File: concepts-requires19.C

package info (click to toggle)
gcc-arm-none-eabi 15%3A14.2.rel1-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 1,099,328 kB
  • sloc: cpp: 3,627,108; ansic: 2,571,498; ada: 834,230; f90: 235,082; makefile: 79,231; asm: 74,984; xml: 51,692; exp: 39,736; sh: 33,298; objc: 15,629; python: 15,069; fortran: 14,429; pascal: 7,003; awk: 5,070; perl: 3,106; ml: 285; lisp: 253; lex: 204; haskell: 135
file content (58 lines) | stat: -rw-r--r-- 1,085 bytes parent folder | download | duplicates (2) 
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
 
// { dg-do compile { target c++20 } }

template<typename T>
concept check_c = false;

template<typename T>
concept c1 = requires (T x) {
 requires check_c<decltype(x)>;
};

template<c1 T>
void f1() { }

template<typename T>
void f2(T x) requires requires { requires check_c<decltype(x)>; } { }


template<typename T>
constexpr bool check_f() { return false; }

template<typename T>
concept c2 = requires (T x) {
 requires check_f<decltype(x)>();
};

template<c2 T>
void f3() { }

template<typename T>
void f4(T x) requires requires { requires check_f<decltype(x)>(); } { }


template<typename T>
constexpr bool check_v = false;

template<typename T>
concept c3 = requires (T x) {
 requires check_v<decltype(x)>;
};

template<c3 T>
void f5() { }

template<typename T>
void f6(T x) requires requires { requires check_v<decltype(x)>; } { }


void test()
{
  f1<int>(); // { dg-error "no match" }
  f2(0); // { dg-error "no match" }

  f3<int>(); // { dg-error "no match" }
  f4(0); // { dg-error "no match" }

  f5<int>(); // { dg-error "no match" }
  f6(0); // { dg-error "no match" }
}