#ifndef MATRIX_PROXY_H
#define MATRIX_PROXY_H

#include "range.h"
#include "matrix_expression.h"

/*****************************************************
 * matrix_proxy class
 ****************************************************/
class matrix_proxy : public matrix_expression {
 private:
  matrix_expression& M;   // reference to the underlying source matrix
  const range rows;       // copy of range describe extent of rows
  const range cols;       // copy of range describing extent of columns

 public:

  // use inherited assignment operator (rather than default)
  using matrix_expression::operator=;
  matrix_proxy& operator=(const matrix_proxy& other);

  // constructor
  matrix_proxy(matrix_expression& src, const range& r, const range& c);

  int numRows() const;

  int numColumns() const;

  // we need following declaration to properly inherit the version of
  // operator() for ranges.  Then we can define our additional ones.
  using matrix_expression::operator();

  // read-only version of indexing operator
  double operator()(int r, int c) const;

  // write-access version of indexing operator
  double& operator()(int r, int c);

};


#endif