chess game - error in abstract class - c++

Question

#pragma once
#include <string>
#include <iostream>
using namespace std;
class Chess_tool
{
public:
Chess_tool(string color, char name);
virtual bool legal_movement(int source[], int dest[]) const = 0;
private:
string _color;
char _name;
};
Im trying to create chess game, so I create abstract class for chess tool (queen, king, rook...)
I also created king tool to check my code:
#pragma once
#include "Chess_tool.h"
class King : Chess_tool
{
public:
King(string color, char name);
virtual bool legal_movement(int source[], int dest[]);
};
and I create game_board class:
#pragma once
#include "Game_board.h"
#include "Chess_tool.h"
#include <iostream>
#define BOARD_SIZE 8
using namespace std;
class Chess_tool;
class Game_board
{
public:
Game_board();
~Game_board();
void move(string panel);
protected:
Chess_tool* _board[BOARD_SIZE][BOARD_SIZE];
};
the problem is here, when i try to add object to the matrix its show me error :
1 IntelliSense: object of abstract class type "King" is not allowed:
pure virtual function "Chess_tool::legal_movement" has no overrider
#pragma once
#include "Chess_tool.h"
#include "Game_board.h"
#include "King.h"
using namespace std;
enum Turn { WIHTE, BLACK };
class Manager : Game_board
{
public:
Manager();
~Manager();
virtual bool legal_movement(int source[], int dest[]) const = 0;
};
....
#include "Manager.h"
Manager::Manager()
{
_board[0][0] = new King();
}

Answer 1

The member function in the base class is const-qualified, not in the derived class.
So these are not the same functions through inheritance. You've declared a new virtual function, not overriden the first one.
Add const to the second one so that it actually override the base class function.
Remember that for virtual function overriding to kick in, there are a few condition to actually satisfy. They must have:
the same name
the same return type
the same parameters count and type
the same const-qualification (our case here)
a few other minor things (for example, compatible exceptions specifications)
If any condition isn't satisfied, you create a very similar, but different, function for the compiler.
With C++11, you should use override for the functions you want to override, so the compiler knows your intention and tells you that you've made a mistake. E.g.:
virtual bool legal_movement(int source[], int dest[]) override;
// ^^^^^^^^