Re: [boost] SmartPtrs: Making Code Self-Describing. Do we need more SmartPtrs?

From: Ulrich Eckhardt (uli_at_[hidden])
Date: 2005-04-27 15:39:31

On Monday 25 April 2005 17:35, Pavel Chikulaev wrote:
> Example 1:
>
> We are the developer of function Foo. And we need to mark somehow that
> returned pointer is property of
> Foo internals and it shouldn't be deleted by the client function. We can 
> achieve this using weak_ptr, but what if Foo internals doesn't have any
> shared_ptr's ? What to return then? Plain pointer? No Way! We need a way to
> explicitly say that we return copy of pointer that can't be deleted and no
> synchronization is needed.

First thought is to return a reference instead of a pointer. If there really 
is need to sometimes return a null pointer, one could use boost::optional 
with a reference.

> Example 2:
>
> We are developer of function Foo again. And now we need to mark that
> pointer argument is needed only for time of execution of Foo (it wasn't
> collected anywhere), and user cares about deallocation. How are we going to
> write such code and make it self-describing at the same time? Plain
> pointer? No Way! That would be a C-style, but we need something like
> C++-style... This time we don't have even one std or boost candidate for
> such job.

Isn't this the same thing but this time the object being passed into the 
function instead of out of it? Anyhow, I think the same solution applies. For 
the case of null pointers, there is even the additional possibility of 
overloading.

Uli