What are advanced function objects in C++?

What are advanced function objects in C++?

Advanced function objects, or functors, are objects that can be called as if they were functions. They allow for more complex behavior than regular functions.

Can you give me an example of a functor?

Sure! Here's a simple example: a functor that adds a specific value to its input. You can define a class with an operator() method.

How do I implement a functor in C++?

To implement a functor, create a class with a public operator() method. Here's a quick example:

class Adder {
public:
    Adder(int x) : x_(x) {}
    int operator()(int y) const { return x_ + y; }
private:
    int x_;
};

You can then use it like this: Adder add5(5); int result = add5(10); // result is 15.

What are the advantages of using functors over regular functions?

Functors can maintain state, can be passed around like objects, and can be more flexible in terms of behavior compared to regular functions.