Re: [PATCH v26 05/13] libstdc++: Optimize std::add_pointer compilation performance

[Jonathan Wakely]

On 11/05/24 02:01 -0700, Ken Matsui wrote:

This patch optimizes the compilation performance of std::add_pointer
by dispatching to the new __add_pointer built-in trait.

OK, thanks.

libstdc++-v3/ChangeLog:

        * include/std/type_traits (add_pointer): Use __add_pointer
        built-in trait.

Signed-off-by: Ken Matsui <kmat...@gcc.gnu.org>
---
libstdc++-v3/include/std/type_traits | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/std/type_traits 
b/libstdc++-v3/include/std/type_traits
index 1562757f886..6313fde94c2 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -2149,6 +2149,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    { };
#endif

+  /// add_pointer
+#if _GLIBCXX_USE_BUILTIN_TRAIT(__add_pointer)
+  template<typename _Tp>
+    struct add_pointer
+    { using type = __add_pointer(_Tp); };
+#else
  template<typename _Tp, typename = void>
    struct __add_pointer_helper
    { using type = _Tp; };
@@ -2157,7 +2163,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    struct __add_pointer_helper<_Tp, __void_t<_Tp*>>
    { using type = _Tp*; };

-  /// add_pointer
  template<typename _Tp>
    struct add_pointer
    : public __add_pointer_helper<_Tp>
@@ -2170,6 +2175,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
  template<typename _Tp>
    struct add_pointer<_Tp&&>
    { using type = _Tp*; };
+#endif

#if __cplusplus > 201103L
  /// Alias template for remove_pointer
--
2.44.0