--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libstdc++-v3/testsuite/24_iterators/insert_iterator/constexpr.cc	Mon May 25 07:50:57 2020 +0900
@@ -0,0 +1,63 @@
+// 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 <iterator>
+
+#ifndef __cpp_lib_constexpr_iterator
+# error "Feature test macro for constexpr insert iterators is missing in <iterator>"
+#elif __cpp_lib_constexpr_iterator < 201811L
+# error "Feature test macro for constexpr insert iterators has wrong value in <iterator>"
+#endif
+
+struct container
+{
+  using value_type = int;
+
+  constexpr int* begin() { return std::begin(data); }
+  constexpr int* end() { return last; }
+
+  constexpr int* insert(int* pos, int val)
+  {
+    if (last == std::end(data))
+      throw val;
+    for (int* i = last++; i != pos; --i)
+      i[1] = i[0];
+    *pos = val;
+    return pos;
+  }
+
+  int data[3];
+  int* last = std::begin(data);
+};
+
+constexpr bool
+test01()
+{
+  container c;
+  std::insert_iterator<container> iter;
+  iter = std::inserter(c, c.begin());
+  *iter++ = 1;
+  int i = 2;
+  *iter = i;
+  *++iter = 3;
+  return c.data[0] == 1 && c.data[1] == 2 && c.data[2] == 3;
+}
+
+static_assert( test01() );