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Diffstat (limited to 'src/stable/variant.h')
-rw-r--r-- | src/stable/variant.h | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/src/stable/variant.h b/src/stable/variant.h new file mode 100644 index 0000000..45e3339 --- /dev/null +++ b/src/stable/variant.h | |||
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1 | /* | ||
2 | * Copyright (C) 2007-2011 Xagasoft, All rights reserved. | ||
3 | * | ||
4 | * This file is part of the libbu++ library and is released under the | ||
5 | * terms of the license contained in the file LICENSE. | ||
6 | */ | ||
7 | |||
8 | #ifndef BU_VARIANT_H | ||
9 | #define BU_VARIANT_H | ||
10 | |||
11 | //#include <bu/string.h> | ||
12 | #include <typeinfo> | ||
13 | // #include <bu/formatter.h> | ||
14 | |||
15 | #ifndef NULL | ||
16 | #define NULL (0L) | ||
17 | #endif | ||
18 | |||
19 | #include "bu/exceptionbase.h" | ||
20 | |||
21 | namespace Bu | ||
22 | { | ||
23 | class String; | ||
24 | class Formatter; | ||
25 | class Variant; | ||
26 | /** @cond DEVEL */ | ||
27 | template<class t> class VariantType; | ||
28 | |||
29 | class VariantTypeRoot | ||
30 | { | ||
31 | public: | ||
32 | VariantTypeRoot(); | ||
33 | virtual ~VariantTypeRoot(); | ||
34 | |||
35 | virtual const std::type_info &getType() const=0; | ||
36 | virtual VariantTypeRoot *clone() const=0; | ||
37 | virtual void format( Bu::Formatter &f ) const=0; | ||
38 | }; | ||
39 | |||
40 | template<class t> | ||
41 | class VariantType : public VariantTypeRoot | ||
42 | { | ||
43 | friend class Variant; | ||
44 | private: | ||
45 | VariantType() | ||
46 | { | ||
47 | } | ||
48 | |||
49 | VariantType( const t &d ) : | ||
50 | data( d ) | ||
51 | { | ||
52 | } | ||
53 | |||
54 | VariantType( const VariantType<t> &vt ) : | ||
55 | data( vt.data ) | ||
56 | { | ||
57 | } | ||
58 | |||
59 | virtual ~VariantType() | ||
60 | { | ||
61 | } | ||
62 | |||
63 | public: | ||
64 | t &getData() | ||
65 | { | ||
66 | return data; | ||
67 | } | ||
68 | |||
69 | const t &getData() const | ||
70 | { | ||
71 | return data; | ||
72 | } | ||
73 | |||
74 | virtual void format( Formatter &f ) const | ||
75 | { | ||
76 | f << data; | ||
77 | } | ||
78 | |||
79 | virtual const std::type_info &getType() const | ||
80 | { | ||
81 | return typeid( data ); | ||
82 | } | ||
83 | |||
84 | VariantType<t> operator=( const t &rhs ) | ||
85 | { | ||
86 | data = rhs; | ||
87 | |||
88 | return *this; | ||
89 | } | ||
90 | |||
91 | virtual VariantTypeRoot *clone() const | ||
92 | { | ||
93 | return new VariantType<t>( *this ); | ||
94 | } | ||
95 | |||
96 | private: | ||
97 | t data; | ||
98 | }; | ||
99 | /** @endcond */ | ||
100 | |||
101 | /** | ||
102 | * Store any data type and access it safely. Variant gives you a way to | ||
103 | * pass arbitrary data types around without having to worry about what | ||
104 | * type a variable is. It allows code to be easily extended and to manage | ||
105 | * data without having to know what type it is ahead of time. | ||
106 | * | ||
107 | * Because of the generic method that this class was implemented it may seem | ||
108 | * to have some drawbacks compared to other Variant classes you may have | ||
109 | * seen, however it is fairly easy to get it to do just about anything you | ||
110 | * may need. It is also very low overhead. On most compilers the class | ||
111 | * itself has only 3 words of overhead + the size of the variable you store | ||
112 | * in it. And, since many parts of it are templatized they can often be | ||
113 | * optimized quite a bit. | ||
114 | */ | ||
115 | class Variant | ||
116 | { | ||
117 | friend Bu::Formatter &operator<<( Bu::Formatter &f, const Variant &v ); | ||
118 | public: | ||
119 | Variant(); | ||
120 | Variant( const Variant &v ); | ||
121 | Variant( const char *t ); | ||
122 | template<class t> | ||
123 | Variant( const t &v ) : | ||
124 | pCore( new VariantType<t>() ) | ||
125 | { | ||
126 | (*dynamic_cast<VariantType<t> *>(pCore)) = v; | ||
127 | } | ||
128 | virtual ~Variant(); | ||
129 | |||
130 | Bu::String toString() const; | ||
131 | bool isSet() const; | ||
132 | const std::type_info &getType() const; | ||
133 | |||
134 | Variant &operator=( const Variant &rhs ); | ||
135 | |||
136 | template<class t> | ||
137 | Variant &operator=( const t &rhs ) | ||
138 | { | ||
139 | if( pCore ) // && pCore->getType() != typeid(t) ) | ||
140 | { | ||
141 | delete pCore; | ||
142 | pCore = NULL; | ||
143 | } | ||
144 | pCore = new VariantType<t>(); | ||
145 | (*dynamic_cast<VariantType<t> *>(pCore)) = rhs; | ||
146 | return *this; | ||
147 | } | ||
148 | |||
149 | template<class t> | ||
150 | t &get() | ||
151 | { | ||
152 | if( !pCore ) | ||
153 | { | ||
154 | throw Bu::ExceptionBase("No data!"); | ||
155 | } | ||
156 | if( pCore->getType() != typeid(t) ) | ||
157 | { | ||
158 | throw Bu::ExceptionBase("Invalid type conversion."); | ||
159 | } | ||
160 | return dynamic_cast<VariantType<t> *>(pCore)->getData(); | ||
161 | } | ||
162 | |||
163 | template<class t> | ||
164 | t &get() const | ||
165 | { | ||
166 | if( !pCore ) | ||
167 | { | ||
168 | throw Bu::ExceptionBase("No data!"); | ||
169 | } | ||
170 | if( pCore->getType() != typeid(t) ) | ||
171 | { | ||
172 | throw Bu::ExceptionBase("Invalid type conversion."); | ||
173 | } | ||
174 | return dynamic_cast<VariantType<t> *>(pCore)->getData(); | ||
175 | } | ||
176 | |||
177 | template<class t> | ||
178 | void set( const t &val ) | ||
179 | { | ||
180 | if( pCore && pCore->getType() != typeid(t) ) | ||
181 | { | ||
182 | delete pCore; | ||
183 | pCore = NULL; | ||
184 | } | ||
185 | pCore = new VariantType<t>(); | ||
186 | (*dynamic_cast<VariantType<t> *>(pCore)) = val; | ||
187 | } | ||
188 | |||
189 | template<class t> | ||
190 | bool isType() const | ||
191 | { | ||
192 | return pCore->getType() == typeid(t); | ||
193 | } | ||
194 | |||
195 | template<class t> | ||
196 | operator t() | ||
197 | { | ||
198 | if( !pCore ) | ||
199 | { | ||
200 | throw Bu::ExceptionBase("No data!"); | ||
201 | } | ||
202 | if( pCore->getType() != typeid(t) ) | ||
203 | { | ||
204 | throw Bu::ExceptionBase("Invalid type conversion."); | ||
205 | } | ||
206 | return dynamic_cast<VariantType<t> *>(pCore)->getData(); | ||
207 | } | ||
208 | |||
209 | template<class t> | ||
210 | operator t() const | ||
211 | { | ||
212 | if( !pCore ) | ||
213 | { | ||
214 | throw Bu::ExceptionBase("No data!"); | ||
215 | } | ||
216 | if( pCore->getType() != typeid(t) ) | ||
217 | { | ||
218 | throw Bu::ExceptionBase("Invalid type conversion."); | ||
219 | } | ||
220 | return dynamic_cast<VariantType<t> *>(pCore)->getData(); | ||
221 | } | ||
222 | |||
223 | private: | ||
224 | VariantTypeRoot *pCore; | ||
225 | }; | ||
226 | /* | ||
227 | template<class t> | ||
228 | Bu::Formatter &operator<<( Bu::Formatter &f, const VariantType<t> &vt ) | ||
229 | { | ||
230 | return f << vt.getData; | ||
231 | }*/ | ||
232 | |||
233 | Bu::Formatter &operator<<( Bu::Formatter &f, const Variant &v ); | ||
234 | }; | ||
235 | |||
236 | #endif | ||