1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 **********************************************************************
5 *   Copyright (C) 1998-2014, International Business Machines
6 *   Corporation and others.  All Rights Reserved.
7 **********************************************************************
8 *
9 * File ustring.h
10 *
11 * Modification History:
12 *
13 *   Date        Name        Description
14 *   12/07/98    bertrand    Creation.
15 ******************************************************************************
16 */
17 
18 #ifndef USTRING_H
19 #define USTRING_H
20 
21 #include "unicode/utypes.h"
22 #include "unicode/putil.h"
23 #include "unicode/uiter.h"
24 
25 /**
26  * \def UBRK_TYPEDEF_UBREAK_ITERATOR
27  * @internal
28  */
29 
30 #ifndef UBRK_TYPEDEF_UBREAK_ITERATOR
31 #   define UBRK_TYPEDEF_UBREAK_ITERATOR
32 /** Simple declaration for u_strToTitle() to avoid including unicode/ubrk.h. @stable ICU 2.1*/
33     typedef struct UBreakIterator UBreakIterator;
34 #endif
35 
36 /**
37  * \file
38  * \brief C API: Unicode string handling functions
39  *
40  * These C API functions provide general Unicode string handling.
41  *
42  * Some functions are equivalent in name, signature, and behavior to the ANSI C <string.h>
43  * functions. (For example, they do not check for bad arguments like NULL string pointers.)
44  * In some cases, only the thread-safe variant of such a function is implemented here
45  * (see u_strtok_r()).
46  *
47  * Other functions provide more Unicode-specific functionality like locale-specific
48  * upper/lower-casing and string comparison in code point order.
49  *
50  * ICU uses 16-bit Unicode (UTF-16) in the form of arrays of UChar code units.
51  * UTF-16 encodes each Unicode code point with either one or two UChar code units.
52  * (This is the default form of Unicode, and a forward-compatible extension of the original,
53  * fixed-width form that was known as UCS-2. UTF-16 superseded UCS-2 with Unicode 2.0
54  * in 1996.)
55  *
56  * Some APIs accept a 32-bit UChar32 value for a single code point.
57  *
58  * ICU also handles 16-bit Unicode text with unpaired surrogates.
59  * Such text is not well-formed UTF-16.
60  * Code-point-related functions treat unpaired surrogates as surrogate code points,
61  * i.e., as separate units.
62  *
63  * Although UTF-16 is a variable-width encoding form (like some legacy multi-byte encodings),
64  * it is much more efficient even for random access because the code unit values
65  * for single-unit characters vs. lead units vs. trail units are completely disjoint.
66  * This means that it is easy to determine character (code point) boundaries from
67  * random offsets in the string.
68  *
69  * Unicode (UTF-16) string processing is optimized for the single-unit case.
70  * Although it is important to support supplementary characters
71  * (which use pairs of lead/trail code units called "surrogates"),
72  * their occurrence is rare. Almost all characters in modern use require only
73  * a single UChar code unit (i.e., their code point values are <=0xffff).
74  *
75  * For more details see the User Guide Strings chapter (http://icu-project.org/userguide/strings.html).
76  * For a discussion of the handling of unpaired surrogates see also
77  * Jitterbug 2145 and its icu mailing list proposal on 2002-sep-18.
78  */
79 
80 /**
81  * \defgroup ustring_ustrlen String Length
82  * \ingroup ustring_strlen
83  */
84 /*@{*/
85 /**
86  * Determine the length of an array of UChar.
87  *
88  * @param s The array of UChars, NULL (U+0000) terminated.
89  * @return The number of UChars in <code>chars</code>, minus the terminator.
90  * @stable ICU 2.0
91  */
92 U_STABLE int32_t U_EXPORT2
93 u_strlen(const UChar *s);
94 /*@}*/
95 
96 /**
97  * Count Unicode code points in the length UChar code units of the string.
98  * A code point may occupy either one or two UChar code units.
99  * Counting code points involves reading all code units.
100  *
101  * This functions is basically the inverse of the U16_FWD_N() macro (see utf.h).
102  *
103  * @param s The input string.
104  * @param length The number of UChar code units to be checked, or -1 to count all
105  *               code points before the first NUL (U+0000).
106  * @return The number of code points in the specified code units.
107  * @stable ICU 2.0
108  */
109 U_STABLE int32_t U_EXPORT2
110 u_countChar32(const UChar *s, int32_t length);
111 
112 /**
113  * Check if the string contains more Unicode code points than a certain number.
114  * This is more efficient than counting all code points in the entire string
115  * and comparing that number with a threshold.
116  * This function may not need to scan the string at all if the length is known
117  * (not -1 for NUL-termination) and falls within a certain range, and
118  * never needs to count more than 'number+1' code points.
119  * Logically equivalent to (u_countChar32(s, length)>number).
120  * A Unicode code point may occupy either one or two UChar code units.
121  *
122  * @param s The input string.
123  * @param length The length of the string, or -1 if it is NUL-terminated.
124  * @param number The number of code points in the string is compared against
125  *               the 'number' parameter.
126  * @return Boolean value for whether the string contains more Unicode code points
127  *         than 'number'. Same as (u_countChar32(s, length)>number).
128  * @stable ICU 2.4
129  */
130 U_STABLE UBool U_EXPORT2
131 u_strHasMoreChar32Than(const UChar *s, int32_t length, int32_t number);
132 
133 /**
134  * Concatenate two ustrings.  Appends a copy of <code>src</code>,
135  * including the null terminator, to <code>dst</code>. The initial copied
136  * character from <code>src</code> overwrites the null terminator in <code>dst</code>.
137  *
138  * @param dst The destination string.
139  * @param src The source string.
140  * @return A pointer to <code>dst</code>.
141  * @stable ICU 2.0
142  */
143 U_STABLE UChar* U_EXPORT2
144 u_strcat(UChar     *dst,
145     const UChar     *src);
146 
147 /**
148  * Concatenate two ustrings.
149  * Appends at most <code>n</code> characters from <code>src</code> to <code>dst</code>.
150  * Adds a terminating NUL.
151  * If src is too long, then only <code>n-1</code> characters will be copied
152  * before the terminating NUL.
153  * If <code>n&lt;=0</code> then dst is not modified.
154  *
155  * @param dst The destination string.
156  * @param src The source string (can be NULL/invalid if n<=0).
157  * @param n The maximum number of characters to append; no-op if <=0.
158  * @return A pointer to <code>dst</code>.
159  * @stable ICU 2.0
160  */
161 U_STABLE UChar* U_EXPORT2
162 u_strncat(UChar     *dst,
163      const UChar     *src,
164      int32_t     n);
165 
166 /**
167  * Find the first occurrence of a substring in a string.
168  * The substring is found at code point boundaries.
169  * That means that if the substring begins with
170  * a trail surrogate or ends with a lead surrogate,
171  * then it is found only if these surrogates stand alone in the text.
172  * Otherwise, the substring edge units would be matched against
173  * halves of surrogate pairs.
174  *
175  * @param s The string to search (NUL-terminated).
176  * @param substring The substring to find (NUL-terminated).
177  * @return A pointer to the first occurrence of <code>substring</code> in <code>s</code>,
178  *         or <code>s</code> itself if the <code>substring</code> is empty,
179  *         or <code>NULL</code> if <code>substring</code> is not in <code>s</code>.
180  * @stable ICU 2.0
181  *
182  * @see u_strrstr
183  * @see u_strFindFirst
184  * @see u_strFindLast
185  */
186 U_STABLE UChar * U_EXPORT2
187 u_strstr(const UChar *s, const UChar *substring);
188 
189 /**
190  * Find the first occurrence of a substring in a string.
191  * The substring is found at code point boundaries.
192  * That means that if the substring begins with
193  * a trail surrogate or ends with a lead surrogate,
194  * then it is found only if these surrogates stand alone in the text.
195  * Otherwise, the substring edge units would be matched against
196  * halves of surrogate pairs.
197  *
198  * @param s The string to search.
199  * @param length The length of s (number of UChars), or -1 if it is NUL-terminated.
200  * @param substring The substring to find (NUL-terminated).
201  * @param subLength The length of substring (number of UChars), or -1 if it is NUL-terminated.
202  * @return A pointer to the first occurrence of <code>substring</code> in <code>s</code>,
203  *         or <code>s</code> itself if the <code>substring</code> is empty,
204  *         or <code>NULL</code> if <code>substring</code> is not in <code>s</code>.
205  * @stable ICU 2.4
206  *
207  * @see u_strstr
208  * @see u_strFindLast
209  */
210 U_STABLE UChar * U_EXPORT2
211 u_strFindFirst(const UChar *s, int32_t length, const UChar *substring, int32_t subLength);
212 
213 /**
214  * Find the first occurrence of a BMP code point in a string.
215  * A surrogate code point is found only if its match in the text is not
216  * part of a surrogate pair.
217  * A NUL character is found at the string terminator.
218  *
219  * @param s The string to search (NUL-terminated).
220  * @param c The BMP code point to find.
221  * @return A pointer to the first occurrence of <code>c</code> in <code>s</code>
222  *         or <code>NULL</code> if <code>c</code> is not in <code>s</code>.
223  * @stable ICU 2.0
224  *
225  * @see u_strchr32
226  * @see u_memchr
227  * @see u_strstr
228  * @see u_strFindFirst
229  */
230 U_STABLE UChar * U_EXPORT2
231 u_strchr(const UChar *s, UChar c);
232 
233 /**
234  * Find the first occurrence of a code point in a string.
235  * A surrogate code point is found only if its match in the text is not
236  * part of a surrogate pair.
237  * A NUL character is found at the string terminator.
238  *
239  * @param s The string to search (NUL-terminated).
240  * @param c The code point to find.
241  * @return A pointer to the first occurrence of <code>c</code> in <code>s</code>
242  *         or <code>NULL</code> if <code>c</code> is not in <code>s</code>.
243  * @stable ICU 2.0
244  *
245  * @see u_strchr
246  * @see u_memchr32
247  * @see u_strstr
248  * @see u_strFindFirst
249  */
250 U_STABLE UChar * U_EXPORT2
251 u_strchr32(const UChar *s, UChar32 c);
252 
253 /**
254  * Find the last occurrence of a substring in a string.
255  * The substring is found at code point boundaries.
256  * That means that if the substring begins with
257  * a trail surrogate or ends with a lead surrogate,
258  * then it is found only if these surrogates stand alone in the text.
259  * Otherwise, the substring edge units would be matched against
260  * halves of surrogate pairs.
261  *
262  * @param s The string to search (NUL-terminated).
263  * @param substring The substring to find (NUL-terminated).
264  * @return A pointer to the last occurrence of <code>substring</code> in <code>s</code>,
265  *         or <code>s</code> itself if the <code>substring</code> is empty,
266  *         or <code>NULL</code> if <code>substring</code> is not in <code>s</code>.
267  * @stable ICU 2.4
268  *
269  * @see u_strstr
270  * @see u_strFindFirst
271  * @see u_strFindLast
272  */
273 U_STABLE UChar * U_EXPORT2
274 u_strrstr(const UChar *s, const UChar *substring);
275 
276 /**
277  * Find the last occurrence of a substring in a string.
278  * The substring is found at code point boundaries.
279  * That means that if the substring begins with
280  * a trail surrogate or ends with a lead surrogate,
281  * then it is found only if these surrogates stand alone in the text.
282  * Otherwise, the substring edge units would be matched against
283  * halves of surrogate pairs.
284  *
285  * @param s The string to search.
286  * @param length The length of s (number of UChars), or -1 if it is NUL-terminated.
287  * @param substring The substring to find (NUL-terminated).
288  * @param subLength The length of substring (number of UChars), or -1 if it is NUL-terminated.
289  * @return A pointer to the last occurrence of <code>substring</code> in <code>s</code>,
290  *         or <code>s</code> itself if the <code>substring</code> is empty,
291  *         or <code>NULL</code> if <code>substring</code> is not in <code>s</code>.
292  * @stable ICU 2.4
293  *
294  * @see u_strstr
295  * @see u_strFindLast
296  */
297 U_STABLE UChar * U_EXPORT2
298 u_strFindLast(const UChar *s, int32_t length, const UChar *substring, int32_t subLength);
299 
300 /**
301  * Find the last occurrence of a BMP code point in a string.
302  * A surrogate code point is found only if its match in the text is not
303  * part of a surrogate pair.
304  * A NUL character is found at the string terminator.
305  *
306  * @param s The string to search (NUL-terminated).
307  * @param c The BMP code point to find.
308  * @return A pointer to the last occurrence of <code>c</code> in <code>s</code>
309  *         or <code>NULL</code> if <code>c</code> is not in <code>s</code>.
310  * @stable ICU 2.4
311  *
312  * @see u_strrchr32
313  * @see u_memrchr
314  * @see u_strrstr
315  * @see u_strFindLast
316  */
317 U_STABLE UChar * U_EXPORT2
318 u_strrchr(const UChar *s, UChar c);
319 
320 /**
321  * Find the last occurrence of a code point in a string.
322  * A surrogate code point is found only if its match in the text is not
323  * part of a surrogate pair.
324  * A NUL character is found at the string terminator.
325  *
326  * @param s The string to search (NUL-terminated).
327  * @param c The code point to find.
328  * @return A pointer to the last occurrence of <code>c</code> in <code>s</code>
329  *         or <code>NULL</code> if <code>c</code> is not in <code>s</code>.
330  * @stable ICU 2.4
331  *
332  * @see u_strrchr
333  * @see u_memchr32
334  * @see u_strrstr
335  * @see u_strFindLast
336  */
337 U_STABLE UChar * U_EXPORT2
338 u_strrchr32(const UChar *s, UChar32 c);
339 
340 /**
341  * Locates the first occurrence in the string <code>string</code> of any of the characters
342  * in the string <code>matchSet</code>.
343  * Works just like C's strpbrk but with Unicode.
344  *
345  * @param string The string in which to search, NUL-terminated.
346  * @param matchSet A NUL-terminated string defining a set of code points
347  *                 for which to search in the text string.
348  * @return A pointer to the  character in <code>string</code> that matches one of the
349  *         characters in <code>matchSet</code>, or NULL if no such character is found.
350  * @stable ICU 2.0
351  */
352 U_STABLE UChar * U_EXPORT2
353 u_strpbrk(const UChar *string, const UChar *matchSet);
354 
355 /**
356  * Returns the number of consecutive characters in <code>string</code>,
357  * beginning with the first, that do not occur somewhere in <code>matchSet</code>.
358  * Works just like C's strcspn but with Unicode.
359  *
360  * @param string The string in which to search, NUL-terminated.
361  * @param matchSet A NUL-terminated string defining a set of code points
362  *                 for which to search in the text string.
363  * @return The number of initial characters in <code>string</code> that do not
364  *         occur in <code>matchSet</code>.
365  * @see u_strspn
366  * @stable ICU 2.0
367  */
368 U_STABLE int32_t U_EXPORT2
369 u_strcspn(const UChar *string, const UChar *matchSet);
370 
371 /**
372  * Returns the number of consecutive characters in <code>string</code>,
373  * beginning with the first, that occur somewhere in <code>matchSet</code>.
374  * Works just like C's strspn but with Unicode.
375  *
376  * @param string The string in which to search, NUL-terminated.
377  * @param matchSet A NUL-terminated string defining a set of code points
378  *                 for which to search in the text string.
379  * @return The number of initial characters in <code>string</code> that do
380  *         occur in <code>matchSet</code>.
381  * @see u_strcspn
382  * @stable ICU 2.0
383  */
384 U_STABLE int32_t U_EXPORT2
385 u_strspn(const UChar *string, const UChar *matchSet);
386 
387 /**
388  * The string tokenizer API allows an application to break a string into
389  * tokens. Unlike strtok(), the saveState (the current pointer within the
390  * original string) is maintained in saveState. In the first call, the
391  * argument src is a pointer to the string. In subsequent calls to
392  * return successive tokens of that string, src must be specified as
393  * NULL. The value saveState is set by this function to maintain the
394  * function's position within the string, and on each subsequent call
395  * you must give this argument the same variable. This function does
396  * handle surrogate pairs. This function is similar to the strtok_r()
397  * the POSIX Threads Extension (1003.1c-1995) version.
398  *
399  * @param src String containing token(s). This string will be modified.
400  *            After the first call to u_strtok_r(), this argument must
401  *            be NULL to get to the next token.
402  * @param delim Set of delimiter characters (Unicode code points).
403  * @param saveState The current pointer within the original string,
404  *              which is set by this function. The saveState
405  *              parameter should the address of a local variable of type
406  *              UChar *. (i.e. defined "UChar *myLocalSaveState" and use
407  *              &myLocalSaveState for this parameter).
408  * @return A pointer to the next token found in src, or NULL
409  *         when there are no more tokens.
410  * @stable ICU 2.0
411  */
412 U_STABLE UChar * U_EXPORT2
413 u_strtok_r(UChar    *src,
414      const UChar    *delim,
415            UChar   **saveState);
416 
417 /**
418  * Compare two Unicode strings for bitwise equality (code unit order).
419  *
420  * @param s1 A string to compare.
421  * @param s2 A string to compare.
422  * @return 0 if <code>s1</code> and <code>s2</code> are bitwise equal; a negative
423  * value if <code>s1</code> is bitwise less than <code>s2,</code>; a positive
424  * value if <code>s1</code> is bitwise greater than <code>s2</code>.
425  * @stable ICU 2.0
426  */
427 U_STABLE int32_t  U_EXPORT2
428 u_strcmp(const UChar     *s1,
429          const UChar     *s2);
430 
431 /**
432  * Compare two Unicode strings in code point order.
433  * See u_strCompare for details.
434  *
435  * @param s1 A string to compare.
436  * @param s2 A string to compare.
437  * @return a negative/zero/positive integer corresponding to whether
438  * the first string is less than/equal to/greater than the second one
439  * in code point order
440  * @stable ICU 2.0
441  */
442 U_STABLE int32_t U_EXPORT2
443 u_strcmpCodePointOrder(const UChar *s1, const UChar *s2);
444 
445 /**
446  * Compare two Unicode strings (binary order).
447  *
448  * The comparison can be done in code unit order or in code point order.
449  * They differ only in UTF-16 when
450  * comparing supplementary code points (U+10000..U+10ffff)
451  * to BMP code points near the end of the BMP (i.e., U+e000..U+ffff).
452  * In code unit order, high BMP code points sort after supplementary code points
453  * because they are stored as pairs of surrogates which are at U+d800..U+dfff.
454  *
455  * This functions works with strings of different explicitly specified lengths
456  * unlike the ANSI C-like u_strcmp() and u_memcmp() etc.
457  * NUL-terminated strings are possible with length arguments of -1.
458  *
459  * @param s1 First source string.
460  * @param length1 Length of first source string, or -1 if NUL-terminated.
461  *
462  * @param s2 Second source string.
463  * @param length2 Length of second source string, or -1 if NUL-terminated.
464  *
465  * @param codePointOrder Choose between code unit order (FALSE)
466  *                       and code point order (TRUE).
467  *
468  * @return <0 or 0 or >0 as usual for string comparisons
469  *
470  * @stable ICU 2.2
471  */
472 U_STABLE int32_t U_EXPORT2
473 u_strCompare(const UChar *s1, int32_t length1,
474              const UChar *s2, int32_t length2,
475              UBool codePointOrder);
476 
477 /**
478  * Compare two Unicode strings (binary order)
479  * as presented by UCharIterator objects.
480  * Works otherwise just like u_strCompare().
481  *
482  * Both iterators are reset to their start positions.
483  * When the function returns, it is undefined where the iterators
484  * have stopped.
485  *
486  * @param iter1 First source string iterator.
487  * @param iter2 Second source string iterator.
488  * @param codePointOrder Choose between code unit order (FALSE)
489  *                       and code point order (TRUE).
490  *
491  * @return <0 or 0 or >0 as usual for string comparisons
492  *
493  * @see u_strCompare
494  *
495  * @stable ICU 2.6
496  */
497 U_STABLE int32_t U_EXPORT2
498 u_strCompareIter(UCharIterator *iter1, UCharIterator *iter2, UBool codePointOrder);
499 
500 /**
501  * Compare two strings case-insensitively using full case folding.
502  * This is equivalent to
503  *   u_strCompare(u_strFoldCase(s1, options),
504  *                u_strFoldCase(s2, options),
505  *                (options&U_COMPARE_CODE_POINT_ORDER)!=0).
506  *
507  * The comparison can be done in UTF-16 code unit order or in code point order.
508  * They differ only when comparing supplementary code points (U+10000..U+10ffff)
509  * to BMP code points near the end of the BMP (i.e., U+e000..U+ffff).
510  * In code unit order, high BMP code points sort after supplementary code points
511  * because they are stored as pairs of surrogates which are at U+d800..U+dfff.
512  *
513  * This functions works with strings of different explicitly specified lengths
514  * unlike the ANSI C-like u_strcmp() and u_memcmp() etc.
515  * NUL-terminated strings are possible with length arguments of -1.
516  *
517  * @param s1 First source string.
518  * @param length1 Length of first source string, or -1 if NUL-terminated.
519  *
520  * @param s2 Second source string.
521  * @param length2 Length of second source string, or -1 if NUL-terminated.
522  *
523  * @param options A bit set of options:
524  *   - U_FOLD_CASE_DEFAULT or 0 is used for default options:
525  *     Comparison in code unit order with default case folding.
526  *
527  *   - U_COMPARE_CODE_POINT_ORDER
528  *     Set to choose code point order instead of code unit order
529  *     (see u_strCompare for details).
530  *
531  *   - U_FOLD_CASE_EXCLUDE_SPECIAL_I
532  *
533  * @param pErrorCode Must be a valid pointer to an error code value,
534  *                  which must not indicate a failure before the function call.
535  *
536  * @return <0 or 0 or >0 as usual for string comparisons
537  *
538  * @stable ICU 2.2
539  */
540 U_STABLE int32_t U_EXPORT2
541 u_strCaseCompare(const UChar *s1, int32_t length1,
542                  const UChar *s2, int32_t length2,
543                  uint32_t options,
544                  UErrorCode *pErrorCode);
545 
546 /**
547  * Compare two ustrings for bitwise equality.
548  * Compares at most <code>n</code> characters.
549  *
550  * @param ucs1 A string to compare (can be NULL/invalid if n<=0).
551  * @param ucs2 A string to compare (can be NULL/invalid if n<=0).
552  * @param n The maximum number of characters to compare; always returns 0 if n<=0.
553  * @return 0 if <code>s1</code> and <code>s2</code> are bitwise equal; a negative
554  * value if <code>s1</code> is bitwise less than <code>s2</code>; a positive
555  * value if <code>s1</code> is bitwise greater than <code>s2</code>.
556  * @stable ICU 2.0
557  */
558 U_STABLE int32_t U_EXPORT2
559 u_strncmp(const UChar     *ucs1,
560      const UChar     *ucs2,
561      int32_t     n);
562 
563 /**
564  * Compare two Unicode strings in code point order.
565  * This is different in UTF-16 from u_strncmp() if supplementary characters are present.
566  * For details, see u_strCompare().
567  *
568  * @param s1 A string to compare.
569  * @param s2 A string to compare.
570  * @param n The maximum number of characters to compare.
571  * @return a negative/zero/positive integer corresponding to whether
572  * the first string is less than/equal to/greater than the second one
573  * in code point order
574  * @stable ICU 2.0
575  */
576 U_STABLE int32_t U_EXPORT2
577 u_strncmpCodePointOrder(const UChar *s1, const UChar *s2, int32_t n);
578 
579 /**
580  * Compare two strings case-insensitively using full case folding.
581  * This is equivalent to u_strcmp(u_strFoldCase(s1, options), u_strFoldCase(s2, options)).
582  *
583  * @param s1 A string to compare.
584  * @param s2 A string to compare.
585  * @param options A bit set of options:
586  *   - U_FOLD_CASE_DEFAULT or 0 is used for default options:
587  *     Comparison in code unit order with default case folding.
588  *
589  *   - U_COMPARE_CODE_POINT_ORDER
590  *     Set to choose code point order instead of code unit order
591  *     (see u_strCompare for details).
592  *
593  *   - U_FOLD_CASE_EXCLUDE_SPECIAL_I
594  *
595  * @return A negative, zero, or positive integer indicating the comparison result.
596  * @stable ICU 2.0
597  */
598 U_STABLE int32_t U_EXPORT2
599 u_strcasecmp(const UChar *s1, const UChar *s2, uint32_t options);
600 
601 /**
602  * Compare two strings case-insensitively using full case folding.
603  * This is equivalent to u_strcmp(u_strFoldCase(s1, at most n, options),
604  * u_strFoldCase(s2, at most n, options)).
605  *
606  * @param s1 A string to compare.
607  * @param s2 A string to compare.
608  * @param n The maximum number of characters each string to case-fold and then compare.
609  * @param options A bit set of options:
610  *   - U_FOLD_CASE_DEFAULT or 0 is used for default options:
611  *     Comparison in code unit order with default case folding.
612  *
613  *   - U_COMPARE_CODE_POINT_ORDER
614  *     Set to choose code point order instead of code unit order
615  *     (see u_strCompare for details).
616  *
617  *   - U_FOLD_CASE_EXCLUDE_SPECIAL_I
618  *
619  * @return A negative, zero, or positive integer indicating the comparison result.
620  * @stable ICU 2.0
621  */
622 U_STABLE int32_t U_EXPORT2
623 u_strncasecmp(const UChar *s1, const UChar *s2, int32_t n, uint32_t options);
624 
625 /**
626  * Compare two strings case-insensitively using full case folding.
627  * This is equivalent to u_strcmp(u_strFoldCase(s1, n, options),
628  * u_strFoldCase(s2, n, options)).
629  *
630  * @param s1 A string to compare.
631  * @param s2 A string to compare.
632  * @param length The number of characters in each string to case-fold and then compare.
633  * @param options A bit set of options:
634  *   - U_FOLD_CASE_DEFAULT or 0 is used for default options:
635  *     Comparison in code unit order with default case folding.
636  *
637  *   - U_COMPARE_CODE_POINT_ORDER
638  *     Set to choose code point order instead of code unit order
639  *     (see u_strCompare for details).
640  *
641  *   - U_FOLD_CASE_EXCLUDE_SPECIAL_I
642  *
643  * @return A negative, zero, or positive integer indicating the comparison result.
644  * @stable ICU 2.0
645  */
646 U_STABLE int32_t U_EXPORT2
647 u_memcasecmp(const UChar *s1, const UChar *s2, int32_t length, uint32_t options);
648 
649 /**
650  * Copy a ustring. Adds a null terminator.
651  *
652  * @param dst The destination string.
653  * @param src The source string.
654  * @return A pointer to <code>dst</code>.
655  * @stable ICU 2.0
656  */
657 U_STABLE UChar* U_EXPORT2
658 u_strcpy(UChar     *dst,
659     const UChar     *src);
660 
661 /**
662  * Copy a ustring.
663  * Copies at most <code>n</code> characters.  The result will be null terminated
664  * if the length of <code>src</code> is less than <code>n</code>.
665  *
666  * @param dst The destination string.
667  * @param src The source string (can be NULL/invalid if n<=0).
668  * @param n The maximum number of characters to copy; no-op if <=0.
669  * @return A pointer to <code>dst</code>.
670  * @stable ICU 2.0
671  */
672 U_STABLE UChar* U_EXPORT2
673 u_strncpy(UChar     *dst,
674      const UChar     *src,
675      int32_t     n);
676 
677 #if !UCONFIG_NO_CONVERSION
678 
679 /**
680  * Copy a byte string encoded in the default codepage to a ustring.
681  * Adds a null terminator.
682  * Performs a host byte to UChar conversion
683  *
684  * @param dst The destination string.
685  * @param src The source string.
686  * @return A pointer to <code>dst</code>.
687  * @stable ICU 2.0
688  */
689 U_STABLE UChar* U_EXPORT2 u_uastrcpy(UChar *dst,
690                const char *src );
691 
692 /**
693  * Copy a byte string encoded in the default codepage to a ustring.
694  * Copies at most <code>n</code> characters.  The result will be null terminated
695  * if the length of <code>src</code> is less than <code>n</code>.
696  * Performs a host byte to UChar conversion
697  *
698  * @param dst The destination string.
699  * @param src The source string.
700  * @param n The maximum number of characters to copy.
701  * @return A pointer to <code>dst</code>.
702  * @stable ICU 2.0
703  */
704 U_STABLE UChar* U_EXPORT2 u_uastrncpy(UChar *dst,
705             const char *src,
706             int32_t n);
707 
708 /**
709  * Copy ustring to a byte string encoded in the default codepage.
710  * Adds a null terminator.
711  * Performs a UChar to host byte conversion
712  *
713  * @param dst The destination string.
714  * @param src The source string.
715  * @return A pointer to <code>dst</code>.
716  * @stable ICU 2.0
717  */
718 U_STABLE char* U_EXPORT2 u_austrcpy(char *dst,
719             const UChar *src );
720 
721 /**
722  * Copy ustring to a byte string encoded in the default codepage.
723  * Copies at most <code>n</code> characters.  The result will be null terminated
724  * if the length of <code>src</code> is less than <code>n</code>.
725  * Performs a UChar to host byte conversion
726  *
727  * @param dst The destination string.
728  * @param src The source string.
729  * @param n The maximum number of characters to copy.
730  * @return A pointer to <code>dst</code>.
731  * @stable ICU 2.0
732  */
733 U_STABLE char* U_EXPORT2 u_austrncpy(char *dst,
734             const UChar *src,
735             int32_t n );
736 
737 #endif
738 
739 /**
740  * Synonym for memcpy(), but with UChars only.
741  * @param dest The destination string
742  * @param src The source string (can be NULL/invalid if count<=0)
743  * @param count The number of characters to copy; no-op if <=0
744  * @return A pointer to <code>dest</code>
745  * @stable ICU 2.0
746  */
747 U_STABLE UChar* U_EXPORT2
748 u_memcpy(UChar *dest, const UChar *src, int32_t count);
749 
750 /**
751  * Synonym for memmove(), but with UChars only.
752  * @param dest The destination string
753  * @param src The source string (can be NULL/invalid if count<=0)
754  * @param count The number of characters to move; no-op if <=0
755  * @return A pointer to <code>dest</code>
756  * @stable ICU 2.0
757  */
758 U_STABLE UChar* U_EXPORT2
759 u_memmove(UChar *dest, const UChar *src, int32_t count);
760 
761 /**
762  * Initialize <code>count</code> characters of <code>dest</code> to <code>c</code>.
763  *
764  * @param dest The destination string.
765  * @param c The character to initialize the string.
766  * @param count The maximum number of characters to set.
767  * @return A pointer to <code>dest</code>.
768  * @stable ICU 2.0
769  */
770 U_STABLE UChar* U_EXPORT2
771 u_memset(UChar *dest, UChar c, int32_t count);
772 
773 /**
774  * Compare the first <code>count</code> UChars of each buffer.
775  *
776  * @param buf1 The first string to compare.
777  * @param buf2 The second string to compare.
778  * @param count The maximum number of UChars to compare.
779  * @return When buf1 < buf2, a negative number is returned.
780  *      When buf1 == buf2, 0 is returned.
781  *      When buf1 > buf2, a positive number is returned.
782  * @stable ICU 2.0
783  */
784 U_STABLE int32_t U_EXPORT2
785 u_memcmp(const UChar *buf1, const UChar *buf2, int32_t count);
786 
787 /**
788  * Compare two Unicode strings in code point order.
789  * This is different in UTF-16 from u_memcmp() if supplementary characters are present.
790  * For details, see u_strCompare().
791  *
792  * @param s1 A string to compare.
793  * @param s2 A string to compare.
794  * @param count The maximum number of characters to compare.
795  * @return a negative/zero/positive integer corresponding to whether
796  * the first string is less than/equal to/greater than the second one
797  * in code point order
798  * @stable ICU 2.0
799  */
800 U_STABLE int32_t U_EXPORT2
801 u_memcmpCodePointOrder(const UChar *s1, const UChar *s2, int32_t count);
802 
803 /**
804  * Find the first occurrence of a BMP code point in a string.
805  * A surrogate code point is found only if its match in the text is not
806  * part of a surrogate pair.
807  * A NUL character is found at the string terminator.
808  *
809  * @param s The string to search (contains <code>count</code> UChars).
810  * @param c The BMP code point to find.
811  * @param count The length of the string.
812  * @return A pointer to the first occurrence of <code>c</code> in <code>s</code>
813  *         or <code>NULL</code> if <code>c</code> is not in <code>s</code>.
814  * @stable ICU 2.0
815  *
816  * @see u_strchr
817  * @see u_memchr32
818  * @see u_strFindFirst
819  */
820 U_STABLE UChar* U_EXPORT2
821 u_memchr(const UChar *s, UChar c, int32_t count);
822 
823 /**
824  * Find the first occurrence of a code point in a string.
825  * A surrogate code point is found only if its match in the text is not
826  * part of a surrogate pair.
827  * A NUL character is found at the string terminator.
828  *
829  * @param s The string to search (contains <code>count</code> UChars).
830  * @param c The code point to find.
831  * @param count The length of the string.
832  * @return A pointer to the first occurrence of <code>c</code> in <code>s</code>
833  *         or <code>NULL</code> if <code>c</code> is not in <code>s</code>.
834  * @stable ICU 2.0
835  *
836  * @see u_strchr32
837  * @see u_memchr
838  * @see u_strFindFirst
839  */
840 U_STABLE UChar* U_EXPORT2
841 u_memchr32(const UChar *s, UChar32 c, int32_t count);
842 
843 /**
844  * Find the last occurrence of a BMP code point in a string.
845  * A surrogate code point is found only if its match in the text is not
846  * part of a surrogate pair.
847  * A NUL character is found at the string terminator.
848  *
849  * @param s The string to search (contains <code>count</code> UChars).
850  * @param c The BMP code point to find.
851  * @param count The length of the string.
852  * @return A pointer to the last occurrence of <code>c</code> in <code>s</code>
853  *         or <code>NULL</code> if <code>c</code> is not in <code>s</code>.
854  * @stable ICU 2.4
855  *
856  * @see u_strrchr
857  * @see u_memrchr32
858  * @see u_strFindLast
859  */
860 U_STABLE UChar* U_EXPORT2
861 u_memrchr(const UChar *s, UChar c, int32_t count);
862 
863 /**
864  * Find the last occurrence of a code point in a string.
865  * A surrogate code point is found only if its match in the text is not
866  * part of a surrogate pair.
867  * A NUL character is found at the string terminator.
868  *
869  * @param s The string to search (contains <code>count</code> UChars).
870  * @param c The code point to find.
871  * @param count The length of the string.
872  * @return A pointer to the last occurrence of <code>c</code> in <code>s</code>
873  *         or <code>NULL</code> if <code>c</code> is not in <code>s</code>.
874  * @stable ICU 2.4
875  *
876  * @see u_strrchr32
877  * @see u_memrchr
878  * @see u_strFindLast
879  */
880 U_STABLE UChar* U_EXPORT2
881 u_memrchr32(const UChar *s, UChar32 c, int32_t count);
882 
883 /**
884  * Unicode String literals in C.
885  * We need one macro to declare a variable for the string
886  * and to statically preinitialize it if possible,
887  * and a second macro to dynamically initialize such a string variable if necessary.
888  *
889  * The macros are defined for maximum performance.
890  * They work only for strings that contain "invariant characters", i.e.,
891  * only latin letters, digits, and some punctuation.
892  * See utypes.h for details.
893  *
894  * A pair of macros for a single string must be used with the same
895  * parameters.
896  * The string parameter must be a C string literal.
897  * The length of the string, not including the terminating
898  * `NUL`, must be specified as a constant.
899  * The U_STRING_DECL macro should be invoked exactly once for one
900  * such string variable before it is used.
901  *
902  * Usage:
903  *
904  *     U_STRING_DECL(ustringVar1, "Quick-Fox 2", 11);
905  *     U_STRING_DECL(ustringVar2, "jumps 5%", 8);
906  *     static UBool didInit=FALSE;
907  *
908  *     int32_t function() {
909  *         if(!didInit) {
910  *             U_STRING_INIT(ustringVar1, "Quick-Fox 2", 11);
911  *             U_STRING_INIT(ustringVar2, "jumps 5%", 8);
912  *             didInit=TRUE;
913  *         }
914  *         return u_strcmp(ustringVar1, ustringVar2);
915  *     }
916  *
917  * Note that the macros will NOT consistently work if their argument is another #`define`.
918  * The following will not work on all platforms, don't use it.
919  *
920  *     #define GLUCK "Mr. Gluck"
921  *     U_STRING_DECL(var, GLUCK, 9)
922  *     U_STRING_INIT(var, GLUCK, 9)
923  *
924  * Instead, use the string literal "Mr. Gluck"  as the argument to both macro
925  * calls.
926  *
927  *
928  * @stable ICU 2.0
929  */
930 #if defined(U_DECLARE_UTF16)
931 #   define U_STRING_DECL(var, cs, length) static const UChar *var=(const UChar *)U_DECLARE_UTF16(cs)
932     /**@stable ICU 2.0 */
933 #   define U_STRING_INIT(var, cs, length)
934 #elif U_SIZEOF_WCHAR_T==U_SIZEOF_UCHAR && (U_CHARSET_FAMILY==U_ASCII_FAMILY || (U_SIZEOF_UCHAR == 2 && defined(U_WCHAR_IS_UTF16)))
935 #   define U_STRING_DECL(var, cs, length) static const UChar var[(length)+1]=L ## cs
936     /**@stable ICU 2.0 */
937 #   define U_STRING_INIT(var, cs, length)
938 #elif U_SIZEOF_UCHAR==1 && U_CHARSET_FAMILY==U_ASCII_FAMILY
939 #   define U_STRING_DECL(var, cs, length) static const UChar var[(length)+1]=cs
940     /**@stable ICU 2.0 */
941 #   define U_STRING_INIT(var, cs, length)
942 #else
943 #   define U_STRING_DECL(var, cs, length) static UChar var[(length)+1]
944     /**@stable ICU 2.0 */
945 #   define U_STRING_INIT(var, cs, length) u_charsToUChars(cs, var, length+1)
946 #endif
947 
948 /**
949  * Unescape a string of characters and write the resulting
950  * Unicode characters to the destination buffer.  The following escape
951  * sequences are recognized:
952  *
953  * \\uhhhh       4 hex digits; h in [0-9A-Fa-f]
954  * \\Uhhhhhhhh   8 hex digits
955  * \\xhh         1-2 hex digits
956  * \\x{h...}     1-8 hex digits
957  * \\ooo         1-3 octal digits; o in [0-7]
958  * \\cX          control-X; X is masked with 0x1F
959  *
960  * as well as the standard ANSI C escapes:
961  *
962  * \\a => U+0007, \\b => U+0008, \\t => U+0009, \\n => U+000A,
963  * \\v => U+000B, \\f => U+000C, \\r => U+000D, \\e => U+001B,
964  * \\&quot; => U+0022, \\' => U+0027, \\? => U+003F, \\\\ => U+005C
965  *
966  * Anything else following a backslash is generically escaped.  For
967  * example, "[a\\-z]" returns "[a-z]".
968  *
969  * If an escape sequence is ill-formed, this method returns an empty
970  * string.  An example of an ill-formed sequence is "\\u" followed by
971  * fewer than 4 hex digits.
972  *
973  * The above characters are recognized in the compiler's codepage,
974  * that is, they are coded as 'u', '\\', etc.  Characters that are
975  * not parts of escape sequences are converted using u_charsToUChars().
976  *
977  * This function is similar to UnicodeString::unescape() but not
978  * identical to it.  The latter takes a source UnicodeString, so it
979  * does escape recognition but no conversion.
980  *
981  * @param src a zero-terminated string of invariant characters
982  * @param dest pointer to buffer to receive converted and unescaped
983  * text and, if there is room, a zero terminator.  May be NULL for
984  * preflighting, in which case no UChars will be written, but the
985  * return value will still be valid.  On error, an empty string is
986  * stored here (if possible).
987  * @param destCapacity the number of UChars that may be written at
988  * dest.  Ignored if dest == NULL.
989  * @return the length of unescaped string.
990  * @see u_unescapeAt
991  * @see UnicodeString#unescape()
992  * @see UnicodeString#unescapeAt()
993  * @stable ICU 2.0
994  */
995 U_STABLE int32_t U_EXPORT2
996 u_unescape(const char *src,
997            UChar *dest, int32_t destCapacity);
998 
999 U_CDECL_BEGIN
1000 /**
1001  * Callback function for u_unescapeAt() that returns a character of
1002  * the source text given an offset and a context pointer.  The context
1003  * pointer will be whatever is passed into u_unescapeAt().
1004  *
1005  * @param offset pointer to the offset that will be passed to u_unescapeAt().
1006  * @param context an opaque pointer passed directly into u_unescapeAt()
1007  * @return the character represented by the escape sequence at
1008  * offset
1009  * @see u_unescapeAt
1010  * @stable ICU 2.0
1011  */
1012 typedef UChar (U_CALLCONV *UNESCAPE_CHAR_AT)(int32_t offset, void *context);
1013 U_CDECL_END
1014 
1015 /**
1016  * Unescape a single sequence. The character at offset-1 is assumed
1017  * (without checking) to be a backslash.  This method takes a callback
1018  * pointer to a function that returns the UChar at a given offset.  By
1019  * varying this callback, ICU functions are able to unescape char*
1020  * strings, UnicodeString objects, and UFILE pointers.
1021  *
1022  * If offset is out of range, or if the escape sequence is ill-formed,
1023  * (UChar32)0xFFFFFFFF is returned.  See documentation of u_unescape()
1024  * for a list of recognized sequences.
1025  *
1026  * @param charAt callback function that returns a UChar of the source
1027  * text given an offset and a context pointer.
1028  * @param offset pointer to the offset that will be passed to charAt.
1029  * The offset value will be updated upon return to point after the
1030  * last parsed character of the escape sequence.  On error the offset
1031  * is unchanged.
1032  * @param length the number of characters in the source text.  The
1033  * last character of the source text is considered to be at offset
1034  * length-1.
1035  * @param context an opaque pointer passed directly into charAt.
1036  * @return the character represented by the escape sequence at
1037  * offset, or (UChar32)0xFFFFFFFF on error.
1038  * @see u_unescape()
1039  * @see UnicodeString#unescape()
1040  * @see UnicodeString#unescapeAt()
1041  * @stable ICU 2.0
1042  */
1043 U_STABLE UChar32 U_EXPORT2
1044 u_unescapeAt(UNESCAPE_CHAR_AT charAt,
1045              int32_t *offset,
1046              int32_t length,
1047              void *context);
1048 
1049 /**
1050  * Uppercase the characters in a string.
1051  * Casing is locale-dependent and context-sensitive.
1052  * The result may be longer or shorter than the original.
1053  * The source string and the destination buffer are allowed to overlap.
1054  *
1055  * @param dest      A buffer for the result string. The result will be zero-terminated if
1056  *                  the buffer is large enough.
1057  * @param destCapacity The size of the buffer (number of UChars). If it is 0, then
1058  *                  dest may be NULL and the function will only return the length of the result
1059  *                  without writing any of the result string.
1060  * @param src       The original string
1061  * @param srcLength The length of the original string. If -1, then src must be zero-terminated.
1062  * @param locale    The locale to consider, or "" for the root locale or NULL for the default locale.
1063  * @param pErrorCode Must be a valid pointer to an error code value,
1064  *                  which must not indicate a failure before the function call.
1065  * @return The length of the result string. It may be greater than destCapacity. In that case,
1066  *         only some of the result was written to the destination buffer.
1067  * @stable ICU 2.0
1068  */
1069 U_STABLE int32_t U_EXPORT2
1070 u_strToUpper(UChar *dest, int32_t destCapacity,
1071              const UChar *src, int32_t srcLength,
1072              const char *locale,
1073              UErrorCode *pErrorCode);
1074 
1075 /**
1076  * Lowercase the characters in a string.
1077  * Casing is locale-dependent and context-sensitive.
1078  * The result may be longer or shorter than the original.
1079  * The source string and the destination buffer are allowed to overlap.
1080  *
1081  * @param dest      A buffer for the result string. The result will be zero-terminated if
1082  *                  the buffer is large enough.
1083  * @param destCapacity The size of the buffer (number of UChars). If it is 0, then
1084  *                  dest may be NULL and the function will only return the length of the result
1085  *                  without writing any of the result string.
1086  * @param src       The original string
1087  * @param srcLength The length of the original string. If -1, then src must be zero-terminated.
1088  * @param locale    The locale to consider, or "" for the root locale or NULL for the default locale.
1089  * @param pErrorCode Must be a valid pointer to an error code value,
1090  *                  which must not indicate a failure before the function call.
1091  * @return The length of the result string. It may be greater than destCapacity. In that case,
1092  *         only some of the result was written to the destination buffer.
1093  * @stable ICU 2.0
1094  */
1095 U_STABLE int32_t U_EXPORT2
1096 u_strToLower(UChar *dest, int32_t destCapacity,
1097              const UChar *src, int32_t srcLength,
1098              const char *locale,
1099              UErrorCode *pErrorCode);
1100 
1101 #if !UCONFIG_NO_BREAK_ITERATION
1102 
1103 /**
1104  * Titlecase a string.
1105  * Casing is locale-dependent and context-sensitive.
1106  * Titlecasing uses a break iterator to find the first characters of words
1107  * that are to be titlecased. It titlecases those characters and lowercases
1108  * all others.
1109  *
1110  * The titlecase break iterator can be provided to customize for arbitrary
1111  * styles, using rules and dictionaries beyond the standard iterators.
1112  * It may be more efficient to always provide an iterator to avoid
1113  * opening and closing one for each string.
1114  * The standard titlecase iterator for the root locale implements the
1115  * algorithm of Unicode TR 21.
1116  *
1117  * This function uses only the setText(), first() and next() methods of the
1118  * provided break iterator.
1119  *
1120  * The result may be longer or shorter than the original.
1121  * The source string and the destination buffer are allowed to overlap.
1122  *
1123  * @param dest      A buffer for the result string. The result will be zero-terminated if
1124  *                  the buffer is large enough.
1125  * @param destCapacity The size of the buffer (number of UChars). If it is 0, then
1126  *                  dest may be NULL and the function will only return the length of the result
1127  *                  without writing any of the result string.
1128  * @param src       The original string
1129  * @param srcLength The length of the original string. If -1, then src must be zero-terminated.
1130  * @param titleIter A break iterator to find the first characters of words
1131  *                  that are to be titlecased.
1132  *                  If none is provided (NULL), then a standard titlecase
1133  *                  break iterator is opened.
1134  * @param locale    The locale to consider, or "" for the root locale or NULL for the default locale.
1135  * @param pErrorCode Must be a valid pointer to an error code value,
1136  *                  which must not indicate a failure before the function call.
1137  * @return The length of the result string. It may be greater than destCapacity. In that case,
1138  *         only some of the result was written to the destination buffer.
1139  * @stable ICU 2.1
1140  */
1141 U_STABLE int32_t U_EXPORT2
1142 u_strToTitle(UChar *dest, int32_t destCapacity,
1143              const UChar *src, int32_t srcLength,
1144              UBreakIterator *titleIter,
1145              const char *locale,
1146              UErrorCode *pErrorCode);
1147 
1148 #endif
1149 
1150 /**
1151  * Case-folds the characters in a string.
1152  *
1153  * Case-folding is locale-independent and not context-sensitive,
1154  * but there is an option for whether to include or exclude mappings for dotted I
1155  * and dotless i that are marked with 'T' in CaseFolding.txt.
1156  *
1157  * The result may be longer or shorter than the original.
1158  * The source string and the destination buffer are allowed to overlap.
1159  *
1160  * @param dest      A buffer for the result string. The result will be zero-terminated if
1161  *                  the buffer is large enough.
1162  * @param destCapacity The size of the buffer (number of UChars). If it is 0, then
1163  *                  dest may be NULL and the function will only return the length of the result
1164  *                  without writing any of the result string.
1165  * @param src       The original string
1166  * @param srcLength The length of the original string. If -1, then src must be zero-terminated.
1167  * @param options   Either U_FOLD_CASE_DEFAULT or U_FOLD_CASE_EXCLUDE_SPECIAL_I
1168  * @param pErrorCode Must be a valid pointer to an error code value,
1169  *                  which must not indicate a failure before the function call.
1170  * @return The length of the result string. It may be greater than destCapacity. In that case,
1171  *         only some of the result was written to the destination buffer.
1172  * @stable ICU 2.0
1173  */
1174 U_STABLE int32_t U_EXPORT2
1175 u_strFoldCase(UChar *dest, int32_t destCapacity,
1176               const UChar *src, int32_t srcLength,
1177               uint32_t options,
1178               UErrorCode *pErrorCode);
1179 
1180 #if defined(U_WCHAR_IS_UTF16) || defined(U_WCHAR_IS_UTF32) || !UCONFIG_NO_CONVERSION
1181 /**
1182  * Convert a UTF-16 string to a wchar_t string.
1183  * If it is known at compile time that wchar_t strings are in UTF-16 or UTF-32, then
1184  * this function simply calls the fast, dedicated function for that.
1185  * Otherwise, two conversions UTF-16 -> default charset -> wchar_t* are performed.
1186  *
1187  * @param dest          A buffer for the result string. The result will be zero-terminated if
1188  *                      the buffer is large enough.
1189  * @param destCapacity  The size of the buffer (number of wchar_t's). If it is 0, then
1190  *                      dest may be NULL and the function will only return the length of the
1191  *                      result without writing any of the result string (pre-flighting).
1192  * @param pDestLength   A pointer to receive the number of units written to the destination. If
1193  *                      pDestLength!=NULL then *pDestLength is always set to the
1194  *                      number of output units corresponding to the transformation of
1195  *                      all the input units, even in case of a buffer overflow.
1196  * @param src           The original source string
1197  * @param srcLength     The length of the original string. If -1, then src must be zero-terminated.
1198  * @param pErrorCode    Must be a valid pointer to an error code value,
1199  *                      which must not indicate a failure before the function call.
1200  * @return The pointer to destination buffer.
1201  * @stable ICU 2.0
1202  */
1203 U_STABLE wchar_t* U_EXPORT2
1204 u_strToWCS(wchar_t *dest,
1205            int32_t destCapacity,
1206            int32_t *pDestLength,
1207            const UChar *src,
1208            int32_t srcLength,
1209            UErrorCode *pErrorCode);
1210 /**
1211  * Convert a wchar_t string to UTF-16.
1212  * If it is known at compile time that wchar_t strings are in UTF-16 or UTF-32, then
1213  * this function simply calls the fast, dedicated function for that.
1214  * Otherwise, two conversions wchar_t* -> default charset -> UTF-16 are performed.
1215  *
1216  * @param dest          A buffer for the result string. The result will be zero-terminated if
1217  *                      the buffer is large enough.
1218  * @param destCapacity  The size of the buffer (number of UChars). If it is 0, then
1219  *                      dest may be NULL and the function will only return the length of the
1220  *                      result without writing any of the result string (pre-flighting).
1221  * @param pDestLength   A pointer to receive the number of units written to the destination. If
1222  *                      pDestLength!=NULL then *pDestLength is always set to the
1223  *                      number of output units corresponding to the transformation of
1224  *                      all the input units, even in case of a buffer overflow.
1225  * @param src           The original source string
1226  * @param srcLength     The length of the original string. If -1, then src must be zero-terminated.
1227  * @param pErrorCode    Must be a valid pointer to an error code value,
1228  *                      which must not indicate a failure before the function call.
1229  * @return The pointer to destination buffer.
1230  * @stable ICU 2.0
1231  */
1232 U_STABLE UChar* U_EXPORT2
1233 u_strFromWCS(UChar   *dest,
1234              int32_t destCapacity,
1235              int32_t *pDestLength,
1236              const wchar_t *src,
1237              int32_t srcLength,
1238              UErrorCode *pErrorCode);
1239 #endif /* defined(U_WCHAR_IS_UTF16) || defined(U_WCHAR_IS_UTF32) || !UCONFIG_NO_CONVERSION */
1240 
1241 /**
1242  * Convert a UTF-16 string to UTF-8.
1243  * If the input string is not well-formed, then the U_INVALID_CHAR_FOUND error code is set.
1244  *
1245  * @param dest          A buffer for the result string. The result will be zero-terminated if
1246  *                      the buffer is large enough.
1247  * @param destCapacity  The size of the buffer (number of chars). If it is 0, then
1248  *                      dest may be NULL and the function will only return the length of the
1249  *                      result without writing any of the result string (pre-flighting).
1250  * @param pDestLength   A pointer to receive the number of units written to the destination. If
1251  *                      pDestLength!=NULL then *pDestLength is always set to the
1252  *                      number of output units corresponding to the transformation of
1253  *                      all the input units, even in case of a buffer overflow.
1254  * @param src           The original source string
1255  * @param srcLength     The length of the original string. If -1, then src must be zero-terminated.
1256  * @param pErrorCode    Must be a valid pointer to an error code value,
1257  *                      which must not indicate a failure before the function call.
1258  * @return The pointer to destination buffer.
1259  * @stable ICU 2.0
1260  * @see u_strToUTF8WithSub
1261  * @see u_strFromUTF8
1262  */
1263 U_STABLE char* U_EXPORT2
1264 u_strToUTF8(char *dest,
1265             int32_t destCapacity,
1266             int32_t *pDestLength,
1267             const UChar *src,
1268             int32_t srcLength,
1269             UErrorCode *pErrorCode);
1270 
1271 /**
1272  * Convert a UTF-8 string to UTF-16.
1273  * If the input string is not well-formed, then the U_INVALID_CHAR_FOUND error code is set.
1274  *
1275  * @param dest          A buffer for the result string. The result will be zero-terminated if
1276  *                      the buffer is large enough.
1277  * @param destCapacity  The size of the buffer (number of UChars). If it is 0, then
1278  *                      dest may be NULL and the function will only return the length of the
1279  *                      result without writing any of the result string (pre-flighting).
1280  * @param pDestLength   A pointer to receive the number of units written to the destination. If
1281  *                      pDestLength!=NULL then *pDestLength is always set to the
1282  *                      number of output units corresponding to the transformation of
1283  *                      all the input units, even in case of a buffer overflow.
1284  * @param src           The original source string
1285  * @param srcLength     The length of the original string. If -1, then src must be zero-terminated.
1286  * @param pErrorCode    Must be a valid pointer to an error code value,
1287  *                      which must not indicate a failure before the function call.
1288  * @return The pointer to destination buffer.
1289  * @stable ICU 2.0
1290  * @see u_strFromUTF8WithSub
1291  * @see u_strFromUTF8Lenient
1292  */
1293 U_STABLE UChar* U_EXPORT2
1294 u_strFromUTF8(UChar *dest,
1295               int32_t destCapacity,
1296               int32_t *pDestLength,
1297               const char *src,
1298               int32_t srcLength,
1299               UErrorCode *pErrorCode);
1300 
1301 /**
1302  * Convert a UTF-16 string to UTF-8.
1303  *
1304  * Same as u_strToUTF8() except for the additional subchar which is output for
1305  * illegal input sequences, instead of stopping with the U_INVALID_CHAR_FOUND error code.
1306  * With subchar==U_SENTINEL, this function behaves exactly like u_strToUTF8().
1307  *
1308  * @param dest          A buffer for the result string. The result will be zero-terminated if
1309  *                      the buffer is large enough.
1310  * @param destCapacity  The size of the buffer (number of chars). If it is 0, then
1311  *                      dest may be NULL and the function will only return the length of the
1312  *                      result without writing any of the result string (pre-flighting).
1313  * @param pDestLength   A pointer to receive the number of units written to the destination. If
1314  *                      pDestLength!=NULL then *pDestLength is always set to the
1315  *                      number of output units corresponding to the transformation of
1316  *                      all the input units, even in case of a buffer overflow.
1317  * @param src           The original source string
1318  * @param srcLength     The length of the original string. If -1, then src must be zero-terminated.
1319  * @param subchar       The substitution character to use in place of an illegal input sequence,
1320  *                      or U_SENTINEL if the function is to return with U_INVALID_CHAR_FOUND instead.
1321  *                      A substitution character can be any valid Unicode code point (up to U+10FFFF)
1322  *                      except for surrogate code points (U+D800..U+DFFF).
1323  *                      The recommended value is U+FFFD "REPLACEMENT CHARACTER".
1324  * @param pNumSubstitutions Output parameter receiving the number of substitutions if subchar>=0.
1325  *                      Set to 0 if no substitutions occur or subchar<0.
1326  *                      pNumSubstitutions can be NULL.
1327  * @param pErrorCode    Pointer to a standard ICU error code. Its input value must
1328  *                      pass the U_SUCCESS() test, or else the function returns
1329  *                      immediately. Check for U_FAILURE() on output or use with
1330  *                      function chaining. (See User Guide for details.)
1331  * @return The pointer to destination buffer.
1332  * @see u_strToUTF8
1333  * @see u_strFromUTF8WithSub
1334  * @stable ICU 3.6
1335  */
1336 U_STABLE char* U_EXPORT2
1337 u_strToUTF8WithSub(char *dest,
1338             int32_t destCapacity,
1339             int32_t *pDestLength,
1340             const UChar *src,
1341             int32_t srcLength,
1342             UChar32 subchar, int32_t *pNumSubstitutions,
1343             UErrorCode *pErrorCode);
1344 
1345 /**
1346  * Convert a UTF-8 string to UTF-16.
1347  *
1348  * Same as u_strFromUTF8() except for the additional subchar which is output for
1349  * illegal input sequences, instead of stopping with the U_INVALID_CHAR_FOUND error code.
1350  * With subchar==U_SENTINEL, this function behaves exactly like u_strFromUTF8().
1351  *
1352  * @param dest          A buffer for the result string. The result will be zero-terminated if
1353  *                      the buffer is large enough.
1354  * @param destCapacity  The size of the buffer (number of UChars). If it is 0, then
1355  *                      dest may be NULL and the function will only return the length of the
1356  *                      result without writing any of the result string (pre-flighting).
1357  * @param pDestLength   A pointer to receive the number of units written to the destination. If
1358  *                      pDestLength!=NULL then *pDestLength is always set to the
1359  *                      number of output units corresponding to the transformation of
1360  *                      all the input units, even in case of a buffer overflow.
1361  * @param src           The original source string
1362  * @param srcLength     The length of the original string. If -1, then src must be zero-terminated.
1363  * @param subchar       The substitution character to use in place of an illegal input sequence,
1364  *                      or U_SENTINEL if the function is to return with U_INVALID_CHAR_FOUND instead.
1365  *                      A substitution character can be any valid Unicode code point (up to U+10FFFF)
1366  *                      except for surrogate code points (U+D800..U+DFFF).
1367  *                      The recommended value is U+FFFD "REPLACEMENT CHARACTER".
1368  * @param pNumSubstitutions Output parameter receiving the number of substitutions if subchar>=0.
1369  *                      Set to 0 if no substitutions occur or subchar<0.
1370  *                      pNumSubstitutions can be NULL.
1371  * @param pErrorCode    Pointer to a standard ICU error code. Its input value must
1372  *                      pass the U_SUCCESS() test, or else the function returns
1373  *                      immediately. Check for U_FAILURE() on output or use with
1374  *                      function chaining. (See User Guide for details.)
1375  * @return The pointer to destination buffer.
1376  * @see u_strFromUTF8
1377  * @see u_strFromUTF8Lenient
1378  * @see u_strToUTF8WithSub
1379  * @stable ICU 3.6
1380  */
1381 U_STABLE UChar* U_EXPORT2
1382 u_strFromUTF8WithSub(UChar *dest,
1383               int32_t destCapacity,
1384               int32_t *pDestLength,
1385               const char *src,
1386               int32_t srcLength,
1387               UChar32 subchar, int32_t *pNumSubstitutions,
1388               UErrorCode *pErrorCode);
1389 
1390 /**
1391  * Convert a UTF-8 string to UTF-16.
1392  *
1393  * Same as u_strFromUTF8() except that this function is designed to be very fast,
1394  * which it achieves by being lenient about malformed UTF-8 sequences.
1395  * This function is intended for use in environments where UTF-8 text is
1396  * expected to be well-formed.
1397  *
1398  * Its semantics are:
1399  * - Well-formed UTF-8 text is correctly converted to well-formed UTF-16 text.
1400  * - The function will not read beyond the input string, nor write beyond
1401  *   the destCapacity.
1402  * - Malformed UTF-8 results in "garbage" 16-bit Unicode strings which may not
1403  *   be well-formed UTF-16.
1404  *   The function will resynchronize to valid code point boundaries
1405  *   within a small number of code points after an illegal sequence.
1406  * - Non-shortest forms are not detected and will result in "spoofing" output.
1407  *
1408  * For further performance improvement, if srcLength is given (>=0),
1409  * then it must be destCapacity>=srcLength.
1410  *
1411  * There is no inverse u_strToUTF8Lenient() function because there is practically
1412  * no performance gain from not checking that a UTF-16 string is well-formed.
1413  *
1414  * @param dest          A buffer for the result string. The result will be zero-terminated if
1415  *                      the buffer is large enough.
1416  * @param destCapacity  The size of the buffer (number of UChars). If it is 0, then
1417  *                      dest may be NULL and the function will only return the length of the
1418  *                      result without writing any of the result string (pre-flighting).
1419  *                      Unlike for other ICU functions, if srcLength>=0 then it
1420  *                      must be destCapacity>=srcLength.
1421  * @param pDestLength   A pointer to receive the number of units written to the destination. If
1422  *                      pDestLength!=NULL then *pDestLength is always set to the
1423  *                      number of output units corresponding to the transformation of
1424  *                      all the input units, even in case of a buffer overflow.
1425  *                      Unlike for other ICU functions, if srcLength>=0 but
1426  *                      destCapacity<srcLength, then *pDestLength will be set to srcLength
1427  *                      (and U_BUFFER_OVERFLOW_ERROR will be set)
1428  *                      regardless of the actual result length.
1429  * @param src           The original source string
1430  * @param srcLength     The length of the original string. If -1, then src must be zero-terminated.
1431  * @param pErrorCode    Pointer to a standard ICU error code. Its input value must
1432  *                      pass the U_SUCCESS() test, or else the function returns
1433  *                      immediately. Check for U_FAILURE() on output or use with
1434  *                      function chaining. (See User Guide for details.)
1435  * @return The pointer to destination buffer.
1436  * @see u_strFromUTF8
1437  * @see u_strFromUTF8WithSub
1438  * @see u_strToUTF8WithSub
1439  * @stable ICU 3.6
1440  */
1441 U_STABLE UChar * U_EXPORT2
1442 u_strFromUTF8Lenient(UChar *dest,
1443                      int32_t destCapacity,
1444                      int32_t *pDestLength,
1445                      const char *src,
1446                      int32_t srcLength,
1447                      UErrorCode *pErrorCode);
1448 
1449 /**
1450  * Convert a UTF-16 string to UTF-32.
1451  * If the input string is not well-formed, then the U_INVALID_CHAR_FOUND error code is set.
1452  *
1453  * @param dest          A buffer for the result string. The result will be zero-terminated if
1454  *                      the buffer is large enough.
1455  * @param destCapacity  The size of the buffer (number of UChar32s). If it is 0, then
1456  *                      dest may be NULL and the function will only return the length of the
1457  *                      result without writing any of the result string (pre-flighting).
1458  * @param pDestLength   A pointer to receive the number of units written to the destination. If
1459  *                      pDestLength!=NULL then *pDestLength is always set to the
1460  *                      number of output units corresponding to the transformation of
1461  *                      all the input units, even in case of a buffer overflow.
1462  * @param src           The original source string
1463  * @param srcLength     The length of the original string. If -1, then src must be zero-terminated.
1464  * @param pErrorCode    Must be a valid pointer to an error code value,
1465  *                      which must not indicate a failure before the function call.
1466  * @return The pointer to destination buffer.
1467  * @see u_strToUTF32WithSub
1468  * @see u_strFromUTF32
1469  * @stable ICU 2.0
1470  */
1471 U_STABLE UChar32* U_EXPORT2
1472 u_strToUTF32(UChar32 *dest,
1473              int32_t  destCapacity,
1474              int32_t  *pDestLength,
1475              const UChar *src,
1476              int32_t  srcLength,
1477              UErrorCode *pErrorCode);
1478 
1479 /**
1480  * Convert a UTF-32 string to UTF-16.
1481  * If the input string is not well-formed, then the U_INVALID_CHAR_FOUND error code is set.
1482  *
1483  * @param dest          A buffer for the result string. The result will be zero-terminated if
1484  *                      the buffer is large enough.
1485  * @param destCapacity  The size of the buffer (number of UChars). If it is 0, then
1486  *                      dest may be NULL and the function will only return the length of the
1487  *                      result without writing any of the result string (pre-flighting).
1488  * @param pDestLength   A pointer to receive the number of units written to the destination. If
1489  *                      pDestLength!=NULL then *pDestLength is always set to the
1490  *                      number of output units corresponding to the transformation of
1491  *                      all the input units, even in case of a buffer overflow.
1492  * @param src           The original source string
1493  * @param srcLength     The length of the original string. If -1, then src must be zero-terminated.
1494  * @param pErrorCode    Must be a valid pointer to an error code value,
1495  *                      which must not indicate a failure before the function call.
1496  * @return The pointer to destination buffer.
1497  * @see u_strFromUTF32WithSub
1498  * @see u_strToUTF32
1499  * @stable ICU 2.0
1500  */
1501 U_STABLE UChar* U_EXPORT2
1502 u_strFromUTF32(UChar   *dest,
1503                int32_t destCapacity,
1504                int32_t *pDestLength,
1505                const UChar32 *src,
1506                int32_t srcLength,
1507                UErrorCode *pErrorCode);
1508 
1509 /**
1510  * Convert a UTF-16 string to UTF-32.
1511  *
1512  * Same as u_strToUTF32() except for the additional subchar which is output for
1513  * illegal input sequences, instead of stopping with the U_INVALID_CHAR_FOUND error code.
1514  * With subchar==U_SENTINEL, this function behaves exactly like u_strToUTF32().
1515  *
1516  * @param dest          A buffer for the result string. The result will be zero-terminated if
1517  *                      the buffer is large enough.
1518  * @param destCapacity  The size of the buffer (number of UChar32s). If it is 0, then
1519  *                      dest may be NULL and the function will only return the length of the
1520  *                      result without writing any of the result string (pre-flighting).
1521  * @param pDestLength   A pointer to receive the number of units written to the destination. If
1522  *                      pDestLength!=NULL then *pDestLength is always set to the
1523  *                      number of output units corresponding to the transformation of
1524  *                      all the input units, even in case of a buffer overflow.
1525  * @param src           The original source string
1526  * @param srcLength     The length of the original string. If -1, then src must be zero-terminated.
1527  * @param subchar       The substitution character to use in place of an illegal input sequence,
1528  *                      or U_SENTINEL if the function is to return with U_INVALID_CHAR_FOUND instead.
1529  *                      A substitution character can be any valid Unicode code point (up to U+10FFFF)
1530  *                      except for surrogate code points (U+D800..U+DFFF).
1531  *                      The recommended value is U+FFFD "REPLACEMENT CHARACTER".
1532  * @param pNumSubstitutions Output parameter receiving the number of substitutions if subchar>=0.
1533  *                      Set to 0 if no substitutions occur or subchar<0.
1534  *                      pNumSubstitutions can be NULL.
1535  * @param pErrorCode    Pointer to a standard ICU error code. Its input value must
1536  *                      pass the U_SUCCESS() test, or else the function returns
1537  *                      immediately. Check for U_FAILURE() on output or use with
1538  *                      function chaining. (See User Guide for details.)
1539  * @return The pointer to destination buffer.
1540  * @see u_strToUTF32
1541  * @see u_strFromUTF32WithSub
1542  * @stable ICU 4.2
1543  */
1544 U_STABLE UChar32* U_EXPORT2
1545 u_strToUTF32WithSub(UChar32 *dest,
1546              int32_t destCapacity,
1547              int32_t *pDestLength,
1548              const UChar *src,
1549              int32_t srcLength,
1550              UChar32 subchar, int32_t *pNumSubstitutions,
1551              UErrorCode *pErrorCode);
1552 
1553 /**
1554  * Convert a UTF-32 string to UTF-16.
1555  *
1556  * Same as u_strFromUTF32() except for the additional subchar which is output for
1557  * illegal input sequences, instead of stopping with the U_INVALID_CHAR_FOUND error code.
1558  * With subchar==U_SENTINEL, this function behaves exactly like u_strFromUTF32().
1559  *
1560  * @param dest          A buffer for the result string. The result will be zero-terminated if
1561  *                      the buffer is large enough.
1562  * @param destCapacity  The size of the buffer (number of UChars). If it is 0, then
1563  *                      dest may be NULL and the function will only return the length of the
1564  *                      result without writing any of the result string (pre-flighting).
1565  * @param pDestLength   A pointer to receive the number of units written to the destination. If
1566  *                      pDestLength!=NULL then *pDestLength is always set to the
1567  *                      number of output units corresponding to the transformation of
1568  *                      all the input units, even in case of a buffer overflow.
1569  * @param src           The original source string
1570  * @param srcLength     The length of the original string. If -1, then src must be zero-terminated.
1571  * @param subchar       The substitution character to use in place of an illegal input sequence,
1572  *                      or U_SENTINEL if the function is to return with U_INVALID_CHAR_FOUND instead.
1573  *                      A substitution character can be any valid Unicode code point (up to U+10FFFF)
1574  *                      except for surrogate code points (U+D800..U+DFFF).
1575  *                      The recommended value is U+FFFD "REPLACEMENT CHARACTER".
1576  * @param pNumSubstitutions Output parameter receiving the number of substitutions if subchar>=0.
1577  *                      Set to 0 if no substitutions occur or subchar<0.
1578  *                      pNumSubstitutions can be NULL.
1579  * @param pErrorCode    Pointer to a standard ICU error code. Its input value must
1580  *                      pass the U_SUCCESS() test, or else the function returns
1581  *                      immediately. Check for U_FAILURE() on output or use with
1582  *                      function chaining. (See User Guide for details.)
1583  * @return The pointer to destination buffer.
1584  * @see u_strFromUTF32
1585  * @see u_strToUTF32WithSub
1586  * @stable ICU 4.2
1587  */
1588 U_STABLE UChar* U_EXPORT2
1589 u_strFromUTF32WithSub(UChar *dest,
1590                int32_t destCapacity,
1591                int32_t *pDestLength,
1592                const UChar32 *src,
1593                int32_t srcLength,
1594                UChar32 subchar, int32_t *pNumSubstitutions,
1595                UErrorCode *pErrorCode);
1596 
1597 /**
1598  * Convert a 16-bit Unicode string to Java Modified UTF-8.
1599  * See http://java.sun.com/javase/6/docs/api/java/io/DataInput.html#modified-utf-8
1600  *
1601  * This function behaves according to the documentation for Java DataOutput.writeUTF()
1602  * except that it does not encode the output length in the destination buffer
1603  * and does not have an output length restriction.
1604  * See http://java.sun.com/javase/6/docs/api/java/io/DataOutput.html#writeUTF(java.lang.String)
1605  *
1606  * The input string need not be well-formed UTF-16.
1607  * (Therefore there is no subchar parameter.)
1608  *
1609  * @param dest          A buffer for the result string. The result will be zero-terminated if
1610  *                      the buffer is large enough.
1611  * @param destCapacity  The size of the buffer (number of chars). If it is 0, then
1612  *                      dest may be NULL and the function will only return the length of the
1613  *                      result without writing any of the result string (pre-flighting).
1614  * @param pDestLength   A pointer to receive the number of units written to the destination. If
1615  *                      pDestLength!=NULL then *pDestLength is always set to the
1616  *                      number of output units corresponding to the transformation of
1617  *                      all the input units, even in case of a buffer overflow.
1618  * @param src           The original source string
1619  * @param srcLength     The length of the original string. If -1, then src must be zero-terminated.
1620  * @param pErrorCode    Pointer to a standard ICU error code. Its input value must
1621  *                      pass the U_SUCCESS() test, or else the function returns
1622  *                      immediately. Check for U_FAILURE() on output or use with
1623  *                      function chaining. (See User Guide for details.)
1624  * @return The pointer to destination buffer.
1625  * @stable ICU 4.4
1626  * @see u_strToUTF8WithSub
1627  * @see u_strFromJavaModifiedUTF8WithSub
1628  */
1629 U_STABLE char* U_EXPORT2
1630 u_strToJavaModifiedUTF8(
1631         char *dest,
1632         int32_t destCapacity,
1633         int32_t *pDestLength,
1634         const UChar *src,
1635         int32_t srcLength,
1636         UErrorCode *pErrorCode);
1637 
1638 /**
1639  * Convert a Java Modified UTF-8 string to a 16-bit Unicode string.
1640  * If the input string is not well-formed and no substitution char is specified,
1641  * then the U_INVALID_CHAR_FOUND error code is set.
1642  *
1643  * This function behaves according to the documentation for Java DataInput.readUTF()
1644  * except that it takes a length parameter rather than
1645  * interpreting the first two input bytes as the length.
1646  * See http://java.sun.com/javase/6/docs/api/java/io/DataInput.html#readUTF()
1647  *
1648  * The output string may not be well-formed UTF-16.
1649  *
1650  * @param dest          A buffer for the result string. The result will be zero-terminated if
1651  *                      the buffer is large enough.
1652  * @param destCapacity  The size of the buffer (number of UChars). If it is 0, then
1653  *                      dest may be NULL and the function will only return the length of the
1654  *                      result without writing any of the result string (pre-flighting).
1655  * @param pDestLength   A pointer to receive the number of units written to the destination. If
1656  *                      pDestLength!=NULL then *pDestLength is always set to the
1657  *                      number of output units corresponding to the transformation of
1658  *                      all the input units, even in case of a buffer overflow.
1659  * @param src           The original source string
1660  * @param srcLength     The length of the original string. If -1, then src must be zero-terminated.
1661  * @param subchar       The substitution character to use in place of an illegal input sequence,
1662  *                      or U_SENTINEL if the function is to return with U_INVALID_CHAR_FOUND instead.
1663  *                      A substitution character can be any valid Unicode code point (up to U+10FFFF)
1664  *                      except for surrogate code points (U+D800..U+DFFF).
1665  *                      The recommended value is U+FFFD "REPLACEMENT CHARACTER".
1666  * @param pNumSubstitutions Output parameter receiving the number of substitutions if subchar>=0.
1667  *                      Set to 0 if no substitutions occur or subchar<0.
1668  *                      pNumSubstitutions can be NULL.
1669  * @param pErrorCode    Pointer to a standard ICU error code. Its input value must
1670  *                      pass the U_SUCCESS() test, or else the function returns
1671  *                      immediately. Check for U_FAILURE() on output or use with
1672  *                      function chaining. (See User Guide for details.)
1673  * @return The pointer to destination buffer.
1674  * @see u_strFromUTF8WithSub
1675  * @see u_strFromUTF8Lenient
1676  * @see u_strToJavaModifiedUTF8
1677  * @stable ICU 4.4
1678  */
1679 U_STABLE UChar* U_EXPORT2
1680 u_strFromJavaModifiedUTF8WithSub(
1681         UChar *dest,
1682         int32_t destCapacity,
1683         int32_t *pDestLength,
1684         const char *src,
1685         int32_t srcLength,
1686         UChar32 subchar, int32_t *pNumSubstitutions,
1687         UErrorCode *pErrorCode);
1688 
1689 #endif
1690