ICU 70.1  70.1
char16ptr.h
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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 
23 U_NAMESPACE_BEGIN
24 
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 
43 public:
49  inline Char16Ptr(char16_t *p);
50 #if !U_CHAR16_IS_TYPEDEF
56  inline Char16Ptr(uint16_t *p);
57 #endif
58 #if U_SIZEOF_WCHAR_T==2 || defined(U_IN_DOXYGEN)
65  inline Char16Ptr(wchar_t *p);
66 #endif
72  inline Char16Ptr(std::nullptr_t p);
77  inline ~Char16Ptr();
78 
84  inline char16_t *get() const;
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) {
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 
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) {}
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; }
139 
140 char16_t *Char16Ptr::get() const { return u_.cp; }
141 
142 #endif
144 
150 public:
156  inline ConstChar16Ptr(const char16_t *p);
157 #if !U_CHAR16_IS_TYPEDEF
163  inline ConstChar16Ptr(const uint16_t *p);
164 #endif
165 #if U_SIZEOF_WCHAR_T==2 || defined(U_IN_DOXYGEN)
172  inline ConstChar16Ptr(const wchar_t *p);
173 #endif
179  inline ConstChar16Ptr(const std::nullptr_t p);
180 
185  inline ~ConstChar16Ptr();
186 
192  inline const char16_t *get() const;
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) {
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 
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) {}
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; }
247 
248 const char16_t *ConstChar16Ptr::get() const { return u_.cp; }
249 
250 #endif
252 
260 inline const UChar *toUCharPtr(const char16_t *p) {
261 #ifdef U_ALIASING_BARRIER
263 #endif
264  return reinterpret_cast<const UChar *>(p);
265 }
266 
274 inline UChar *toUCharPtr(char16_t *p) {
275 #ifdef U_ALIASING_BARRIER
277 #endif
278  return reinterpret_cast<UChar *>(p);
279 }
280 
288 inline const OldUChar *toOldUCharPtr(const char16_t *p) {
289 #ifdef U_ALIASING_BARRIER
291 #endif
292  return reinterpret_cast<const OldUChar *>(p);
293 }
294 
302 inline OldUChar *toOldUCharPtr(char16_t *p) {
303 #ifdef U_ALIASING_BARRIER
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__
#define U_ALIASING_BARRIER(ptr)
Barrier for pointer anti-aliasing optimizations even across function boundaries.
Definition: char16ptr.h:35
char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types.
Definition: char16ptr.h:42
Char16Ptr(std::nullptr_t p)
nullptr constructor.
~Char16Ptr()
Destructor.
Char16Ptr(uint16_t *p)
Converts the pointer to char16_t *.
Char16Ptr(wchar_t *p)
Converts the pointer to char16_t *.
char16_t * get() const
Pointer access.
Char16Ptr(char16_t *p)
Copies the pointer.
const char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types.
Definition: char16ptr.h:149
ConstChar16Ptr(const char16_t *p)
Copies the pointer.
const char16_t * get() const
Pointer access.
ConstChar16Ptr(const uint16_t *p)
Converts the pointer to char16_t *.
~ConstChar16Ptr()
Destructor.
ConstChar16Ptr(const wchar_t *p)
Converts the pointer to char16_t *.
ConstChar16Ptr(const std::nullptr_t p)
nullptr constructor.
const OldUChar * toOldUCharPtr(const char16_t *p)
Converts from const char16_t * to const OldUChar *.
Definition: char16ptr.h:288
const UChar * toUCharPtr(const char16_t *p)
Converts from const char16_t * to const UChar *.
Definition: char16ptr.h:260
#define U_FINAL
Defined to the C++11 "final" keyword if available.
Definition: umachine.h:141
char16_t UChar
The base type for UTF-16 code units and pointers.
Definition: umachine.h:418
uint16_t OldUChar
Default ICU 58 definition of UChar.
Definition: umachine.h:447
Basic definitions for ICU, for both C and C++ APIs.
#define U_COMMON_API
Set to export library symbols from inside the common library, and to import them from outside.
Definition: utypes.h:300