Re: [boost] Request for rationale

From: Ulrich Eckhardt (doomster_at_[hidden])
Date: 2007-11-09 01:05:53

On Sunday 04 November 2007 00:45:47 Mike Tegtmeyer wrote:
> I agree but it quickly becomes a pain because you end up writing a
> wrapper for every thing of this type to satisfy this 'wart' with
> shared_ptr:
>
> pthread_create ...
> opendir
> fopen
> open
> free
> COM objects
>
> the list goes on.

I'd take that even further, not all such resources are represented as pointer 
(think filedescriptors or win32 HANDLEs), so shared_ptr doesn't help at all. 
Further, you usually only need a scope-based lifetime, not true sharing with 
reference counting, so std::auto_ptr or boost::scoped_ptr should be enough. 
Lastly, you don't need a smart pointer at all, because the overloads of -> 
and * are typically never used with those opaque handles. However, sometimes 
things like returning them from functions is used, but in those cases the 
behaviour of std::auto_ptr (i.e. ownership transfer) is fully sufficient.

I posted a wrapper that gives you just that some time ago here, asking for 
comments. I didn't get any, probably because it was in the hot phase of the 
last release. I'll post the whole mail again, the subject is "helper for 
managing legacy resources".

Uli