Re: [boost] shared_ptr bug?

From: Peter Dimov (pdimov_at_[hidden])
Date: 2001-10-18 10:27:43

From: "Darin Adler" <darin_at_[hidden]>
> on 10/18/01 5:15 AM, Peter Dimov at pdimov_at_[hidden] wrote:
> 
> > void reset(T * p = 0)
> > {
> >   shared_ptr(p).swap(*this);
> > }
> 
> [Lets try that again without the bugs.]
> 
> Wow. That is definitely the right solution:
> 
>    template<typename Y>
>       shared_ptr& operator=(const shared_ptr<Y>& r) {
>          shared_ptr copy(r);
>          swap(copy);
>          return *this;
>       }
> 
>    template<typename Y>
>       shared_ptr& operator=(std::auto_ptr<Y>& r)
>          { reset(r.release()); }
> 
>    void reset(T* p=0) { shared_ptr(p).swap(*this); }

I'd simply make all assignments follow the same pattern:

shared_ptr & operator= (T & t)
{
    shared_ptr(t).swap(*this);
    return *this;
}

This is the easiest way to avoid exception safety bugs. :-)

--
Peter Dimov
Multi Media Ltd.