C++ Function return statement Returning reference values

#include <iostream>
using namespace std;
int x;                   // global variable
int& setx();             // function declaration
int main()/* ww w . j a v a 2 s .c o  m*/
{                     // set x to a value, using
    setx() = 92;          // function call on left side
    cout << "x=" << x << endl;  // display new value in x
    return 0;
}
int& setx()
{
    return x;             // returns the value to be modified
}