How can I use function objects in C++ for advanced algorithms?

How can I use function objects in C++ for advanced algorithms?

Function objects, or functors, are objects that can be called as if they are functions. They are useful in algorithms like std::sort.

Can you give me an example of a function object?

Sure! Here's a simple example:

struct Add {
    int operator()(int a, int b) const {
        return a + b;
    }
};

You can use this Add functor with algorithms.

How do I use this functor with std::sort?

You can use it like this:

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

This will sort the vector using the Add functor.

What are the advantages of using function objects over regular functions?

Function objects can maintain state, are more flexible, and can be inlined by the compiler for better performance.