模仿std::endl函数

使用vs2008编译器。

 

myend函数就是模拟endl函数的。它是个全局函数。为了达到与endl一样的用法，还定义了：

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

 

#include "stdafx.h"//非vc编译器可去掉 #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) //这个是模仿std::endl函数 { ms._str = ms._ss.str(); //没做什么，仅仅是给ms._str赋值。 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; //调用1，2，3；然后调用4，而4又调用5 cout << mystr<<endl; //输出mystr._str到屏幕，调用6 return 0; }