1 // Structured binding in C++ can bind identifiers to subobjects of an object.
2 //
3 // There are three cases we need to test:
4 // 1) arrays
5 // 2) tuples like objects
6 // 3) non-static data members
7 //
8 // They can also bind by copy, reference or rvalue reference.
9 
10 #include <tuple>
11 
12 struct A {
13   int x;
14   int y;
15 };
16 
17 // We want to cover a mix of types and also different sizes to make sure we
18 // hande the offsets correctly.
19 struct MixedTypesAndSizesStruct {
20   A a;
21   char b1;
22   char b2;
23   short b3;
24   int b4;
25   char b5;
26 };
27 
28 int main() {
29   MixedTypesAndSizesStruct b{{20, 30}, 'a', 'b', 50, 60, 'c'};
30 
31   auto [a1, b1, c1, d1, e1, f1] = b;
32   auto &[a2, b2, c2, d2, e2, f2] = b;
33   auto &&[a3, b3, c3, d3, e3, f3] =
34       MixedTypesAndSizesStruct{{20, 30}, 'a', 'b', 50, 60, 'c'};
35 
36   // Array with different sized types
37   char carr[]{'a', 'b', 'c'};
38   short sarr[]{11, 12, 13};
39   int iarr[]{22, 33, 44};
40 
41   auto [carr_copy1, carr_copy2, carr_copy3] = carr;
42   auto [sarr_copy1, sarr_copy2, sarr_copy3] = sarr;
43   auto [iarr_copy1, iarr_copy2, iarr_copy3] = iarr;
44 
45   auto &[carr_ref1, carr_ref2, carr_ref3] = carr;
46   auto &[sarr_ref1, sarr_ref2, sarr_ref3] = sarr;
47   auto &[iarr_ref1, iarr_ref2, iarr_ref3] = iarr;
48 
49   auto &&[carr_rref1, carr_rref2, carr_rref3] = carr;
50   auto &&[sarr_rref1, sarr_rref2, sarr_rref3] = sarr;
51   auto &&[iarr_rref1, iarr_rref2, iarr_rref3] = iarr;
52 
53   float x{4.0};
54   char y{'z'};
55   int z{10};
56 
57   std::tuple<float, char, int> tpl(x, y, z);
58   auto [tx1, ty1, tz1] = tpl;
59   auto &[tx2, ty2, tz2] = tpl;
60 
61   return a1.x + b1 + c1 + d1 + e1 + f1 + a2.y + b2 + c2 + d2 + e2 + f2 + a3.x +
62          b3 + c3 + d3 + e3 + f3 + carr_copy1 + carr_copy2 + carr_copy3 +
63          sarr_copy1 + sarr_copy2 + sarr_copy3 + iarr_copy1 + iarr_copy2 +
64          iarr_copy3 + carr_ref1 + carr_ref2 + carr_ref3 + sarr_ref1 +
65          sarr_ref2 + sarr_ref3 + iarr_ref1 + iarr_ref2 + iarr_ref3 +
66          carr_rref1 + carr_rref2 + carr_rref3 + sarr_rref1 + sarr_rref2 +
67          sarr_rref3 + iarr_rref1 + iarr_rref2 + iarr_rref3 + tx1 + ty1 + tz1 +
68          tx2 + ty2 + tz2; // break here
69 }
70