passing pointer to member function that is const

Hi,
my problem is the following
let's say we have a class MyClass:

class MyClass {
int val;
bool check(int) const;
};
bool MyClass::check(int i) const {
return i==val;
}


and a global function f:

void f( bool (*g)(int) ) {
cout << (*g)(3) ;


now what I would like to be able to do is to pass MyClass::check to the function f.

simply doing

f(&MyClass::check);

is not working because the compiler complains it cannot convert 'bool (Myclass::*) (int)' to 'bool (*)(int)'
and I don't want to make the member function static because it has to access non static attributes. also I don't want my global function to be bound to any specific class (it should only take a function that accept a int and return a bool)

does anyone know how to solve this problem?

thanks

cla

Code:

---

class Checkable {
public:
  bool check(int i) const=0;
};

---

Make the function virtual. Any class that you want to be able to check should implement the Checkable interface. Then, change the signature of f to something like this

void f(Checkable* g);

Here, while you can do this with any class you write (just make it support Checkable interface), you can't pass functions to it.

Alternatively, you could use templates

Code:

---

#include <iostream>

bool retFalseFunc(int i) {
 return false;
}

class EqualityFunctor {
 int privInt;
public:
 bool operator()(int i) const {
  return i == privInt;
 }
 EqualityFunctor(int i) : privInt(i) { }
};

template <typename func> void f(func g) {
 std::cout << "function like thing g returns " << g(2) << " when passed a 2 " << std::endl;
}

int main() {
 f(retFalseFunc);
 f(EqualityFunctor(3));
 f(EqualityFunctor(2));
 return 0;
}

---

Thanx A LOT
i didn't think about the templated solution which is exactly what I needed.
cla