module pind.samples.ja.nested.nested_3;

import std.stdio;
import std.array;

auto alternatingEnds(T)(T[] slice) {
    bool isFromFront = true;

    struct EndAlternatingRange {
        bool empty() const {
            return slice.empty;
        }

        T front() const {
            return isFromFront ? slice.front : slice.back;
        }

        void popFront() {
            if (isFromFront) {
                slice.popFront();
                isFromFront = false;

            } else {
                slice.popBack();
                isFromFront = true;
            }
        }
    }

    return EndAlternatingRange();
}

void main() {
    auto a = alternatingEnds([ 1, 2, 3, 4, 5 ]);
    writeln(a);
}