Re: [Boost-users] Re: boost::bind and member functions

From: David Morrison (dave_at_[hidden])
Date: 2005-03-23 04:04:19

Peter Dimov wrote:
> David Morrison wrote:
> 
>> Peter Dimov wrote:
>>
>>> Change this to boost::mem_fn( f )( a1, a2, a3 ) and you'll be there.
>>
>>
>> Yep, that's much cleaner, thanks.
>>
>> I was hoping that there'd be some clever way to use type_traits to
>> magically select the right way of invoking the function f.  That way,
>> one could have a (possibly enhanced version of?) apply.hpp so that
>> code to invoke apply on a set of member and non-member functions
>> would look the same.
> 
> On a reasonably conforming compiler, adding an overload to apply<> 
> should work:
> 
>    template<class F, class A1, class A2, class A3>
>        result_type operator()
>        (F & f, A1 & a1, A2 & a2, A3 & a3) const
>    {
>        return f(a1, a2, a3);
>    }
> 
>    // add this
> 
>    template<class M, class T, class A1, class A2, class A3>
>        result_type operator()
>        (M T::* pm, A1 & a1, A2 & a2, A3 & a3) const
>    {
>        return mem_fn(pm)(a1, a2, a3);
>    }
> 
> It might be a good idea to add this to apply.hpp, but I would need to 
> write a test for apply<> first.
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-- 
David Morrison  Brookhaven National Laboratory  phone: [phone]
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