Re: [boost] [Range] initial feedback on return values of algorithms

From: Thorsten Ottosen (tottosen_at_[hidden])
Date: 2006-02-03 11:25:31

David Abrahams wrote:
> Thorsten Ottosen <tottosen_at_[hidden]> writes:

>>>There is also the issue of O(1) size, for which you have not got
>>>support in your concept hierarchy.  
>>
>>Did I forget to mention this? Anyway, size() is now O(1). If you want
>>a generic version, dictance(rng) is supplied instead.
> 
> 
> That's not what I mean.  Is there a way to distinguish, at
> compile-time, a range that has support for O(1) size from one that
> does not?  One needs that for important "benefit and
> beauty"-destroying optimzations that you dislike so.

ok, if range_category<R>::type is convertible to 
std::random_access_iterator_tag, then you may call boost::size(rng)

>> > And then there's property maps.
>>
>>How do they relate to this?
> 
> 
> They're an important part of a generalized range concept.

perhaps, but its hard for me to see how and why they are it.
how do you imagine that property maps would affect the
interface of range-based algorithms?

isn't range concepts orthogonal to PMs?

-Thorsten