Welcome to our exploration of using custom classes and comparators in C++ maps. In today's lesson, we'll learn how to use custom objects as keys in standard maps. This approach enhances data organization and access. With the addition of comparators, we can dictate the order in such maps, ensuring efficient and predictable data retrieval.

In C++, a std::map is a collection of key-value pairs where the keys are automatically ordered based on a comparison function — by default, using the < operator. This arrangement makes operations like searching for keys within a range efficient.

Notice how, in the above code snippet, iterating the map yields the same order of keys even though they have been declared differently.

Custom classes allow us to create objects that align with our data structures — such as a Person class for employee information or a Book class for a library database. In C++, classes act as blueprints for creating objects with defined attributes and methods.

Consider this simple class example: