Re: [Boost-users] Template operator() overloading for types in a mpl::vector

Subject: Re: [Boost-users] Template operator() overloading for types in a mpl::vector
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2009-11-02 10:34:32

AMDG

Olivier Tournaire wrote:
> I am currently trying to write a simple functor, and I would like to have
> the same overload for the operator () for all types in a mpl::vector.
>
> <snip>
>
> struct any_view_min_max
> {
>     typedef std::pair<float, float> result_type;
>
>     template <typename View>
>     result_type operator()(const View& v) const
>     {
>         typedef typename View::iterator iterator;
>         std::pair< iterator, iterator > result = boost::minmax_element(
> v.begin() , v.end() , pixel_compare_less() );
>         return std::make_pair( *(result.first) , *(result.second) );
>     }
> };
>
> This works fine for 'gray_image_types', but need to be specialized for types
> in rgb_image_types. The specialization is the same, so, I am looking for an
> automated way to do this. "Manually", I can write this:
>
> <snip>
>   

You can define two overloads of operator() and use enable_if to
distinguish them.

In Christ,
Steven Watanabe