Lecture
Any binary operation Å can be defined in two ways: either as a component function with one parameter, or as a global (possibly friendly) function with two parameters. In the first case, x Å y means calling x.operator Å (y) , in the second case - calling operator Å (x, y).
· Operations overloaded within a class can only be overloaded with non-static component functions with parameters. The called class object is automatically taken as the first operand.
· Operations that are reloaded outside the scope of a class must have two operands, one of which must have a class type.
Examples
1) class person {...};
class adresbook
{// contains as component data a set of objects of type // person, represented as a dynamic array, list or tree
...
public:
person & operator [] (int); // access to the i-th object
};
person & adresbook:: operator [] (int i) {. . .}
void main ()
{class adresbook persons;
class person record;
...
record = persons [3];
}
2) class person {...};
class adresbook
{// contains as component data a set of objects of type // person, represented as a dynamic array, list or tree
...
public:
friend person & operator [] (const adresbook &, int); // access to the i-th object
};
person & operator [] (const adresbook & ob, int i) {. . .}
void main ()
{class adresbook persons;
class person record;
...
record = persons [3];
}
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