Move Assignment Releases What It Held

1#include <iostream>
2#include <string>
3#include <utility>
4using namespace std;
5 
6class Buffer {
7    int* m_data;
8    int m_size;
9    string m_name;
10public:
11    Buffer(const string& name, int size) : m_size(size), m_name(name) {
12        m_data = new int[size];
13        cout << "alloc " << m_name << endl;
14    }
15    Buffer& operator=(Buffer&& other) noexcept {
16        if (this != &other) {
17            delete[] m_data;
18            cout << "release " << m_name << endl;
19            m_data = other.m_data;
20            m_size = other.m_size;
21            m_name = other.m_name;
22            other.m_data = nullptr;
23            other.m_size = 0;
24            other.m_name = "";
25        }
26        return *this;
27    }
28    ~Buffer() {
29        delete[] m_data;
30        cout << "free " << (m_name.empty() ? "nothing" : m_name) << endl;
31    }
32    int size() const { return m_size; }
33};
34 
35int main() {
36    Buffer a("a", 2);
37    Buffer b("b", 5);
38    b = std::move(a);
39    cout << b.size() << " " << a.size() << endl;
40    Buffer& r = b;
41    b = std::move(r);
42    cout << "end" << endl;
43    return 0;
44}