A proper way to create a matrix in c++

Question

I want to create an adjacency matrix for a graph. Since I read it is not safe to use arrays of the form matrix[x][y] because they don\'t check for range, I deci

Answer 1

Best way:

Make your own matrix class, that way you control every last aspect of it, including range checking.

eg. If you like the "[x][y]" notation, do this:

class my_matrix {
  std::vector >m;
public:
  my_matrix(unsigned int x, unsigned int y) {
    m.resize(x, std::vector(y,false));
  }
  class matrix_row {
    std::vector& row;
  public:
    matrix_row(std::vector& r) : row(r) {
    }
    bool& operator[](unsigned int y) {
      return row.at(y);
    }
  };
  matrix_row& operator[](unsigned int x) {
    return matrix_row(m.at(x));
  }
};
// Example usage
my_matrix mm(100,100);
mm[10][10] = true;

nb. If you program like this then C++ is just as safe as all those other "safe" languages.