c++: One more spaceship test.

Jakub suggested adding a variant where we actually try to call the
implicitly deleted operator.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp2a/spaceship-synth8a.C: New test.

diff --git a/gcc/testsuite/g++.dg/cpp2a/spaceship-synth8a.C b/gcc/testsuite/g++.dg/cpp2a/spaceship-synth8a.C
new file mode 100644 (file)
index 0000000..42a32da
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/spaceship-synth8a.C
@@ -0,0 +1,25 @@
+// PR c++/94907
+// { dg-do compile { target c++20 } }
+
+namespace std { struct strong_ordering {
+  int _v;
+  constexpr strong_ordering (int v) :_v(v) {}
+  constexpr operator int (void) const { return _v; }
+  static const strong_ordering less;
+  static const strong_ordering equal;
+  static const strong_ordering greater;
+};
+constexpr strong_ordering strong_ordering::less = -1;
+constexpr strong_ordering strong_ordering::equal = 0;
+constexpr strong_ordering strong_ordering::greater = 1;
+}
+
+struct E;
+struct D {
+  virtual std::strong_ordering operator<=>(const struct E&) const = 0;
+};
+struct E : D {                                                        // { dg-error "no match" }
+  std::strong_ordering operator<=>(const E&) const override = default; // { dg-message "default" }
+};
+
+auto x = E() <=> E();          // { dg-error "deleted" }