Re: [Boost-users] [shared_ptr] Can the custom deleter be a simplefunction?

Subject: Re: [Boost-users] [shared_ptr] Can the custom deleter be a simplefunction?
From: Robert Jones (robertgbjones_at_[hidden])
Date: 2011-11-07 10:26:35

On Mon, Nov 7, 2011 at 3:15 PM, Peter Dimov <pdimov_at_[hidden]> wrote:

> Robert Jones wrote:
>
>> Thanks Gents - The phrasing of my question was hopelessly lax: I
>> appreciate in the
>> general case why one might choose to use a functor rather than a function
>> as a callable
>> object, what I didn't grasp (and there may be nothing to grasp), was why
>> this (from the
>> shared_ptr docs)
>>
>> struct null_deleter
>> {
>>    void operator()(void const *) const
>>    {
>>    }
>> };
>>
>> Is implemented as a functor rather than a function.
>>
>
> There's nothing to grasp. The only difference is that sizeof( null_deleter
> ) is 1, whereas sizeof the function would be 4 or 8, but due to alignment,
> they both will take up the same space in the actual control block, so it
> doesn't matter one bit. Using a functor here is purely coding style - the
> size difference, the fact that operator() would be inlined, the ability to
> template operator() could all have been relevant in another context.
>
>
Thank you Peter - your confirmation is appreciated.

- Rob.