1// PR c++/65398
2// { dg-do compile { target c++11 } }
3
4#define SA(X) static_assert((X),#X)
5
6constexpr char s[] = "abc";
7constexpr char c1 = *(&s[0] + 0);
8constexpr char c2 = *(&s[0] + 1);
9constexpr char c3 = *(&s[1] + 0);
10constexpr char c4 = *(&s[1] + 1);
11constexpr char c5 = *(&s[2] + 0);
12constexpr char c6 = *(&s[0] + 2);
13constexpr char c7 = *(&s[2] + 1);
14
15constexpr char d1 = *(&s[4] - 0); // { dg-error "array subscript out of bound" }
16constexpr char d2 = *(&s[4] - 1);
17constexpr char d3 = *(&s[4] - 2);
18constexpr char d4 = *(&s[4] - 3);
19constexpr char d5 = *(&s[4] - 4);
20constexpr char d6 = *(&s[4] - 5);  // { dg-error "negative array subscript" }
21
22/* Don't accept invalid stuff.  */
23constexpr char e1 = *(&s[5] - 1); // { dg-error "is not a constant expression" }
24constexpr char e2 = *(&s[5] - 2); // { dg-error "is not a constant expression" }
25constexpr char e3 = *(&s[5] - 3); // { dg-error "is not a constant expression" }
26
27SA (c1 == 'a');
28SA (c2 == 'b');
29SA (c3 == 'b');
30SA (c4 == 'c');
31SA (c5 == 'c');
32SA (c6 == 'c');
33SA (c7 == '\0');
34SA (d2 == '\0');
35SA (d3 == 'c');
36SA (d4 == 'b');
37SA (d5 == 'a');
38
39constexpr int l[] = { 'c', 'd', 'e', '\0' };
40constexpr int i1 = *(&l[0] + 0);
41constexpr int i2 = *(&l[0] + 1);
42constexpr int i3 = *(&l[1] + 0);
43constexpr int i4 = *(&l[1] + 1);
44constexpr int i5 = *(&l[2] + 0);
45constexpr int i6 = *(&l[0] + 2);
46constexpr int i7 = *(&l[2] + 1);
47
48constexpr char j1 = *(&l[4] - 0); // { dg-error "array subscript out of bound" }
49constexpr char j2 = *(&l[4] - 1);
50constexpr char j3 = *(&l[4] - 2);
51constexpr char j4 = *(&l[4] - 3);
52constexpr char j5 = *(&l[4] - 4);
53constexpr char j6 = *(&l[4] - 5);  // { dg-error "negative array subscript" }
54
55/* Don't accept invalid stuff.  */
56constexpr char k1 = *(&l[5] - 1); // { dg-error "is not a constant expression" }
57constexpr char k2 = *(&l[5] - 2); // { dg-error "is not a constant expression" }
58constexpr char k3 = *(&l[5] - 3); // { dg-error "is not a constant expression" }
59
60SA (i1 == 'c');
61SA (i2 == 'd');
62SA (i3 == 'd');
63SA (i4 == 'e');
64SA (i5 == 'e');
65SA (i6 == 'e');
66SA (i7 == '\0');
67SA (j2 == '\0');
68SA (j3 == 'e');
69SA (j4 == 'd');
70SA (j5 == 'c');
71