import std.stdio;

void main()

{

    int[] array = [0, 10, 1, 11, 2, 12, 3, 13, 4, 14, 5, 15, 6, 16, 7, 17, 8, 18, 9, 19];

    size_t i=0, j=0;

    while (i < array.length)

    {

        //doSomething(array[i]);

        if ((array[i] <= 9))

            j++;//don't keep

        if (j < i)

            array[j] = array[i];

        i++;

        array.writeln;

    }

    array.length = j;

    array.writeln;

}