Re: [Boost-users] [shared_ptr] Using a custom delete function that is a class member function

Subject: Re: [Boost-users] [shared_ptr] Using a custom delete function that is a class member function
From: Shane Baker (sbaker_at_[hidden])
Date: 2009-10-10 03:46:50

Since the deleter is parameterized, why space optimization be a concern.
I've never tried using a functor as a deleter, but I don't see why it
wouldn't work.  If it was only a free function that would work, I don't
think they would need the parameterized type D.

Have you tried removing the boost::mem_fun part?  I think the shared_ptr
constructor might not be able to deduce the return type of the member
function correctly.  I'm basing my comment on this documentation:

http://www.boost.org/doc/libs/1_40_0/libs/bind/bind.html#with_member_pointers

On Sat, Oct 10, 2009 at 3:13 AM, Alex MDC <alex.mdc_at_[hidden]> wrote:

> 2009/10/10 Ryan McConnehey <mccorywork_at_[hidden]>
>
>> I have a class that provides a shared_ptr number.  At the end of the
>> number's life cycle it should be placed back on a list of available numbers.
>>  The shared_ptr's custom deleter function looks like what I need.  I'm able
>> to get a free function to compile as the deleter just fine.  In trying to
>> use a class member function as the custom deleter I've run into compile
>> errors.  I'm not sure where I'm going wrong.  I know the custom deleter need
>> to be copy constructible and I'm probably breaking some assumed requirement.
>>  Any help on what I'm doing wrong would be appreciated.
>> Ryan
>>
>
> I'm pretty sure you can't provide a functor as the custom deleter, only a
> free function. Probably due to space efficiency within the shared_ptr blob
> (4 byte pointer vs ~32 bytes for a boost::function).
>
> Alex
>
>
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