Re: [boost] [congif] BOOST_BEFRIEND_TEMPLATE, BOOST_PRIVATE

From: Peter Dimov (pdimov_at_[hidden])
Date: 2005-03-03 18:32:03

Jonathan Turkanis wrote:
> Hi,
> 
> <boost/shared_ptr.hpp> contains the following in the public section
> of the class definition (reformatted):
> 
>    // Tasteless as this may seem, making all members public
>    // allows member templates to work in the absence of member
>    // template friends. (Matthew Langston)
> 
>    #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
> 
>    private:
> 
>        template<class Y> friend class shared_ptr;
>        template<class Y> friend class weak_ptr;
> 
> 
>    #endif
> 
>        T * px;                     // contained pointer
>        detail::shared_count pn;    // reference counter
> 
> This has become a pretty common technique, I believe. I certainly use
> it a lot, at any rate.
> 
> I'd like to suggest two macros which would allow code like the above
> to be simplified as follows:
> 
>    BOOST_PRIVATE:
>          BOOST_BEFRIEND_TEMPLATE(shared_ptr, Y, 1)
>          BOOST_BEFRIEND_TEMPLATE(weak_ptr, Y, 1)
> 
>          T * px;                     // contained pointer
>          detail::shared_count pn;    // reference counter

This doesn't look any better to me than the original, sorry. ;-)