optionalData.H
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6 \\/ M anipulation |
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11 This file is part of OpenFOAM.
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25
26Class
27 Foam::optionalData
28
29Description
30 A simplified version of std::optional (c++17), with much simpler
31 construction semantics.
32
33\*---------------------------------------------------------------------------*/
34
35#ifndef optionalData_H
36#define optionalData_H
37
38// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
39
40namespace Foam
41{
42
43/*---------------------------------------------------------------------------*\
44 Class optionalData Declaration
45\*---------------------------------------------------------------------------*/
46
47template<class T>
48class optionalData
49{
50 // Private Data
51
52 //- Validity of the value
53 bool good_;
54
55 //- The value
56 T value_;
57
58
59public:
60
61 // Generated Methods
62
63 //- Copy construct
64 optionalData(const optionalData<T>&) = default;
65
66 //- Move construct
67 optionalData(optionalData<T>&&) = default;
68
69 //- Copy assignment
70 optionalData<T>& operator=(const optionalData<T>&) = default;
71
72 //- Move assignment
74
75
76 // Constructors
77
78 //- Default construct
80 :
81 good_(false),
82 value_()
83 {}
84
85 //- Copy construct from value
86 optionalData(const T& val)
87 :
88 good_(true),
89 value_(val)
90 {}
91
92 //- Move construct from value
93 optionalData(T&& val)
94 :
95 good_(true),
96 value_(std::move(val))
97 {}
98
99
100 // Member Functions
101
102 //- True if it has a value
103 bool has_value() const noexcept
104 {
105 return good_;
106 }
107
108 //- Access to the value
109 T& value() noexcept
110 {
111 return value_;
112 }
113
114 //- Access to the value
115 const T& value() const noexcept
116 {
117 return value_;
118 }
119
120 //- Return value or default
121 const T& value_or(const T& deflt) const
122 {
123 return good_ ? value_ : deflt;
124 }
125
126
127 // Member Operators
128
129 //- True if it has a value
130 explicit operator bool() const noexcept
131 {
132 return good_;
133 }
134
135 //- Access the value
136 const T& operator*() const noexcept
137 {
138 return value_;
139 }
140
141 //- Access the value
143 {
144 return value_;
145 }
146
147 //- Copy assignment from value
148 void operator=(const T& val)
149 {
150 good_ = true;
151 value_ = val;
152 }
153
154 //- Move assignment from value
155 void operator=(T&& val)
156 {
157 good_ = true;
158 value_ = std::move(val);
159 }
160};
161
162
163// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
164
165} // End namespace Foam
166
167// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
168
169#endif
170
171// ************************************************************************* //
A simplified version of std::optional (c++17), with much simpler construction semantics.
Definition: optionalData.H:48
optionalData(T &&val)
Move construct from value.
Definition: optionalData.H:92
void operator=(const T &val)
Copy assignment from value.
Definition: optionalData.H:147
optionalData(const T &val)
Copy construct from value.
Definition: optionalData.H:85
optionalData()
Default construct.
Definition: optionalData.H:78
T & value() noexcept
Access to the value.
Definition: optionalData.H:108
const T & operator*() const noexcept
Access the value.
Definition: optionalData.H:135
bool has_value() const noexcept
True if it has a value.
Definition: optionalData.H:102
optionalData< T > & operator=(optionalData< T > &&)=default
Move assignment.
optionalData< T > & operator=(const optionalData< T > &)=default
Copy assignment.
optionalData(optionalData< T > &&)=default
Move construct.
const T & value() const noexcept
Access to the value.
Definition: optionalData.H:114
optionalData(const optionalData< T > &)=default
Copy construct.
T & operator*() noexcept
Access the value.
Definition: optionalData.H:141
const T & value_or(const T &deflt) const
Return value or default.
Definition: optionalData.H:120
void operator=(T &&val)
Move assignment from value.
Definition: optionalData.H:154
const volScalarField & T
bool
Definition: EEqn.H:20
Namespace for OpenFOAM.
const direction noexcept
Definition: Scalar.H:223