// file: circular_buffer/cb_opt_0.cc//// isip include files//#include "CircularBuffer.h"// method: operator//// arguments:////  int dim: (input) indicated dimension//  int index: (input) indicated index//// return: float_8 the value of corresponding element//// this method overloads () operator.//float_8 Circular_buffer::operator() (int dim, int index) {  // note that the index is actually an offset from idx_d  //  int idx = idx_d[dim] + index;  // check the index  //  if (idx >= size_d)    {idx -= size_d;}  else if (idx < (int)0)    {idx += size_d;}  // return the corresponding value  //  return buf_d[dim][idx];}