[Boost-users] Re: Re: why doesn't scoped_ptr have a custom

From: Pablo Aguilar (pablo.aguilar_at_[hidden])
Date: 2005-01-06 14:33:05

Good point, I just didn't bother writing a handle class given I knew I could 
use shared_ptr and the space/time overhead wasn't important.

Anyway, I'll take a shot at writing an auto_handle class.

"Ben Hutchings" <ben.hutchings_at_[hidden]> wrote in message 
news:41DD3C48.8090300_at_businesswebsoftware.com...
> Pablo Aguilar wrote:
>> Thanks for your reply...
>>
>> You're right, "reset" would delete the pointer... but when you're getting 
>> rid of a pointer obtained from a factory, like I was in my case, pointers 
>> don't always get disposed of using delete, but rather another function 
>> (like p->release())
>>
>> And rather than writing special purpose smart pointers for each type of 
>> deleting function (p->dispose(), p->release(), api_function_free(p), 
>> etc..) you can use shared_ptr with a custom deleter (here: 
>> mem_fn(&pointer_type::dispose) or bind(&api_function_free, _1))
>
> In some cases you can avoid the space and time overhead of shared_ptr by 
> using a smart pointer template for which the custom deleter is a template 
> argument.  In fact you can get even more general than that quite easily; I 
> have a class template called auto_handle which with minimal work can be 
> used to encapsulate all kinds of things with custom deleters, including 
> Windows handles and POSIX file descriptors.
>
> Ben.