moveFront

1 auto a = [ 1, 2, 3 ];
2 assert(moveFront(a) == 1);
3 assert(a.length == 3);
4 
5 // define a perfunctory input range
6 struct InputRange
7 {
8     enum bool empty = false;
9     enum int front = 7;
10     void popFront() {}
11     int moveFront() { return 43; }
12 }
13 InputRange r;
14 // calls r.moveFront
15 assert(moveFront(r) == 43);