Functional list

c

#include <iostream>
#include <memory>

template<class T>
struct Node
{
    Node(T v, std::shared_ptr<const Node> tail): value(v), next(tail) {
//	std::cout << "Node " << value << tail << std::endl;
    };
    const T value;
    std::shared_ptr<const Node> next;
};



template<class T>
class List{
public:
    List(): head(nullptr), size(0) {};
    List(T val, List tail): head( std::make_shared<Node<T>>(val, tail.head) ), size(tail.size + 1) {
	std::cout << "Size " << size << std::endl;
	};
private:
    size_t size;
    std::shared_ptr<Node<T>>  head;
    explicit List (std::shared_ptr<Node<T>>  item) : head(item), size(1) {};
public:
    T front() const
    {
        assert(!isEmpty());
        return head->value;
    }

    bool isEmpty(){
        return head == nullptr;
    }

    List append(T value){
        return List(value, *this);
    }
    
    size_t getSize() {
    	return size;
    }
private:
    List pop_front() const
    {
        assert(!isEmpty());
        return List(head->next);
    }
};

template<typename T>
void printList(List<T> * list){
    return;
}

int main(int argc, char** argv){
   std::cout << "Start" << std::endl;  
   List<int> list;   
   list = list.append(5);
   list = list.append(3);
   std::cout << list.getSize() << std::endl;
   return 0;
}