Re: [boost] Re: [MPL] Type detection

From: Brian McNamara (lorgon_at_[hidden])
Date: 2003-10-23 19:55:43

I see now where I misunderstood.

On Fri, Oct 24, 2003 at 07:32:51AM +0800, Joel de Guzman wrote:
> I posed 2 solutions:
> 
> 1) Have all iterators inherit from a base:
>  (using CRTP: curriously recurring...)
> 
>     template <class I>
>     inline typename mpl::deref<I>::type
>     operator*(iterator_base<I> const&); 

Somehow I missed that this (using the base class as a way to narrow the
overload set) was one of the alternatives you were proposing...

> 2) Have an is_tuple_iterator<I> meta-function 
> 
>     template <class I>
>     inline typename lazy_enable_if<
>         is_iterator<T>
>       , mpl::deref<I> 
>     >::type
>     operator*(I);

... and I thought both of your proposed solutions were a variation of 
this (using some version of enable_if).  Now that I've gone back and
re-read the whole thread again, I see what you were/are saying.

I definitely think #2 is the right way to go.

Thanks for clarifying!

-- 
-Brian McNamara (lorgon_at_[hidden])