How to intialize pointer to member function inside ctor

How to intialize pointer to member function inside constructor.

Code:

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class Foo{
private:
  void (Foo::*func)();
  void _func(){}
public:
  Foo(){
    func = &Foo::_func;
    // _func = 0x0, func = someaddress
    printf("func: 0x%08X, _func: 0x0%08X", func, &Foo::_func);
  }
};

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If you actually want to initialise it, the constructor should be defined as:

Code:

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Foo() : func(&Foo::_func) {}

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As for printing the member function pointer: the %X format specifier is not appropriate. The %p format specifier might be appropriate with a cast to void*, but if I remember correctly it is not guaranteed that there is a valid conversion from a pointer to a function or member function to void*. You may be better off using formatted output with a std::ostream like std::cout instead.

EDIT:
By the way, why do you want to do this in the first place?

I think this code can make you understand what you want

Code:

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#include <stdio.h>

class Test {
private:
  int (Test::*m_FuncPtr)(const int, const int);

public:
  Test() : m_FuncPtr(NULL) {}

  Test(int (Test::*FuncPtr)(const int, const int)) :
      m_FuncPtr(FuncPtr) {}

  int Sum(const int a, const int b) { return a + b; }
};

int main() {
  Test obj(&Test::Sum);
  return 0;
}

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