Re: [boost] New Library Proposal: dual_state

From: Andrey Melnikov (melnikov_at_[hidden])
Date: 2005-07-16 09:24:40

David Abrahams wrote:
> 
> FYI, I might tend to use a dual_state object that either yields a
> contained _reference_ or the result of invoking a function, because
> you usually don't want to pay for copy construction of a contained
> object if you don't have to, and it feels nonuniform to have 
> lightweight copy only when the default is going to be used.
>
Well, I had a lot of problems with bottlenecks in VC7.0 code related to 
redundant copy operations, so I'm very afraid of extra copies.
But we can have both copy- and nocopy- versions. The version with a copy 
operation could be simpler to use, so the both versions have reasons to 
exist.

Andrey