Re: [boost] [range] RFC: span(iterator, size)

Subject: Re: [boost] [range] RFC: span(iterator, size)
From: Evgeny Panasyuk (evgeny.panasyuk_at_[hidden])
Date: 2013-10-30 04:59:47

30.10.2013 12:18, TONGARI J:
>>>> Especially you mentioned that you plan to preserve same range category as
>>>> original iterator has - what about BidirectionalIterators?
>>> That's my mistake, they should be ForwardIterators.
>> 1. What about RandomAccessIterators?
> For RandomAccessIterators, 'span' will return the iterator as is, no
> wrapping.

So, you are talking about following mapping:
  Original       | Wrapped
_____________________________
   Input         |  Input
   Forward       |  Forward
   Bidirectional |  Forward
   RandomAccess  |  RandomAccess

+ dereference of end of returned will be undefined (even if it was legal 
in "original" range).
+ comparison of iterators from different span(..) invocations (with 
different args) on same range will be also undefined.

Ok, I thought maybe you are talking about something more generally 
applicable.

-- 
Evgeny Panasyuk