Function main

Examples/Modules/Chapter 19/Ex19_01/Ex19_01.cpp:7–17

long product(long a, long b);       // Function prototype

int main()
{
  long(*fun_ptr)(long, long) {};    // Pointer to function

  fun_ptr = product;
  std::cout << "3 * 5 = " << fun_ptr(3, 5) << std::endl; // Call product() thru fun_ptr

  fun_ptr = sum;                    // Reassign pointer to sum()
  std::cout << "3 * (4+5) + 6 = "   // Call sum() thru fun_ptr twice
    << fun_ptr(product(3, fun_ptr(4, 5)), 6) << std::endl; 
}

// Function to multiply two values
long product(long a, long b) { return a * b; }