How do I use custom comparators with C++11 algorithms?

Can you explain how to use custom comparators with C++11 algorithms?

Sure! In C++11, you can use custom comparators with algorithms like std::sort by defining a function or a functor.

What is a functor in this context?

A functor is an object that can be called as if it were a function. You can define a class with an operator() to create a functor.

Can you give me an example of a custom comparator?

Absolutely! Here's a simple example: a comparator that sorts integers in descending order:

struct Descending {
    bool operator()(int a, int b) const {
        return a > b;
    }
};

You can use this with std::sort like this:

std::vector<int> vec = {1, 2, 3, 4, 5};
std::sort(vec.begin(), vec.end(), Descending());