• vicentico1 (10/10) May 29 2003 how do i define a pointer-to-member for any class? what i want is to mak...
• Richard Grant (19/21) May 29 2003 class a { public: int plus(int i,int j) { return i + j; } } classa;

vicentico1 <vicentico1_member pathlink.com> writes:

how do i define a pointer-to-member for any class? what i want is to make a
typedef of a member function of any class.

something like 
typedef int(*name)(int,int);

class a { public: int aa(int,int) } classa;
class b { public: int ba(int,int) } classb;

and then passit to a function like this

name var = classa.aa, var2 = classsb.ba;

is this possible??


vicentico

Richard Grant <fractal clark.net> writes:

In article <bb5c6q$uqp$1 digitaldaemon.com>, vicentico1 says...
how do i define a pointer-to-member for any class? what i want is to make a
typedef of a member function of any class.

class a { public: int plus(int i,int j) { return i + j; } } classa;
class b { public: int multiply(int i,int j) { return i * j; } } classb;

template <class T> struct functor {
functor(T* t, int (T::*fn)(int, int)) : m_(t), m_f(fn) {}
int operator()(int lhs, int rhs) {
return (*m_.*m_f)(lhs, rhs);
}
private:
T* m_;
int (T::*m_f)(int, int);
};

int main() {
functor<a> fa(&classa, classa.plus);
functor<b> fb(&classb, classb.multiply);
std::cout << fa(1000, -2000) << std::endl;
std::cout << fb(70, 54);
}

Richard