Quoting from C++ FAQ: Note: It’s imperative that the function’s definition (the part between the {…}) be placed in a header file, unless the function is used only in a single .cpp file. In particular, if you put the inline function’s definition into a .cpp file and you call it from some other .cpp file, … Read more
At the time you declare your member, you are still defining the A class, so the type A is still undefined. However, when you write A*, the compiler already knows that A stands for a class name, and so the type “pointer to A” is defined. That’s why you can embed a pointer to the … Read more
The Sun page you link to has some key differences between the two: A nested class is a member of its enclosing class. Non-static nested classes (inner classes) have access to other members of the enclosing class, even if they are declared private. Static nested classes do not have access to other members of the … Read more
To call a member function by pointer, you need two things: A pointer to the object and a pointer to the function. You need both in MenuButton::SetButton() template <class object> void MenuButton::SetButton(int xPos, int yPos, LPCWSTR normalFilePath, LPCWSTR hoverFilePath, LPCWSTR pressedFilePath, int Width, int Height, object *ButtonObj, void (object::*ButtonFunc)()) { BUTTON::SetButton(xPos, yPos, normalFilePath, hoverFilePath, pressedFilePath, … Read more
Instead of having static methods and passing around a pointer to the class instance, you could use functionality in the new C++11 standard: std::function and std::bind: #include <functional> class EventHandler { public: void addHandler(std::function<void(int)> callback) { cout << “Handler added…” << endl; // Let’s pretend an event just occured callback(1); } }; The addHandler method … Read more
If you have only one instance anyway, it’s best to make all variables per-instance, simply because they will be accessed (a little bit) faster (one less level of “lookup” due to the “inheritance” from class to instance), and there are no downsides to weigh against this small advantage.