1 : /*
2 : ******************************************************************************
3 : *
4 : * Copyright (C) 2002-2006, International Business Machines
5 : * Corporation and others. All Rights Reserved.
6 : *
7 : ******************************************************************************
8 : * file name: uobject.h
9 : * encoding: US-ASCII
10 : * tab size: 8 (not used)
11 : * indentation:4
12 : *
13 : * created on: 2002jun26
14 : * created by: Markus W. Scherer
15 : */
16 :
17 : #ifndef __UOBJECT_H__
18 : #define __UOBJECT_H__
19 :
20 : #include "unicode/utypes.h"
21 :
22 : U_NAMESPACE_BEGIN
23 :
24 : /**
25 : * \file
26 : * \brief C++ API: Common ICU base class UObject.
27 : */
28 :
29 : /** U_OVERRIDE_CXX_ALLOCATION - Define this to override operator new and
30 : * delete in UMemory. Enabled by default for ICU.
31 : *
32 : * Enabling forces all allocation of ICU object types to use ICU's
33 : * memory allocation. On Windows, this allows the ICU DLL to be used by
34 : * applications that statically link the C Runtime library, meaning that
35 : * the app and ICU will be using different heaps.
36 : *
37 : * @stable ICU 2.2
38 : */
39 : #ifndef U_OVERRIDE_CXX_ALLOCATION
40 : #define U_OVERRIDE_CXX_ALLOCATION 1
41 : #endif
42 :
43 : /** U_HAVE_PLACEMENT_NEW - Define this to define the placement new and
44 : * delete in UMemory for STL.
45 : *
46 : * @stable ICU 2.6
47 : */
48 : #ifndef U_HAVE_PLACEMENT_NEW
49 : #define U_HAVE_PLACEMENT_NEW 1
50 : #endif
51 :
52 :
53 : #ifndef U_HIDE_DRAFT_API
54 : /** U_HAVE_DEBUG_LOCATION_NEW - Define this to define the MFC debug
55 : * version of the operator new.
56 : *
57 : * @draft ICU 3.4
58 : */
59 : #ifndef U_HAVE_DEBUG_LOCATION_NEW
60 : #define U_HAVE_DEBUG_LOCATION_NEW 0
61 : #endif
62 : #endif /*U_HIDE_DRAFT_API*/
63 :
64 : /**
65 : * UMemory is the common ICU base class.
66 : * All other ICU C++ classes are derived from UMemory (starting with ICU 2.4).
67 : *
68 : * This is primarily to make it possible and simple to override the
69 : * C++ memory management by adding new/delete operators to this base class.
70 : *
71 : * To override ALL ICU memory management, including that from plain C code,
72 : * replace the allocation functions declared in cmemory.h
73 : *
74 : * UMemory does not contain any virtual functions.
75 : * Common "boilerplate" functions are defined in UObject.
76 : *
77 : * @stable ICU 2.4
78 : */
79 26 : class U_COMMON_API UMemory {
80 : public:
81 :
82 : #if U_OVERRIDE_CXX_ALLOCATION
83 : /**
84 : * Override for ICU4C C++ memory management.
85 : * simple, non-class types are allocated using the macros in common/cmemory.h
86 : * (uprv_malloc(), uprv_free(), uprv_realloc());
87 : * they or something else could be used here to implement C++ new/delete
88 : * for ICU4C C++ classes
89 : * @stable ICU 2.4
90 : */
91 : static void * U_EXPORT2 operator new(size_t size);
92 :
93 : /**
94 : * Override for ICU4C C++ memory management.
95 : * See new().
96 : * @stable ICU 2.4
97 : */
98 : static void * U_EXPORT2 operator new[](size_t size);
99 :
100 : /**
101 : * Override for ICU4C C++ memory management.
102 : * simple, non-class types are allocated using the macros in common/cmemory.h
103 : * (uprv_malloc(), uprv_free(), uprv_realloc());
104 : * they or something else could be used here to implement C++ new/delete
105 : * for ICU4C C++ classes
106 : * @stable ICU 2.4
107 : */
108 : static void U_EXPORT2 operator delete(void *p);
109 :
110 : /**
111 : * Override for ICU4C C++ memory management.
112 : * See delete().
113 : * @stable ICU 2.4
114 : */
115 : static void U_EXPORT2 operator delete[](void *p);
116 :
117 : #if U_HAVE_PLACEMENT_NEW
118 : /**
119 : * Override for ICU4C C++ memory management for STL.
120 : * See new().
121 : * @stable ICU 2.6
122 : */
123 : static inline void * U_EXPORT2 operator new(size_t, void *ptr) { return ptr; }
124 :
125 : /**
126 : * Override for ICU4C C++ memory management for STL.
127 : * See delete().
128 : * @stable ICU 2.6
129 : */
130 : static inline void U_EXPORT2 operator delete(void *, void *) {}
131 : #endif /* U_HAVE_PLACEMENT_NEW */
132 : #if U_HAVE_DEBUG_LOCATION_NEW
133 : /**
134 : * This method overrides the MFC debug version of the operator new
135 : *
136 : * @param size The requested memory size
137 : * @param file The file where the allocation was requested
138 : * @param line The line where the allocation was requested
139 : */
140 : static void * U_EXPORT2 operator new(size_t size, const char* file, int line);
141 : /**
142 : * This method provides a matching delete for the MFC debug new
143 : *
144 : * @param p The pointer to the allocated memory
145 : * @param file The file where the allocation was requested
146 : * @param line The line where the allocation was requested
147 : */
148 : static void U_EXPORT2 operator delete(void* p, const char* file, int line);
149 : #endif /* U_HAVE_DEBUG_LOCATION_NEW */
150 : #endif /* U_OVERRIDE_CXX_ALLOCATION */
151 :
152 : /*
153 : * Assignment operator not declared. The compiler will provide one
154 : * which does nothing since this class does not contain any data members.
155 : * API/code coverage may show the assignment operator as present and
156 : * untested - ignore.
157 : * Subclasses need this assignment operator if they use compiler-provided
158 : * assignment operators of their own. An alternative to not declaring one
159 : * here would be to declare and empty-implement a protected or public one.
160 : UMemory &UMemory::operator=(const UMemory &);
161 : */
162 : };
163 :
164 : /**
165 : * UObject is the common ICU "boilerplate" class.
166 : * UObject inherits UMemory (starting with ICU 2.4),
167 : * and all other public ICU C++ classes
168 : * are derived from UObject (starting with ICU 2.2).
169 : *
170 : * UObject contains common virtual functions like for ICU's "poor man's RTTI".
171 : * It does not contain default implementations of virtual methods
172 : * like getDynamicClassID to allow derived classes such as Format
173 : * to declare these as pure virtual.
174 : *
175 : * The clone() function is not available in UObject because it is not
176 : * implemented by all ICU classes.
177 : * Many ICU services provide a clone() function for their class trees,
178 : * defined on the service's C++ base class, and all subclasses within that
179 : * service class tree return a pointer to the service base class
180 : * (which itself is a subclass of UObject).
181 : * This is because some compilers do not support covariant (same-as-this)
182 : * return types; cast to the appropriate subclass if necessary.
183 : *
184 : * @stable ICU 2.2
185 : */
186 26 : class U_COMMON_API UObject : public UMemory {
187 : public:
188 : /**
189 : * Destructor.
190 : *
191 : * @stable ICU 2.2
192 : */
193 : virtual ~UObject();
194 :
195 : /**
196 : * ICU4C "poor man's RTTI", returns a UClassID for the actual ICU class.
197 : *
198 : * @stable ICU 2.2
199 : */
200 : virtual UClassID getDynamicClassID() const = 0;
201 :
202 : protected:
203 : // the following functions are protected to prevent instantiation and
204 : // direct use of UObject itself
205 :
206 : // default constructor
207 : // commented out because UObject is abstract (see getDynamicClassID)
208 : // inline UObject() {}
209 :
210 : // copy constructor
211 : // commented out because UObject is abstract (see getDynamicClassID)
212 : // inline UObject(const UObject &other) {}
213 :
214 : #if 0
215 : // TODO Sometime in the future. Implement operator==().
216 : // (This comment inserted in 2.2)
217 : // some or all of the following "boilerplate" functions may be made public
218 : // in a future ICU4C release when all subclasses implement them
219 :
220 : // assignment operator
221 : // (not virtual, see "Taligent's Guide to Designing Programs" pp.73..74)
222 : // commented out because the implementation is the same as a compiler's default
223 : // UObject &operator=(const UObject &other) { return *this; }
224 :
225 : // comparison operators
226 : virtual inline UBool operator==(const UObject &other) const { return this==&other; }
227 : inline UBool operator!=(const UObject &other) const { return !operator==(other); }
228 :
229 : // clone() commented out from the base class:
230 : // some compilers do not support co-variant return types
231 : // (i.e., subclasses would have to return UObject * as well, instead of SubClass *)
232 : // see also UObject class documentation.
233 : // virtual UObject *clone() const;
234 : #endif
235 :
236 : /*
237 : * Assignment operator not declared. The compiler will provide one
238 : * which does nothing since this class does not contain any data members.
239 : * API/code coverage may show the assignment operator as present and
240 : * untested - ignore.
241 : * Subclasses need this assignment operator if they use compiler-provided
242 : * assignment operators of their own. An alternative to not declaring one
243 : * here would be to declare and empty-implement a protected or public one.
244 : UObject &UObject::operator=(const UObject &);
245 : */
246 :
247 : // Future implementation for RTTI that support subtyping. [alan]
248 : //
249 : // public:
250 : // /**
251 : // * @internal
252 : // */
253 : // static UClassID getStaticClassID();
254 : //
255 : // /**
256 : // * @internal
257 : // */
258 : // UBool instanceOf(UClassID type) const;
259 : };
260 :
261 : /**
262 : * This is a simple macro to add ICU RTTI to an ICU object implementation.
263 : * This does not go into the header. This should only be used in *.cpp files.
264 : *
265 : * @param myClass The name of the class that needs RTTI defined.
266 : * @internal
267 : */
268 : #define UOBJECT_DEFINE_RTTI_IMPLEMENTATION(myClass) \
269 : UClassID U_EXPORT2 myClass::getStaticClassID() { \
270 : static char classID = 0; \
271 : return (UClassID)&classID; \
272 : } \
273 : UClassID myClass::getDynamicClassID() const \
274 : { return myClass::getStaticClassID(); }
275 :
276 :
277 : /**
278 : * This macro adds ICU RTTI to an ICU abstract class implementation.
279 : * This macro should be invoked in *.cpp files. The corresponding
280 : * header should declare getStaticClassID.
281 : *
282 : * @param myClass The name of the class that needs RTTI defined.
283 : * @internal
284 : */
285 : #define UOBJECT_DEFINE_ABSTRACT_RTTI_IMPLEMENTATION(myClass) \
286 : UClassID U_EXPORT2 myClass::getStaticClassID() { \
287 : static char classID = 0; \
288 : return (UClassID)&classID; \
289 : }
290 :
291 : // /**
292 : // * This macro adds ICU RTTI to an ICU concrete class implementation.
293 : // * This macro should be invoked in *.cpp files. The corresponding
294 : // * header should declare getDynamicClassID and getStaticClassID.
295 : // *
296 : // * @param myClass The name of the class that needs RTTI defined.
297 : // * @param myParent The name of the myClass's parent.
298 : // * @internal
299 : // */
300 : /*#define UOBJECT_DEFINE_RTTI_IMPLEMENTATION(myClass, myParent) \
301 : UOBJECT_DEFINE_ABSTRACT_RTTI_IMPLEMENTATION(myClass, myParent) \
302 : UClassID myClass::getDynamicClassID() const { \
303 : return myClass::getStaticClassID(); \
304 : }
305 : */
306 :
307 :
308 : U_NAMESPACE_END
309 :
310 : #endif
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