템플릿 클래스 비교 오류(C2678)

#include <iostream>
#include <string>
using namespace std;
 
class Complex {
private:
	float real, imaginary;
public:
	Complex(float _real, float _imaginary) : real(_real), imaginary(_imaginary) {};
};
 
class MyString {
private:
	const char *str;
public:
	MyString():str(""){}
	MyString( const char *_str) : str(_str) {}
};
 
template <class T, int size>
class List {
	T *elem;
	int size;
	int currentSize;
public:
	List() : currentSize(0) {}
	List(int _size) : size(_size), currentSize(0) { elem = new T[_size]; }
	List(const List& another) : size(another.size), currentSize(another.currentSize) {
		elem = new T[size];
		for (int i = 0; i < currentSize; i++) {
			elem[i] = another.elem[i];
		}
	}
	int add(const T &anElem) {
		elem[currentSize] = anElem;
		return currentSize++;
	}
 
 
	void find(const T &anElem) {
		for (int i = 0; i < currentSize; i++) {
			if (elem[i] == anElem) {
				cout << "exist" << endl;
			}
			else {
				cout << "not exist" << endl;
			}
		}
	}
	void remove(const T &anElem) {
		for (int i = 0; i < currentSize; i++) {
			if (elem[i] == anElem) {
				for (int j = i; j < (currentSize - 1); j++) {
					elem[j] = elem[j + 1];
				}
			}
			else {
				cout << "not exist" << endl;
			}
		}
	}
	void remove(const int location) {
		for (int j = location; j < (currentSize - 1); j++) {
			elem[j] = elem[j + 1];
		}
	}
 
	List operator = (const List& L){
		for (int i = 0; i < currentSize; i++) {
			L.elem[i] = elem[i];
		}
	}
};
 
 
int main() {
	List<Complex, 100> cList;
	List<MyString, 200> sList;
 
	int i1 = cList.add(Complex(0, 0));
	cList.add(Complex(1, 1));
	int i2 = sList.add("abc");
	sList.add("def");
	cList.find(Complex(1, 0));
	sList.find("def");
	cList.remove(i1);
	sList.remove("abc");
 
	List<MyString, 200> s2List(sList);
	List<MyString, 200> s3List;
	s3List.add("123");
	s3List = s2List;
	s3List.remove("def");
}