Re: [boost] [shared_ptr] dangerous implementation of moveconstructor

From: Peter Dimov (pdimov_at_[hidden])
Date: 2007-04-17 05:56:47

Joe Gottman wrote:

> But note that it is possible to efficiently make q hold a null pointer
> after a move assignment:
>
>  shared_ptr & operator=( shared_ptr && r ) // never throws
> {
>     pn.swap(r.pn);
>     px = r.px;
>     r.px = 0;
>     return *this;
> }

Yes, I know. This still leaves r half-empty, except that now it is the other 
half. If we're going to the trouble to clear r, I'd rather have it in a 
completely specified state.