Re: [boost] [iterator] could non-small predicates/functors be stored as boost::optional<T> to avoid double construction?

Subject: Re: [boost] [iterator] could non-small predicates/functors be stored as boost::optional<T> to avoid double construction?
From: Thorsten Ottosen (thorsten.ottosen_at_[hidden])
Date: 2008-09-04 09:47:51

Arno Schödl skrev:
>> Hi,
> 
>> The headline pretty much says it all. Take transform iterator. When the 
>> predicate is not trivial, we also have a redundant construction of the 
>> object in the end iterator. Maybe that could be removed?
> 
>> best regards
> 
>> -Thorsten
> 
> I guess that would be restricted to forward iterators.

This has nothing to do with the wrapped iterator's type. A transform 
iterator currently stores a functor by value in addition to the wrapped 
iterator.

-Thorsten