fig20_05.cpp

// fig20_05.cpp
// Demonstrating operators .* and ->*.
#include <iostream>

// class Test definition
class Test {
public:
   Test(int x) : value{x} {};

   void testFunction() {
      std::cout << "testFunction called\n";
   }

   int value; // public data member
};

void arrowStar(Test* ptr); // prototype
void dotStar(Test* ptr); // prototype

int main() {
   Test test{8};
   arrowStar(&test); // pass address to arrowStar
   dotStar(&test); // pass address to dotStar
}

// access member function of Test object using ->*
void arrowStar(Test* ptr) {
   auto functionPtr{&Test::testFunction}; // pointer to a member function
   (ptr->*functionPtr)(); // invoke function indirectly              
}

// access members of Test object data member using .*
void dotStar(Test* ptr) {
   auto valuePtr{&Test::value}; // pointer to a data member  
   std::cout << "value is " << (*ptr).*valuePtr << "\n"; // access value
}


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