copy constructor 안에서 length constructor 호출을 했는데 워닝이 나오는 이유가 궁금합니다.

안녕하세요.

visual studio 사용하고 있습니다.

24번째 줄에서 Warning이 뜹니다.

C26444 Don't try to declare a local variable with no name (es.84)

copy constructor 안에서 length constructor 호출을 했는데 워닝이 나오는 이유가 궁금합니다.

#pragma once

#include <iostream>

class Resource {
public:
	int* m_data = nullptr;
	unsigned int m_length = 0;
public:
	Resource() {
		std::cout << "Resource default constructed\n";
	}

	Resource(unsigned int length) {
		std::cout << "Resource length constructed\n";
		this->m_data = new int[length];
		this->m_length = length;
	}

	Resource(const Resource& res) {
		std::cout << "Resource copy constructed\n";

		// 1. ...
		Resource(res.m_length);

		//// 2 ...
		//this->m_data = new int[res.m_length];
		//this->m_length = res.m_length;

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

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

	Resource& operator = (Resource& res) {
		std::cout << "Resource copy assignmnet\n";
		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 int i = 0; i < m_length; ++i) {
			m_data[i] = res.m_data[i];
		}

		return *this;
	}

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