copy很骚的用法

int main() {
    vector<int> v;
    for (int i=0;i<10;++i)
        v.push_back(i);
    sort(v.begin(),v.end(),[] (int a,int b) {
        return a > b;
    });
    ostream_iterator<int> osi(cout,",");
    copy(v.begin(),v.end(),osi);
    return 0;
}