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39
40#ifndef QPOINTER_H
41#define QPOINTER_H
42
43#include <QtCore/qsharedpointer.h>
44#include <QtCore/qtypeinfo.h>
45
46#ifndef QT_NO_QOBJECT
47
48QT_BEGIN_NAMESPACE
49
50class QVariant;
51
52template <class T>
53class QPointer
54{
55 static_assert(!std::is_pointer<T>::value, "QPointer's template type must not be a pointer type");
56
57 using QObjectType =
58 typename std::conditional<std::is_const<T>::value, const QObject, QObject>::type;
59 QWeakPointer<QObjectType> wp;
60public:
61 QPointer() = default;
62 inline QPointer(T *p) : wp(p, true) { }
63 // compiler-generated copy/move ctor/assignment operators are fine!
64 // compiler-generated dtor is fine!
65
66#ifdef Q_QDOC
67 // Stop qdoc from complaining about missing function
68 ~QPointer();
69#endif
70
71 inline void swap(QPointer &other) noexcept { wp.swap(other.wp); }
72
73 inline QPointer<T> &operator=(T* p)
74 { wp.assign(static_cast<QObjectType*>(p)); return *this; }
75
76 inline T* data() const
77 { return static_cast<T*>(wp.internalData()); }
78 inline T* get() const
79 { return data(); }
80 inline T* operator->() const
81 { return data(); }
82 inline T& operator*() const
83 { return *data(); }
84 inline operator T*() const
85 { return data(); }
86
87 inline bool isNull() const
88 { return wp.isNull(); }
89
90 inline void clear()
91 { wp.clear(); }
92
93#define DECLARE_COMPARE_SET(T1, A1, T2, A2) \
94 friend bool operator==(T1, T2) \
95 { return A1 == A2; } \
96 friend bool operator!=(T1, T2) \
97 { return A1 != A2; }
98
99#define DECLARE_TEMPLATE_COMPARE_SET(T1, A1, T2, A2) \
100 template <typename X> \
101 friend bool operator==(T1, T2) noexcept \
102 { return A1 == A2; } \
103 template <typename X> \
104 friend bool operator!=(T1, T2) noexcept \
105 { return A1 != A2; }
106
107 DECLARE_TEMPLATE_COMPARE_SET(const QPointer &p1, p1.data(), const QPointer<X> &p2, p2.data())
108 DECLARE_TEMPLATE_COMPARE_SET(const QPointer &p1, p1.data(), X *ptr, ptr)
109 DECLARE_TEMPLATE_COMPARE_SET(X *ptr, ptr, const QPointer &p2, p2.data())
110 DECLARE_COMPARE_SET(const QPointer &p1, p1.data(), std::nullptr_t, nullptr)
111 DECLARE_COMPARE_SET(std::nullptr_t, nullptr, const QPointer &p2, p2.data())
112#undef DECLARE_COMPARE_SET
113#undef DECLARE_TEMPLATE_COMPARE_SET
114};
115template <class T> Q_DECLARE_TYPEINFO_BODY(QPointer<T>, Q_MOVABLE_TYPE);
116
117template<typename T>
118QPointer<T>
119qPointerFromVariant(const QVariant &variant)
120{
121 const auto wp = QtSharedPointer::weakPointerFromVariant_internal(variant);
122 return QPointer<T>{qobject_cast<T*>(QtPrivate::EnableInternalData::internalData(wp))};
123}
124
125template <class T>
126inline void swap(QPointer<T> &p1, QPointer<T> &p2) noexcept
127{ p1.swap(p2); }
128
129QT_END_NAMESPACE
130
131#endif // QT_NO_QOBJECT
132
133#endif // QPOINTER_H
134