stackoverflow question code

----------------------Mean.h-----------------------------
// Copyright 2019 Ian McDowell
#ifndef _CSCE240_HW_HW6_INC_MEAN_H //NOLINT
#define _CSCE240_HW_HW6_INC_MEAN_H //NOLINT

/* This class inherits from the Statistic class such that it may be used
 * polymorphically.
 */
#include <statistic.h>
#include <list>

namespace csce240 {

class Mean : public std::list<double>, public Statistic {
 public:

  /* Stores data (datum) such than an average may be calculated.
   * - NOTE: You do not necessarily need to store each datum.
   */
  void Collect(double datum);

  /* Returns the mean of the data (datum) from the Collect method.
   */
  double Calculate() const;
};

} // namespace csce240

#endif //NOLINT


----------------------Mean.cc-----------------------------
// Copyright 2019 Ian McDowell
#include <mean.h>
using std::list;

namespace csce240 {

void Mean::Collect(double datum) {
    push_front(datum);
}

double Mean::Calculate() const {
    list<double> tempList;
    int i = 0;
    double temp;
    double avg = 0;

    while (!empty()) {
        temp = back();
        avg += temp;
        tempList.push_front(temp);
        pop_back();
        ++i;
    }

    avg = avg / i;

    while(!tempList.empty()) {
        push_front(tempList.back());
        tempList.pop_back();
    }

    return avg;
}


} // namespace csce240