Question

class Board {
public:

  virtual void init() = 0;
  virtual void print_board() const = 0;
  virtual Board* clone() const = 0;
  virtual bool less_than(const Board& b2) const = 0;
  inline friend bool operator< (const Board& b1, const Board& b2);
};

inline bool operator< (const Board& b1, const Board& b2){
  std::cout<<"TEST1"<<std::endl;
  return b1.less_than(b2);
}

Test1 isn’t being printed at all when I insert using mymap[board] = evaluate;
The map is map<Board*, int>.

Answer 1

It’s calling operator<(Board*, Board*), which just compares the pointers. Either construct your map as map<Board, Board> – or create a functor for comparing two map pointers and use it as a template parameter:

struct compareBoards {
    bool operator()(Board const * b1, Board const * b2) const {
        return *b1 < *b2; }
}

And

map<Board*, int, compareBoards> boardMap;