C / C++ / MFC

#include <iostream>

using namespace std;

class A
{
	int a;public:	A(){a=0;}	
	virtual int do_things(int a){this->a = a; return 0;}
};

class AB: virtual public A
{	
	int ab;
public:
	AB(){ab=1; A * pA = this; pA->do_things(1);}
	virtual int do_things(int a){A::do_things(a);this->ab = a+1; return 1;}
};

class AC: virtual public A
{
	int ac;
public:	
	AC(){ac=2; A * pA = this; pA->do_things(2);}
	virtual int do_things(int a){A::do_things(a);this->ac = a+2; return 2;}
};

class ABAC: public AB, public AC
{
	int abac;
public:
	ABAC(){abac = 4;}
	virtual int do_things(int a){AB::do_things(a);AC::do_things(a);this->abac = a+4; return 4;}
};

int main()
{
	ABAC abac;

	return 0;
}

-		abac	{abac=4 }	ABAC
-		AB	{ab=2 }	AB
-		A	{a=2 }	A
-		__vfptr	0x00415700 const ABAC::`vftable'	*
		[0]	0x0041122b [thunk]:ABAC::do_things`vtordisp{4294967292,0}' (int)	*
		a	2	int
		ab	2	int
-		AC	{ac=4 }	AC
-		A	{a=2 }	A
-		__vfptr	0x00415700 const ABAC::`vftable'	*
		[0]	0x0041122b [thunk]:ABAC::do_things`vtordisp{4294967292,0}' (int)	*
		a	2	int
		ac	4	int
		abac	4	int

Jung Seng Won wrote:

USB control system is allowing computer to use USB that is registered by administrator.
if you want to use USB in your computer, you should input your password.

Jung Seng Won wrote:

but i just have idea , and i don't know what should i do first....

My friend don't know ...

so can you please give me tip and
recommand book which i can reference?

Jung Seng Won wrote:

(i can do c, c++ not winapi or MFC)

clever101 wrote:

(Press Retry to debug the application)

Mark Salsbery
Microsoft MVP - Visual C++

chinakknd wrote:

I dont know the login button's name or ID

Jim Crafton wrote:

What am I missing??!

Jim Crafton wrote:

If I remove the operator char() converter then it compiles fine. But why does this work in the first case and not the second?

m.s = t;

std::string b = t;