Function Parameter

#include <iostream>

using namespace std;

void swap1(int a, int b)
{
    // value
    cout << __FUNCTION__ << "\t$a = " << a << "\t$b = " << b << endl;

    int tmp = b;
    b = a;
    a = tmp;

    cout << __FUNCTION__ << "\t$a = " << a << "\t$b = " << b << endl;
}

void swap2(int& a, int& b)
{
    // reference
    cout << __FUNCTION__ << "\t$a = " << a << "\t$b = " << b << endl;

    int tmp = b;
    b = a;
    a = tmp;

    cout << __FUNCTION__ << "\t$a = " << a << "\t$b = " << b << endl;
}

void swap3(int* a, int* b)
{
    // pointer
    cout << __FUNCTION__ << "\t$a = " << *a << "\t$b = " << *b << endl;

    int tmp = *b;
    *b = *a;
    *a = tmp;

    cout << __FUNCTION__ << "\t$a = " << *a << "\t$b = " << *b << endl;
}

int main()
{
    int a, b;

    a = 2, b = 5;
    cout << __FUNCTION__ << "\t$a = " << a << "\t$b = " << b << endl;
    swap1(a, b);
    cout << __FUNCTION__ << "\t$a = " << a << "\t$b = " << b << endl;

    cout << endl;

    a = 8, b = 10;
    cout << __FUNCTION__ << "\t$a = " << a << "\t$b = " << b << endl;
    swap2(a, b);
    cout << __FUNCTION__ << "\t$a = " << a << "\t$b = " << b << endl;

    cout << endl;

    a = 33, b = 55;
    cout << __FUNCTION__ << "\t$a = " << a << "\t$b = " << b << endl;
    swap3(&a, &b);
    cout << __FUNCTION__ << "\t$a = " << a << "\t$b = " << b << endl;
}