Non-Operator Overloads in Functors

Yes, a functor class can contain non-operator member functions, just like any other class. These functions can be called using the dot notation on an instance of the functor.

Here's an example of a functor with a regular member function:

1#include <iostream>
2
3class Functor {
4public:
5  void operator()() const {
6    std::cout << "Calling operator()\n";
7  }
8
9  void SayHello() const {
10    std::cout << "Hello from Functor!\n";
11  }
12};
13
14int main() {
15  Functor f;
16  f(); // Call operator()
17  f.SayHello(); // Call SayHello() 
18}

1Calling operator()
2Hello from Functor!

You can also call non-operator member functions on a temporary functor instance:

1#include <iostream>
2
3class Functor {
4 public:
5  void SayHello() const {
6    std::cout << "Hello from Functor!\n";
7  }
8};
9
10int main() {
11  Functor().SayHello();  
12}

1Hello from Functor!

This creates a temporary Functor object, calls SayHello() on it, and then immediately destroys the temporary object.

Non-operator member functions in functors can be useful for providing additional functionality related to the callable, such as setting up state or returning information about the functor's current state.