"the last change" for ranges

[Brad Roberts]

Andrei Alexandrescu wrote:
> dsimcha wrote:
>> Please, please, please PLEASE, PRETTY PLEASE FOR THE LOVE OF GOD
>> ALMIGHTY tell me
>> you're not serious!!!  Isn't changing the interface such that forward
>> ranges are
>> no longer effectively a subtype of input ranges a bit drastic?  Or do
>> you have
>> some magic up your sleeve that, given any forward range, will
>> automatically call
>> popFront, and then front, when popNext is called, using extension
>> function hacks
>> or something?
> 
> Consider:
> 
> struct R
> {
>     bool empty();
>     ref int front();
>     void popFront();
> }
> 
> ref int popNext(ref R fwdRange)
> {
>     auto result = & fwdRange.front();
>     fwdRange.popFront;
>     return *result;
> }
> 
> void main()
> {
>     R r;
>     int x = r.popNext;
> }
> 
> This should work, I just noticed with surprise it doesn't. It's a bug,
> specifically bug 3015:
> 
> http://d.puremagic.com/issues/show_bug.cgi?id=3015
> 
> Andrei

It was in the talk at the first conference as a 'todo for v2', but it's still on
the todo list. :)

Later,
Brad