copy函数与ostream_iterator、reverse_iterator

#include <iostream>
#include <iterator>
#include <vector>

int main()
{
    using namespace std;
    int casts[10]={6,7,2,9,4,11,8,7,10,5};
    vector<int> dice(10);
    copy(casts,casts+10,dice.begin());
    cout << "Let the dice be cast!\n";
    ostream_iterator<int,char> out_iter(cout," ");
    copy(dice.begin(),dice.end(),out_iter);
    cout << endl;
    cout << "Implicit use of reverse iterator.\n";
    copy(dice.rbegin(),dice.rend(),out_iter);
    cout << endl;
    cout << "Explicit use fo reverse iterator.\n";
    vector<int>::reverse_iterator ri;
    for(ri=dice.rbegin();ri!=dice.rend();ri++)
        cout << *ri << ' ';
    cout << endl;
    return 0;
}