What features of D are you using now which you thought you'd never goint to use?

[Vladimir Panteleev]

On Sunday, 23 June 2013 at 09:54:56 UTC, monarch_dodra wrote:
>> Isn't this what `until` does?
>
> Not quite, it returns an object that returns those items when 
> iterated on. But it is not the same type.

OK, I think we had a misunderstanding what "iterate" meant. I 
used it in the meaning "iterate the range at the time of the 
call" as opposed to "return a range that, when iterated, iterates 
its parameter".

> The problem always boils down the fact that while we can get 
> the same iteration scheme, it's never the same range type:
>
> Range r = some_range;
> r = r.until!"a == 5"; //Does not compile Until!Range and Range 
> do not match
> r = r.take(5); //Does not compile: Take!Range and Range do not 
> match

So is it all about reusing a variable?

For this, you can use the InputRange interface, and the 
InputRangeObject template which creates a crass type that 
inherits from the InputRange interface.

Of course, since what you are requesting is essentially runtime 
polymorphism, this will come with a performance cost of a virtual 
method call for every range primitive.