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39 | |
40 | #ifndef QQMLNULLABLEVALUE_P_H |
41 | #define QQMLNULLABLEVALUE_P_H |
42 | |
43 | // |
44 | // W A R N I N G |
45 | // ------------- |
46 | // |
47 | // This file is not part of the Qt API. It exists purely as an |
48 | // implementation detail. This header file may change from version to |
49 | // version without notice, or even be removed. |
50 | // |
51 | // We mean it. |
52 | // |
53 | |
54 | QT_BEGIN_NAMESPACE |
55 | |
56 | template<typename T> |
57 | struct QQmlNullableValue |
58 | { |
59 | QQmlNullableValue() |
60 | : value(T()) {} |
61 | QQmlNullableValue(const QQmlNullableValue<T> &o) |
62 | : isNull(o.isNull), value(o.value) {} |
63 | QQmlNullableValue(const T &t) |
64 | : isNull(false), value(t) {} |
65 | QQmlNullableValue<T> &operator=(const T &t) |
66 | { isNull = false; value = t; return *this; } |
67 | QQmlNullableValue<T> &operator=(const QQmlNullableValue<T> &o) |
68 | { isNull = o.isNull; value = o.value; return *this; } |
69 | operator T() const { return value; } |
70 | |
71 | void invalidate() { isNull = true; } |
72 | bool isValid() const { return !isNull; } |
73 | bool isNull = true; |
74 | T value; |
75 | }; |
76 | |
77 | QT_END_NAMESPACE |
78 | |
79 | #endif // QQMLNULLABLEVALUE_P_H |
80 | |