模仿std::endl函數

使用vs2008編譯器。

 

myend函數就是模擬endl函數的。它是個全局函數。爲了達到與endl一樣的用法，還定義了：

mystream& operator<<(mystream& (*fun)(mystream&) );

 

#include "stdafx.h"//非vc編譯器可去掉 #include <iostream> #include <sstream> #include <cassert> using namespace std; class mystream { private: stringstream _ss; string _str; public: friend mystream& myend(mystream& ms); //5 friend ostream& operator <<(ostream& os, const mystream& ms); //6 public: mystream& operator<< (const int& val ) //1 { _ss <<val; return *this; } mystream& operator<< (const char* s ) //2 { _ss <<s; return *this; } mystream& operator<< (const double& val ) //3 { _ss <<val; return *this; } mystream& operator<<(mystream& (*fun)(mystream&) ); //4 }; mystream& myend(mystream& ms) //這個是模仿std::endl函數 { ms._str = ms._ss.str(); //沒做什麼，僅僅是給ms._str賦值。 return ms; } ostream& operator <<(ostream& os, const mystream& ms) { os<<ms._str; return os; } mystream& mystream::operator<<(mystream& (*fun)(mystream&) ) { assert(NULL != fun); return ((*fun)(*this)); } int main() { mystream mystr; mystr << 5<< "abc" << 3.57<< myend; //調用1，2，3；然後調用4，而4又調用5 cout << mystr<<endl; //輸出mystr._str到屏幕，調用6 return 0; }