ATL / WTL / STL

Quote:

The use of the friend keyword is to allow access to protected or private variables of the other class

Quote:

but you still need an instance of the class to access them.

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It's most useful when the friend class inherits the other one

bkelly13 wrote:

Class M starts running and creates class C to do a bunch of startup work. C is owned by M but does not inherit from M. C is deleted immediately upon completing its work.

bkelly13 wrote:

I am leery of public variables

Quote:

then I can't see a lot of problem in making M a friend of C.

class M
{
    // Somewhere in the declaration of M...
    friend class C;
};

class C2;
class C1
{
public:
	int public_var;
protected:
	int protected_var;
private:
	int private_var;
friend class C2;
};

class C2
{
public:
	class C1 member;
	void set_private_var (int v) { member.private_var = v; } 
	void set_protected_var (int v) { member.protected_var = v; } 
};

void Test()
{
	C2 obj;
	
	obj.member.public_var = 100; // ok

	// ERROR: can't access protected and private member
	// obj.member.protected_var = 100; 
	// obj.member.private_var = 200; 

	obj.set_protected_var(100); // ok
	obj.set_private_var(200);   // ok
}

class C1
{
public:
	int public_var;
protected:
	int protected_var;
private:
	int private_var;
};

class C1B : public C1
{
friend C2;
}

class C2
{
public:
	class C1B member;        
	void set_protected_var (int v) { member.protected_var = v; } 
};

void Test()
{
	C2 obj;
	
	obj.member.public_var = 100; // ok

	// ERROR: can't access protected and private member
	// obj.member.protected_var = 100; 
	// obj.member.private_var = 200; 

	obj.set_protected_var(100); // ok	
}

bkelly13 wrote:

This is the first time I have considered using inheritance. Code efficiency overrides simplicity.

Is this the right way to go?

Should the core class be abstract? Or would that be getting a bit advanced for me.

bkelly13 wrote:

At the lowest level, the TCP class starts a completion thread for the send side and soon will start another completion thread for the receive side.

bkelly13 wrote:

TCP is the only method we have to transfer data between computers. --------------------------. Our mission system is contained within a single room and the Ethernet bandwidth is 1Gbps.

bkelly13 wrote:

Our display system only accepts data via TCP/IP.

econy wrote:

file.Open(fileName,CFile::typeBinary | CFile::modeRead);