另一个类成员函数中另一个类的对象

Question

I have following code:

class A
{
public:
    A();

private:
    void slot();
};

The second class B looks like:

class B
{
public:
    B();

private:
    // Some stuff...
};

In file1.cpp there are static objects of both classes:

static A a;
static B b;

Now in file2.cpp(containing the class implementation) I would need in the slot function of class A the object b , which was created in file1.cpp. What is the best way to get it? How is this done using C++?

Answer 1

static means "local to this translation unit". What you are trying to do is impossible.

An alternative design would use non-static namespace scope objects, like:

globals.hpp:

extern A a;
extern B b;

globals.cpp:

#include "globals.hpp"
A a;
B b;

A.cpp:

#include "globals.hpp"
void A::slot(){
    //use b
}

You need to be careful with this design to ensure that you do not call A::slot before b has been constructed.