title: Child class inheriting from Multiple parents c++
body: <p>I am making a windows console rpg for a project, I changed a class from inheriting 1 parent class, and taking in an object, to inheriting 2 parent classes, it's causing issues when I run it now as the second base class is undefined<br>
  The header class is below</p>
  
  <pre><code> #include "GameObject.h"
    #include "BattleObject.h"
    #include "Player.h"  
    #include "Weapon.h"
    #include &lt;string&gt;
    #include &lt;vector&gt;
  using namespace std;
  class Monster :
      public GameObject,
      public BattleObject
  {
  private :
      string m_name;
      vector&lt;string&gt; m_drops;
  
  public:
      Monster(std::pair&lt;int, int&gt; coordinates, string name, vector&lt;string&gt; drops, int health, int attack, int defence);
      string getName();
  
  };
  </code></pre>
  
  <p>I expect it to take in 2 base classes, but it won't run because of this</p>
  
  <p>it Crashes and and says Battle Object base class is undefined.</p>