Prettier iterator implementations in D?

[Bill Baxter]

Reiner Pope wrote:
> The proposal looks good (as long as it creates no syntactical 
> ambiguities) but if we had variadic template parameters (see 
> http://www.generic-programming.org/~dgregor/cpp/variadic-templates.html 
> for a good version for C++) then you could do it much more easily with 
> templates:
> 
> template IterFunc(type ...)
> {
>     alias int delegate(type ...) IterFunc;
> }

Ooh, I missed this "Implicit Template Properties" thing.  That's an 
improvement over what I had even without the variadic bit.  Just means I 
need an IterFunc1, IterFunc2,... etc.

> 
> and then you could just declare your iterators:
> 
> int opApply(IterFunc!(int) dg)
> [...]
> Unfortunately, this wouldn't handle 'inout' parameters, since you can't 
> instantiate a template with an inout parameter...

Ah, that's a pity.  Is that a spec limitation or just something still on 
the "todo" list?

--bb