Re: [boost] Re: boost::noncopyable

From: Peter Dimov (pdimov_at_[hidden])
Date: 2004-12-19 08:04:48

Maxim Yegorushkin wrote:
>
> Does it really make any sense making only implementation noncopyable,
> rather than interface?

This would prevent you from making a copyable implementation of the 
interface.

> If you deal with interfaces only it won't save
> you from errors like this:
>
>     std::auto_ptr<Interface> create() { return
> std::auto_ptr<Interface>(new Implementation); }
>
>     void foo()
>     {
>         std::auto_ptr<Interface> a(create()), b(create());

Assuming you mean boost::shared_ptr here. auto_ptr doesn't work.

>         *a = *b; // oops, no error here, Implementation::operator= is
> not considered

This is (1) a no-op, nothing dangerous happens; (2) pretty rare, in my 
experience.

If you really want to catch that, you can make the assignment operator of 
Interface protected.

>     }