Re: [Boost-Users] suggestion: harness destructor in scoped_ptr<>::reset

From: Jon Kalb (kalb_at_[hidden])
Date: 2002-04-02 12:34:04

At 4:36 PM +0000 4/2/02, jlehrer wrote:
>Before I propose this to main boost mailing list, I wanted to see
>what others thought of this idea.
>
>I propose changing the following method on scoped_ptr<>:
>
>void reset(T* p=0) {if(ptr!=p) {checked_delete(ptr); ptr=p;}}
>
>to
>
>void reset(T* p=0) {if(ptr!=p) {scoped_ptr<T>(p).swap(*this);}}
>void swap(scoped_ptr<T>& other) {std::swap(ptr,other.ptr);}
>
>Of course, we would then have global methods for std::swap, as there
>are for the other smart pointers, to map to this method.
>
>Finally, the same change should be made to scoped_array<>. 
>shared_ptr<> and shared_array<> already have these semantics.
>
>
>The idea is to harness the destructor of the scoped_ptr in order to
>delete the pointer, rather than calling checked_delete in two places.
>
>This has a few advantages over the old code:
>
>1- destruction is handled in one place, the destructor.  This seems
>natural, and gives developers one place to look to see what happens
>when a pointer is deleted
>
>2- I have had occasion to specialize the destructor of the
>scoped_ptr<> class to do something other than delete.  In that case,
>I needed to specialize the destructor AND the reset method.  With
>this change, one would only need to specialize the destructor and
>reset would harness that specialization as well.
>
>Comments?

Sound OK to me.

While I don't think this is off topic for this, I don't see any 
reason not to post it directly to developers list. This is, after 
all, a question about improving the implementation.
-- 
Jon Kalb
Kalb_at_[hidden]