Generic Single Linked List, No Viable overloaded = - c++

Question

I am creating a generic single linked list for the first time. I have this error that states:
No viable overloaded '='
So I decided to overload the '=' operator to make it work but I am still receiving the same error and I am not sure why. Here is my header file:
#ifndef LinkedList_hpp
#define LinkedList_hpp
#include <iostream>
template<class T>
struct Node {
T data;
Node<T>* next;
};
template<class T>
class SingleLinkedList {
private:
Node<T>* head, tail;
SingleLinkedList & operator=(const SingleLinkedList &rhs) {
head = rhs.head;
tail = rhs.tail;
return *this;
}
public:
SingleLinkedList() {
head = nullptr;
tail = nullptr;
}
void createNode(const T& theData) {
Node<T>* temp = new Node<T>;
temp->data = theData;
temp->next = nullptr;
if(head == nullptr) {
head = temp;
tail = temp;
temp = nullptr;
}
else {
tail->next = temp;
tail = temp;
}
}
void display() {
Node<T>* temp = new Node<T>;
temp = head;
while(temp != nullptr) {
std::cout << temp->data << "\t";
temp = temp->next;
}
}
void insert_start(const T& theData) {
Node<T>* temp = new Node<T>;
temp->data = theData;
temp->next = head;
head = temp;
}
void insert_position(int pos, const T& theData) {
Node<T>* previous = new Node<T>;
Node<T>* current = new Node<T>;
Node<T>* temp = new Node<T>;
temp = head;
for(int i = 1; i < pos; i++) {
previous = current;
current = current->next;
}
temp->data = theData;
previous->next = temp;
temp->next = current;
}
void delete_first() {
Node<T>* temp = new Node<T>;
temp = head;
head = head->next;
delete temp;
}
void delete_last() {
Node<T>* previous = new Node<T>;
Node<T>* current = new Node<T>;
current = head;
while(current->next != nullptr) {
previous = current;
current = current->next;
}
tail = previous;
previous->next = nullptr;
delete current;
}
void delete_position(int pos) {
Node<T>* previous = new Node<T>;
Node<T>* current = new Node<T>;
current = head;
for(int i = 1; i < pos; i++) {
previous = current;
current = current->next;
}
previous->next = current->next;
}
Node<T>* search(Node<T>* head, const T& target) {
}
};
Should I create an assignment operator in the struct Node? I am not sure what else to try.
Here is where I am getting an error: