Создать класс матрицы реальных чисел (от 1х1 до 8х8)

#include <ctime>
#include <cstdlib>
#include <iostream>
#include <iomanip>
#include <stdexcept>
 
class Matrix {
 public:
  Matrix(size_t width, size_t height) : width(width), height(height), matrix(NULL) {
    createMatrix();
    fillZero();
  }
  Matrix(const Matrix &other) : width(0), height(0), matrix(NULL) {
    copyFrom(other);
  }
  double get(int row, int col) const {
    if (row >= height || col >= width)
      throw std::range_error("matrix index is out of range");
    return matrix[row][col];
  }
  void set(int row, int col, double value) {
    if (row >= height || col >= width)
      throw std::range_error("matrix index is out of range");
    matrix[row][col] = value;
  }
  size_t getHeight() const { return width; }
  size_t getWidth() const { return width; }
  void copyFrom(const Matrix &other) {
    width = other.width;
    height = other.height;
    createMatrix();
    for (int i = 0; i < height; ++i)
      for (int j = 0; j < width; ++j)
        matrix[i][j] = other.matrix[i][j];
  }
  void fillZero() {
    for (int i = 0; i < height; ++i)
      for (int j = 0; j < width; ++j)
        matrix[i][j] = 0;
  }
  void fillRandom() {
    for (int i = 0; i < height; ++i)
      for (int j = 0; j < width; ++j)
        matrix[i][j] = rand() % 10000 / 100.0;
  }
  Matrix &operator=(const Matrix &other) {
    copyFrom(other);
  }  
  virtual ~Matrix() {
    destroyMatrix();
  }
 private:    
  void createMatrix() {
    destroyMatrix();
    matrix = new double*[height];
    for (int i = 0; i < height; ++i)
      matrix[i] = new double[width];
  }
  void destroyMatrix() {
    if (matrix != NULL) {
      for (int i = 0; i < height; ++i)
        delete [] matrix[i];
      delete [] matrix;
    }
    matrix = NULL;
  }
  size_t width;
  size_t height;
  double **matrix;
};
 
std::ostream &operator<<(std::ostream &stream, const Matrix &matrix) {
  for (int i = 0; i < matrix.getHeight(); ++i) {
    stream.precision(4);
    for (int j = 0; j < matrix.getHeight(); ++j)
      stream << std::setw(10) << std::fixed << std::setprecision(4) << matrix.get(i, j);
    stream << std::endl;
  }
  return stream;
}
 
Matrix operator+(const Matrix &a, const Matrix &b) {
  if (a.getWidth() == b.getWidth() && a.getHeight() == b.getHeight()) {
    Matrix result(a);
    for (int i = 0; i < result.getHeight(); ++i)
      for (int j = 0; j < result.getHeight(); ++j)
        result.set(i, j, result.get(i, j) + b.get(i, j));
    return result;
  } else {
    throw std::range_error("matrix's dimensions must match");
  }
}
 
Matrix operator-(const Matrix &matrix) {
  Matrix result(matrix);
  for (int i = 0; i < result.getHeight(); ++i)
    for (int j = 0; j < result.getHeight(); ++j)
      result.set(i, j, -result.get(i, j));
  return result;
}
 
Matrix operator-(const Matrix &a, const Matrix &b) {
  return a + (-b);
}
 
int main(int argc, char *argv[]) {
  srand(time(0));
 
  Matrix a(4, 5);
  Matrix b(4, 5);
  a.fillRandom();
  b.fillRandom();
  std::cout << a << std::endl << " - " << std::endl
    << b << std::endl << " = " << std::endl
    << a - b << std::endl;
};