pointerrange_locator.h

// Description: Pointer-range locator
// Documentation: locators.txt

#ifndef PASTELSYS_POINTERRANGE_LOCATOR_H
#define PASTELSYS_POINTERRANGE_LOCATOR_H

#include "pastel/sys/locator/locator_concept.h"
#include "pastel/sys/point/point_concept.h"
#include "pastel/sys/ensure.h"

namespace Pastel
{

    template <typename Real_, integer N_ = Dynamic>
    class PointerRange_Locator
    {
    public:
        static constexpr integer N = N_;
        using Real = Real_;
        using Point = const Real*;

        explicit PointerRange_Locator(
            integer begin = 0, 
            integer end = ((N > 0) ? N : 0))
            : begin_(begin)
            , end_(end)
        {
            ENSURE(N == Dynamic || end == N);
            ENSURE_OP(begin, <=, end);
        }

        integer n() const
        {
            return end_ - begin_;
        }

        integer n(const Point& point) const
        {
            return n();
        }

        const Real& operator()(Point point, integer i) const
        {
            PENSURE_OP(i, >=, 0);
            PENSURE_OP(i, <, n());
            return (point + begin_)[i];
        }

    private:
        integer begin_;
        integer end_;
    };

    template <typename Real_, integer N_ = Dynamic>
    decltype(auto) pointerRangeLocator(integer begin = 0, integer end = N_)
    {
        return PointerRange_Locator<Real_, N_>(begin, end);
    }

    template <typename Real>
    decltype(auto) pointerRangePoint(Real* point, integer begin, integer end)
    {
        return location(
            point,
            PointerRange_Locator<Real>(begin, end));
    }

}

#endif