errors result when creating header file - visual c++

hi,
i have written the following code, still in the learning stage:
#include<iostream.h>

class CBox {

public:
// Constructor definition
CBox(double lv, double bv = 1.0, double hv = 1.0) : m_Length(lv),
m_Breadth(bv), m_Height(hv)
{
cout << endl << "Constructor called";
}

// Default Constructor
CBox() {
cout << endl
<< "Default constructor called.";
m_Length = m_Breadth = m_Height = 1.0;
}

// Function to calculate the volume of a box
double Volume() const {
return m_Length * m_Breadth * m_Height;
}

private:
double m_Length;
double m_Breadth;
double m_Height;
};
int main() {
CBox boxes[5];
CBox cigar(8.0, 5.0, 1.0);

cout << endl
<< "Volume of boxes[3] = " << boxes[3].Volume()
<< endl
<< "Volume of cigar = " <<cigar.Volume();

cout << endl;
return 0;
}
when i try to break it into a header and source file, 2 separate
files, i get errors:
source file:
#include <iostream.h>
class CBox;

int main() {
CBox boxes[5];
CBox cigar(8.0, 5.0, 1.0);

cout << endl
<< "Volume of boxes[3] = " << boxes[3].Volume()
<< endl
<< "Volume of cigar = " <<cigar.Volume();

cout << endl;
return 0;
}
CBox.h:
#include<iostream.h>

class CBox {

public:
// Constructor definition
CBox(double lv, double bv = 1.0, double hv = 1.0) : m_Length(lv),
m_Breadth(bv), m_Height(hv)
{
cout << endl << "Constructor called";
}

// Default Constructor
CBox() {
cout << endl
<< "Default constructor called.";
m_Length = m_Breadth = m_Height = 1.0;
}

// Function to calculate the volume of a box
double Volume() const {
return m_Length * m_Breadth * m_Height;
}

private:
double m_Length;
double m_Breadth;
double m_Height;
};
\Microsoft Visual Studio .NET\Vc7\include\useoldio.h(29): warning
C4995: '_OLD_IOSTREAMS_ARE_DEPRECATED': name was marked as #pragma
deprecated
Test.cpp(5): error C2133: 'boxes' : unknown size
Test.cpp(5): error C2512: 'CBox' : no appropriate default constructor
available
Test.cpp(5): error C2262: 'boxes' : cannot be destroyed
Test.cpp(6): error C2079: 'cigar' uses undefined class 'CBox'
Test.cpp(6): error C2078: too many initializers
Test.cpp(6): warning C4244: 'initializing' : conversion from 'double'
to 'int', possible loss of data
Test.cpp(9): error C2036: 'CBox *' : unknown size
Test.cpp(9): error C2027: use of undefined type 'CBox'
Test.cpp(9): error C2228: left of '.Volume' must have
class/struct/union type
Test.cpp(11): error C2228: left of '.Volume' must have
class/struct/union type
is there a way to make it so that i can keep the files apart, if i
wanted all my classes to be in a header and the source to be separate,
please note that i wanted to make the constructors and the Volume
method inline that's why i put the code in the header.

Thank you.

when i try to break it into a header and source file, 2 separate
files, i get errors:
source file:
#include <iostream.h>
#include <iostream> /* for std::cout */
#include <ostream> /* for std::endl */
class CBox;
// replace with:

#include "CBox.h"

int main() {
using std::cout; /* so we can write cout instead of std::cout */
using std::endl; /* ... */
CBox boxes[5];
CBox cigar(8.0, 5.0, 1.0);

cout << endl
<< "Volume of boxes[3] = " << boxes[3].Volume()
<< endl
<< "Volume of cigar = " <<cigar.Volume();

cout << endl;
return 0;
}
CBox.h:
#include<iostream.h>

#include <iostream> /* for std::cout */
#include <ostream> /* for std::endl */

class CBox {

public:
// Constructor definition
CBox(double lv, double bv = 1.0, double hv = 1.0) : m_Length(lv),
m_Breadth(bv), m_Height(hv)
{
cout << endl << "Constructor called";
std::cout << std::endl << "Constructor called";
}

// Default Constructor
CBox() {
cout << endl
std::cout << std::endl

<< "Default constructor called.";
m_Length = m_Breadth = m_Height = 1.0;
}

// Function to calculate the volume of a box
double Volume() const {
return m_Length * m_Breadth * m_Height;
}

private:
double m_Length;
double m_Breadth;
double m_Height;
};

I'm not sure of the file split,

#include <iostream> /* for std::cout */
#include <ostream> /* for std::endl */

Rob Williscroft wrote:

#include <iostream> /* for std::cout */
#include <ostream> /* for std::endl */
Is that really necessary? According to my "C++ Programming Language:
Special Edition" p 633: "Manipulators taking istream and ostream are
presented in <istream> and <ostream>, respectively, and also in
<iostream>". std::endl is an ostream manipulator.

Logic's good so far.
Also, since std::cout is an std::ostream object, and is defined in
<iostream>, doesn't it follow that <ostream> has to have been included
by <iostream>?

Rob Williscroft wrote:

#include <iostream> /* for std::cout */
#include <ostream> /* for std::endl */
Is that really necessary? According to my "C++ Programming Language:
Special Edition" p 633: "Manipulators taking istream and ostream are
presented in <istream> and <ostream>, respectively, and also in
<iostream>". std::endl is an ostream manipulator.

This is what usually happens, but it isn't what the standard says.
It's what most people (including me - untill I was told otherwise)
expect to happen.
Also, since std::cout is an std::ostream object, and is defined in
<iostream>, doesn't it follow that <ostream> has to have been included
by <iostream>?

John L Fjellstad wrote in news:bd***********@192.168.1.1:

My appologees for the previous post. I clicked send before
I was finnished.

Rob Williscroft wrote:

#include <iostream> /* for std::cout */
#include <ostream> /* for std::endl */

Is that really necessary? According to my "C++ Programming Language:
Special Edition" p 633: "Manipulators taking istream and ostream are
presented in <istream> and <ostream>, respectively, and also in
<iostream>". std::endl is an ostream manipulator.

This is what usually happens, but it isn't what the standard says.
It's what most people (including me - untill I was told otherwise)
expect to happen.

Also, since std::cout is an std::ostream object, and is defined in
<iostream>, doesn't it follow that <ostream> has to have been included
by <iostream>?

<iostream> needs to declare the objects cin, cout, cerr etc.
The simplest way to do that is to:

#include <istream>
#include <ostream>

and then declare:

namespace std
{
extern istream cin;
extern ostream cout;
...
}

But it doesen't have to work like that. All it *has* to do is
include enough of the declaration's of std::basic_istream<> and
std::basic_ostream<> and possibly the typedef's std::istream and
std::ostream, so that it can declare the cin, cout ... objects.

It could miss out all the non-inline member defenition's.

It could also miss out defenition's for the constructor's and
destructor's for the basic_?stream<>'s even if they are inlined
as cin etc are magicly constructed before main() is entered and
aren't destroyed.

Most importantly, It dosent need to include the declaration and/or
defenition's for std::endl, std::ends, or std::flush. Firstly
because the standard dosen't require it too and secondly because
they aren't required for functioning cin, cout ... objects.

Instead, point out (if necessary) that they might run into people who
incorrectly think that the common practice is incorrect.

I agree (kind off) but where do you draw the line. std::endl in
<iostream> std::make_pair in <map> or maybe:

((some_class_type)0)->some_non_virtual_member();