Re: [boost] UTF8 library - second call for informal review

From: Nemanja Trifunovic (nemanja_trifunovic_at_[hidden])
Date: 2006-12-14 08:10:46

David Abrahams <dave <at> boost-consulting.com> writes:

> 
> Anthony Williams <anthony_w.geo <at> yahoo.com> writes:
> 
> > Nemanja Trifunovic <nemanja_trifunovic <at> yahoo.com> writes:
> >
> >>> Just because the vast majority of sequences will be random access 
doesn't 
> >> mean
> >>> we should limit ourselves to that, when it is so easy to allow the use of
> >>> Forward Iterators.
> >>> 
> >>
> >> Bidirectional maybe, but using a forward iterator would break some 
important 
> >> functionality: for instance, if an invalid sequence is detected, we step 
back 
> >> to the beginning of the sequence before reporting the error. 
> >
> > Forward Iterators are copyable, so you can do this by keeping a copy of the
> > beginning of the sequence, and returning that on error.
> 
> Yeah, I *hope* you'd do the same with bidirectional iterators.
> 

Sorry for the late answer.

Not in this case. "Stepping back" occurs only in case of an invalid UTF-8 
sequence which is an exceptional case. If we decide to keep a copy of the 
iterator, we would need to do it for each function call.