References as Function Parameters
References are often used as function parameters. References as function parameters offer three advantages:
1) They eliminate the overhead associated with passing large data structures as parameters and with returning large data structures from functions.
2) They eliminate the pointer dereferencing notation used in functions to which you pass references as arguments.
3) Like pointers, they can allow the called function to operate on and possibly modify the caller's copy of the data.
Consider the following example,
void func( int & x )
{
x = x + 20 ;
}
int main ( )
{
int m = 10 ;
func( m ) ;
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return 0;
}
When the function call func( m ) is executed, the following initialization occurs:
int & x = m ;
Thus x becomes an alias of m after executing the statement
func( m ) ;
The value of m becomes 30 after the function is executed. Such function calls are known as call by reference
