Implementing Iterator to support foreach

[tcak via Digitalmars-d-learn]

I am planning to implement "Iterator" class. But looking at 
"foreach" statement, it takes a range only.

So is there any way other than returning an array from a function 
that is to be passed foreach statement? So I could write like 
that:

Iterator iter = new MyList();

foreach(item; iter){
}


Otherwise I will need to write like that:

foreach(item; iter.getArrayOfAvailableItems()){
}