C++ Function Pointer

// return_type (*pointer_name)(parameter_type_1, parameter_type_2, ...);

int (*operationPtr)(int, int); 

int add(int a, int b) {
    return a + b;
}

// Both initializations are strictly equivalent
int (*ptr1)(int, int) = add;
int (*ptr2)(int, int) = &add; 

// Implicit dereference (Standard C++ style)
int result1 = ptr1(5, 3);

// Explicit dereference (Legacy C style)
int result2 = (*ptr1)(5, 3);

// Legacy typedef approach
typedef int (*OperationFunc)(int, int);

// Modern C++ type alias approach (Recommended)
using OperationFuncAlias = int (*)(int, int);

// Usage
OperationFuncAlias myPtr = add;

class Calculator {
public:
    int multiply(int a, int b) { return a * b; }
};

// Declaration of a pointer to a member function of Calculator
int (Calculator::*memPtr)(int, int) = &Calculator::multiply;

Calculator calc;
Calculator* calcPtr = &calc;

// Invocation via object instance
int res1 = (calc.*memPtr)(4, 5);

// Invocation via object pointer
int res2 = (calcPtr->*memPtr)(4, 5);