grid_key_expression.hpp

#ifndef GRID_KEY_EXPRESSION
#define GRID_KEY_EXPRESSION

#include "util/common.hpp"

template<unsigned int dim> class grid_key_dx;
template<int dim, typename exp1, typename exp2> class grid_key_dx_sum;
template<int dim, typename exp1, typename exp2> class grid_key_dx_sub;


template<unsigned int dim, typename exp>
class grid_key_dx_expression
{
public:

    mem_id value(int i) const
    {
        return static_cast<const exp &>(*this).value(i);
    }

    /* \brief subtract this expression with another expression
     *
     * \param key to subtract
     *
     * \return a grid_key_dx_expression that encapsulate the expression
     *
     */
    inline grid_key_dx_sub<dim,grid_key_dx_expression<dim,exp>,grid_key_dx<dim>> operator-(const grid_key_dx<dim> & key) const
    {
        grid_key_dx_sub<dim,grid_key_dx_expression<dim,exp>,grid_key_dx<dim>> exp_sum(*this,key);

        return exp_sum;
    }

    /* \brief subtract this expression a grid key
     *
     * \param key to subtract
     *
     * \return a grid_key_dx_expression that encapsulate the expression
     *
     */
    template <typename T> inline grid_key_dx_sub<dim,grid_key_dx_expression<dim,exp>,grid_key_dx_expression<dim,T> > operator-(const grid_key_dx_expression<dim,T> & key) const
    {
        grid_key_dx_sub< dim,grid_key_dx_expression<dim,exp>,grid_key_dx_expression<dim,T> > exp_sum(*this,key);

        return exp_sum;
    }
};


template<int dim, typename exp1, typename exp2>
class grid_key_dx_sum : public grid_key_dx_expression<dim,grid_key_dx_sum<dim,exp1,exp2>>
{
    const exp1 & e1;
    const exp2 & e2;

public:

    grid_key_dx_sum(const exp1 & ex1, const exp2 & ex2)
    :e1(ex1),e2(ex2)
    {}

    mem_id value(int i) const
    {
        return e1.value(i) + e2.value(i);
    }
};

template<int dim, typename exp1, typename exp2>
class grid_key_dx_sub : public grid_key_dx_expression<dim,grid_key_dx_sub<dim,exp1,exp2>>
{
    const exp1 & e1;
    const exp2 & e2;

public:

    grid_key_dx_sub(const exp1 & ex1, const exp2 & ex2)
    :e1(ex1),e2(ex2)
    {}

    mem_id value(int i) const
    {
        return e1.value(i) - e2.value(i);
    }
};

#endif