Shout out to D at cppcon, when talkign about ranges.

[bitwise via Digitalmars-d]

On Thursday, 1 October 2015 at 05:47:25 UTC, Eric Niebler wrote:
> On Thursday, 1 October 2015 at 04:08:00 UTC, bitwise wrote:
>> I understand, but the C++ committee seems very conservative to 
>> me, so when it's this easy to add for(:) support by giving 
>> ranges begin()/end() functions, it makes me doubt they will 
>> actually change the language for it.
>
> As of C++11, C++ has the for(auto e:range) control structure 
> you are looking for. I would be using it here except for one 
> thing: in my proposal, begin() and end() don't have to return 
> objects of the same type! begin() must return an iterator and 
> end() must return something that is EqualityComparable with the 
> iterator -- but it doesn't have to be an iterator. That makes 
> many types of iterators vastly simpler to implement and more 
> efficient at runtime.
>
> C++'s built-in range-based for(:) loop expects begin() and 
> end() to return objects of the same type. The committee is 
> already talking about loosening that constraint so that the 
> ranges I'm proposing Just Work with the existing built-in 
> looping construct. Until then, there is an ugly macro. It's a 
> temporary hack, nothing more.

Did you look at my example(this one is updated)?
http://ideone.com/X1JAEn

I've factored out a 'range_iterator' in this version. I would 
probably rethink the way I've done the chaining, but there is 
nothing complicated about adding foreach support as I've 
implemented it in my example. From the callers point of view, 
it's a typedef and two functions.

I really doubt anything could be done that would offer a 
perceptible performance gain over what I've done in my example.

I suppose it's a moot point if C++ is actually planning native 
range support.

     Bit