Boost logo

Boost :

From: Sebastian Redl (sebastian.redl_at_[hidden])
Date: 2008-04-11 03:38:33

Thorsten Ottosen wrote:
> Andrey Semashev skrev:
>> Thorsten Ottosen wrote:
>>> Andrey Semashev skrev:
>>>> Your approach requires the T to be default constructible which is not
>>>> always the case.
>>> Why is this better than the far more expensive copy-construction?
>> 1. It adds a new requirement to T.
> But only for swap().
It's still a new requirement, which I find quite unacceptable. Suddenly
I can't swap types without default constructors anymore?

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.


Boost list run by bdawes at, gregod at, cpdaniel at, john at