I am playing around with C++11 and I am trying to add elements to an unordered set and if I already added an element to my unordered\_set I don't want to add it again (i.e.) don't add cat again to the unordered set below.

```
    std::unordered_set<std::string> s;
    std::vector<std::string> myString;

    myString.push_back("cat");
    myString.push_back("dog");
    myString.push_back("bird");
    myString.push_back("cat");

for(auto &i : myString){
        //add elements from myString to unordered_set s
}

```

I am not exactly sure how to do this. I realize that I need to have a `std::pair` equal to my `s.insert(i)` however I'm not quite sure how to set this up so I can do this.

Any help would be greatly appreciated