Why is “&&” being used in closure arguments?
a is of type [i32; 3]; an array of three i32s. [i32; 3] does not implement an iter method, but it does dereference into &[i32]. &[i32] implements an iter method which produces an iterator. This iterator implements Iterator<Item=&i32>. It uses &i32 rather than i32 because the iterator has to work on arrays of any type, … Read more