cpp/algorithm/ranges/copy backward

@1@ Copies the elements from the range, defined by, to another range , where. The elements are copied in reverse order (the last element is copied first), but their relative order is preserved. The behavior is undefined if is within. In such a case can be used instead.

@2@ Same as, but uses as the source range, as if using  as , and  as.

Return value
.

Complexity
Exactly assignments.