc++: get std::is_object to dispatch to new built-in traits |

Commit Message

Ken Matsui June 12, 2023, 10:47 p.m. UTC 
  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 <kmatsui@cs.washington.edu>
---
 libstdc++-v3/include/std/type_traits | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

Comments

Patrick Palka June 20, 2023, 4:07 p.m. UTC | #1 
On Mon, 12 Jun 2023, 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.

LGTM

> 
> Signed-off-by: Ken Matsui <kmatsui@cs.washington.edu>
> ---
>  libstdc++-v3/include/std/type_traits | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
> index 0e7a9c9c7f3..2a14df7e5f9 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)
> +  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>
> @@ -3192,12 +3199,19 @@ template <typename _Tp>
>    inline constexpr bool is_class_v = __is_class(_Tp);
>  template <typename _Tp>
>    inline constexpr bool is_function_v = is_function<_Tp>::value;
> +
> +#if __has_builtin(__is_reference)
> +template <typename _Tp>
> +  inline constexpr bool is_reference_v = __is_reference(_Tp);
> +#else
>  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;
> +#endif
> +
>  template <typename _Tp>
>    inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
>  template <typename _Tp>
> -- 
> 2.41.0
> 
>
diff mbox series

Patch

diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
index 0e7a9c9c7f3..2a14df7e5f9 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)
+  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>
@@ -3192,12 +3199,19 @@  template <typename _Tp>
   inline constexpr bool is_class_v = __is_class(_Tp);
 template <typename _Tp>
   inline constexpr bool is_function_v = is_function<_Tp>::value;
+
+#if __has_builtin(__is_reference)
+template <typename _Tp>
+  inline constexpr bool is_reference_v = __is_reference(_Tp);
+#else
 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;
+#endif
+
 template <typename _Tp>
   inline constexpr bool is_arithmetic_v = is_arithmetic<_Tp>::value;
 template <typename _Tp>