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39
40//
41// W A R N I N G
42// -------------
43//
44// This file is not part of the Qt API. It exists purely as an
45// implementation detail. This header file may change from version to
46// version without notice, or even be removed.
47//
48// We mean it.
49
50#ifndef QPatternist_ReferenceCountedValue_p_h
51#define QPatternist_ReferenceCountedValue_p_h
52
53QT_BEGIN_NAMESPACE
54
55namespace QPatternist
56{
57/*!
58 \class ReferenceCountedValue
59 \internal
60 \since 4.4
61 \brief A template class that reference counts a value.
62
63 This class is useful when an instance needs to have ownership semantics
64 as if it was value based. A typical examples is a QObject pointer, which
65 doesn't have a single owner.
66
67 This is achieved through storing a copy of the object as
68 a member inside ReferenceCountedValue, which never is copied. It will
69 stay in scope until the last reference to the ReferenceCountedValue instance
70 is removed, and subsequently ReferenceCountedValue is deleted and hence also
71 the contained value. One should use ReferenceCountedValue by passing around
72 copies of Ptr, which is a typedef for the QExplicitlySharedDataPointer
73 smart pointer.
74*/
75 template<typename T>
76 class ReferenceCountedValue : public QSharedData
77 {
78 public:
79 typedef QExplicitlySharedDataPointer<ReferenceCountedValue<T> > Ptr;
80
81 inline ReferenceCountedValue(T *const v) : value(v)
82 {
83 }
84
85 inline ~ReferenceCountedValue()
86 {
87 delete value;
88 }
89
90 T *const value;
91 private:
92 /*!
93 Disabled, no implementation provided.
94 */
95 inline ReferenceCountedValue();
96 Q_DISABLE_COPY(ReferenceCountedValue)
97 };
98}
99
100QT_END_NAMESPACE
101
102#endif
103

source code of qtxmlpatterns/src/xmlpatterns/api/qreferencecountedvalue_p.h