Re: [boost] Re: Overload resolution & boost::bind

From: Arturo_Cuebas_at_[hidden]
Date: 2004-08-18 12:11:18

>"David Abrahams" <dave_at_[hidden]> wrote:
>
>> I don't buy the ideas that involve using function types as in
>>
>>   select_overload<int(int)>
>>
>> because it requires specifying the return type, which is irrelevant.
>
> Current pratice is to speficy the entire signature, including the
> (irrelevant) return type and the (redundant) class name. Arturo's
> suggestion gets rid of the return type and class name, but introduces
> the (irrelevant) arity. 

When overloads differ only in the number of parameters and not 
the parameter types, arity becomes the only thing that's relevant.
That's why I thought the ideal use would look like this when that's
the case:

whatever_cast<1>(&P::f)

And like this when it's not:

whatever_cast<char>(&P::f)

I doubt that's possible though. :(

> Using function types eliminates the class name but keeps the return 
> type. So neither is quite right, althought I tend to prefer using 
> function types.

whatever_cast becomes more useful the further away we get from the 
static_cast form. IMO, the arity-specifying form is further away from 
that than the function-signature form. Consider that the return type 
can have a super-long name:

whatever_cast
<long_name_templatized_type<unsigned long, unsigned char> (char)>
(&P::f)

> The essential information that needs to be supplied is just a
> typelist. 
> [snip]

Is it possible to implement whatever_cast in such a way that it mimics
what mpl::list does - in its acceptance of a variable number of template
parameters - but produces a function?