字符串流sstream-part2

//验证字符串流不会主动释放内存
#include <iostream>
#include <sstream>
#include <iomanip>
using namespace std;
int main()
{
    ostringstream foo("hello world");
    cout<<foo.str()<<endl;        //hello world
    cout<<foo.str()<<endl;        //hello world

    istringstream bar("hello world");
    string word;
    while(bar>>word)
        cout<<word;               //helloworld
    cout<<endl;    
    cout<<bar.str()<<endl;        //hello world

    stringstream ss;
    string str;
    while(1)
    {
        ss<<"abcdefg";
        ss>>str;
        cout<<"Size of stream = "<<ss.str().length()<<endl;        //7\n14\n21\n28...
        ss.clear();            //每次循环需要清除错误标识，因为ss>>str没有读取到数据时，会置位failbit，如果不清楚错误标识，将导致接下来的I/O无效
         system("pause");
    }
    system("pause");
    return 0;
}

//清除错误标识及清空string buffer
#include <iostream>
#include <sstream>
#include <iomanip>
using namespace std;
int main()
{
    stringstream ss("hello world");
    char ch;
    while(ss.get(ch))
        cout<<ch;                  //hello world
    cout<<endl;

    ss.clear();                    //清除ss.get()置位的failbit
    ss.str("");                    //清空string buffer
    ss<<"hello c++";    
    cout<<ss.str()<<endl;

    system("pause");
    return 0;
}