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1/*!
2 * C++ Rule of Five full example
3 * Author: Gary Huang <gh.nctu+code [AT] gmail.com>
4 */
5#ifndef FOO_H
6#define FOO_H
7
8#include <iostream>
9#include <string>
10
11class Foo
12{
13  public:
14    Foo() : m_name(), m_size(0), m_data(nullptr)
15    {
16        std::cout << this << ": construct()" << std::endl;
17    }
18    Foo(std::string name, size_t size)
19        : m_name(std::move(name)),
20          m_size(size),
21          m_data(m_size ? new int[m_size] : nullptr)
22    {
23        std::cout << this << ": construct(name, size)" << std::endl;
24    }
25    Foo(const Foo &other)
26        : m_name(other.m_name),
27          m_size(other.m_size),
28          m_data(m_size ? new int[m_size] : nullptr)
29        // or just
30        // : Foo(name, size)
31    {
32        std::cout << this << ": copy constructor" << std::endl;
33        std::copy(other.m_data, other.m_data + other.m_size, m_data);
34    }
35    Foo(Foo &&other) noexcept
36        : m_name(std::move(other.m_name)),
37          m_size(other.m_size),
38          m_data(other.m_data)
39    {
40        std::cout << this << ": move constructor" << std::endl;
41        other.m_size = 0;
42        other.m_data = nullptr;
43    }
44#if 0
45    // naive
46    Foo &operator=(const Foo &other)
47    {
48        std::cout << this << ": copy assignment" << std::endl;
49        if (this != &other)
50        {
51            size_t n_size = other.m_size;
52            int *n_data = n_size ? new int[n_size] : nullptr;
53            std::copy(other.m_data, other.m_data + other.m_size, n_data);
54
55            delete [] m_data;
56            m_name = other.m_name;
57            m_size = n_size;
58            m_data = n_data;
59        }
60        return *this;
61    }
62    Foo &operator=(Foo &&other) noexcept
63    {
64        std::cout << this << ": move assignment" << std::endl;
65        if (this != &other)
66        {
67            delete [] m_data;
68            m_name = std::move(other.m_name);
69            m_size = other.m_size;
70            m_data = other.m_data;
71            other.m_size = 0;
72            other.m_data = nullptr;
73        }
74        return *this;
75    }
76#else
77    // copy-and-swap idiom
78    // DEPRECATED due to too slow
79    // Foo(Foo &&other)
80    //     : m_name(), m_size(0), m_data(nullptr)
81    //     // or just
82    //     // : Foo()
83    // {
84    //     std::cout << this << ": move constructor" << std::endl;
85    //     swap(*this, other);
86    // }
87    Foo &operator=(Foo other) noexcept
88    {
89        std::cout << this << ": move/copy assignment" << std::endl;
90        swap(*this, other);
91        return *this;
92    }
93#endif
94    ~Foo()
95    {
96        std::cout << this << ": destruct" << std::endl;
97        delete [] m_data;
98    }
99
100    std::string name() const { return m_name; }
101    size_t size() const      { return m_size; }
102
103    friend void swap(Foo &first, Foo &second)
104    {
105        using std::swap;
106        swap(first.m_name, second.m_name);
107        swap(first.m_size, second.m_size);
108        swap(first.m_data, second.m_data);
109    }
110
111  private:
112    std::string m_name;
113    size_t m_size;
114    int *m_data;
115};
116
117#endif // FOO_H