1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
// 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}}
}
|
