[PATCH v18 14/26] libstdc++: Optimize std::remove_all_extents compilation performance

[Ken Matsui]

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

libstdc++-v3/ChangeLog:

        * include/std/type_traits (remove_all_extents): Use
        __remove_all_extents built-in trait.

Signed-off-by: Ken Matsui <kmat...@gcc.gnu.org>
---
 libstdc++-v3/include/std/type_traits | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libstdc++-v3/include/std/type_traits 
b/libstdc++-v3/include/std/type_traits
index 58281c2e38c..5b74e44d0a6 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -2111,6 +2111,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 #endif
 
   /// remove_all_extents
+#if _GLIBCXX_USE_BUILTIN_TRAIT(__remove_all_extents)
+  template<typename _Tp>
+    struct remove_all_extents
+    { using type = __remove_all_extents(_Tp); };
+#else
   template<typename _Tp>
     struct remove_all_extents
     { using type = _Tp; };
@@ -2122,6 +2127,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   template<typename _Tp>
     struct remove_all_extents<_Tp[]>
     { using type = typename remove_all_extents<_Tp>::type; };
+#endif
 
 #if __cplusplus > 201103L
   /// Alias template for remove_extent
-- 
2.44.0