Question

As long as new issues are growing out of my previous question Overloaded assignment operator causes warning about recursion, I was legitimately urged to post this as new one. I have a reference class member in my class Player and I want to implement the copy constructor and the assignment operator (=) of this class. I have to mention that the purpose is the fine working of the function vector.erase because without that it does not work properly as far as I am concerned. I use a vector: vector allPlayers; The members of the class Player are:

class Player
{

  private:
  int ID;
  int pMoney;
  int doubleIndicator;
  int squarePosition;
  Bank& bank;
  string pName;
  Square* capturedSquare;
  multimap<string, PropertySquare*> squaresColBought;
  multimap<string, House*> housesColBuilt;

}

Is it mandatory to avoid the use of reference as class member if I want to implement the assignment operator? What about the map members? How should I finally implement the assignment operator?

Another issue of utmost importance of which I am unaware is what happens to the objects pointed by pointers class members when I erase the iterator of the vector which hold the Player. Any help?

Answer 1

I would refrain from using a reference member when you want an assignment operator. If you use a (smart) pointer instead, you can just do

Player &operator=(Player const &other)
{
    bankPtr = other.bankPtr;
    // copy other members
}

In the current situation, bank = other.bank will copy the contents of other.bank instead of pointing this->bank to the contents referenced by other.bank.

As for the multimap-typed members, they can be copied without problems, but do keep in mind that you’ll get a “deep” copy of the keys (since they’re of type string) but a “shallow” pointer copy of the values, so you end up with shared state. You might want to use shared_ptr for the values.