1 // RUN: %clang_cc1 -std=c++2a -verify %s
2
3 struct A {};
operator <=>(A a,A b)4 constexpr int operator<=>(A a, A b) { return 42; }
5 static_assert(operator<=>(A(), A()) == 42);
6
7 int operator<=>(); // expected-error {{overloaded 'operator<=>' must have at least one parameter of class or enumeration type}}
8 int operator<=>(A); // expected-error {{overloaded 'operator<=>' must be a binary operator}}
9 int operator<=>(int, int); // expected-error {{overloaded 'operator<=>' must have at least one parameter of class or enumeration type}}
10 int operator<=>(A, A, A); // expected-error {{overloaded 'operator<=>' must be a binary operator}}
11 int operator<=>(A, A, ...); // expected-error {{overloaded 'operator<=>' cannot be variadic}}
12 int operator<=>(int, A = {}); // expected-error {{parameter of overloaded 'operator<=>' cannot have a default argument}}
13
14 struct B {
15 int &operator<=>(int);
16 friend int operator<=>(A, B);
17
18 friend int operator<=>(int, int); // expected-error {{overloaded 'operator<=>' must have at least one parameter of class or enumeration type}}
19 void operator<=>(); // expected-error {{overloaded 'operator<=>' must be a binary operator}};
20 void operator<=>(A, ...); // expected-error {{overloaded 'operator<=>' cannot be variadic}}
21 void operator<=>(A, A); // expected-error {{overloaded 'operator<=>' must be a binary operator}};
22 };
23
24 int &r = B().operator<=>(0);
25