pointset_locator.h

// Description: Locator of a point-set
// DocumentationOf: pointset_concept.h

#ifndef PASTELSYS_POINTSET_LOCATOR_H
#define PASTELSYS_POINTSET_LOCATOR_H

#include "pastel/sys/pointset/pointset_concept.h"
#include "pastel/sys/point/point_concept.h"
#include "pastel/sys/locator/location_set.h"
#include "pastel/sys/set/set_concept.h"
#include "pastel/sys/locator/default_locator.h"

namespace Pastel
{

    namespace PointSet_
    {

        struct MemberPointSetLocator_Concept
        {
            template <typename Type>
            auto requires_(Type&& t) -> decltype
            (
                conceptCheck(
                    Concept::holds<
                        Models<decltype(addConst(t).pointSetLocator()), Locator_Concept>
                    >()
                )
            );
        };

    }

    template <typename Type>
    using HasMemberPointSetLocator = 
        Models<Type, PointSet_::MemberPointSetLocator_Concept>;

}

namespace Pastel
{

    //! Returns the member-locator of a point-set.
    template <
        typename Type,
        Requires<
            HasMemberPointSetLocator<Type>
        > = 0
    >
    decltype(auto) pointSetLocator(Type&& that)
    {
        return std::forward<Type>(that).pointSetLocator();
    }

    //! Returns the default locator of point-set elements.
    template <
        typename Set,
        Requires<
            Models<Set, Set_Concept>,
            Models<Set_Element<Set>, Point_Concept>,
            // Give priority to the member-locator.
            Not<HasMemberPointSetLocator<Set>>
        > = 0
    >
    decltype(auto) pointSetLocator(const Set& set)
    {
        using Point = Set_Element<Set>;
        using Real = Point_Real<Point>;
        static constexpr integer N = Point_N<Point>::value;

        return Default_Locator<Point, Real, N>(N);
    }

}

namespace Pastel
{

    template <typename PointSet>
    struct PointSet_Locator_F 
        : Identity_F<
            RemoveCvRef<decltype(pointSetLocator(std::declval<PointSet>()))>>
    {};

    template <typename PointSet>
    using PointSet_Locator =
        typename PointSet_Locator_F<PointSet>::type;

}

#endif