FuncPtr<void(const char *)> func(puts);
func("hello!\n"); // prints hello!

// Simple C functions
void func();
FuncPtr<void()> fp(func);

// C++ Methods
struct Thing { void func(); };
Thing thing;
FuncPtr<void()> fp(&thing, &Thing::func);

// C functions with context
void func(Thing *);
FuncPtr<void()> fp(&thing, func);

// Function objects
struct Thing { void operator()(); };
Thing thing;
FuncPtr<void()> fp(&thing);

// Function binding
Binder<void(const char *), const char *> bind(putc, "hi!");
bind(); // prints hi!

// Function composition
Composer<int(const char *), const char *(int)> comp(puts, itoa);
comp(10); // prints 10

// Function chaining
Chainer<void(const char *), 2> chain;
chain.attach(puts);
chain.attach(puts);
chain("hi!\n"); // prints hi! twice

class Thing {
public:
    // The following two methods are sufficient for supporting 
    // every supported function type
    void attach(FuncPtr<void()> func) {
        _func.attach(func);
    }

    template<typename T, typename M>
    void attach(T *obj, M method) {
        attach(FuncPtr<void()>(obj, method));
    }

private:
    FuncPtr<void()> _func;
}

// C style callbacks
void register_callback(void (*callback)(void *), void *data);

register_callback(&FuncPtr<void()>::thunk, &func);

// C style functions without context
void register_callback(void (*callback)());

Thunker thunk(func);
register_callback(thunk);

// mbed style callbacks
void register_callback(T *obj, void (T::*M)());

register_callback(&func, &FuncPtr<void()>::call);