warning C4511

Hi,
I am using MSVC to compile a C++ application and getting these

warnings:
warning C4511: 'serialCom' : copy constructor could not be generated
warning C4512: 'serialCom' : assignment operator could not be generated

The .h file is below. The warnings occur when I add the line std:fstream logfile;

I have read the msdn website and I know how to turn off the warnings form being displayed but I want to know how to eliminate it. Any help would be greatly appreciated. Thanks
Amish

Code:

/*
 * serialCom.h
 * This header file contains all the functions required to use the serialCom class
 *
 * Author: Amish Rughoonundon
 * Date: 19 Dec 2005
 * Version 1.0: Initial
 *
 */

#pragma once

#include <windows.h> /*This header contains function used only in windows*/
#include <string>
#include <iostream> /* iostream is used for input and output */
#include <fstream>/* fstream is used for file accessing*/

class serialCom
{
public:
	/* Variables */

	/* Functions */

	/* 
	 * serialCom()
	 *
	 * This is the constructor for the class serialCom.
	 *
	 * Param:  None
	 *
	 */
	serialCom(void);

	/* The destructor for makeSimFile Class */
	~serialCom(void);

private:
	/* Variables */
	std::ofstream logfile;
	/* Functions */

	/*
	 *
	 * This function sets up the serial serial port communication.
	 * Baud rate: B115200 
	 * Data size 8bit, non-parity, 1 stop bit with Hardware flow control.
	 *
	 * PARAM: portname:- The name of the serial port
	 *        fd:- The handle of the serial port
	 *
	 * Return: Return an error code which is a negative number 
	 *         depending on what went wrong in the function.
	 *         Refer to Errors.info for more information
	 *         If no errors 0 is returned.
	 *
	 */
	int setupConnection(char* portname, HANDLE *fd);
};

Add your own copy constructor and assignment operator?

[edit]http://www.parashift.com/c++-faq-lit...html#faq-27.10

• A class with any of {destructor, assignment operator, copy constructor} generally needs all 3

Thanks for the answer although these websites I found provided more in depth information on the subject:
http://cplus.about.com/od/beginnerct.../aa072802a.htm
http://www.concentric.net/~rtgillam/pubs/assign.html

Hopefully they can help other people.
Amish

Specifically, the problem is that std::ofstream does not have a copy constructor (how would it work with exclusively opened files?), therefore the compiler can not generate a default member-wise copy constructor for any class that contains a std::ofstream.