Question

I have a function pointer defined by:

typedef void (*EventFunction)(int nEvent); 

Is there a way to handle that function with a specific instance of a C++ object?

class A { private:     EventFunction handler;  public:     void SetEvent(EventFunction func) { handler = func; }      void EventOne() { handler(1); } };  class B { private:     A a; public:     B() { a.SetEvent(EventFromA); }  // What do I do here?      void EventFromA(int nEvent) { // do stuff } }; 

Edit: Orion pointed out the options that Boost offers such as:

boost::function<int (int)> f; X x; f = std::bind1st(       std::mem_fun(&X::foo), &x); f(5); // Call x.foo(5) 

Unfortunately Boost is not an option for me. Is there some sort of ‘currying’ function that can be written in C++ that will do this kind of wrapping of a pointer to a member function in to a normal function pointer?

Answer 1

I highly recommend Don Clugston’s excellent FastDelegate library. It provides all the things you’d expect of a real delegate and compiles down to a few ASM instructions in most cases. The accompanying article is a good read on member function pointers as well.

http://www.codeproject.com/KB/cpp/FastDelegate.aspx