Re: [boost] [optional] problems with swap()

From: Corrado Zoccolo (czoccolo_at_[hidden])
Date: 2008-04-11 03:47:00

On Fri, Apr 11, 2008 at 9:38 AM, Sebastian Redl <
sebastian.redl_at_[hidden]> wrote:

>
> If this variant of swap() is really more efficient, perhaps
> metaprogramming could be used to support it *if* the type has a default
> constructor. But I don't know how to detect this. TypeTraits doesn't
> contain a has_default_constructor trait. It may be that this will only
> work with 09 concepts - DefaultConstructible.
>

We can use has_nothrow_default_constructor .
This will also exclude the specialization when the default constructor
performs some allocation, and could result in lower performance.

Corrado

> Sebastian
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