1 | // |
2 | // Void.h |
3 | // |
4 | // Library: Foundation |
5 | // Package: Core |
6 | // Module: Void |
7 | // |
8 | // Definition of the Void class. |
9 | // |
10 | // Copyright (c) 2006, Applied Informatics Software Engineering GmbH. |
11 | // and Contributors. |
12 | // |
13 | // SPDX-License-Identifier: BSL-1.0 |
14 | // |
15 | |
16 | |
17 | #ifndef Foundation_Void_INCLUDED |
18 | #define Foundation_Void_INCLUDED |
19 | |
20 | |
21 | #include "Poco/Foundation.h" |
22 | |
23 | |
24 | namespace Poco { |
25 | |
26 | |
27 | class Foundation_API Void |
28 | /// A dummy class with value-type semantics, |
29 | /// mostly useful as a template argument. |
30 | /// |
31 | /// This class is typically used together with ActiveMethod, |
32 | /// if no argument or return value is needed. |
33 | { |
34 | public: |
35 | Void(); |
36 | /// Creates the Void. |
37 | |
38 | Void(const Void& v); |
39 | /// Creates the Void from another Void. |
40 | /// |
41 | /// The philosophical aspects of this operation |
42 | /// remain undiscussed for now. |
43 | |
44 | ~Void(); |
45 | /// Destroys the Void. |
46 | |
47 | Void& operator = (const Void& v); |
48 | /// Assigns another void. |
49 | |
50 | bool operator ==(const Void& v) const; |
51 | /// Will return always true due to Voids having no members. |
52 | |
53 | bool operator !=(const Void& v) const; |
54 | /// Will return always false due to Voids having no members. |
55 | }; |
56 | |
57 | |
58 | inline bool Void::operator ==(const Void& /*v*/) const |
59 | { |
60 | return true; |
61 | } |
62 | |
63 | |
64 | inline bool Void::operator !=(const Void& /*v*/) const |
65 | { |
66 | return false; |
67 | } |
68 | |
69 | |
70 | } // namespace Poco |
71 | |
72 | |
73 | #endif // Foundation_Void_INCLUDED |
74 | |