Passing member function pointer to member object in c++

Question

I have a problem with using a pointer to function in C++. Here is my example:

#include 

using namespace std;

class bar
{
public:
    void (         


        

Answer 1

As the error says, methods belong to the class, not to individual instances. For this reason pointers to free functions and pointers to non-static methods are completely different things. You'll also need an instance to call the method on.

//declaring and taking the address of a foo's method 
void (foo::*method)() = &foo::hello; //as the compiler nicely suggests

//calling a function through pointer
free_func();

//calling a method through pointer
foo instance;
(instance.*method)();

You can use libraries like Boost.Bind and Boost.Function (also in std::tr1 I think) to abstract away the difference and also bind an instance to the method:

#include 
#include 
#include 

using namespace std;

class foo
{
public:
    void hello(){cout << "hello" << endl;};
};

void byebye()
{
    cout << "bye" << endl;
}


int main()
{
    foo testFoo;

    boost::function helloFunc(boost::bind(&foo::hello, testFoo));
    boost::function byeFunc(byebye);

    helloFunc();
    byeFunc();
    return 0;
}