Several build errors, stumped

[MarchingBands]

I was required to make most of the functions be under main, and it's giving me countless build issues. I kept trying to search the error codes, but had no luck finding a permanent solution, as it kept giving me different errors. Thank you.

  #include <iostream>
#include <iomanip>
#include <string>
#include <sstream>
#include <fstream>

using namespace std;

const int ROWS = 3;
const int COLS = 3;

//Function Prototypes
void RenderBoard(char[][COLS], int);
void CheckRow(char[][COLS], int);
void CheckCol(char[][COLS], int);
void CheckDiag(char[][COLS], int);
void AnnounceWin();
void IsGameOver(bool);
void PlayMove(int);

//Main Function
int main()
{
	char board[3][3] =
	{
		{ '.','.','.' },
		{ '.','.','.' },
		{ '.','.','.' }
	};
	RenderBoard(board,ROWS);
	for (;;)
	{
		PlayMove(1);
		RenderBoard(board,ROWS);
		if (IsGameOver == 1);
		PlayMove(2);
		RenderBoard(board,ROWS);
		if (IsGameOver == 2);
		return false;
	}
	void RenderBoard(char board[][COLS], int size);
	{
		cout << "+-------+" << endl;
		for (int row = 0; row < ROWS; row++)
		{
			cout << "|";
			for (int col = 0; col < COLS; col++)
			{
				cout << " " << board[row][col];
			}
			cout << " |" << endl;
		}
		cout << "+-------+" << endl;
		return 0;
	}

	//Getting the moves from the players
	void PlayMove(int playerNum, char[][COLS], int);
	{
		int row = -1, col = -1;
		string line;
		stringstream ss;
		for (;;)
		{
			cout << "Player #" << playerNum << ", please enter your move (row col)(space inbetween): ";
			cin >> row >> col;
			while (row < 1 || row > 3 || col < 1 || col > 3)
			{
				cout << "Invalid move, please try again!" << endl;
				cout << "Player #" << playerNum << ", please enter your move (row col)(space inbetween): ";
				cin >> row >> col;
			}
			board[row - 1][col - 1] = ((playerNum == 1) ? 'X' : 'O');
			continue;
		}


	

		return 0;
	}



		//Checking Rows
	int CheckRow(int row, int RenderBoard, char[][COLS], int)
		{
			if (board[row][0] == board[row][1] && board[row][1] == board[row][2])
			{
				return (board[row][0] == 'X') ? 1 : ((board[row][0] == 'O') ? 2 : 0);
			}
			return int;
		}
		//Checking Columns
		int CheckCol(int col, int RenderBoard, char[][COLS], int)
		{
			if (board[0][col] == board[1][col] && board[1][col] == board[2][col])
			{
				return (board[0][col] == 'X') ? 1 : ((board[0][col] == 'O') ? 2 : 0);
			}
			return int;
		}
		//Checking Diagnals
		int CheckDiag(int RenderBoard, char[][COLS], int)
		{
			if (
				(board[0][0] == board[1][1] && board[1][1] == board[2][2])
				||
				(board[2][0] == board[1][1] && board[1][1] == board[0][2])
				)
			{
				return (board[1][1] == 'X') ? 1 : ((board[1][1] == 'O') ? 2 : 0);
			}
			return int;
		}
		//Declares the winner, and then outputs it.
		void AnnounceWin(int player, int RenderBoard)
		{
			cout << "Player #" << player << " wins!" << endl;
			return int;
		}


		//Checks to see if the game is over
		bool IsGameOver(char board[][COLS], int size)
		{
			int winner;
			for (int row = 0; row < ROWS; row++)
			{
				winner = CheckRow(board, row);
				if (winner != 0)
				{
					AnnounceWin(winner);
					return true;
				}
			}
			for (int col = 0; col < COLS; col++)
			{
				winner = CheckCol(board, col);
				if (winner != 0)
				{
					AnnounceWin(winner);
					return true;
				}
			}
			winner = CheckDiag(board, row);
			if (winner != 0)
			{
				AnnounceWin(winner);
				return true;
			}
			if (totalMoves <= 9)
			{
				cout << "It's a tie..." << endl;
				return true;
			}
			return true;
		}
		
	//Attempting to provide definitions, suggested fixes.
		int RenderBoard(board, ROWS)
		{
		}

		void RenderBoard(char[][COLS], int)
		{
		}

		void CheckRow(char[][COLS], int)
		{
		}

		void CheckCol(char[][COLS], int)
		{
		}

		void CheckDiag(char[][COLS], int)
		{
		}

		void AnnounceWin()
		{
		}

		void IsGameOver(bool)
		{
		}

		void IsGameOver()
		{
		}

		void PlayMove(int)
		{
		}

[keskiverto]

Start with the first error. Each compiler error message should list a line-number.

Online compiler finds first error in this:

void IsGameOver(bool);

int main () {
  if ( isGameOver == 1 ) // error, cannot compare (name of) function to integer value
  {}
}

A function definition* cannot be inside another function.

int foo(int); // declaration

int main() {
  int foo(int x) // error, definition inside function
  {
    return x+42;
  }
  return 0;
}

Make sure that they are outside.

int foo(int); // function declaration

int main() {
  int y = foo( 7 ); // function call
  return 0;
}

int foo(int x) // definition
{
  return x+42;
}

* Although C++11 does have lambdas that can.

[AbstractionAnon]

In addition to what keskiverto mentioned, I see the following problems:

Lines 14-17: Your forward declarations don't match your implementations.

line 35,38: These lines do nothing. The ; terminates the if statement. There is no conditional execution. isGameOVer() is a void function. You can't use a void function in an if statement.

Line 38: Comparison of a bool function to 2 is not valid.

line 30,41,58: The ; terminates the function header making this a function declaration, not the start of a function definition. Remove the ;

Line 35,38: IsGameOver() requires a bool argument.

Line 54,80: void functions can not return a value.

Line 18,125: The signatures of your forward declaration and your implementation do not agree.

Line 58,95.104: Second argument is not named. You want board here.

lines 92,101,114,120: You can't return the keyword int You need to return a value.

Line 42,161,165: You have multiple implementations of RenderBoard().