209 lines · cpp
1// This test is for the [class.compare.default]p3 added by P2002R02// Also covers modifications made by P2448R23 4// RUN: %clang_cc1 -std=c++2a -verify=expected,cxx2a %s5// RUN: %clang_cc1 -std=c++23 -verify=expected %s6 7namespace std {8 struct strong_ordering {9 int n;10 constexpr operator int() const { return n; }11 static const strong_ordering less, equal, greater;12 };13 constexpr strong_ordering strong_ordering::less = {-1};14 constexpr strong_ordering strong_ordering::equal = {0};15 constexpr strong_ordering strong_ordering::greater = {1};16}17 18struct A {19 friend bool operator==(const A&, const A&) = default;20 friend bool operator!=(const A&, const A&) = default;21 22 friend std::strong_ordering operator<=>(const A&, const A&) = default;23 friend bool operator<(const A&, const A&) = default;24 friend bool operator<=(const A&, const A&) = default;25 friend bool operator>(const A&, const A&) = default;26 friend bool operator>=(const A&, const A&) = default;27};28struct TestA {29 friend constexpr bool operator==(const A&, const A&) noexcept;30 friend constexpr bool operator!=(const A&, const A&) noexcept;31 32 friend constexpr std::strong_ordering operator<=>(const A&, const A&) noexcept;33 friend constexpr bool operator<(const A&, const A&);34 friend constexpr bool operator<=(const A&, const A&);35 friend constexpr bool operator>(const A&, const A&);36 friend constexpr bool operator>=(const A&, const A&);37};38 39// Declaration order doesn't matter, even though the secondary operators need40// to know whether the primary ones are constexpr.41struct ReversedA {42 friend bool operator>=(const ReversedA&, const ReversedA&) = default;43 friend bool operator>(const ReversedA&, const ReversedA&) = default;44 friend bool operator<=(const ReversedA&, const ReversedA&) = default;45 friend bool operator<(const ReversedA&, const ReversedA&) = default;46 friend std::strong_ordering operator<=>(const ReversedA&, const ReversedA&) = default;47 48 friend bool operator!=(const ReversedA&, const ReversedA&) = default;49 friend bool operator==(const ReversedA&, const ReversedA&) = default;50};51struct TestReversedA {52 friend constexpr bool operator>=(const ReversedA&, const ReversedA&);53 friend constexpr bool operator>(const ReversedA&, const ReversedA&);54 friend constexpr bool operator<=(const ReversedA&, const ReversedA&);55 friend constexpr bool operator<(const ReversedA&, const ReversedA&);56 friend constexpr std::strong_ordering operator<=>(const ReversedA&, const ReversedA&) noexcept;57 58 friend constexpr bool operator!=(const ReversedA&, const ReversedA&) noexcept;59 friend constexpr bool operator==(const ReversedA&, const ReversedA&) noexcept;60};61 62struct B {63 A a;64 friend bool operator==(const B&, const B&) = default;65 friend bool operator!=(const B&, const B&) = default;66 67 friend std::strong_ordering operator<=>(const B&, const B&) = default;68 friend bool operator<(const B&, const B&) = default;69 friend bool operator<=(const B&, const B&) = default;70 friend bool operator>(const B&, const B&) = default;71 friend bool operator>=(const B&, const B&) = default;72};73struct TestB {74 friend constexpr bool operator==(const B&, const B&) noexcept;75 friend constexpr bool operator!=(const B&, const B&) noexcept;76 77 friend constexpr std::strong_ordering operator<=>(const B&, const B&);78 friend constexpr bool operator<(const B&, const B&);79 friend constexpr bool operator<=(const B&, const B&);80 friend constexpr bool operator>(const B&, const B&);81 friend constexpr bool operator>=(const B&, const B&);82};83 84struct C {85 friend bool operator==(const C&, const C&); // expected-note {{previous}} \86 // cxx2a-note 2{{declared here}}87 friend bool operator!=(const C&, const C&) = default; // expected-note {{previous}}88 89 friend std::strong_ordering operator<=>(const C&, const C&); // expected-note {{previous}} \90 // cxx2a-note 2{{declared here}}91 friend bool operator<(const C&, const C&) = default; // expected-note {{previous}}92 friend bool operator<=(const C&, const C&) = default; // expected-note {{previous}}93 friend bool operator>(const C&, const C&) = default; // expected-note {{previous}}94 friend bool operator>=(const C&, const C&) = default; // expected-note {{previous}}95};96struct TestC {97 friend constexpr bool operator==(const C&, const C&); // expected-error {{non-constexpr}}98 friend constexpr bool operator!=(const C&, const C&); // expected-error {{non-constexpr}}99 100 friend constexpr std::strong_ordering operator<=>(const C&, const C&); // expected-error {{non-constexpr}}101 friend constexpr bool operator<(const C&, const C&); // expected-error {{non-constexpr}}102 friend constexpr bool operator<=(const C&, const C&); // expected-error {{non-constexpr}}103 friend constexpr bool operator>(const C&, const C&); // expected-error {{non-constexpr}}104 friend constexpr bool operator>=(const C&, const C&); // expected-error {{non-constexpr}}105};106 107struct D {108 A a;109 C c;110 A b;111 friend bool operator==(const D&, const D&) = default; // expected-note {{previous}}112 friend bool operator!=(const D&, const D&) = default; // expected-note {{previous}}113 114 friend std::strong_ordering operator<=>(const D&, const D&) = default; // expected-note {{previous}}115 friend bool operator<(const D&, const D&) = default; // expected-note {{previous}}116 friend bool operator<=(const D&, const D&) = default; // expected-note {{previous}}117 friend bool operator>(const D&, const D&) = default; // expected-note {{previous}}118 friend bool operator>=(const D&, const D&) = default; // expected-note {{previous}}119};120struct TestD {121 friend constexpr bool operator==(const D&, const D&); // expected-error {{non-constexpr}}122 friend constexpr bool operator!=(const D&, const D&); // expected-error {{non-constexpr}}123 124 friend constexpr std::strong_ordering operator<=>(const D&, const D&); // expected-error {{non-constexpr}}125 friend constexpr bool operator<(const D&, const D&); // expected-error {{non-constexpr}}126 friend constexpr bool operator<=(const D&, const D&); // expected-error {{non-constexpr}}127 friend constexpr bool operator>(const D&, const D&); // expected-error {{non-constexpr}}128 friend constexpr bool operator>=(const D&, const D&); // expected-error {{non-constexpr}}129};130 131 132struct E {133 A a;134 C c; // cxx2a-note 2{{non-constexpr comparison function would be used to compare member 'c'}}135 A b;136 friend constexpr bool operator==(const E&, const E&) = default; // cxx2a-error {{cannot be declared constexpr}}137 friend constexpr bool operator!=(const E&, const E&) = default;138 139 friend constexpr std::strong_ordering operator<=>(const E&, const E&) = default; // cxx2a-error {{cannot be declared constexpr}}140 friend constexpr bool operator<(const E&, const E&) = default;141 friend constexpr bool operator<=(const E&, const E&) = default;142 friend constexpr bool operator>(const E&, const E&) = default;143 friend constexpr bool operator>=(const E&, const E&) = default;144};145 146struct E2 : A, C { // cxx2a-note 2{{non-constexpr comparison function would be used to compare base class 'C'}}147 friend constexpr bool operator==(const E2&, const E2&) = default; // cxx2a-error {{cannot be declared constexpr}}148 friend constexpr bool operator!=(const E2&, const E2&) = default;149 150 friend constexpr std::strong_ordering operator<=>(const E2&, const E2&) = default; // cxx2a-error {{cannot be declared constexpr}}151 friend constexpr bool operator<(const E2&, const E2&) = default;152 friend constexpr bool operator<=(const E2&, const E2&) = default;153 friend constexpr bool operator>(const E2&, const E2&) = default;154 friend constexpr bool operator>=(const E2&, const E2&) = default;155};156 157struct F {158 friend bool operator==(const F&, const F&); // cxx2a-note {{declared here}}159 friend constexpr bool operator!=(const F&, const F&) = default; // cxx2a-error {{cannot be declared constexpr}}160 161 friend std::strong_ordering operator<=>(const F&, const F&); // cxx2a-note 4{{non-constexpr comparison function declared here}}162 friend constexpr bool operator<(const F&, const F&) = default; // cxx2a-error {{cannot be declared constexpr}}163 friend constexpr bool operator<=(const F&, const F&) = default; // cxx2a-error {{cannot be declared constexpr}}164 friend constexpr bool operator>(const F&, const F&) = default; // cxx2a-error {{cannot be declared constexpr}}165 friend constexpr bool operator>=(const F&, const F&) = default; // cxx2a-error {{cannot be declared constexpr}}166};167 168// No implicit 'constexpr' if it's not the first declaration.169// FIXME: This rule creates problems for reordering of declarations; is this170// really the right model?171struct G;172bool operator==(const G&, const G&); // expected-note {{previous declaration}}173bool operator!=(const G&, const G&); // expected-note {{previous declaration}}174std::strong_ordering operator<=>(const G&, const G&); // expected-note {{previous declaration}}175bool operator<(const G&, const G&); // expected-note {{previous declaration}}176bool operator<=(const G&, const G&); // expected-note {{previous declaration}}177bool operator>(const G&, const G&); // expected-note {{previous declaration}}178bool operator>=(const G&, const G&); // expected-note {{previous declaration}}179struct G {180 friend bool operator==(const G&, const G&) = default; // expected-error {{because it was already declared outside}}181 friend bool operator!=(const G&, const G&) = default; // expected-error {{because it was already declared outside}}182 183 friend std::strong_ordering operator<=>(const G&, const G&) = default; // expected-error {{because it was already declared outside}}184 friend bool operator<(const G&, const G&) = default; // expected-error {{because it was already declared outside}}185 friend bool operator<=(const G&, const G&) = default; // expected-error {{because it was already declared outside}}186 friend bool operator>(const G&, const G&) = default; // expected-error {{because it was already declared outside}}187 friend bool operator>=(const G&, const G&) = default; // expected-error {{because it was already declared outside}}188};189bool operator==(const G&, const G&);190bool operator!=(const G&, const G&);191 192std::strong_ordering operator<=>(const G&, const G&);193bool operator<(const G&, const G&);194bool operator<=(const G&, const G&);195bool operator>(const G&, const G&);196bool operator>=(const G&, const G&);197 198namespace PR44721 {199 template <typename T> bool operator==(T const &, T const &) { return true; }200 template <typename T, typename U> bool operator!=(T const &, U const &) { return true; }201 template <typename T> int operator<=>(T const &, T const &) { return 0; }202 203 struct S {204 friend bool operator==(const S &, const S &) = default;205 friend bool operator<=>(const S &, const S &) = default;206 int x;207 };208}209