c 2b 2b operator overloading

1// money.h -- define the prototype
2class Money
3{
4   public:
5      Money & operator += (const Money &rhs);
6}
7
8// money.cpp -- define the implementation
9Money& Money :: operator += (const Money &rhs)
10{
11   // Yadda Yadda
12  
13   return *this;
14}

1#include <iostream>
2
3class ExampleClass {
4  public:
5    ExampleClass() {}
6  	ExampleClass(int ex) {
7      example_ = 0;
8    }
9    int&       example()        { return example_; }
10    const int& example() const  { return example_; }
11  	//Overload the "+" Operator
12  	ExampleClass operator+ (const ExampleClass& second_object_of_class) {
13    	ExampleClass object_of_class;
14    	object_of_class.example() = this -> example() + second_object_of_class.example();
15    	return object_of_class;
16  	}
17  private:
18  	int example_;
19};
20
21int main() {
22  ExampleClass c1, c2;
23  c1.example() = 1;
24  c2.example() = 2;
25  ExampleClass c3 = c1 + c2;
26  //Calls operator+() of c1 with c2 as second_object_of_class
27  //c3 gets set to object_of_class
28  std::cout << c3.example();
29}

1#include <iostream>
2#include <string>
3 
4class Car
5{
6private:
7    std::string m_make;
8    std::string m_model;
9 
10public:
11    Car(const std::string& make, const std::string& model)
12        : m_make{ make }, m_model{ model }
13    {
14    }
15 
16    friend bool operator== (const Car &c1, const Car &c2);
17    friend bool operator!= (const Car &c1, const Car &c2);
18};
19 
20bool operator== (const Car &c1, const Car &c2)
21{
22    return (c1.m_make== c2.m_make &&
23            c1.m_model== c2.m_model);
24}
25 
26bool operator!= (const Car &c1, const Car &c2)
27{
28    return !(c1== c2);
29}
30 
31int main()
32{
33    Car corolla{ "Toyota", "Corolla" };
34    Car camry{ "Toyota", "Camry" };
35 
36    if (corolla == camry)
37        std::cout << "a Corolla and Camry are the same.\n";
38 
39    if (corolla != camry)
40        std::cout << "a Corolla and Camry are not the same.\n";
41 
42    return 0;
43}

1Box operator+(const Box&);
2

1ostream &operator<<(ostream &output, const MyClass &myObject)
2{ 
3  output << "P : " << myObject.property;
4  return output;            
5}
6

1inline bool operator==(const X& lhs, const X& rhs){ /* do actual comparison */ }
2inline bool operator!=(const X& lhs, const X& rhs){ return !(lhs == rhs); }