C / C++ / MFC

T.RATHA KRISHNAN wrote:

I've printed the same variable inside another derived class. But it prints nothing.

#include <iostream>
class A
{
protected:
  int a;
public:
  A(int a):a(a){}
  void show(){ std::cout << "this is A, a=" << a << std::endl;}
};

class B: public A
{

public:
  B(int b):A(b){}
  void show(){ std::cout << "this is B, a=" << a << std::endl;}
};

class C: public B
{

public:
  C(int c):B(c){}
  void show(){ std::cout << "this is C, a=" << a << std::endl;}
};


int main()
{
  A a(3);
  B b(4);
  C c(5);

  a.show();
  b.show();
  c.show();

  return 0;
}

T.RATHA KRISHNAN wrote:

I've declared a protected variable in a base class. I've assigned value and print the variable in a derived class. It prints correctly. I've printed the same variable inside another derived class. But it prints nothing. How to print the variable that is altered inside another derived class?

class A
{
protected:
    static int my_class_variable;
};

int CGameState::musicVolume = 0;

Code-o-mat wrote:

What did CreateFileMapping fail with, call GetLastError and see what it says, maybe it helps to decypher the problem.

Code-o-mat wrote:

Are you completely sure that the only difference between the two "versions" is the creation of the mutex?

Code-o-mat wrote:

Is it possible that you specified the same name for the mutex and the file mapping object?

Code-o-mat wrote:

Try creating an unnamed mutex and see if that changes anything. I know you will need a named one but this is just for testing.