C + + operator overloading

One, operator overloading:

Operator overloading is a polymorphic type that extends the functionality of operators so that operators are not only used for built-in data types.

Ii. rules for operator overloading:

　　1.c++ does not allow users to define new operators themselves, only the existing C + + operators can be overloaded;

2. Overloading cannot change the number of operator operands (that is, shoving count), and cannot have default parameters, otherwise it also changes the number of operands, for example: "+" operator overload or only binocular operator;

3. Overloading does not change the precedence and associativity of operators;

4. Overloaded operators must be used with objects of a user-defined custom type, with at least one parameter that is a class object (or a reference to a class object);

5. Operators for class objects must generally be overloaded, but with two exceptions, operators "=" and "&" do not have to be overloaded;

6. The function of the overloaded operator should be similar to the function that the operator implements when it acts on a standard type of data;

7. An operator overload function can be a member function of a class, a friend function of a class, a non-class member function, or a common function of a friend function.

There are two ways to implement operator overloading:

1.friend function:

class class Name: {public:    operatoroperator  operator (formal parameter list) {     // definition }

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2. Class member functions:

class class Name {public:    operator  operator (formal parameter list);}; return type class Name::operator  operator (formal parameter list) {    // definition }

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Iv. overloads of different operators:

1.

C + + operator overloading