Sandbox/DefaultMethods.cpp

   1 #include "DefaultMethods.h"
   2
   3 #include <iostream>
   4 using namespace std;
   5
   6 namespace DefaultMethods
   7 {
   8     class C
   9     {
  10         int a;
  11
  12     public:
  13         // Default constructor (here we remove the default one).
  14         C() = delete;
  15
  16         // Copy constructor.
  17         C(const C& other);
  18
  19         // Move constructor.
  20         C(C&& other) noexcept;
  21
  22         // A custom constructor.
  23         C(int a);
  24
  25         // Copy-assignment operator.
  26         C& operator=(const C& other);
  27
  28         // Move-assignment operator.
  29         C& operator=(C&& other) noexcept;
  30
  31         ~C() noexcept;
  32
  33         int getA();
  34     };
  35
  36     C::C(const C& other)
  37     {
  38         cout << "Copy ctor, other.a = " << other.a << endl;
  39         this->a = other.a;
  40     }
  41
  42     C::C(C&& other) noexcept
  43     {
  44         cout << "Move ctor, other.a = " << other.a << endl;
  45         this->a = other.a;
  46         other.a = 0;
  47     }
  48
  49     C::C(int a)
  50         : a{ a }
  51     {
  52         cout << "ctor, a = " << a << endl;
  53     }
  54
  55     C& C::operator=(const C& other)
  56     {
  57         cout << "Copy assignment operator" << endl;
  58         this->a = other.a;
  59         return *this;
  60     }
  61
  62     C& C::operator=(C&& other) noexcept
  63     {
  64         cout << "Move assignment operator" << endl;
  65         this->a = other.a;
  66         other.a = 0;
  67         return *this;
  68     }
  69
  70     C::~C() noexcept
  71     {
  72         cout << "Destructor, a = " << this->a << endl;
  73     }
  74
  75     int C::getA()
  76     {
  77         return this->a;
  78     }
  79 }
  80
  81 void DefaultMethods::tests()
  82 {
  83     // Use of universal initialization.
  84     C c1{ 42 };
  85
  86     C c2 = move(c1); // Force to treat 'c1' as a right-hand value.
  87     C c3{ c1 };
  88     C c4{ 42 };
  89     cout << "c1.a = " << c1.getA() << endl;
  90     cout << "c2.a = " << c2.getA() << endl;
  91     cout << "c3.a = " << c3.getA() << endl;
  92     cout << "c4.a = " << c4.getA() << endl;
  93
  94     cout << "--- copy some values" << endl;
  95     c1 = c2;
  96     c2 = C{ 321 };
  97     cout << "c1.a = " << c1.getA() << endl;
  98     cout << "c2.a = " << c2.getA() << endl;
  99 }