1 | // © 2017 and later: Unicode, Inc. and others. |
2 | // License & terms of use: http://www.unicode.org/copyright.html |
3 | |
4 | // char16ptr.h |
5 | // created: 2017feb28 Markus W. Scherer |
6 | |
7 | #ifndef __CHAR16PTR_H__ |
8 | #define __CHAR16PTR_H__ |
9 | |
10 | #include "unicode/utypes.h" |
11 | |
12 | #if U_SHOW_CPLUSPLUS_API |
13 | |
14 | #include <cstddef> |
15 | |
16 | /** |
17 | * \file |
18 | * \brief C++ API: char16_t pointer wrappers with |
19 | * implicit conversion from bit-compatible raw pointer types. |
20 | * Also conversion functions from char16_t * to UChar * and OldUChar *. |
21 | */ |
22 | |
23 | U_NAMESPACE_BEGIN |
24 | |
25 | /** |
26 | * \def U_ALIASING_BARRIER |
27 | * Barrier for pointer anti-aliasing optimizations even across function boundaries. |
28 | * @internal |
29 | */ |
30 | #ifdef U_ALIASING_BARRIER |
31 | // Use the predefined value. |
32 | #elif (defined(__clang__) || defined(__GNUC__)) && U_PLATFORM != U_PF_BROWSER_NATIVE_CLIENT |
33 | # define U_ALIASING_BARRIER(ptr) asm volatile("" : : "rm"(ptr) : "memory") |
34 | #elif defined(U_IN_DOXYGEN) |
35 | # define U_ALIASING_BARRIER(ptr) |
36 | #endif |
37 | |
38 | /** |
39 | * char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types. |
40 | * @stable ICU 59 |
41 | */ |
42 | class U_COMMON_API Char16Ptr final { |
43 | public: |
44 | /** |
45 | * Copies the pointer. |
46 | * @param p pointer |
47 | * @stable ICU 59 |
48 | */ |
49 | inline Char16Ptr(char16_t *p); |
50 | #if !U_CHAR16_IS_TYPEDEF |
51 | /** |
52 | * Converts the pointer to char16_t *. |
53 | * @param p pointer to be converted |
54 | * @stable ICU 59 |
55 | */ |
56 | inline Char16Ptr(uint16_t *p); |
57 | #endif |
58 | #if U_SIZEOF_WCHAR_T==2 || defined(U_IN_DOXYGEN) |
59 | /** |
60 | * Converts the pointer to char16_t *. |
61 | * (Only defined if U_SIZEOF_WCHAR_T==2.) |
62 | * @param p pointer to be converted |
63 | * @stable ICU 59 |
64 | */ |
65 | inline Char16Ptr(wchar_t *p); |
66 | #endif |
67 | /** |
68 | * nullptr constructor. |
69 | * @param p nullptr |
70 | * @stable ICU 59 |
71 | */ |
72 | inline Char16Ptr(std::nullptr_t p); |
73 | /** |
74 | * Destructor. |
75 | * @stable ICU 59 |
76 | */ |
77 | inline ~Char16Ptr(); |
78 | |
79 | /** |
80 | * Pointer access. |
81 | * @return the wrapped pointer |
82 | * @stable ICU 59 |
83 | */ |
84 | inline char16_t *get() const; |
85 | /** |
86 | * char16_t pointer access via type conversion (e.g., static_cast). |
87 | * @return the wrapped pointer |
88 | * @stable ICU 59 |
89 | */ |
90 | inline operator char16_t *() const { return get(); } |
91 | |
92 | private: |
93 | Char16Ptr() = delete; |
94 | |
95 | #ifdef U_ALIASING_BARRIER |
96 | template<typename T> static char16_t *cast(T *t) { |
97 | U_ALIASING_BARRIER(t); |
98 | return reinterpret_cast<char16_t *>(t); |
99 | } |
100 | |
101 | char16_t *p_; |
102 | #else |
103 | union { |
104 | char16_t *cp; |
105 | uint16_t *up; |
106 | wchar_t *wp; |
107 | } u_; |
108 | #endif |
109 | }; |
110 | |
111 | /// \cond |
112 | #ifdef U_ALIASING_BARRIER |
113 | |
114 | Char16Ptr::Char16Ptr(char16_t *p) : p_(p) {} |
115 | #if !U_CHAR16_IS_TYPEDEF |
116 | Char16Ptr::Char16Ptr(uint16_t *p) : p_(cast(p)) {} |
117 | #endif |
118 | #if U_SIZEOF_WCHAR_T==2 |
119 | Char16Ptr::Char16Ptr(wchar_t *p) : p_(cast(p)) {} |
120 | #endif |
121 | Char16Ptr::Char16Ptr(std::nullptr_t p) : p_(p) {} |
122 | Char16Ptr::~Char16Ptr() { |
123 | U_ALIASING_BARRIER(p_); |
124 | } |
125 | |
126 | char16_t *Char16Ptr::get() const { return p_; } |
127 | |
128 | #else |
129 | |
130 | Char16Ptr::Char16Ptr(char16_t *p) { u_.cp = p; } |
131 | #if !U_CHAR16_IS_TYPEDEF |
132 | Char16Ptr::Char16Ptr(uint16_t *p) { u_.up = p; } |
133 | #endif |
134 | #if U_SIZEOF_WCHAR_T==2 |
135 | Char16Ptr::Char16Ptr(wchar_t *p) { u_.wp = p; } |
136 | #endif |
137 | Char16Ptr::Char16Ptr(std::nullptr_t p) { u_.cp = p; } |
138 | Char16Ptr::~Char16Ptr() {} |
139 | |
140 | char16_t *Char16Ptr::get() const { return u_.cp; } |
141 | |
142 | #endif |
143 | /// \endcond |
144 | |
145 | /** |
146 | * const char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types. |
147 | * @stable ICU 59 |
148 | */ |
149 | class U_COMMON_API ConstChar16Ptr final { |
150 | public: |
151 | /** |
152 | * Copies the pointer. |
153 | * @param p pointer |
154 | * @stable ICU 59 |
155 | */ |
156 | inline ConstChar16Ptr(const char16_t *p); |
157 | #if !U_CHAR16_IS_TYPEDEF |
158 | /** |
159 | * Converts the pointer to char16_t *. |
160 | * @param p pointer to be converted |
161 | * @stable ICU 59 |
162 | */ |
163 | inline ConstChar16Ptr(const uint16_t *p); |
164 | #endif |
165 | #if U_SIZEOF_WCHAR_T==2 || defined(U_IN_DOXYGEN) |
166 | /** |
167 | * Converts the pointer to char16_t *. |
168 | * (Only defined if U_SIZEOF_WCHAR_T==2.) |
169 | * @param p pointer to be converted |
170 | * @stable ICU 59 |
171 | */ |
172 | inline ConstChar16Ptr(const wchar_t *p); |
173 | #endif |
174 | /** |
175 | * nullptr constructor. |
176 | * @param p nullptr |
177 | * @stable ICU 59 |
178 | */ |
179 | inline ConstChar16Ptr(const std::nullptr_t p); |
180 | |
181 | /** |
182 | * Destructor. |
183 | * @stable ICU 59 |
184 | */ |
185 | inline ~ConstChar16Ptr(); |
186 | |
187 | /** |
188 | * Pointer access. |
189 | * @return the wrapped pointer |
190 | * @stable ICU 59 |
191 | */ |
192 | inline const char16_t *get() const; |
193 | /** |
194 | * char16_t pointer access via type conversion (e.g., static_cast). |
195 | * @return the wrapped pointer |
196 | * @stable ICU 59 |
197 | */ |
198 | inline operator const char16_t *() const { return get(); } |
199 | |
200 | private: |
201 | ConstChar16Ptr() = delete; |
202 | |
203 | #ifdef U_ALIASING_BARRIER |
204 | template<typename T> static const char16_t *cast(const T *t) { |
205 | U_ALIASING_BARRIER(t); |
206 | return reinterpret_cast<const char16_t *>(t); |
207 | } |
208 | |
209 | const char16_t *p_; |
210 | #else |
211 | union { |
212 | const char16_t *cp; |
213 | const uint16_t *up; |
214 | const wchar_t *wp; |
215 | } u_; |
216 | #endif |
217 | }; |
218 | |
219 | /// \cond |
220 | #ifdef U_ALIASING_BARRIER |
221 | |
222 | ConstChar16Ptr::ConstChar16Ptr(const char16_t *p) : p_(p) {} |
223 | #if !U_CHAR16_IS_TYPEDEF |
224 | ConstChar16Ptr::ConstChar16Ptr(const uint16_t *p) : p_(cast(p)) {} |
225 | #endif |
226 | #if U_SIZEOF_WCHAR_T==2 |
227 | ConstChar16Ptr::ConstChar16Ptr(const wchar_t *p) : p_(cast(p)) {} |
228 | #endif |
229 | ConstChar16Ptr::ConstChar16Ptr(const std::nullptr_t p) : p_(p) {} |
230 | ConstChar16Ptr::~ConstChar16Ptr() { |
231 | U_ALIASING_BARRIER(p_); |
232 | } |
233 | |
234 | const char16_t *ConstChar16Ptr::get() const { return p_; } |
235 | |
236 | #else |
237 | |
238 | ConstChar16Ptr::ConstChar16Ptr(const char16_t *p) { u_.cp = p; } |
239 | #if !U_CHAR16_IS_TYPEDEF |
240 | ConstChar16Ptr::ConstChar16Ptr(const uint16_t *p) { u_.up = p; } |
241 | #endif |
242 | #if U_SIZEOF_WCHAR_T==2 |
243 | ConstChar16Ptr::ConstChar16Ptr(const wchar_t *p) { u_.wp = p; } |
244 | #endif |
245 | ConstChar16Ptr::ConstChar16Ptr(const std::nullptr_t p) { u_.cp = p; } |
246 | ConstChar16Ptr::~ConstChar16Ptr() {} |
247 | |
248 | const char16_t *ConstChar16Ptr::get() const { return u_.cp; } |
249 | |
250 | #endif |
251 | /// \endcond |
252 | |
253 | /** |
254 | * Converts from const char16_t * to const UChar *. |
255 | * Includes an aliasing barrier if available. |
256 | * @param p pointer |
257 | * @return p as const UChar * |
258 | * @stable ICU 59 |
259 | */ |
260 | inline const UChar *toUCharPtr(const char16_t *p) { |
261 | #ifdef U_ALIASING_BARRIER |
262 | U_ALIASING_BARRIER(p); |
263 | #endif |
264 | return reinterpret_cast<const UChar *>(p); |
265 | } |
266 | |
267 | /** |
268 | * Converts from char16_t * to UChar *. |
269 | * Includes an aliasing barrier if available. |
270 | * @param p pointer |
271 | * @return p as UChar * |
272 | * @stable ICU 59 |
273 | */ |
274 | inline UChar *toUCharPtr(char16_t *p) { |
275 | #ifdef U_ALIASING_BARRIER |
276 | U_ALIASING_BARRIER(p); |
277 | #endif |
278 | return reinterpret_cast<UChar *>(p); |
279 | } |
280 | |
281 | /** |
282 | * Converts from const char16_t * to const OldUChar *. |
283 | * Includes an aliasing barrier if available. |
284 | * @param p pointer |
285 | * @return p as const OldUChar * |
286 | * @stable ICU 59 |
287 | */ |
288 | inline const OldUChar *toOldUCharPtr(const char16_t *p) { |
289 | #ifdef U_ALIASING_BARRIER |
290 | U_ALIASING_BARRIER(p); |
291 | #endif |
292 | return reinterpret_cast<const OldUChar *>(p); |
293 | } |
294 | |
295 | /** |
296 | * Converts from char16_t * to OldUChar *. |
297 | * Includes an aliasing barrier if available. |
298 | * @param p pointer |
299 | * @return p as OldUChar * |
300 | * @stable ICU 59 |
301 | */ |
302 | inline OldUChar *toOldUCharPtr(char16_t *p) { |
303 | #ifdef U_ALIASING_BARRIER |
304 | U_ALIASING_BARRIER(p); |
305 | #endif |
306 | return reinterpret_cast<OldUChar *>(p); |
307 | } |
308 | |
309 | U_NAMESPACE_END |
310 | |
311 | #endif /* U_SHOW_CPLUSPLUS_API */ |
312 | |
313 | #endif // __CHAR16PTR_H__ |
314 | |