2020-01-29 Jonathan Wakely <jwakely@redhat.com>
+ PR libstdc++/93479
+ * libsupc++/compare (__3way_builtin_ptr_cmp): Require <=> to be valid.
+ * testsuite/18_support/comparisons/object/93479.cc: New test.
+
* testsuite/std/ranges/access/end.cc: Do not assume test_range::end()
returns the same type as test_range::begin(). Add comments.
* testsuite/std/ranges/access/rbegin.cc: Likewise.
// BUILTIN-PTR-THREE-WAY(T, U)
template<typename _Tp, typename _Up>
concept __3way_builtin_ptr_cmp
- = convertible_to<_Tp, const volatile void*>
+ = requires(_Tp&& __t, _Up&& __u)
+ { static_cast<_Tp&&>(__t) <=> static_cast<_Up&&>(__u); }
+ && convertible_to<_Tp, const volatile void*>
&& convertible_to<_Up, const volatile void*>
&& ! requires(_Tp&& __t, _Up&& __u)
{ operator<=>(static_cast<_Tp&&>(__t), static_cast<_Up&&>(__u)); }
--- /dev/null
+// 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 <compare>
+
+void
+test01()
+{
+ // PR libstdc++/93479
+ int i[1];
+ int j[1];
+ std::compare_three_way{}(i, j); // { dg-error "no match" }
+}
+
+void
+test02()
+{
+ struct X
+ {
+ operator const char*() const noexcept { return "!"; }
+ void operator<=>(X) const = delete;
+ void operator<=>(const void*) const = delete;
+ } x;
+ std::compare_three_way{}(x, x); // { dg-error "no match" }
+ std::compare_three_way{}(x, ""); // { dg-error "no match" }
+ std::compare_three_way{}("", x); // { dg-error "no match" }
+}