[boost] Re: Generalizing the shared_ptr

From: Larry Evans (cppljevans_at_[hidden])
Date: 2004-07-12 16:33:19

On 07/12/2004 03:42 PM, Maciej Sobczak wrote:
[snip]
> Exactly, that was my point. There are third-party APIs (and even 
> operating system interfaces, like file descriptors) where resources are 
> not handled by explicit pointers, but by "handles", which are usually 
> lightweight copyable types.

[snip]

> I guess that policy-based smart pointer design + template typedefs would 
> solve this problem (and many others) definitely. :)
> 
> 
>> I think there might have been talk of getting a policy base smart 
>> pointer to do this kind of thing as well.
>>
>> I guess that nothing much has happened yet because the need isn't that 
>> great.
> 
> 
> Well, that depends on how you look at it.
> I'd risk a claim that 95% of programmers would need smart handles more 
> often than, say, 50% of what is currently in Boost, especially 
> considering the fact that smart handle would not be a foreign concept - 
> this is just a smart pointer concept applied to generic resource. Quite 
> common stuff, I think.
> Of course, your mileages may vary.

[snip]

I've been thinking about generalizing it for reflection.  For example,
for every type which is to be "reflected", the instances of that
type would be stored in a reflector handle.  The "reflection" (i.e.
information on all the reflector handles) of a type, T, would be
stored in reflection<T>.  This information is similar to that used
for garbage collection of cycles; hence, I think the code in:
 
http://cvs.sourceforge.net/viewcvs.py/boost-sandbox/boost-sandbox/boost/managed_ptr/

could be used.