ICU 78.1 78.1

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 || U_SHOW_CPLUSPLUS_HEADER_API
13
14 #include <cstddef>
15 #include <string_view>
16 #include <type_traits>
17
18 #endif
19
32 #ifdef U_ALIASING_BARRIER
33 // Use the predefined value.
34 #elif (defined(__clang__) || defined(__GNUC__)) && U_PLATFORM != U_PF_BROWSER_NATIVE_CLIENT
35 # define U_ALIASING_BARRIER(ptr) asm volatile("" : : "rm"(ptr) : "memory")
36 #elif defined(U_IN_DOXYGEN)
37 # define U_ALIASING_BARRIER(ptr)
38 #endif
39
40 // ICU DLL-exported
41 #if U_SHOW_CPLUSPLUS_API
42
43 U_NAMESPACE_BEGIN
44
49 class U_COMMON_API Char16Ptr final {
50 public:
56 inline Char16Ptr(char16_t *p);
57 #if !U_CHAR16_IS_TYPEDEF
63 inline Char16Ptr(uint16_t *p);
64 #endif
65 #if U_SIZEOF_WCHAR_T==2 || defined(U_IN_DOXYGEN)
72 inline Char16Ptr(wchar_t *p);
73 #endif
79 inline Char16Ptr(std::nullptr_t p);
84 inline ~Char16Ptr();
85
91 inline char16_t *get() const;
97 inline operator char16_t *() const { return get(); }
98
99 private:
100 Char16Ptr() = delete;
101
102 #ifdef U_ALIASING_BARRIER
103 template<typename T> static char16_t *cast(T *t) {
104 U_ALIASING_BARRIER(t);
105 return reinterpret_cast<char16_t *>(t);
106 }
107
108 char16_t *p_;
109 #else
110 union {
111 char16_t *cp;
112 uint16_t *up;
113 wchar_t *wp;
114 } u_;
115 #endif
116 };
117
119 #ifdef U_ALIASING_BARRIER
120
121 Char16Ptr::Char16Ptr(char16_t *p) : p_(p) {}
122 #if !U_CHAR16_IS_TYPEDEF
123 Char16Ptr::Char16Ptr(uint16_t *p) : p_(cast(p)) {}
124 #endif
125 #if U_SIZEOF_WCHAR_T==2
126 Char16Ptr::Char16Ptr(wchar_t *p) : p_(cast(p)) {}
127 #endif
128 Char16Ptr::Char16Ptr(std::nullptr_t p) : p_(p) {}
129 Char16Ptr::~Char16Ptr() {
130 U_ALIASING_BARRIER(p_);
131 }
132
133 char16_t *Char16Ptr::get() const { return p_; }
134
135 #else
136
137 Char16Ptr::Char16Ptr(char16_t *p) { u_.cp = p; }
138 #if !U_CHAR16_IS_TYPEDEF
139 Char16Ptr::Char16Ptr(uint16_t *p) { u_.up = p; }
140 #endif
141 #if U_SIZEOF_WCHAR_T==2
142 Char16Ptr::Char16Ptr(wchar_t *p) { u_.wp = p; }
143 #endif
144 Char16Ptr::Char16Ptr(std::nullptr_t p) { u_.cp = p; }
145 Char16Ptr::~Char16Ptr() {}
146
147 char16_t *Char16Ptr::get() const { return u_.cp; }
148
149 #endif
151
156 class U_COMMON_API ConstChar16Ptr final {
157 public:
163 inline ConstChar16Ptr(const char16_t *p);
164 #if !U_CHAR16_IS_TYPEDEF
170 inline ConstChar16Ptr(const uint16_t *p);
171 #endif
172 #if U_SIZEOF_WCHAR_T==2 || defined(U_IN_DOXYGEN)
179 inline ConstChar16Ptr(const wchar_t *p);
180 #endif
186 inline ConstChar16Ptr(const std::nullptr_t p);
187
192 inline ~ConstChar16Ptr();
193
199 inline const char16_t *get() const;
205 inline operator const char16_t *() const { return get(); }
206
207 private:
208 ConstChar16Ptr() = delete;
209
210 #ifdef U_ALIASING_BARRIER
211 template<typename T> static const char16_t *cast(const T *t) {
212 U_ALIASING_BARRIER(t);
213 return reinterpret_cast<const char16_t *>(t);
214 }
215
216 const char16_t *p_;
217 #else
218 union {
219 const char16_t *cp;
220 const uint16_t *up;
221 const wchar_t *wp;
222 } u_;
223 #endif
224 };
225
227 #ifdef U_ALIASING_BARRIER
228
229 ConstChar16Ptr::ConstChar16Ptr(const char16_t *p) : p_(p) {}
230 #if !U_CHAR16_IS_TYPEDEF
231 ConstChar16Ptr::ConstChar16Ptr(const uint16_t *p) : p_(cast(p)) {}
232 #endif
233 #if U_SIZEOF_WCHAR_T==2
234 ConstChar16Ptr::ConstChar16Ptr(const wchar_t *p) : p_(cast(p)) {}
235 #endif
236 ConstChar16Ptr::ConstChar16Ptr(const std::nullptr_t p) : p_(p) {}
237 ConstChar16Ptr::~ConstChar16Ptr() {
238 U_ALIASING_BARRIER(p_);
239 }
240
241 const char16_t *ConstChar16Ptr::get() const { return p_; }
242
243 #else
244
245 ConstChar16Ptr::ConstChar16Ptr(const char16_t *p) { u_.cp = p; }
246 #if !U_CHAR16_IS_TYPEDEF
247 ConstChar16Ptr::ConstChar16Ptr(const uint16_t *p) { u_.up = p; }
248 #endif
249 #if U_SIZEOF_WCHAR_T==2
250 ConstChar16Ptr::ConstChar16Ptr(const wchar_t *p) { u_.wp = p; }
251 #endif
252 ConstChar16Ptr::ConstChar16Ptr(const std::nullptr_t p) { u_.cp = p; }
253 ConstChar16Ptr::~ConstChar16Ptr() {}
254
255 const char16_t *ConstChar16Ptr::get() const { return u_.cp; }
256
257 #endif
259
260 U_NAMESPACE_END
261
262 #endif // U_SHOW_CPLUSPLUS_API
263
264 // Usable in header-only definitions
265 #if U_SHOW_CPLUSPLUS_API || U_SHOW_CPLUSPLUS_HEADER_API
266
267 namespace U_ICU_NAMESPACE_OR_INTERNAL {
268
269 #ifndef U_FORCE_HIDE_INTERNAL_API
271 template<typename T, typename = std::enable_if_t<std::is_same_v<T, UChar>>>
272 inline const char16_t *uprv_char16PtrFromUChar(const T *p) {
273 if constexpr (std::is_same_v<UChar, char16_t>) {
274 return p;
275 } else {
276 #if U_SHOW_CPLUSPLUS_API
277 return ConstChar16Ptr(p).get();
278 #else
279 #ifdef U_ALIASING_BARRIER
280 U_ALIASING_BARRIER(p);
281 #endif
282 return reinterpret_cast<const char16_t *>(p);
283 #endif
284 }
285 }
286 #if !U_CHAR16_IS_TYPEDEF && (!defined(_LIBCPP_VERSION) || _LIBCPP_VERSION < 180000)
288 inline const char16_t *uprv_char16PtrFromUint16(const uint16_t *p) {
289 #if U_SHOW_CPLUSPLUS_API
290 return ConstChar16Ptr(p).get();
291 #else
292 #ifdef U_ALIASING_BARRIER
293 U_ALIASING_BARRIER(p);
294 #endif
295 return reinterpret_cast<const char16_t *>(p);
296 #endif
297 }
298 #endif
299 #if U_SIZEOF_WCHAR_T==2
301 inline const char16_t *uprv_char16PtrFromWchar(const wchar_t *p) {
302 #if U_SHOW_CPLUSPLUS_API
303 return ConstChar16Ptr(p).get();
304 #else
305 #ifdef U_ALIASING_BARRIER
306 U_ALIASING_BARRIER(p);
307 #endif
308 return reinterpret_cast<const char16_t *>(p);
309 #endif
310 }
311 #endif
312 #endif
313
321 inline const UChar *toUCharPtr(const char16_t *p) {
322 #ifdef U_ALIASING_BARRIER
323 U_ALIASING_BARRIER(p);
324 #endif
325 return reinterpret_cast<const UChar *>(p);
326 }
327
335 inline UChar *toUCharPtr(char16_t *p) {
336 #ifdef U_ALIASING_BARRIER
337 U_ALIASING_BARRIER(p);
338 #endif
339 return reinterpret_cast<UChar *>(p);
340 }
341
349 inline const OldUChar *toOldUCharPtr(const char16_t *p) {
350 #ifdef U_ALIASING_BARRIER
351 U_ALIASING_BARRIER(p);
352 #endif
353 return reinterpret_cast<const OldUChar *>(p);
354 }
355
363 inline OldUChar *toOldUCharPtr(char16_t *p) {
364 #ifdef U_ALIASING_BARRIER
365 U_ALIASING_BARRIER(p);
366 #endif
367 return reinterpret_cast<OldUChar *>(p);
368 }
369
370 } // U_ICU_NAMESPACE_OR_INTERNAL
371
372 #endif // U_SHOW_CPLUSPLUS_API || U_SHOW_CPLUSPLUS_HEADER_API
373
374 // ICU DLL-exported
375 #if U_SHOW_CPLUSPLUS_API
376
377 U_NAMESPACE_BEGIN
378
379 #ifndef U_FORCE_HIDE_INTERNAL_API
384 template<typename T>
385 constexpr bool ConvertibleToU16StringView =
386 std::is_convertible_v<T, std::u16string_view>
387 #if !U_CHAR16_IS_TYPEDEF && (!defined(_LIBCPP_VERSION) || _LIBCPP_VERSION < 180000)
388 || std::is_convertible_v<T, std::basic_string_view<uint16_t>>
389 #endif
390 #if U_SIZEOF_WCHAR_T==2
391 || std::is_convertible_v<T, std::wstring_view>
392 #endif
393 ;
394
395 namespace internal {
400 inline std::u16string_view toU16StringView(std::u16string_view sv) { return sv; }
401
402 #if !U_CHAR16_IS_TYPEDEF && (!defined(_LIBCPP_VERSION) || _LIBCPP_VERSION < 180000)
408 inline std::u16string_view toU16StringView(std::basic_string_view<uint16_t> sv) {
409 return { ConstChar16Ptr(sv.data()), sv.length() };
410 }
411 #endif
412
413 #if U_SIZEOF_WCHAR_T==2
419 inline std::u16string_view toU16StringView(std::wstring_view sv) {
420 return { ConstChar16Ptr(sv.data()), sv.length() };
421 }
422 #endif
423
428 template <typename T,
429 typename = typename std::enable_if_t<!std::is_pointer_v<std::remove_reference_t<T>>>>
430 inline std::u16string_view toU16StringViewNullable(const T& text) {
431 return toU16StringView(text);
432 }
433
438 template <typename T,
439 typename = typename std::enable_if_t<std::is_pointer_v<std::remove_reference_t<T>>>,
440 typename = void>
441 inline std::u16string_view toU16StringViewNullable(const T& text) {
442 if (text == nullptr) return {}; // For backward compatibility.
443 return toU16StringView(text);
444 }
445
446 } // internal
447 #endif // U_FORCE_HIDE_INTERNAL_API
448
449 U_NAMESPACE_END
450
451 #endif // U_SHOW_CPLUSPLUS_API
452
453 #endif // __CHAR16PTR_H__
U_ICU_NAMESPACE_OR_INTERNAL::uprv_char16PtrFromUint16
const char16_t * uprv_char16PtrFromUint16(const uint16_t *p)
Definition: char16ptr.h:288
icu::internal::toU16StringView
std::u16string_view toU16StringView(std::u16string_view sv)
Pass-through overload.
Definition: char16ptr.h:400
U_ICU_NAMESPACE_OR_INTERNAL::toUCharPtr
const UChar * toUCharPtr(const char16_t *p)
Converts from const char16_t * to const UChar *.
Definition: char16ptr.h:321
U_ICU_NAMESPACE_OR_INTERNAL::uprv_char16PtrFromUChar
const char16_t * uprv_char16PtrFromUChar(const T *p)
Definition: char16ptr.h:272
icu::internal::toU16StringViewNullable
std::u16string_view toU16StringViewNullable(const T &text)
Pass-through overload.
Definition: char16ptr.h:430
U_ALIASING_BARRIER
#define U_ALIASING_BARRIER(ptr)
Barrier for pointer anti-aliasing optimizations even across function boundaries.
Definition: char16ptr.h:37
U_ICU_NAMESPACE_OR_INTERNAL::toOldUCharPtr
const OldUChar * toOldUCharPtr(const char16_t *p)
Converts from const char16_t * to const OldUChar *.
Definition: char16ptr.h:349
icu::Char16Ptr
char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types.
Definition: char16ptr.h:49
icu::Char16Ptr::Char16Ptr
Char16Ptr(std::nullptr_t p)
nullptr constructor.
icu::Char16Ptr::~Char16Ptr
~Char16Ptr()
Destructor.
icu::Char16Ptr::Char16Ptr
Char16Ptr(uint16_t *p)
Converts the pointer to char16_t *.
icu::Char16Ptr::Char16Ptr
Char16Ptr(wchar_t *p)
Converts the pointer to char16_t *.
icu::Char16Ptr::get
char16_t * get() const
Pointer access.
icu::Char16Ptr::Char16Ptr
Char16Ptr(char16_t *p)
Copies the pointer.
icu::ConstChar16Ptr
const char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types.
Definition: char16ptr.h:156
icu::ConstChar16Ptr::ConstChar16Ptr
ConstChar16Ptr(const char16_t *p)
Copies the pointer.
icu::ConstChar16Ptr::get
const char16_t * get() const
Pointer access.
icu::ConstChar16Ptr::ConstChar16Ptr
ConstChar16Ptr(const uint16_t *p)
Converts the pointer to char16_t *.
icu::ConstChar16Ptr::~ConstChar16Ptr
~ConstChar16Ptr()
Destructor.
icu::ConstChar16Ptr::ConstChar16Ptr
ConstChar16Ptr(const wchar_t *p)
Converts the pointer to char16_t *.
icu::ConstChar16Ptr::ConstChar16Ptr
ConstChar16Ptr(const std::nullptr_t p)
nullptr constructor.
icu::ConvertibleToU16StringView
constexpr bool ConvertibleToU16StringView
Is T convertible to a std::u16string_view or some other 16-bit string view?
Definition: char16ptr.h:385
UChar
char16_t UChar
The base type for UTF-16 code units and pointers.
Definition: umachine.h:400
OldUChar
uint16_t OldUChar
Default ICU 58 definition of UChar.
Definition: umachine.h:429
utypes.h
Basic definitions for ICU, for both C and C++ APIs.
U_COMMON_API
#define U_COMMON_API
Set to export library symbols from inside the common library, and to import them from outside.
Definition: utypes.h:315