Overriding iteration

[Magnus Lie Hetland]

>From what I understand, when you override iteration, you can either 
implement the basic range primitives, permitting foreach to 
destructively iterate over your object, or you can implement a custom 
method that's called, and that must perform the iteration. The 
destructiveness of the first option can, of course, be mitigated if you 
use a struct rather than a class, and make sure that anything that 
would be destroyed by popFront() is copied.

What I'm wondering is whether there is a way to do what Python does -- 
to construct/return an iterator (or, in this case, a range) that is 
used during the iteration, rather than the object itself?

I'm thinking about when you iterate directly over the object here. As 
far as I can see, the solution used in the std.container is to use 
opSlice() for this functionality. In other words, in order to iterate 
over container foo, you need to use foreach(e; foo[])? Is there no way 
to get this functionality directly (i.e., for foreach(e; foo))?

-- 
Magnus Lie Hetland
http://hetland.org