// RUN: %clang_cc1 -std=c++2a -verify %s // Keep this test before any declarations of operator<=>. namespace PR44786 { template void f(decltype(T{} <=> T{})) {} // expected-note {{previous}} struct S {}; int operator<=>(S const &, S const &); template void f(decltype(T{} <=> T{})) {} // expected-error {{redefinition}} } 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); namespace PR47893 { struct A { void operator<=>(const A&) const; }; template auto f(T a, T b) -> decltype(a < b) = delete; int &f(...); int &r = f(A(), A()); }