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