C / C++ / MFC

// In some header
 
class A
{
public:
   A();
 
protected:
   void OtherFunc();
 
   virtual void MyFunc() = 0;
};
 
class B : public A
{
public:
   B();
 
   virtual void MyFunc();
};
 
// Source file a1.cpp
 
A::A()
{
   OtherFunc();
}
 
void A::OtherFunc()
{
   MyFunc();
}
 
B::B()
{
}
 
void B::MyFunc()
{
}

ParallelPortTest error LNK2005: "void __cdecl outportb(unsigned short,unsigned char)" (?outportb@@YAXGE@Z) already defined in ParallelPortTest.obj
ParallelPortTest error LNK2005: "unsigned char __cdecl inportb(unsigned short)" (?inportb@@YAEG@Z) already defined in ParallelPortTest.obj
ParallelPortTest error LNK2005: "unsigned char __cdecl OpenPortTalk(void)" (?OpenPortTalk@@YAEXZ) already defined in ParallelPortTest.obj
ParallelPortTest error LNK2005: "void __cdecl ClosePortTalk(void)" (?ClosePortTalk@@YAXXZ) already defined in ParallelPortTest.obj

void CHelperDlg::ReadFiles(CString &TheVar, CFile ReadedFile)

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

<italic>Work hard, Work effectively and a bit of luck is the key to success.

#include <atlbase.h> //yes it is available in vc 6.0

CRegKey key;

if(key.Open(HKEY_CURRENT_USER,"Software\\Something\\ProductV1\\ProductV2")==ERROR_SUCCEESS)
{

//for deleting Value
   key.DeleteValue("XXX");
//for deleting subkey
   key.DeleteSubKey("123");

//close key
	key.Close();

}