number of removed elements.
Array!int arr; scope(exit) arr.free(); arr.insertBack([1,2,3]); assert(arr.removeFront(3) == 3); arr.insertBack([1,2,3,4]); assert(arr.removeFront(2) == 2); assert(arr.data == [3,4]); assert(arr.removeFront(3) == 2); assert(arr.length == 0);
Remove n of elements from the start.