Re: [boost] [gil io_new review] Reading images from in-memory sources

Subject: Re: [boost] [gil io_new review] Reading images from in-memory sources
From: Kenny Riddile (kfriddile_at_[hidden])
Date: 2010-12-06 13:13:59

On 12/6/2010 12:56 PM, Mateusz Loskot wrote:
>
> I am not sure about it.
> IMO, the situation is is similar to standard algorithms and predicates:
> if a semantic is not specified in details, any valid semantic is
> possible in terms of presented function prototype/class definition, etc.
>
> Reading about std::remove_if in copy of the n3092, I don't see a word
> about specific move/copy requirements of predicate, however, the
> algorithm is free to make number of copies of the predicate internally.
>
> Back to the Boost.IOStreams, indeed, the docs are incomplete [1]
> but as the the author explained on the list, the devices (Source is a
> device) does not have to follow "must be copy-constructibile" but they
> "can be non-copyable", what means that some may be copyable as well.
>
> [1] http://lists.boost.org/Archives/boost/2005/11/96479.php
> [2] http://lists.boost.org/Archives/boost/2005/10/95939.php
>
> Best regards,

Yes, implementations of a spec are free to implement their requirements 
however they like (assuming no other requirements are violated).  That 
being said, I just looked at the implementation of array_source and it 
appears that none of the data in the array is being copied.