template_base.h

// Description: Find a template base-class
// Documentation: type_traits.txt

#ifndef PASTELSYS_TEMPLATE_BASE_H
#define PASTELSYS_TEMPLATE_BASE_H

namespace Pastel
{

    namespace Template_Base_
    {

        template <template <typename...> class Template, typename... TypeSet>
        Template<TypeSet...> test(Template<TypeSet...>&&);

        template <template <typename...> class Template>
        inline void test(...);

    }

    //! Returns a template base-class.
    /*!
   returns:
   A base-class, or the type itself, which is an instance 
   of the given class-template.
   */
    template <
        template <typename...> class Template,
        typename Type>
    struct TemplateBase_F
    : Identity_F<decltype(Template_Base_::test<Template>(std::declval<Type>()))>
    {};

    template <
        template <typename...> class Template,
        typename Type>
    using TemplateBase =
        typename TemplateBase_F<Template, Type>::type;

}

#endif