| // RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx23 -std=c++23 %s |
| // RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx20 -std=c++20 %s |
| |
| //cxx23-no-diagnostics |
| |
| struct S { |
| constexpr int operator[](int i) { |
| return i; |
| } |
| constexpr int operator[](int a, int b) { // cxx20-error {{overloaded 'operator[]' cannot have more than one parameter before C++23}} |
| return a + b; |
| } |
| constexpr int operator[]() { // cxx20-error {{overloaded 'operator[]' cannot have no parameter before C++23}} |
| return 42; |
| } |
| }; |
| |
| struct Defaults { |
| constexpr int operator[](int i = 0) { // cxx20-error {{overloaded 'operator[]' cannot have a defaulted parameter before C++23}} |
| return 0; |
| } |
| constexpr int operator[](int a, int b, int c = 0) { // cxx20-error {{overloaded 'operator[]' cannot have a defaulted parameter before C++23}}\ |
| // cxx20-error {{cannot have more than one parameter before C++23}} |
| return 0; |
| } |
| }; |
| |
| template <typename... T> |
| struct T1 { |
| constexpr auto operator[](T &&...arg); // cxx20-error {{overloaded 'operator[]' cannot have no parameter before C++23}} \ |
| // cxx20-error {{overloaded 'operator[]' cannot have more than one parameter before C++23}} |
| }; |
| |
| T1<> t10; // cxx20-note {{requested here}} |
| T1<int, int> t12; // cxx20-note {{requested here}} |
| T1<int> t11; |
| |
| struct Variadic { |
| constexpr int operator[](auto &&...arg) { return 0; } |
| }; |
| |
| void f() { |
| S s; |
| (void)s[0]; |
| (void)s[1, 2]; // cxx20-warning {{left operand of comma operator has no effect}}\ |
| // cxx20-warning {{top-level comma expression in array subscript is deprecated in C++20 and unsupported in C++23}} |
| (void)S{}[]; // cxx20-error {{expected expression}} |
| |
| (void)Defaults{}[1]; |
| (void)Defaults{}[]; // cxx20-error {{expected expression}} |
| (void)Defaults{}[1, 2]; // cxx20-warning {{left operand of comma operator has no effect}}\ |
| // cxx20-warning {{top-level comma expression in array subscript is deprecated in C++20 and unsupported in C++23}} |
| |
| Variadic{}[]; // cxx20-error {{expected expression}} |
| Variadic{}[1]; |
| Variadic{}[1, 2]; // cxx20-warning {{left operand of comma operator has no effect}}\ |
| // cxx20-warning {{top-level comma expression in array subscript is deprecated in C++20 and unsupported in C++23}} |
| } |