Inheritance Problems

[Labdabeta]

I have a function that takes a reference to an interface class as a parameter. I have created a derived class from the interface class, but when I try to call the function with an instance of my derived class as an argument I get a compiler error saying "error: no matching call to 'FunctionName(DerivedClassName &)'" Why won't my compiler let me use inheritance?i

[jackmaverick1]

Could you post the code?

[Labdabeta]

Here is the specific code:
PathFindingAI.h:

#include <vector>
#include <limits.h>
using namespace std;
struct GameMove
{
    unsigned char *data;
    int l;
};
struct MoveScore
{
    GameMove move;
    int score;
};
class GameState
{
    public:
    virtual GameState &execute(GameMove)=0;//execute the move
    virtual GameState &undo(GameMove)=0;//undo the move
    virtual unsigned char *data()=0;
};
class GamePlayer
{
    public:
    virtual int evaluate(GameState&)=0;//evaluate the move
    virtual vector<GameMove> getMoves(GameState&)=0;
};
template <unsigned int ply>
MoveScore AlphaBeta(GameState &current, GamePlayer &us, GamePlayer &them, int low=INT_MIN, int high=INT_MAX)
{
    MoveScore best={{NULL,0},0};
    if (ply==0||us.getMoves(current).size()==0)
    {
        best.score=us.evaluate(current);
        return best;
    }
    vector<GameMove> moves=us.getMoves(current);
    for (int i=0; i<moves.size(); i++)
    {
        current.execute(moves[i]);
        MoveScore tmp=AlphaBeta<ply-1>(current,them,us,-high,-low);
        current.undo(moves[i]);
        if (-tmp.score>best.score)
        {
            low=-tmp.score;
            best.move=moves[i];
            best.score=low;
        }
        if (low>=high)
            return best;
    }
    return best;
}

TicTacToeTest.cpp:

#include <iostream>
#include "PathFindingAI.h"
class TicTacToeState:public GameState
{
    private:
    unsigned char board[9];
    public:
    TicTacToeState(){board={' ',' ',' ',' ',' ',' ',' ',' ',' '};}
    virtual GameState &execute(GameMove m)
    {
        if (m.l!=2||(m.data[0]!='X'&&m.data[0]!='O')||m.data[1]>8)
            return *this;
        board[m.data[1]]=m.data[0];
        return *this;
    }
    virtual GameState &undo(GameMove m)
    {
        if (board[m.data[1]]!=m.data[0])
            return *this;
        board[m.data[1]]=' ';
        return *this;
    }
    unsigned char *output()
    {
        unsigned char *ret=new unsigned char[10];
        for (int i=0; i<9; i++)
            ret[i]=board[i];
        ret[9]=0;
        return ret;
    }
    virtual unsigned char *data(){return board;}
};
class TicTacToePlayer:public GamePlayer
{
    private:
    bool isX;
    public:
    TicTacToePlayer(bool isX):isX(isX){};
    virtual int evaluate(GameState &s)
    {
        unsigned char tiars[8][3]={ {s.data()[0],s.data()[1],s.data()[2]},
                                    {s.data()[3],s.data()[4],s.data()[5]},
                                    {s.data()[6],s.data()[7],s.data()[8]},
                                    {s.data()[0],s.data()[4],s.data()[8]},
                                    {s.data()[2],s.data()[4],s.data()[6]},
                                    {s.data()[0],s.data()[3],s.data()[6]},
                                    {s.data()[1],s.data()[4],s.data()[7]},
                                    {s.data()[2],s.data()[5],s.data()[8]}};
        int ret=0;
        for (int i=0; i<8; i++)
        {
            //1st check for win
            if (tiars[i][0]==tiars[i][1]&&tiars[i][1]==tiars[i][2])
            {
                if (isX)
                    return (tiars[i][0]=='X'?INT_MAX:INT_MIN);
                else
                    return (tiars[i][0]=='X'?INT_MIN:INT_MAX);
            }//then return [# of 3-in-a-rows left for me]-[# of 3-in-a-rows left for you]
            else
            {
                if (tiars[i][0]==' '||tiars[i][1]==' '||tiars[i][2]==' ')
                {
                    if (!(tiars[i][0]=='X'||tiars[i][1]=='X'||tiars[i][2]=='X'))//O can get this row!
                        (isX?ret--:ret++);
                    if (!(tiars[i][0]=='O'||tiars[i][1]=='O'||tiars[i][2]=='O'))//X can get this row!
                        (isX?ret++:ret--);
                }
            }
        }
        return ret;
    }
    virtual vector<GameMove> getMoves(GameState &s)
    {
        vector<GameMove> ret;
        for (int i=0; i<9; i++)
        {
            if (s.data()[i]==' ')
            {
                GameMove m;
                m.data=new unsigned char[2];
                m.data[0]=(isX?'X':'O');
                m.data[1]=i;
                ret.push_back(m);
            }
        }
        return ret;
    }
};
int main()
{
    TicTacToeState board;
    TicTacToePlayer x(true),o(false);
    bool isX=true;
    while (x.getMoves(board).size()>0)//if X can go so can O
    {
        cout<<board.output();
        if (isX)
            board.execute(AlphaBeta(board,x,o).move);//here an error
        else
            board.execute(AlphaBeta(board,o,x).move);//and here an error
    }
    return true;
}

The errors say: error: no matching function for call to 'AlphaBeta(TicTacToeState&,TicTacToePlayer&,TicTacToePlayer&)'

[Labdabeta]

I figured it out. Facepalm kind of situation. AlphaBeta is a template function. I never specified the ply!