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39
40#pragma once
41
42#include <QtCore/qglobal.h>
43#include <QtQml/private/qtqmlglobal_p.h>
44
45#include <memory>
46#if __cplusplus > 201402L && __has_include(<optional>)
47#include <optional>
48#else
49
50namespace std {
51
52struct nullopt_t {};
53
54constexpr nullopt_t nullopt {};
55
56template<typename T>
57class optional {
58public:
59 optional() = default;
60 optional(nullopt_t) {}
61 optional(const T &v) : _value(v), _hasValue(true) {}
62 ~optional() = default;
63
64 optional &operator =(nullopt_t) {
65 _value = T();
66 _hasValue = false;
67 return *this;
68 }
69
70 T operator->() { return _value; }
71 T operator*() { return _value; }
72
73 operator bool() const { return _hasValue; }
74 bool has_value() const { return _hasValue; }
75
76 T value() const { return _value; }
77
78private:
79 T _value = T();
80 bool _hasValue = false;
81};
82
83}
84
85#endif
86
87#if __cplusplus < 201402L && !QT_CONFIG(cxx14_make_unique)\
88&& !defined(__cpp_lib_make_unique)
89
90namespace std {
91 template<typename T, class ...Args>
92 unique_ptr<T> make_unique(Args &&...args)
93 { return unique_ptr<T>(new T(std::forward<Args>(args)...)); }
94}
95
96#endif
97

source code of qtdeclarative/src/3rdparty/masm/stubs/wtf/Optional.h