Thread: Pass by reference vs pass by pointer

What is the difference between these two alternatives? Are there performance tradeoffs? Any help appreciated. Examples below.

Code:

//Pass by pointer

void negate(int * pn)
{
 *n=-*n;
}

void func()
{
 int m=10;
 negate(&m);//pass m's address<
 std::cout<<m<<std::endl; //display: -10
}



//Pass by reference
void negate(int & n)
{
 >n=-n;//modifies caller's argument
}
void func()
{
 int m=10;
 negate(m);//pass by reference
 std::cout<<m<<std::endl; //diplay: -10
}