first_modeled_concept.h

// Description: Search for the first modeled concept

#ifndef PASTELSYS_FIRST_MODELED_CONCEPT_H
#define PASTELSYS_FIRST_MODELED_CONCEPT_H

#include "pastel/sys/concept/models.h"

#include <type_traits>

namespace Pastel
{

    namespace FirstModeledConcept_
    {

        template <
            typename Type,
            typename... ConceptSet>
        struct FirstModeledConcept_F;

        template <
            typename Type,
            typename Concept,
            typename... ConceptSet>
        struct FirstModeledConcept_F<Type, Concept, ConceptSet...>
        : std::conditional<
            Models<Type, Concept>::value,
            Concept,
            typename FirstModeledConcept_F<Type, ConceptSet...>::type
        >
        {};

        template <typename Type>
        struct FirstModeledConcept_F<Type>
        : Identity_F<void>
        {};

    }

}

namespace Pastel
{

    //! Returns the first modeled concept.
    /*!
   returns:
   The first concept in ConceptSet whose model Type is.
   If there is no such concept, then void.
   */
    template <
        typename Type,
        typename... ConceptSet>
    using FirstModeledConcept_F =
        FirstModeledConcept_::FirstModeledConcept_F<Type, ConceptSet...>;

    template <
        typename Type,
        typename... ConceptSet>
    using FirstModeledConcept =
        typename FirstModeledConcept_F<Type, ConceptSet...>::type;

}

#endif