blob: 00bda531e59605b4aeb00e22960efa2fde46278a (
plain)
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
|
// { dg-do compile { target c++20 } }
// PR c++/102286
#include "construct_at.h"
struct S { const int a; int b; };
union U { int k; S s; };
constexpr int test1() {
U u {};
std::construct_at(&u.s, S{ 1, 2 });
return u.s.b;
}
static_assert(test1() == 2);
constexpr int test2() {
U u {};
int* p = &u.s.b;
std::construct_at(p, 5); // { dg-message "in .constexpr. expansion" }
return u.s.b;
}
constexpr int x2 = test2(); // { dg-message "in .constexpr. expansion" }
constexpr void foo(S* s) {
s->b = 10; // { dg-error "accessing .U::s. member instead of initialized .U::k." }
}
constexpr int test3() {
U u {};
foo(&u.s); // { dg-message "in .constexpr. expansion" }
return u.s.b;
}
constexpr int x3 = test3(); // { dg-message "in .constexpr. expansion" }
struct S2 { int a; int b; };
union U2 { int k; S2 s; };
constexpr int test4() {
U2 u;
int* p = &u.s.b;
std::construct_at(p, 8); // { dg-message "in .constexpr. expansion" }
return u.s.b;
};
constexpr int x4 = test4(); // { dg-message "in .constexpr. expansion" }
constexpr int test5() {
union {
int data[1];
} u;
std::construct_at(u.data, 0); // { dg-message "in .constexpr. expansion" }
return 0;
}
constexpr int x5 = test5(); // { dg-message "in .constexpr. expansion" }
// { dg-error "accessing (uninitialized member|.* member instead of)" "" { target *-*-* } 0 }
|
