[c++2a] P0515R3: Support for overloaded operator<=>.

No CodeGen support for MSABI yet, we don't know how to mangle this there.

llvm-svn: 319513

1 files changed, 24 insertions, 0 deletions

diff --git a/clang/test/SemaCXX/cxx2a-three-way-comparison.cpp b/clang/test/SemaCXX/cxx2a-three-way-comparison.cpp
new file mode 100644
index 00000000000..eb1480ce610
--- /dev/null
+++ b/clang/test/SemaCXX/cxx2a-three-way-comparison.cpp
@@ -0,0 +1,24 @@
+// RUN: %clang_cc1 -std=c++2a -verify %s
+
+struct A {};
+constexpr int operator<=>(A a, A b) { return 42; }
+static_assert(operator<=>(A(), A()) == 42);
+
+int operator<=>(); // expected-error {{overloaded 'operator<=>' must have at least one parameter of class or enumeration type}}
+int operator<=>(A); // expected-error {{overloaded 'operator<=>' must be a binary operator}}
+int operator<=>(int, int); // expected-error {{overloaded 'operator<=>' must have at least one parameter of class or enumeration type}}
+int operator<=>(A, A, A); // expected-error {{overloaded 'operator<=>' must be a binary operator}}
+int operator<=>(A, A, ...); // expected-error {{overloaded 'operator<=>' cannot be variadic}}
+int operator<=>(int, A = {}); // expected-error {{parameter of overloaded 'operator<=>' cannot have a default argument}}
+
+struct B {
+  int &operator<=>(int);
+  friend int operator<=>(A, B);
+
+  friend int operator<=>(int, int); // expected-error {{overloaded 'operator<=>' must have at least one parameter of class or enumeration type}}
+  void operator<=>(); // expected-error {{overloaded 'operator<=>' must be a binary operator}};
+  void operator<=>(A, ...); // expected-error {{overloaded 'operator<=>' cannot be variadic}}
+  void operator<=>(A, A); // expected-error {{overloaded 'operator<=>' must be a binary operator}};
+};
+
+int &r = B().operator<=>(0);