--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libstdc++-v3/testsuite/ext/new_allocator/89510.cc	Mon May 25 07:50:57 2020 +0900
@@ -0,0 +1,149 @@
+// 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-do compile { target c++11 } }
+
+#include <ext/new_allocator.h>
+#include <memory>
+#include <type_traits>
+
+using __gnu_cxx::new_allocator;
+using AT = std::allocator_traits<new_allocator<int>>;
+
+template<typename...> using void_t = void;
+
+template<typename T, typename U, typename = void>
+struct has_construct
+: std::false_type
+{ };
+
+template<typename T, typename U>
+struct has_construct<T, U,
+    void_t<decltype(std::declval<T&>().construct(std::declval<U*>()))>>
+: std::true_type
+{ };
+
+template<typename T, typename U, typename = void>
+struct has_destroy
+: std::false_type
+{ };
+
+template<typename T, typename U>
+struct has_destroy<T, U,
+    void_t<decltype(std::declval<T&>().destroy(std::declval<U*>()))>>
+: std::true_type
+{ };
+
+template<typename T, typename U, typename = void>
+struct has_traits_construct
+: std::false_type
+{ };
+
+template<typename T, typename U>
+struct has_traits_construct<T, U,
+    void_t<decltype(AT::construct(std::declval<T&>(), std::declval<U*>()))>>
+: std::true_type
+{ };
+
+template<typename T, typename U, typename = void>
+struct has_traits_destroy
+: std::false_type
+{ };
+
+template<typename T, typename U>
+struct has_traits_destroy<T, U,
+    void_t<decltype(AT::destroy(std::declval<T&>(), std::declval<U*>()))>>
+: std::true_type
+{ };
+
+struct NoDefault { NoDefault(int); };
+struct NoDest { private: ~NoDest(); };
+
+// Whether true or false, these should not give errors:
+constexpr bool c = has_construct<new_allocator<NoDefault>, NoDefault>::value;
+constexpr bool c2 = has_traits_construct<new_allocator<int>, NoDefault>::value;
+constexpr bool d = has_destroy<new_allocator<NoDest>, NoDest>::value;
+constexpr bool d2 = has_traits_destroy<new_allocator<int>, NoDest>::value;
+
+new_allocator<int> a;
+
+long* lp;
+#if __cplusplus <= 201703L
+static_assert( noexcept(a.construct(lp)), "" );
+static_assert( noexcept(a.construct(lp, 1L)), "" );
+static_assert( noexcept(a.construct(lp, 2)), "" );
+static_assert( noexcept(a.construct(lp, 2U)), "" );
+static_assert( noexcept(a.destroy(lp)), "" );
+#endif
+static_assert( noexcept(AT::construct(a, lp)), "" );
+static_assert( noexcept(AT::construct(a, lp, 1L)), "" );
+static_assert( noexcept(AT::construct(a, lp, 2)), "" );
+static_assert( noexcept(AT::construct(a, lp, 2U)), "" );
+static_assert( noexcept(AT::destroy(a, lp)), "" );
+
+struct X
+{
+  X() noexcept;
+  X(int) noexcept;
+  ~X() noexcept;
+};
+
+X* xp;
+#if __cplusplus <= 201703L
+static_assert( noexcept(a.construct(xp)), "" );
+static_assert( noexcept(a.construct(xp, 1)), "" );
+static_assert( noexcept(a.destroy(xp)), "" );
+#endif
+static_assert( noexcept(AT::construct(a, xp)), "" );
+static_assert( noexcept(AT::construct(a, xp, 1)), "" );
+static_assert( noexcept(AT::destroy(a, xp)), "" );
+
+struct Y
+{
+  Y() noexcept;
+  Y(int) noexcept(false);
+  ~Y() noexcept;
+};
+
+Y* yp;
+#if __cplusplus <= 201703L
+static_assert( noexcept(a.construct(yp)), "" );
+static_assert( ! noexcept(a.construct(yp, 1)), "" );
+static_assert( noexcept(a.destroy(yp)), "" );
+#endif
+static_assert( noexcept(AT::construct(a, yp)), "" );
+static_assert( ! noexcept(AT::construct(a, yp, 1)), "" );
+static_assert( noexcept(AT::destroy(a, yp)), "" );
+
+struct Z
+{
+  Z() noexcept;
+  Z(int) noexcept;
+  ~Z() noexcept(false);
+};
+
+Z* zp;
+// These construct calls should be noexcept, but they are false because
+// they use is_nothrow_constructible which depends on is_nothrow_destructible.
+#if __cplusplus <= 201703L
+static_assert( ! noexcept(a.construct(zp)), "wrong" );
+static_assert( ! noexcept(a.construct(zp, 1)), "wrong" );
+static_assert( ! noexcept(a.destroy(zp)), "" );
+#endif
+static_assert( ! noexcept(AT::construct(a, zp)), "" );
+static_assert( ! noexcept(AT::construct(a, zp, 1)), "" );
+static_assert( ! noexcept(AT::destroy(a, zp)), "" );