[問題] 函數回傳const reference to object
測試環境: Dev C
各位好~小弟我最近在書上看到一個簡單例子
類似儲存日期功能
其中有一個operator overloading的函數(operator+=)
回傳了物件的 const reference (問題處有用顏色標示)
不太懂那樣的目的為何
我將程式重新精簡過後如下
===========================Date.h=======================================
#include <iostream>
using std::ostream;
class Date
{
friend ostream &operator<<( ostream &,const Date &);
public:
Date( int d=1);
Date &operator++();
const Date &operator+=(int);
private:
int day;
void inc();
};
=========================================================================
===========================Date.cpp======================================
#include <iostream>
#include "Date.h"
Date::Date(int d)
{
day=d;
}
Date &Date::operator++()
{
inc();
return *this;
}
const Date &Date::operator+=(int add)////我想問的地方
{
for (int i=0;i<add;i++)
inc();
return *this;
}
void Date::inc()
{
day++;
}
ostream &operator<<( ostream &output,const Date &d)
{
output<<d.day;
return output;
}
==========================================================================
謝謝!!!
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◆ From: 61.230.228.195
※ 編輯: enjoylife66 來自: 61.230.228.195 (08/14 14:11)
※ 編輯: enjoylife66 來自: 61.230.228.195 (08/14 14:13)
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