1 // RUN: %clang_cc1 -std=c++2a -verify %s
2 
3 template<int> struct X {};
4 
5 X<1> operator<<(X<0>, X<0>);
6 X<2> operator<=>(X<0>, X<1>);
7 X<2> operator<=>(X<1>, X<0>);
8 X<3> operator<(X<0>, X<2>);
9 X<3> operator<(X<2>, X<0>);
10 
f(X<0> x0,X<1> x1)11 void f(X<0> x0, X<1> x1) {
12   X<2> a = x0 <=> x0 << x0;
13   X<2> b = x0 << x0 <=> x0; // expected-warning {{overloaded operator << has higher precedence than comparison operator}} expected-note 2{{}}
14   X<3> c = x0 < x0 <=> x1;
15   X<3> d = x1 <=> x0 < x0;
16   X<3> e = x0 < x0 <=> x0 << x0;
17   X<3> f = x0 << x0 <=> x0 < x0; // expected-warning {{overloaded operator << has higher precedence than comparison operator}} expected-note 2{{}}
18 }
19 
20 struct PR41991 {
21   [[nodiscard]] friend bool operator==(const PR41991&, const PR41991&) = default;
22   [[nodiscard]] friend bool operator!=(const PR41991&, const PR41991&) = delete;
23   [[nodiscard]] friend bool operator<(const PR41991&, const PR41991&); // expected-error {{an attribute list cannot appear here}}
24 };
25