Why a function with pointer arguments accepting actual variables? [duplicate]

Why is the code compiling even though I am passing variables to swap function, instead of pointers or addresses?

#include <iostream>
using namespace std;
    
void swap(int *a, int *b)
{
    int *tmp;
    tmp = a;
    a = b;
    b = tmp;
}
    
int main ()
{
    int x = 1; 
    int y = 2; 
    swap (x,y); /*Note: calling swap function using actual variables, not using addresses*/
    cout << " x = " << x << "  y = " << y << endl;
}