Overloading the relational and logical operators

It is possible to overload the relational and logical operators. When you overload the relational and logical operators so that they behave in their traditional manner, you will not want the operator functions to return an object of the class for which they are defined. Instead, they will return an integer that indicates either true or false. This not only allows the operators to return a true/false value, it also allows the operators to be integrated into larger relational and logical expressions that involves other type of data.
Note if you are using a modern C++ compiler, you can also have an overloaded relational or logical operator function return a value of type bool, although there is no advantage to doing so.
The following program overloads the operators == and &&:
// overload the == and && relative to coord class
#include
using namespace std;
class coord {
int x, y; // coordinate values
public:
coord( ) { x = 0; y = 0; }
coord(int i, int j) { x = i; y = j; }
void get_xy(int &i, int &j) { i = x; j = y; }
int operator==(coord ob2);
int operator&&(int i);
};
// Overload the operator == for coord
int coord::operator==(coord ob2) {
return (x==ob2.x) && (y==ob2.y);
}
// Overload the operator && for coord
int coord::operator&&(coord ob2) {
return (x && ob2.x) && (y && ob2.y);
}
int main( ) {
coord o1(10, 10), o2(5, 3), o3(10, 10), o4(0, 0);

if (o1==o2) cout << "o1 same as o2\n";
else cout << "o1 and o2 differ\n";
if (o1==o3) cout << "o1 same as o3\n";
else cout << "o1 and o3 differ\n";
if (o1&&o2) cout << "o1 && o2 is true\n";
else cout << "o1 && o2 is false\n";
if (o1&&o4) cout << "o1 && o4 is true\n";
else cout << "o1 && o4 is false\n";
return 0;
}