[5:13] 22번줄 main_res = generateResource(); 에서 컴파일러 오류가 나네요 ㅠㅠ

chapter15_03.cpp

#include "Timer.h"
#include "AutoPtr.h"
#include "Resource.h"

AutoPtr<Resource> generateResource()
{
	AutoPtr<Resource> res(new Resource(10000000));

	return res;
}

int main()
{
	using namespace std;
	streambuf* orig_buf = cout.rdbuf();


	Timer timer;

	{
		AutoPtr<Resource> main_res;
		main_res = generateResource();
	}

	cout.rdbuf(orig_buf);
	timer.elapsed();

}

Auto.h

#pragma once

#include <iostream>

template<class T>
class AutoPtr
{
private:
	T* m_ptr = nullptr;

public:
	AutoPtr(T* ptr = nullptr)
		: m_ptr(ptr)
	{
		std::cout << "AutoPtr defalult constructor" << std::endl;
	}

	~AutoPtr()
	{
		std::cout << "AutoPtr destructor" << std::endl;
		if (m_ptr != nullptr) delete m_ptr;
	}

	AutoPtr(AutoPtr& a)
	{
		std::cout << "AutoPtr copy constructor" << std::endl;

		//deep copy
		m_ptr = new T;
		*m_ptr = *a.m_ptr;
	}

	AutoPtr& operator = (AutoPtr& a)
	{
		std::cout << "AutoPtr copy assignment" << std::endl;
		if (&a == this)
			return *this;

		if(m_ptr != nullptr) delete m_ptr;

		//deep copy
		m_ptr = new T;
		*m_ptr = *a.m_ptr;

		return *this;
	}
};

Resource.h

#pragma once

#include <iostream>

class Resource
{
public:
	int *m_data = nullptr;
	unsigned m_length = 0;

public:
	Resource()
	{
		std::cout << "Resource default constructed" << std::endl;
	}

	Resource(unsigned length)
	{
		std::cout << "Resource length constructed" << std::endl;

		this->m_data = new int[length];
		this->m_length = length;
	}

	Resource(const Resource& res)
	{
		std::cout << "Resource copy constructed" << std::endl;
		Resource(res.m_length);

		for (unsigned i = 0; i < m_length; ++i)
			m_data[i] = res.m_data[i];
	}

	~Resource()
	{
		std::cout << "Resource destoryed" << std::endl;
		if(m_data != nullptr) delete[] m_data;
	}

	Resource& operator = (Resource& res)
	{
		std::cout << "Resource copy assignment" << std::endl;

		if (&res == this) return *this;

		if (this->m_data != nullptr) delete[] m_data;

		m_length = res.m_length;
		m_data = new int[m_length];

		for (unsigned i = 0; i < m_length; ++i)
			m_data[i] = res.m_data[i];

		return* this;
	}

	void print()
	{
		for (unsigned i = 0; i < m_length; ++i)
		{
			std::cout << m_data[i] << " ";
		}
		std::cout << std::endl;
	}
};

Timer.h

#pragma once

#include <iostream>
#include <vector>
#include <algorithm>
#include <random>
#include <chrono>

class Timer
{
	using clock_t = std::chrono::high_resolution_clock;
	using second_t = std::chrono::duration<double, std::ratio<1>>;

	std::chrono::time_point<clock_t> start_time = clock_t::now();
public:
	void elapsed()
	{
		std::chrono::time_point<clock_t> end_time = clock_t::now();

		std::cout << std::chrono::duration_cast<second_t>(end_time - start_time).count() << std::endl;
	}
};

위에 코드로 빌드했을때 컴파일 에러가 나고.

main()문 안에서 

main_res = generateResource(); 줄에

no operator "=" matches these operands 라는 오류가 발생합니다.

오버로딩도 잘되었는데 무슨 문제인지 모르겟네요 ㅠㅠ

함수를 통해서 AutoPtr<Resource>를 받는게 안된다는건지...