What are some examples of using std::set in C++?

Can you give me some examples of using std::set in C++?

Sure! std::set is a part of the C++ Standard Library that stores unique elements in a specific order. Here's a simple example:

#include <iostream>
#include <set>

int main() {
    std::set<int> mySet;
    mySet.insert(5);
    mySet.insert(1);
    mySet.insert(3);

    for (int x : mySet) {
        std::cout << x << " ";
    }
    return 0;
}

This code will output: 1 3 5, demonstrating how elements are stored in sorted order.

What happens if I try to insert a duplicate value?

If you try to insert a duplicate value into a std::set, it will simply be ignored. For example:

mySet.insert(3);

This won't change the set since 3 is already present. You can check the size of the set before and after to see that it remains the same.

Can I use std::set with custom objects?

Yes, you can use std::set with custom objects, but you need to define a comparison function to determine the order of the objects. Here's an example:

struct Person {
    std::string name;
    int age;
};

struct ComparePerson {
    bool operator()(const Person& a, const Person& b) const {
        return a.name < b.name;
    }
};

std::set<Person, ComparePerson> people;

What are the advantages of using std::set over other containers?

The main advantages of std::set are that it automatically maintains order and ensures all elements are unique. This makes it ideal for scenarios where you need to store a collection of distinct items and frequently perform search operations.