Dutor

//~ demo.cpp
#include <iostream>
#include <fstream>
#include <string>
#include <streambuf>
using namespace std;
//~ 测试代码 :)
int main()
{
	ifstream in("demo.cpp");
	char buffer[4096]="original content in this buffer";
	cout<<buffer<<endl;
	streambuf * ptrbuff = in.rdbuf(); //~ 将streambuf与文件句柄关联
	ptrbuf->pubsetbuf(bufer, 4096); //~ 设置缓冲区，即设置in的缓冲区
	cout<<buffer<<endl; //~ 此时bufer里面的内容还是original content in this buffer
	string str;
	in>>str; //~ 真正要输入时bufer才被填充为in的内容
	cout<<str<<endl;
	cout<<buffer<<endl;
	return 0;
}