#include <iostream>
#include <unordered_set>
#include <iterator>
void print(std::unordered_set<int> const &us) {
std::copy(us.begin(),
us.end(),
std::ostream_iterator<int>(std::cout, " "));
}
int main()
{
std::unordered_set<int> us = { 1, 5, 2, 7, 4, 9, 12 };
print(us);
return 0;
}
/*
run:
4 7 9 2 12 5 1
*/