Define __cpp_lib_endian feature test macro

This macro was added as part of moving std::endian from <type_traits> to
<bit>.

	* include/std/bit (__cpp_lib_endian): Define.
	* include/std/version (__cpp_lib_endian): Define.
	* testsuite/26_numerics/endian/2.cc: New.
	* testsuite/26_numerics/endian/3.cc: New.
	* testsuite/26_numerics/endian/4.cc: New.

From-SVN: r273828

6 files changed, 90 insertions, 0 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index c9c338f..98807d8 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,11 @@
+2019-07-26  Jonathan Wakely  <jwakely@redhat.com>
+
+	* include/std/bit (__cpp_lib_endian): Define.
+	* include/std/version (__cpp_lib_endian): Define.
+	* testsuite/26_numerics/endian/2.cc: New.
+	* testsuite/26_numerics/endian/3.cc: New.
+	* testsuite/26_numerics/endian/4.cc: New.
+
 2019-07-26  François Dumont  <fdumont@gcc.gnu.org>
 
 	* testsuite/util/testsuite_iterators.h
diff --git a/libstdc++-v3/include/std/bit b/libstdc++-v3/include/std/bit
index d57433c..f01fcd6 100644
--- a/libstdc++-v3/include/std/bit
+++ b/libstdc++-v3/include/std/bit
@@ -315,6 +315,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     log2p1(_Tp __x) noexcept
     { return std::__log2p1(__x); }
 
+#define __cpp_lib_endian 201907L
+
   /// Byte order
   enum class endian
   {
diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version
index d134f7f..6940b44 100644
--- a/libstdc++-v3/include/std/version
+++ b/libstdc++-v3/include/std/version
@@ -156,6 +156,7 @@
 #if __cpp_impl_destroying_delete
 # define __cpp_lib_destroying_delete 201806L
 #endif
+#define __cpp_lib_endian 201907L
 #define __cpp_lib_erase_if 201900L
 #define __cpp_lib_interpolate 201902L
 #ifdef _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED
diff --git a/libstdc++-v3/testsuite/26_numerics/endian/2.cc b/libstdc++-v3/testsuite/26_numerics/endian/2.cc
new file mode 100644
index 0000000..474bae4
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/endian/2.cc
@@ -0,0 +1,27 @@
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <bit>
+
+#ifndef __cpp_lib_endian
+# error "Feature-test macro for endian missing in <bit>"
+#elif __cpp_lib_endian != 201907L
+# error "Feature-test macro for endian has wrong value in <bit>"
+#endif
diff --git a/libstdc++-v3/testsuite/26_numerics/endian/3.cc b/libstdc++-v3/testsuite/26_numerics/endian/3.cc
new file mode 100644
index 0000000..a7af53d
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/endian/3.cc
@@ -0,0 +1,27 @@
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <version>
+
+#ifndef __cpp_lib_endian
+# error "Feature-test macro for endian missing in <version>"
+#elif __cpp_lib_endian != 201907L
+# error "Feature-test macro for endian has wrong value in <version>"
+#endif
diff --git a/libstdc++-v3/testsuite/26_numerics/endian/4.cc b/libstdc++-v3/testsuite/26_numerics/endian/4.cc
new file mode 100644
index 0000000..93bed38
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/endian/4.cc
@@ -0,0 +1,25 @@
+// Copyright (C) 2019 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-do compile { target c++17_down } }
+
+#include <bit>
+#include <version>
+
+#ifdef __cpp_lib_endian
+# error "Feature-test macro for endian defined before C++20"
+#endif