set in C++

```
#include <iostream>
#include <set>
using namespace std;

int main() {
    set<int> s;
    s.insert(0);
    s.insert(1);
    s.insert(0);
    s.insert(2);
    s.erase(2);
    for(auto &i:s) 
        cout << i << ",";
}
```