How do I use std::unordered_set in C++11?

Can you explain how to use std::unordered_set in C++11?

Sure! std::unordered_set is a part of the C++11 standard library that provides a collection of unique elements, stored in no particular order. It uses a hash table for storage.

What are the main advantages of using std::unordered_set?

The main advantages include average constant time complexity for insertions, deletions, and lookups, which makes it very efficient for these operations.

Can you show me a simple example of how to declare and use std::unordered_set?

Of course! Here's a simple example:

#include <iostream>
#include <unordered_set>

int main() {
    std::unordered_set<int> mySet;
    mySet.insert(1);
    mySet.insert(2);
    mySet.insert(3);
    for (const auto& elem : mySet) {
        std::cout << elem << ' ';
    }
    return 0;
}

What happens if I try to insert a duplicate value?

If you try to insert a duplicate value, std::unordered_set will simply ignore it, as it only stores unique elements.