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

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

Sure! The std::set is a part of the C++ Standard Library and is used to store unique elements in a sorted 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);
    mySet.insert(5); // Duplicate, won't be added

    for (int num : mySet) {
        std::cout << num << " "; // Output: 1 3 5
    }
    return 0;
}

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, and the set will remain unchanged. This is because std::set only stores unique elements.

Can I store custom objects in a std::set?

Yes, you can store custom objects in a std::set, but you need to provide a way to compare them. This can be done by overloading the < operator or by providing a custom comparator.

Can you show me an example of storing custom objects?

Certainly! Here's an example of storing custom objects in a std::set:

#include <iostream>
#include <set>
#include <string>

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

    bool operator<(const Person& other) const {
        return name < other.name; // Compare by name
    }
};

int main() {
    std::set<Person> people;
    people.insert({"Alice", 30});
    people.insert({"Bob", 25});
    people.insert({"Alice", 28}); // Duplicate, won't be added

    for (const auto& person : people) {
        std::cout << person.name << " is " << person.age << " years old.\n";
    }
    return 0;
}