Preliminary C + + operator overloading Learning notes <3> Increment decrement operator overloading

Preliminary C + + operator overloading Learning notes <1>Preliminary Discussion on C + + operator overloading Learning notes <2> overloading as friend functions

Increment, decrement operator + + (--) has two forms: former self-increment ++i (self-subtraction). After self-increment i++ (self-reducing i--)

So when we overload the operator, we overload the corresponding form of the operators.

T & operator + + ()//front self-increment ++i

T & operator + + (int)//after self-increment i++

Example:

#include <iostream>using namespace Std;class complex{    double re;    Double im;public:    complex (Double _re,double _im): Re (_re), Im (_im) {};    void print () {cout<<re<< "" <<im<<endl;}    Friend Complex operator+ (const complex &A, const complex &b);  Think about returning why not complex &    complex& operator++ ();    complex& operator++ (int);}; Complex operator+ (const complex &A, const complex &b) {    return complex (A.re + b.re, a.im + b.im);} complex& complex::operator++ ()   //Pre-increment ++i{    re = re + 1;    return *this;} complex& complex::operator++ (int)  //After self-increment i++ int is just the distinction between pre-and post-increment {    im = im + 1;    return *this;} int main () {    complex A ();    Complex B (3,4);    Complex C = a + B;    Complex d = A + B + C;    C.print ();    D.print ();    (c + +) + +;    C.print ();    + + (++d);    D.print ();    return 0;}

The result output is:

After C self-increment two times imaginary part from 6 to 8

D two times since the real part from 10 to 12

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Preliminary C + + operator overloading Learning notes &lt;3&gt; Increment decrement operator overloading