istream_iterator,ostream_iterator与vector的转换

利用istream_iterator可以很方便的从istream里（std::cin,ifstream等）解析出数据放入vector中

ostream_iterator也可以很方便的把vector中的数据放入ostream中。

textin.txt中存放：

1 2 3 4 5 6

int main(){
    vector<double> v1;
    v1.push_back(1.0);
    v1.push_back(2.0);
    v1.push_back(3.2);
    ostream_iterator<double> os(cout," ");
    copy(v1.begin(),v1.end(),os);
    
    vector<int> v2;
    copy(istream_iterator<int>(cin),istream_iterator<int>(),back_inserter(v2));
    ostream_iterator<int> os1(cout," ");
    copy(v2.begin(),v2.end(),os1);

    ifstream fin("E:\\textin.txt");
    vector<int> v3;
    copy(istream_iterator<int>(fin),istream_iterator<int>(),back_inserter(v3));
    ostream_iterator<int> os2(cout," ");
    copy(v3.begin(),v3.end(),os2);
}