1 // This test is for the [class.compare.default]p3 added by P2002R0 2 3 // RUN: %clang_cc1 -std=c++2a -verify %s 4 5 namespace std { 6 struct strong_ordering { 7 int n; operator intstd::strong_ordering8 constexpr operator int() const { return n; } 9 static const strong_ordering less, equal, greater; 10 }; 11 constexpr strong_ordering strong_ordering::less = {-1}; 12 constexpr strong_ordering strong_ordering::equal = {0}; 13 constexpr strong_ordering strong_ordering::greater = {1}; 14 } 15 16 struct A { 17 friend bool operator==(const A&, const A&) = default; 18 friend bool operator!=(const A&, const A&) = default; 19 20 friend std::strong_ordering operator<=>(const A&, const A&) = default; 21 friend bool operator<(const A&, const A&) = default; 22 friend bool 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 }; 26 struct TestA { 27 friend constexpr bool operator==(const A&, const A&) noexcept; 28 friend constexpr bool operator!=(const A&, const A&) noexcept; 29 30 friend constexpr std::strong_ordering operator<=>(const A&, const A&) noexcept; 31 friend constexpr bool operator<(const A&, const A&); 32 friend constexpr bool operator<=(const A&, const A&); 33 friend constexpr bool operator>(const A&, const A&); 34 friend constexpr bool operator>=(const A&, const A&); 35 }; 36 37 // Declaration order doesn't matter, even though the secondary operators need 38 // to know whether the primary ones are constexpr. 39 struct ReversedA { 40 friend bool operator>=(const ReversedA&, const ReversedA&) = default; 41 friend bool operator>(const ReversedA&, const ReversedA&) = default; 42 friend bool operator<=(const ReversedA&, const ReversedA&) = default; 43 friend bool operator<(const ReversedA&, const ReversedA&) = default; 44 friend std::strong_ordering operator<=>(const ReversedA&, const ReversedA&) = default; 45 46 friend bool operator!=(const ReversedA&, const ReversedA&) = default; 47 friend bool operator==(const ReversedA&, const ReversedA&) = default; 48 }; 49 struct TestReversedA { 50 friend constexpr bool operator>=(const ReversedA&, const ReversedA&); 51 friend constexpr bool operator>(const ReversedA&, const ReversedA&); 52 friend constexpr bool operator<=(const ReversedA&, const ReversedA&); 53 friend constexpr bool operator<(const ReversedA&, const ReversedA&); 54 friend constexpr std::strong_ordering operator<=>(const ReversedA&, const ReversedA&) noexcept; 55 56 friend constexpr bool operator!=(const ReversedA&, const ReversedA&) noexcept; 57 friend constexpr bool operator==(const ReversedA&, const ReversedA&) noexcept; 58 }; 59 60 struct B { 61 A a; 62 friend bool operator==(const B&, const B&) = default; 63 friend bool operator!=(const B&, const B&) = default; 64 65 friend std::strong_ordering operator<=>(const B&, const B&) = default; 66 friend bool operator<(const B&, const B&) = default; 67 friend bool 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 }; 71 struct TestB { 72 friend constexpr bool operator==(const B&, const B&) noexcept; 73 friend constexpr bool operator!=(const B&, const B&) noexcept; 74 75 friend constexpr std::strong_ordering operator<=>(const B&, const B&); 76 friend constexpr bool operator<(const B&, const B&); 77 friend constexpr bool operator<=(const B&, const B&); 78 friend constexpr bool operator>(const B&, const B&); 79 friend constexpr bool operator>=(const B&, const B&); 80 }; 81 82 struct C { 83 friend bool operator==(const C&, const C&); // expected-note {{previous}} expected-note 2{{here}} 84 friend bool operator!=(const C&, const C&) = default; // expected-note {{previous}} 85 86 friend std::strong_ordering operator<=>(const C&, const C&); // expected-note {{previous}} expected-note 2{{here}} 87 friend bool operator<(const C&, const C&) = default; // expected-note {{previous}} 88 friend bool operator<=(const C&, const C&) = default; // expected-note {{previous}} 89 friend bool operator>(const C&, const C&) = default; // expected-note {{previous}} 90 friend bool operator>=(const C&, const C&) = default; // expected-note {{previous}} 91 }; 92 struct TestC { 93 friend constexpr bool operator==(const C&, const C&); // expected-error {{non-constexpr}} 94 friend constexpr bool operator!=(const C&, const C&); // expected-error {{non-constexpr}} 95 96 friend constexpr std::strong_ordering operator<=>(const C&, const C&); // expected-error {{non-constexpr}} 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 friend constexpr bool operator>(const C&, const C&); // expected-error {{non-constexpr}} 100 friend constexpr bool operator>=(const C&, const C&); // expected-error {{non-constexpr}} 101 }; 102 103 struct D { 104 A a; 105 C c; 106 A b; 107 friend bool operator==(const D&, const D&) = default; // expected-note {{previous}} 108 friend bool operator!=(const D&, const D&) = default; // expected-note {{previous}} 109 110 friend std::strong_ordering operator<=>(const D&, const D&) = default; // expected-note {{previous}} 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 friend bool operator>(const D&, const D&) = default; // expected-note {{previous}} 114 friend bool operator>=(const D&, const D&) = default; // expected-note {{previous}} 115 }; 116 struct TestD { 117 friend constexpr bool operator==(const D&, const D&); // expected-error {{non-constexpr}} 118 friend constexpr bool operator!=(const D&, const D&); // expected-error {{non-constexpr}} 119 120 friend constexpr std::strong_ordering operator<=>(const D&, const D&); // expected-error {{non-constexpr}} 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 friend constexpr bool operator>(const D&, const D&); // expected-error {{non-constexpr}} 124 friend constexpr bool operator>=(const D&, const D&); // expected-error {{non-constexpr}} 125 }; 126 127 128 struct E { 129 A a; 130 C c; // expected-note 2{{non-constexpr comparison function would be used to compare member 'c'}} 131 A b; 132 friend constexpr bool operator==(const E&, const E&) = default; // expected-error {{cannot be declared constexpr because it invokes a non-constexpr comparison function}} 133 friend constexpr bool operator!=(const E&, const E&) = default; 134 135 friend constexpr std::strong_ordering operator<=>(const E&, const E&) = default; // expected-error {{cannot be declared constexpr because it invokes a non-constexpr comparison function}} 136 friend constexpr bool operator<(const E&, const E&) = default; 137 friend constexpr bool operator<=(const E&, const E&) = default; 138 friend constexpr bool operator>(const E&, const E&) = default; 139 friend constexpr bool operator>=(const E&, const E&) = default; 140 }; 141 142 struct E2 : A, C { // expected-note 2{{non-constexpr comparison function would be used to compare base class 'C'}} 143 friend constexpr bool operator==(const E2&, const E2&) = default; // expected-error {{cannot be declared constexpr because it invokes a non-constexpr comparison function}} 144 friend constexpr bool operator!=(const E2&, const E2&) = default; 145 146 friend constexpr std::strong_ordering operator<=>(const E2&, const E2&) = default; // expected-error {{cannot be declared constexpr because it invokes a non-constexpr comparison function}} 147 friend constexpr bool operator<(const E2&, const E2&) = default; 148 friend constexpr bool operator<=(const E2&, const E2&) = default; 149 friend constexpr bool operator>(const E2&, const E2&) = default; 150 friend constexpr bool operator>=(const E2&, const E2&) = default; 151 }; 152 153 struct F { 154 friend bool operator==(const F&, const F&); // expected-note {{here}} 155 friend constexpr bool operator!=(const F&, const F&) = default; // expected-error {{cannot be declared constexpr because it invokes a non-constexpr comparison function}} 156 157 friend std::strong_ordering operator<=>(const F&, const F&); // expected-note 4{{here}} 158 friend constexpr bool operator<(const F&, const F&) = default; // expected-error {{cannot be declared constexpr because it invokes a non-constexpr comparison function}} 159 friend constexpr bool operator<=(const F&, const F&) = default; // expected-error {{cannot be declared constexpr because it invokes a non-constexpr comparison function}} 160 friend constexpr bool operator>(const F&, const F&) = default; // expected-error {{cannot be declared constexpr because it invokes a non-constexpr comparison function}} 161 friend constexpr bool operator>=(const F&, const F&) = default; // expected-error {{cannot be declared constexpr because it invokes a non-constexpr comparison function}} 162 }; 163 164 // No implicit 'constexpr' if it's not the first declaration. 165 // FIXME: This rule creates problems for reordering of declarations; is this 166 // really the right model? 167 struct G; 168 bool operator==(const G&, const G&); 169 bool operator!=(const G&, const G&); 170 std::strong_ordering operator<=>(const G&, const G&); 171 bool operator<(const G&, const G&); 172 bool operator<=(const G&, const G&); 173 bool operator>(const G&, const G&); 174 bool operator>=(const G&, const G&); 175 struct G { 176 friend bool operator==(const G&, const G&) = default; 177 friend bool operator!=(const G&, const G&) = default; 178 179 friend std::strong_ordering operator<=>(const G&, const G&) = default; 180 friend bool operator<(const G&, const G&) = default; 181 friend bool operator<=(const G&, const G&) = default; 182 friend bool operator>(const G&, const G&) = default; 183 friend bool operator>=(const G&, const G&) = default; 184 }; 185 bool operator==(const G&, const G&); 186 bool operator!=(const G&, const G&); 187 188 std::strong_ordering operator<=>(const G&, const G&); 189 bool operator<(const G&, const G&); 190 bool operator<=(const G&, const G&); 191 bool operator>(const G&, const G&); 192 bool operator>=(const G&, const G&); 193 194 namespace PR44721 { operator ==(T const &,T const &)195 template <typename T> bool operator==(T const &, T const &) { return true; } operator !=(T const &,U const &)196 template <typename T, typename U> bool operator!=(T const &, U const &) { return true; } operator <=>(T const &,T const &)197 template <typename T> int operator<=>(T const &, T const &) { return 0; } 198 199 struct S { 200 friend bool operator==(const S &, const S &) = default; 201 friend bool operator<=>(const S &, const S &) = default; 202 int x; 203 }; 204 } 205