iota access in foreach loop

[Alex via Digitalmars-d-learn]

Hi all!
Could you help me clearify why a iota can't be accessed with two 
arguments in a foreach loop?
following tests show my problem:
What does work:
    int[] ku = [0, 1, 2, 3, 4];
    foreach(i, el; ku)
        writeln("index: ", i, " element: ", el);
What does not work:
    counter = 5;
    foreach(i, el; iota(counter))
        writeln("index: ", i, " element: ", el);
Motivation: In real I want to have:
    counter = 5;
    foreach(i, el; randomCover(iota(counter)))
        writeln("index: ", i, " element: ", el);

so, I could follow a random permutation. Maybe there is another 
simple way to achieve this?

PS: needed imports:
    import std.random : randomCover;
    import std.range : iota;
    import std.stdio : writeln;