Re: [boost] scoped_ptr rationale

From: Peter Dimov (pdimov_at_[hidden])
Date: 2002-09-21 18:16:13

From: "Howard Hinnant" <hinnant_at_[hidden]>
>
> But I think I might see a use in:
>
> T* foo(T* x, /* ... */)
> {
>      scoped_ptr<T> p(new ...);
>      //
>      // big, long, hairy, function
>      // ...
> }
>
> If I knew that scoped_ptr could not transfer resources, no matter what
> (by design of scoped_ptr), then I might immediately have a better
> understanding of how foo worked with respect to p, without having read
> through the whole function.  If instead a move_ptr, or other resource
> transferring smart pointer is used, I've got to read through foo to
> discover the true intent of this use.  Is it just RAII?  Or is p's
> resource transferred out of the function?

Yes, this is the "official" scoped_ptr rationale, but note that foo can
often be rewritten as

T* foo(T* x, /* ... */)
{
     T t;
     //
     // big, long, hairy, function
     // ...
}

and that big, long, hairy functions are problematic either way.