流迭代器的一些做用

 流迭代器通常有下面的几种做用：

 

//利用流迭代器填充vector
    {
        ifstream in("test.txt");
        istream_iterator<string> ibegin(in);
        istream_iterator<string> iend;
        vector<string> vec(ibegin, iend);
        copy(vec.begin(), vec.end(), ostream_iterator<string>(cout, "/n"));
    }

 

//利用输入流填充vector
    {
        vector<string> vec;
        copy(istream_iterator<string>(cin), istream_iterator<string>(), back_inserter(vec));
        sort(vec.begin(), vec.end());
        copy(vec.begin(), vec.end(), ostream_iterator<string>(cout,"/n"));
    }

 

 

//利用流迭代器保存vector内容到文件
    {
        ifstream in("test.txt");
        istream_iterator<string> ibegin(in);
        istream_iterator<string> iend;
        vector<string> vec(ibegin, iend);
        ofstream out("testcopy.txt");
        copy(vec.begin(), vec.end(), ostream_iterator<string>(out, "/n"));    
    }