//: C12:PointerToMemberOperator.cpp // From Thinking in C++, 2nd Edition // Available at http://www.BruceEckel.com // (c) Bruce Eckel 2000 // Copyright notice in Copyright.txt #include using namespace std; class Dog { public: int run(int i) const { cout << "run\n"; return i; } int eat(int i) const { cout << "eat\n"; return i; } int sleep(int i) const { cout << "ZZZ\n"; return i; } typedef int (Dog::*PMF)(int) const; // operator->* must return an object // that has an operator(): class FunctionObject { Dog* ptr; PMF pmem; public: // Save the object pointer and member pointer FunctionObject(Dog* wp, PMF pmf) : ptr(wp), pmem(pmf) { cout << "FunctionObject constructor\n"; } // Make the call using the object pointer // and member pointer int operator()(int i) const { cout << "FunctionObject::operator()\n"; return (ptr->*pmem)(i); // Make the call } }; FunctionObject operator->*(PMF pmf) { cout << "operator->*" << endl; return FunctionObject(this, pmf); } }; int main() { Dog w; Dog::PMF pmf = &Dog::run; cout << (w->*pmf)(1) << endl; pmf = &Dog::sleep; cout << (w->*pmf)(2) << endl; pmf = &Dog::eat; cout << (w->*pmf)(3) << endl; } ///:~