point_axis.h

// Description: Coordinate of a point
// DocumentationOf: point_concept.h

#ifndef PASTELSYS_POINT_AXIS_H
#define PASTELSYS_POINT_AXIS_H

#include "pastel/sys/point/point_concept.h"
#include "pastel/sys/real/real_ring_concept.h"

namespace Pastel
{

    // Coordinates by point.pointAxis(i)

    template <typename T>
    concept Point_HasMemberPointAxis__ = requires(T t) {
        addConst(t).pointAxis((integer)0);
    };

    template <typename T>
    concept Point_HasMemberPointAxis_ =
        Point_HasMemberPointAxis__<RemoveCvRef<T>>;

    template <typename T>
    using Point_HasMemberPointAxis = 
        std::bool_constant<Point_HasMemberPointAxis_<T>>;

    template <Point_HasMemberPointAxis_ Point>
    decltype(auto) pointAxis(Point&& point, integer axis)
    {
        return std::forward<Point>(point).pointAxis(axis);
    }

}

namespace Pastel
{

    // Coordinates by point[i]

    template <typename T>
    concept Point_HasIndexing__ = requires(T t) {
        addConst(t)[(integer)0];
    };

    template <typename T>
    concept Point_HasIndexing_ = 
        Point_HasIndexing__<RemoveCvRef<T>>;

    template <typename T>
    using Point_HasIndexing = 
        std::bool_constant<Point_HasIndexing_<T>>;

    template <Point_HasIndexing_ Point>
    requires (!Point_HasMemberPointAxis<Point>::value)
    decltype(auto) pointAxis(Point&& point, integer axis)
    {
        return std::forward<Point>(point)[axis];
    }

}

namespace Pastel
{

    // Coordinates by point(i)

    template <typename T>
    concept Point_HasMemberCall__ = requires(T t) {
        addConst(t)((integer)0);
    };

    template <typename T>
    concept Point_HasMemberCall_ =
        Point_HasMemberCall__<RemoveCvRef<T>>;

    template <typename T>
    using Point_HasMemberCall = 
        std::bool_constant<Point_HasMemberCall_<T>>;

    template <Point_HasMemberCall_ Point>
    requires
        (!Point_HasMemberPointAxis<Point>::value &&
        !Point_HasIndexing<Point>::value)
    decltype(auto) pointAxis(Point&& point, integer axis)
    {
        return std::forward<Point>(point)(axis);
    }

}

namespace Pastel
{
    // Coordinates by being a number.

    template <Real_Ring_Concept Point>
    requires
        (!Point_HasMemberCall<Point>::value &&
        !Point_HasMemberPointAxis<Point>::value &&
        !Point_HasIndexing<Point>::value)
    Point pointAxis(Point point, integer axis)
    {
        return point;
    }

}

#endif