clang/test/CXX/class/class.compare/class.compare.secondary/p2.cpp

   1 // RUN: %clang_cc1 -std=c++20 -verify %s
   2
   3 struct A {
   4   bool operator!=(const A&) const = default; // expected-warning {{explicitly defaulted equality comparison operator is implicitly deleted}} expected-note{{replace 'default'}}
   5   // expected-note@-1 {{defaulted 'operator!=' is implicitly deleted because there is no viable 'operator==' for 'A'}}
   6 };
   7
   8 struct A2 {
   9   struct E {};
  10   E e;
  11   bool operator==(const A2&) const = default; // expected-warning {{explicitly defaulted equality comparison operator is implicitly deleted}} expected-note{{replace 'default'}}
  12   // expected-note@-2 {{defaulted 'operator==' is implicitly deleted because there is no viable 'operator==' for member 'e'}}
  13 };
  14
  15
  16 struct Q {};
  17 bool operator!=(Q, Q); // expected-note {{defaulted 'operator!=' is implicitly deleted because this non-rewritten comparison function would be the best match for the comparison}}
  18 struct B {
  19   operator Q() const;
  20   bool operator!=(const B&) const = default; // expected-warning {{explicitly defaulted equality comparison operator is implicitly deleted}} expected-note{{replace 'default'}}
  21 };
  22
  23 struct R {};
  24 bool operator==(R, R);
  25 struct B2 {
  26   operator R() const;
  27   bool operator!=(const B2&) const = default; // OK! Converts to use rewritten R comparison.
  28 };
  29
  30 struct C {
  31   operator int() const; // expected-note {{defaulted 'operator!=' is implicitly deleted because a builtin comparison function using this conversion would be the best match for the comparison}}
  32   bool operator!=(const C&) const = default; // expected-warning {{explicitly defaulted equality comparison operator is implicitly deleted}} expected-note{{replace 'default'}}
  33 };
  34
  35 struct D {
  36   bool operator<(const D&) const = default; // expected-warning {{explicitly defaulted relational comparison operator is implicitly deleted}} expected-note{{replace 'default'}}
  37   // expected-note@-1 {{defaulted 'operator<' is implicitly deleted because there is no viable three-way comparison function for 'D'}}
  38 };
  39
  40 bool operator<(Q, Q); // expected-note {{defaulted 'operator<' is implicitly deleted because this non-rewritten comparison function would be the best match for the comparison}}
  41 struct E {
  42   operator Q() const;
  43   bool operator<(const E&) const = default; // expected-warning {{explicitly defaulted relational comparison operator is implicitly deleted}} expected-note{{replace 'default'}}
  44 };
  45
  46 int operator<=>(R, R);
  47 struct E2 {
  48   operator R() const;
  49   bool operator<(const E2&) const = default;
  50 };
  51
  52 struct F {
  53   operator int() const; // expected-note {{defaulted 'operator<' is implicitly deleted because a builtin comparison function using this conversion would be the best match for the comparison}}
  54   bool operator<(const F&) const = default; // expected-warning {{explicitly defaulted relational comparison operator is implicitly deleted}} expected-note{{replace 'default'}}
  55 };