[PATCH] Relocate std::endian from <type_traits> to <bit>

[Jonathan Wakely]

This change to an early C++2a feature was just approved (P1612R1).

	* include/std/bit (endian): Move definition here as per P1612R1.
	* include/std/type_traits (endian): Remove definition from here.
	* testsuite/20_util/endian/1.cc: Rename to ...
	* testsuite/26_numerics/endian/1.cc: ... here. Adjust header.


Tested x86_64-linux, committed to trunk. I'll also backport to gcc-9.


-------------- next part --------------
commit 175a348ce63ad554228e6b58f4fbc6ca559b66cc
Author: redi <redi@138bc75d-0d04-0410-961f-82ee72b054a4>
Date:   Thu Jul 25 20:30:25 2019 +0000

    Relocate std::endian from <type_traits> to <bit>
    
    This change to an early C++2a feature was just approved (P1612R1).
    
            * include/std/bit (endian): Move definition here as per P1612R1.
            * include/std/type_traits (endian): Remove definition from here.
            * testsuite/20_util/endian/1.cc: Rename to ...
            * testsuite/26_numerics/endian/1.cc: ... here. Adjust header.
    
    git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@273816 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/libstdc++-v3/include/std/bit b/libstdc++-v3/include/std/bit
index f17d2f1bd59..d57433c093a 100644
--- a/libstdc++-v3/include/std/bit
+++ b/libstdc++-v3/include/std/bit
@@ -315,6 +315,13 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     log2p1(_Tp __x) noexcept
     { return std::__log2p1(__x); }
 
+  /// Byte order
+  enum class endian
+  {
+    little = __ORDER_LITTLE_ENDIAN__,
+    big    = __ORDER_BIG_ENDIAN__,
+    native = __BYTE_ORDER__
+  };
 #endif // C++2a
 
 _GLIBCXX_END_NAMESPACE_VERSION
diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits
index d8ed1ce120d..9428dadc9d7 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -3226,14 +3226,6 @@ template <typename _From, typename _To>
 #endif // C++17
 
 #if __cplusplus > 201703L
-  /// Byte order
-  enum class endian
-  {
-    little = __ORDER_LITTLE_ENDIAN__,
-    big    = __ORDER_BIG_ENDIAN__,
-    native = __BYTE_ORDER__
-  };
-
   /// Remove references and cv-qualifiers.
   template<typename _Tp>
     struct remove_cvref
diff --git a/libstdc++-v3/testsuite/20_util/endian/1.cc b/libstdc++-v3/testsuite/26_numerics/endian/1.cc
similarity index 98%
rename from libstdc++-v3/testsuite/20_util/endian/1.cc
rename to libstdc++-v3/testsuite/26_numerics/endian/1.cc
+++ b/libstdc++-v3/testsuite/26_numerics/endian/1.cc
@@ -18,7 +18,7 @@
 // { dg-options "-std=gnu++2a" }
 // { dg-do compile { target c++2a } }
 
-#include <type_traits>
+#include <bit>
 
 static_assert( std::is_enum_v<std::endian> );
 static_assert( std::endian::little != std::endian::big );