inheritance - C++ Error in compiling due to pointer class -

my code doesn't compile when try running it. many errors don't understand why errors pop in first place. of errors involve header file. of errors i'm missing ';' before '*' in header file. furthermore says int assumed in header file comment in code happens.

this error im getting compiler:

 1`>\\csupdatevm\labusers\uuu_uuuuu\documents\visual studio 2013\projects\expection\expection\game_implementation.cpp(25): error c2276: '&' : illegal operation on bound member function expression` 

in header file have:

    #include <iostream>     #include <string>     #include <vector>     #include <algorithm>      using namespace std;     //#include <exception>  class board{     public:         void displayboard();         void createboard();         void insert(int temp_move, char temp_player);         bool islegal(int move);         vector<char> getboard();     private:         const int num_squares = 9;         vector<char> board;     };      class abstractplayer{     public:         int virtual move(char temp_player) = 0;         char virtual selectpiece()=0;         char askyesno(string question);         int asknumber(string question, int high, int low = 0);         char winner(vector<char> const & another__temp_board);     protected:         char go_first;         bool first_turn = true;         char human;         char computer;         const char x = 'x';         const char o = 'o';         const char empty = ' ';         const char tie = 't';         const char no_one = 'n';         board another_board;      };      class human:public abstractplayer{     public:         int move(char temp_player);         char selectpiece();     };      class computer:public abstractplayer{     public:         int move(char temp_player);         char selectpiece();     };  class game{     public:         void play();         void instructions();         void announcewinner(char winner, char computer, char human);     private:         human* human;//error         computer* cpu;//error         board board;         char turn = 'x';         int move;     }; 

in human cpp file have:

#include "tictactoe.h"   char human::selectpiece() {      if (first_turn == true)     {         go_first = askyesno("do require first move?");          if (go_first == 'y')         {             cout << "\nthen take first move.  need it.\n";             return 'x';         }         else         {             cout << "\nyour bravery undoing... go first.\n";             return 'o';         }         first_turn = false;     }      else         return 'x';  }  int human::move(char temp_player) {     int move = asknumber("where move?", 9);     while (!another_board.islegal(move))     {         cout << "\nthat square occupied, foolish human.\n";         move = asknumber("where move?", 9);     }     cout << "fine...\n";     return move; } 

in computer cpp file have:

#include "tictactoe.h"  char computer::selectpiece() {     return 'o'; }  int computer::move(char temp_player) {     cout << "i shall take square number ";      vector<char> temp_board_yo=another_board.getboard();      // if computer can win on next move, make move     (int move = 0; move < 9; ++move)     {         if (another_board.islegal(move))         {             temp_board_yo[move] = computer;             if (winner(temp_board_yo) == computer)             {                 cout << move << endl;                 return move;             }             // done checking move, undo             temp_board_yo[move] = empty;         }     }      // if human can win on next move, block move     char human = 'x';     (int move = 0; move < 9; ++move)     {         if (another_board.islegal(move))         {             temp_board_yo[move] = human;             if (winner(temp_board_yo) == human)             {                 cout << move << endl;                 return move;             }             // done checking move, undo             temp_board_yo[move] = empty;         }     }      // best moves make, in order     const int best_moves[] = { 4, 0, 2, 6, 8, 1, 3, 5, 7 };     // since no 1 can win on next move, pick best open square     (int = 0; < 9; ++i)     {         int move = best_moves[i];         if (another_board.islegal(move))         {             cout << move << endl;             return move;         }     } } 

in board cpp file have

#include "tictactoe.h"  void board::createboard() {     (int = 0; < num_squares; i++)         board.push_back(' '); }  void board::displayboard() {     cout << "\n\t" << board[0] << " | " << board[1] << " | " << board[2];     cout << "\n\t" << "---------";     cout << "\n\t" << board[3] << " | " << board[4] << " | " << board[5];     cout << "\n\t" << "---------";     cout << "\n\t" << board[6] << " | " << board[7] << " | " << board[8];     cout << "\n\n"; }  void board::insert(int temp_move,char temp_player) {     board[temp_move] = temp_player; }  bool board::islegal(int move) {     return (board[move] ==' '); }  vector <char> board::getboard() {     return board; } 

in abstractplayer cpp file have:

#include "tictactoe.h"  char abstractplayer::askyesno(string question) {     char response;         {         cout << question << " (y/n): ";         cin >> response;     } while (response != 'y' && response != 'n');      return response; } int abstractplayer::asknumber(string question, int high, int low) {     int number;         {         cout << question << " (" << low << " - " << high << "): ";         cin >> number;     } while (number > high || number < low);      return number; } char abstractplayer::winner(vector<char> const & another_temp_board) {     // possible winning rows     const int winning_rows[8][3] = { { 0, 1, 2 },     { 3, 4, 5 },     { 6, 7, 8 },     { 0, 3, 6 },     { 1, 4, 7 },     { 2, 5, 8 },     { 0, 4, 8 },     { 2, 4, 6 } };     const int total_rows = 8;      // if winning row has 3 values same (and not empty),     // have winner     (int row = 0; row < total_rows; ++row)     {         if ((another_temp_board[winning_rows[row][0]] != empty) &&             (another_temp_board[winning_rows[row][0]] == another_temp_board[winning_rows[row][1]]) &&             (another_temp_board[winning_rows[row][1]] == another_temp_board[winning_rows[row][2]]))         {             return another_temp_board[winning_rows[row][0]];         }     }      // since nobody has won, check tie (no empty squares left)     if (count(another_temp_board.begin(), another_temp_board.end(), empty) == 0)         return tie;      // since nobody has won , isn't tie, game ain't on     return no_one; } 

in game_implementation cpp have

#include "tictactoe.h"  void game::instructions() {     cout << "welcome ultimate man-machine showdown: tic-tac-toe.\n";     cout << "--where human brain pit against silicon processor\n\n";      cout << "make move known entering number, 0 - 8.  number\n";     cout << "corresponds desired board position, illustrated:\n\n";      cout << "       0 | 1 | 2\n";     cout << "       ---------\n";     cout << "       3 | 4 | 5\n";     cout << "       ---------\n";     cout << "       6 | 7 | 8\n\n";      cout << "prepare yourself, human.  battle begin.\n\n"; }  void game::play() {     instructions();     board.createboard();      while (human->winner(board.getboard()) =='n')     {         if (turn == human->selectpiece())//human goes          {              //move = humanmove(board, human);             move = human->move(human->selectpiece());             board.insert(move, human->selectpiece());             turn = cpu->selectpiece();         }         else//computer goes         {             //move = computermove(board, computer);             move = cpu->move(cpu->selectpiece());             board.insert(move, cpu->selectpiece());             turn = human->selectpiece();         }         board.displayboard();     }      announcewinner(cpu->winner(board.getboard()), cpu->selectpiece(), human->selectpiece());//error: says not take 1 argument   }  void game::announcewinner(char winner, char computer, char human) {     if (winner == computer)     {         cout << winner << "'s won!\n";         cout << "as predicted, human, triumphant once more -- proof\n";         cout << "that computers superior humans in regards.\n";     }      else if (winner == human)     {         cout << winner << "'s won!\n";         cout << "no, no!  cannot be!  somehow tricked me, human.\n";         cout << "but never again!  i, computer, swear it!\n";     }      else     {         cout << "it's tie.\n";         cout << "you lucky, human, , somehow managed tie me.\n";         cout << "celebrate... best ever achieve.\n";     } } 

and in test file have

#include "tictactoe.h"  int main() {     game g;      g.play(); } 

the compiler not know human, computer, , board when processes lines:

human* human;//error computer* cpu;//error board board; 

you need add forward declarations of human , computer before definition of game since declaring pointers types in game.

you need move definition of board before definition of game since declaring object of type in game.

p.s. there may other errors need fixed too.

update

while (human->winner(& board.getboard) =='n') 

is not right since board.getboard member function. need there is:

while (human->winner(board.getboard()) =='n')                                 // ^^ missing parens 

however, work, you'll need change interface of abstractplayer::winner

char winner(vector<char> another_temp_board) 

or

char winner(vector<char> const& another_temp_board)