--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libstdc++-v3/testsuite/21_strings/basic_string_view/operations/copy/char/constexpr.cc	Mon May 25 07:50:57 2020 +0900
@@ -0,0 +1,38 @@
+// Copyright (C) 2020 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 <string_view>
+
+#ifndef __cpp_lib_constexpr_string_view
+# error "Feature test macro for constexpr copy is missing in <string_view>"
+#elif __cpp_lib_constexpr_iterator < 201811L
+# error "Feature test macro for constexpr copy has wrong value in <string_view>"
+#endif
+
+constexpr bool
+test01()
+{
+  std::string_view s = "Everything changes and nothing stands still.";
+  char buf[7]{};
+  auto n = s.copy(buf, 7, 11);
+  return std::string_view(buf, n) == "changes";
+}
+
+static_assert( test01() );