xref: /aosp_15_r20/external/icu/libicu/cts_headers/unicode/locid.h (revision 0e209d3975ff4a8c132096b14b0e9364a753506e)
1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /*
4 ******************************************************************************
5 *
6 *   Copyright (C) 1996-2015, International Business Machines
7 *   Corporation and others.  All Rights Reserved.
8 *
9 ******************************************************************************
10 *
11 * File locid.h
12 *
13 * Created by: Helena Shih
14 *
15 * Modification History:
16 *
17 *   Date        Name        Description
18 *   02/11/97    aliu        Changed gLocPath to fgLocPath and added methods to
19 *                           get and set it.
20 *   04/02/97    aliu        Made operator!= inline; fixed return value of getName().
21 *   04/15/97    aliu        Cleanup for AIX/Win32.
22 *   04/24/97    aliu        Numerous changes per code review.
23 *   08/18/98    stephen     Added tokenizeString(),changed getDisplayName()
24 *   09/08/98    stephen     Moved definition of kEmptyString for Mac Port
25 *   11/09/99    weiv        Added const char * getName() const;
26 *   04/12/00    srl         removing unicodestring api's and cached hash code
27 *   08/10/01    grhoten     Change the static Locales to accessor functions
28 ******************************************************************************
29 */
30 
31 #ifndef LOCID_H
32 #define LOCID_H
33 
34 #include "unicode/utypes.h"
35 
36 #if U_SHOW_CPLUSPLUS_API
37 
38 #include "unicode/bytestream.h"
39 #include "unicode/localpointer.h"
40 #include "unicode/strenum.h"
41 #include "unicode/stringpiece.h"
42 #include "unicode/uobject.h"
43 #include "unicode/putil.h"
44 #include "unicode/uloc.h"
45 
46 /**
47  * \file
48  * \brief C++ API: Locale ID object.
49  */
50 
51 U_NAMESPACE_BEGIN
52 
53 // Forward Declarations
54 void U_CALLCONV locale_available_init(); /**< @internal */
55 
56 class StringEnumeration;
57 class UnicodeString;
58 
59 /**
60  * A <code>Locale</code> object represents a specific geographical, political,
61  * or cultural region. An operation that requires a <code>Locale</code> to perform
62  * its task is called <em>locale-sensitive</em> and uses the <code>Locale</code>
63  * to tailor information for the user. For example, displaying a number
64  * is a locale-sensitive operation--the number should be formatted
65  * according to the customs/conventions of the user's native country,
66  * region, or culture.
67  *
68  * The Locale class is not suitable for subclassing.
69  *
70  * <P>
71  * You can create a <code>Locale</code> object using the constructor in
72  * this class:
73  * \htmlonly<blockquote>\endhtmlonly
74  * <pre>
75  *       Locale( const   char*  language,
76  *               const   char*  country,
77  *               const   char*  variant);
78  * </pre>
79  * \htmlonly</blockquote>\endhtmlonly
80  * The first argument to the constructors is a valid <STRONG>ISO
81  * Language Code.</STRONG> These codes are the lower-case two-letter
82  * codes as defined by ISO-639.
83  * You can find a full list of these codes at:
84  * <BR><a href ="http://www.loc.gov/standards/iso639-2/">
85  * http://www.loc.gov/standards/iso639-2/</a>
86  *
87  * <P>
88  * The second argument to the constructors is a valid <STRONG>ISO Country
89  * Code.</STRONG> These codes are the upper-case two-letter codes
90  * as defined by ISO-3166.
91  * You can find a full list of these codes at a number of sites, such as:
92  * <BR><a href="http://www.iso.org/iso/en/prods-services/iso3166ma/index.html">
93  * http://www.iso.org/iso/en/prods-services/iso3166ma/index.html</a>
94  *
95  * <P>
96  * The third constructor requires a third argument--the <STRONG>Variant.</STRONG>
97  * The Variant codes are vendor and browser-specific.
98  * For example, use REVISED for a language's revised script orthography, and POSIX for POSIX.
99  * Where there are two variants, separate them with an underscore, and
100  * put the most important one first. For
101  * example, a Traditional Spanish collation might be referenced, with
102  * "ES", "ES", "Traditional_POSIX".
103  *
104  * <P>
105  * Because a <code>Locale</code> object is just an identifier for a region,
106  * no validity check is performed when you construct a <code>Locale</code>.
107  * If you want to see whether particular resources are available for the
108  * <code>Locale</code> you construct, you must query those resources. For
109  * example, ask the <code>NumberFormat</code> for the locales it supports
110  * using its <code>getAvailableLocales</code> method.
111  * <BR><STRONG>Note:</STRONG> When you ask for a resource for a particular
112  * locale, you get back the best available match, not necessarily
113  * precisely what you asked for. For more information, look at
114  * <code>ResourceBundle</code>.
115  *
116  * <P>
117  * The <code>Locale</code> class provides a number of convenient constants
118  * that you can use to create <code>Locale</code> objects for commonly used
119  * locales. For example, the following refers to a <code>Locale</code> object
120  * for the United States:
121  * \htmlonly<blockquote>\endhtmlonly
122  * <pre>
123  *       Locale::getUS()
124  * </pre>
125  * \htmlonly</blockquote>\endhtmlonly
126  *
127  * <P>
128  * Once you've created a <code>Locale</code> you can query it for information about
129  * itself. Use <code>getCountry</code> to get the ISO Country Code and
130  * <code>getLanguage</code> to get the ISO Language Code. You can
131  * use <code>getDisplayCountry</code> to get the
132  * name of the country suitable for displaying to the user. Similarly,
133  * you can use <code>getDisplayLanguage</code> to get the name of
134  * the language suitable for displaying to the user. Interestingly,
135  * the <code>getDisplayXXX</code> methods are themselves locale-sensitive
136  * and have two versions: one that uses the default locale and one
137  * that takes a locale as an argument and displays the name or country in
138  * a language appropriate to that locale.
139  *
140  * <P>
141  * ICU provides a number of classes that perform locale-sensitive
142  * operations. For example, the <code>NumberFormat</code> class formats
143  * numbers, currency, or percentages in a locale-sensitive manner. Classes
144  * such as <code>NumberFormat</code> have a number of convenience methods
145  * for creating a default object of that type. For example, the
146  * <code>NumberFormat</code> class provides these three convenience methods
147  * for creating a default <code>NumberFormat</code> object:
148  * \htmlonly<blockquote>\endhtmlonly
149  * <pre>
150  *     UErrorCode success = U_ZERO_ERROR;
151  *     Locale myLocale;
152  *     NumberFormat *nf;
153  *
154  *     nf = NumberFormat::createInstance( success );          delete nf;
155  *     nf = NumberFormat::createCurrencyInstance( success );  delete nf;
156  *     nf = NumberFormat::createPercentInstance( success );   delete nf;
157  * </pre>
158  * \htmlonly</blockquote>\endhtmlonly
159  * Each of these methods has two variants; one with an explicit locale
160  * and one without; the latter using the default locale.
161  * \htmlonly<blockquote>\endhtmlonly
162  * <pre>
163  *     nf = NumberFormat::createInstance( myLocale, success );          delete nf;
164  *     nf = NumberFormat::createCurrencyInstance( myLocale, success );  delete nf;
165  *     nf = NumberFormat::createPercentInstance( myLocale, success );   delete nf;
166  * </pre>
167  * \htmlonly</blockquote>\endhtmlonly
168  * A <code>Locale</code> is the mechanism for identifying the kind of object
169  * (<code>NumberFormat</code>) that you would like to get. The locale is
170  * <STRONG>just</STRONG> a mechanism for identifying objects,
171  * <STRONG>not</STRONG> a container for the objects themselves.
172  *
173  * <P>
174  * Each class that performs locale-sensitive operations allows you
175  * to get all the available objects of that type. You can sift
176  * through these objects by language, country, or variant,
177  * and use the display names to present a menu to the user.
178  * For example, you can create a menu of all the collation objects
179  * suitable for a given language. Such classes implement these
180  * three class methods:
181  * \htmlonly<blockquote>\endhtmlonly
182  * <pre>
183  *       static Locale* getAvailableLocales(int32_t& numLocales)
184  *       static UnicodeString& getDisplayName(const Locale&  objectLocale,
185  *                                            const Locale&  displayLocale,
186  *                                            UnicodeString& displayName)
187  *       static UnicodeString& getDisplayName(const Locale&  objectLocale,
188  *                                            UnicodeString& displayName)
189  * </pre>
190  * \htmlonly</blockquote>\endhtmlonly
191  *
192  * @stable ICU 2.0
193  * @see ResourceBundle
194  */
195 class U_COMMON_API Locale : public UObject {
196 public:
197     /** Useful constant for the Root locale. @stable ICU 4.4 */
198     static const Locale& U_EXPORT2 getRoot();
199     /** Useful constant for this language. @stable ICU 2.0 */
200     static const Locale& U_EXPORT2 getEnglish();
201     /** Useful constant for this language. @stable ICU 2.0 */
202     static const Locale& U_EXPORT2 getFrench();
203     /** Useful constant for this language. @stable ICU 2.0 */
204     static const Locale& U_EXPORT2 getGerman();
205     /** Useful constant for this language. @stable ICU 2.0 */
206     static const Locale& U_EXPORT2 getItalian();
207     /** Useful constant for this language. @stable ICU 2.0 */
208     static const Locale& U_EXPORT2 getJapanese();
209     /** Useful constant for this language. @stable ICU 2.0 */
210     static const Locale& U_EXPORT2 getKorean();
211     /** Useful constant for this language. @stable ICU 2.0 */
212     static const Locale& U_EXPORT2 getChinese();
213     /** Useful constant for this language. @stable ICU 2.0 */
214     static const Locale& U_EXPORT2 getSimplifiedChinese();
215     /** Useful constant for this language. @stable ICU 2.0 */
216     static const Locale& U_EXPORT2 getTraditionalChinese();
217 
218     /** Useful constant for this country/region. @stable ICU 2.0 */
219     static const Locale& U_EXPORT2 getFrance();
220     /** Useful constant for this country/region. @stable ICU 2.0 */
221     static const Locale& U_EXPORT2 getGermany();
222     /** Useful constant for this country/region. @stable ICU 2.0 */
223     static const Locale& U_EXPORT2 getItaly();
224     /** Useful constant for this country/region. @stable ICU 2.0 */
225     static const Locale& U_EXPORT2 getJapan();
226     /** Useful constant for this country/region. @stable ICU 2.0 */
227     static const Locale& U_EXPORT2 getKorea();
228     /** Useful constant for this country/region. @stable ICU 2.0 */
229     static const Locale& U_EXPORT2 getChina();
230     /** Useful constant for this country/region. @stable ICU 2.0 */
231     static const Locale& U_EXPORT2 getPRC();
232     /** Useful constant for this country/region. @stable ICU 2.0 */
233     static const Locale& U_EXPORT2 getTaiwan();
234     /** Useful constant for this country/region. @stable ICU 2.0 */
235     static const Locale& U_EXPORT2 getUK();
236     /** Useful constant for this country/region. @stable ICU 2.0 */
237     static const Locale& U_EXPORT2 getUS();
238     /** Useful constant for this country/region. @stable ICU 2.0 */
239     static const Locale& U_EXPORT2 getCanada();
240     /** Useful constant for this country/region. @stable ICU 2.0 */
241     static const Locale& U_EXPORT2 getCanadaFrench();
242 
243     /**
244      * Construct a default locale object, a Locale for the default locale ID.
245      *
246      * @see getDefault
247      * @see uloc_getDefault
248      * @stable ICU 2.0
249      */
250     Locale();
251 
252     /**
253      * Construct a locale from language, country, variant.
254      * If an error occurs, then the constructed object will be "bogus"
255      * (isBogus() will return true).
256      *
257      * @param language Lowercase two-letter or three-letter ISO-639 code.
258      *  This parameter can instead be an ICU style C locale (e.g. "en_US"),
259      *  but the other parameters must not be used.
260      *  This parameter can be nullptr; if so,
261      *  the locale is initialized to match the current default locale.
262      *  (This is the same as using the default constructor.)
263      *  Please note: The Java Locale class does NOT accept the form
264      *  'new Locale("en_US")' but only 'new Locale("en","US")'
265      *
266      * @param country  Uppercase two-letter ISO-3166 code. (optional)
267      * @param variant  Uppercase vendor and browser specific code. See class
268      *                 description. (optional)
269      * @param keywordsAndValues A string consisting of keyword/values pairs, such as
270      *                 "collation=phonebook;currency=euro"
271      *
272      * @see getDefault
273      * @see uloc_getDefault
274      * @stable ICU 2.0
275      */
276     Locale(const char* language,
277            const char* country = nullptr,
278            const char* variant = nullptr,
279            const char* keywordsAndValues = nullptr);
280 
281     /**
282      * Initializes a Locale object from another Locale object.
283      *
284      * @param other The Locale object being copied in.
285      * @stable ICU 2.0
286      */
287     Locale(const    Locale& other);
288 
289     /**
290      * Move constructor; might leave source in bogus state.
291      * This locale will have the same contents that the source locale had.
292      *
293      * @param other The Locale object being moved in.
294      * @stable ICU 63
295      */
296     Locale(Locale&& other) noexcept;
297 
298     /**
299      * Destructor
300      * @stable ICU 2.0
301      */
302     virtual ~Locale() ;
303 
304     /**
305      * Replaces the entire contents of *this with the specified value.
306      *
307      * @param other The Locale object being copied in.
308      * @return      *this
309      * @stable ICU 2.0
310      */
311     Locale& operator=(const Locale& other);
312 
313     /**
314      * Move assignment operator; might leave source in bogus state.
315      * This locale will have the same contents that the source locale had.
316      * The behavior is undefined if *this and the source are the same object.
317      *
318      * @param other The Locale object being moved in.
319      * @return      *this
320      * @stable ICU 63
321      */
322     Locale& operator=(Locale&& other) noexcept;
323 
324     /**
325      * Checks if two locale keys are the same.
326      *
327      * @param other The locale key object to be compared with this.
328      * @return      true if the two locale keys are the same, false otherwise.
329      * @stable ICU 2.0
330      */
331     bool    operator==(const    Locale&     other) const;
332 
333     /**
334      * Checks if two locale keys are not the same.
335      *
336      * @param other The locale key object to be compared with this.
337      * @return      true if the two locale keys are not the same, false
338      *              otherwise.
339      * @stable ICU 2.0
340      */
341     inline bool    operator!=(const    Locale&     other) const;
342 
343     /**
344      * Clone this object.
345      * Clones can be used concurrently in multiple threads.
346      * If an error occurs, then nullptr is returned.
347      * The caller must delete the clone.
348      *
349      * @return a clone of this object
350      *
351      * @see getDynamicClassID
352      * @stable ICU 2.8
353      */
354     Locale *clone() const;
355 
356 #ifndef U_HIDE_SYSTEM_API
357     /**
358      * Common methods of getting the current default Locale. Used for the
359      * presentation: menus, dialogs, etc. Generally set once when your applet or
360      * application is initialized, then never reset. (If you do reset the
361      * default locale, you probably want to reload your GUI, so that the change
362      * is reflected in your interface.)
363      *
364      * More advanced programs will allow users to use different locales for
365      * different fields, e.g. in a spreadsheet.
366      *
367      * Note that the initial setting will match the host system.
368      * @return a reference to the Locale object for the default locale ID
369      * @system
370      * @stable ICU 2.0
371      */
372     static const Locale& U_EXPORT2 getDefault();
373 
374     /**
375      * Sets the default. Normally set once at the beginning of a process,
376      * then never reset.
377      * setDefault() only changes ICU's default locale ID, <strong>not</strong>
378      * the default locale ID of the runtime environment.
379      *
380      * @param newLocale Locale to set to.  If nullptr, set to the value obtained
381      *                  from the runtime environment.
382      * @param success The error code.
383      * @system
384      * @stable ICU 2.0
385      */
386     static void U_EXPORT2 setDefault(const Locale& newLocale,
387                                      UErrorCode&   success);
388 #endif  /* U_HIDE_SYSTEM_API */
389 
390     /**
391      * Returns a Locale for the specified BCP47 language tag string.
392      * If the specified language tag contains any ill-formed subtags,
393      * the first such subtag and all following subtags are ignored.
394      * <p>
395      * This implements the 'Language-Tag' production of BCP 47, and so
396      * supports legacy language tags (marked as “Type: grandfathered” in BCP 47)
397      * (regular and irregular) as well as private use language tags.
398      *
399      * Private use tags are represented as 'x-whatever',
400      * and legacy tags are converted to their canonical replacements where they exist.
401      *
402      * Note that a few legacy tags have no modern replacement;
403      * these will be converted using the fallback described in
404      * the first paragraph, so some information might be lost.
405      *
406      * @param tag     the input BCP47 language tag.
407      * @param status  error information if creating the Locale failed.
408      * @return        the Locale for the specified BCP47 language tag.
409      * @stable ICU 63
410      */
411     static Locale U_EXPORT2 forLanguageTag(StringPiece tag, UErrorCode& status);
412 
413     /**
414      * Returns a well-formed language tag for this Locale.
415      * <p>
416      * <b>Note</b>: Any locale fields which do not satisfy the BCP47 syntax
417      * requirement will be silently omitted from the result.
418      *
419      * If this function fails, partial output may have been written to the sink.
420      *
421      * @param sink    the output sink receiving the BCP47 language
422      *                tag for this Locale.
423      * @param status  error information if creating the language tag failed.
424      * @stable ICU 63
425      */
426     void toLanguageTag(ByteSink& sink, UErrorCode& status) const;
427 
428     /**
429      * Returns a well-formed language tag for this Locale.
430      * <p>
431      * <b>Note</b>: Any locale fields which do not satisfy the BCP47 syntax
432      * requirement will be silently omitted from the result.
433      *
434      * @param status  error information if creating the language tag failed.
435      * @return        the BCP47 language tag for this Locale.
436      * @stable ICU 63
437      */
438     template<typename StringClass>
439     inline StringClass toLanguageTag(UErrorCode& status) const;
440 
441     /**
442      * Creates a locale which has had minimal canonicalization
443      * as per uloc_getName().
444      * @param name The name to create from.  If name is null,
445      *  the default Locale is used.
446      * @return new locale object
447      * @stable ICU 2.0
448      * @see uloc_getName
449      */
450     static Locale U_EXPORT2 createFromName(const char *name);
451 
452     /**
453      * Creates a locale from the given string after canonicalizing
454      * the string according to CLDR by calling uloc_canonicalize().
455      * @param name the locale ID to create from.  Must not be nullptr.
456      * @return a new locale object corresponding to the given name
457      * @stable ICU 3.0
458      * @see uloc_canonicalize
459      */
460     static Locale U_EXPORT2 createCanonical(const char* name);
461 
462     /**
463      * Returns the locale's ISO-639 language code.
464      * @return      An alias to the code
465      * @stable ICU 2.0
466      */
467     inline const char *  getLanguage( ) const;
468 
469     /**
470      * Returns the locale's ISO-15924 abbreviation script code.
471      * @return      An alias to the code
472      * @see uscript_getShortName
473      * @see uscript_getCode
474      * @stable ICU 2.8
475      */
476     inline const char *  getScript( ) const;
477 
478     /**
479      * Returns the locale's ISO-3166 country code.
480      * @return      An alias to the code
481      * @stable ICU 2.0
482      */
483     inline const char *  getCountry( ) const;
484 
485     /**
486      * Returns the locale's variant code.
487      * @return      An alias to the code
488      * @stable ICU 2.0
489      */
490     inline const char *  getVariant( ) const;
491 
492     /**
493      * Returns the programmatic name of the entire locale, with the language,
494      * country and variant separated by underbars. If a field is missing, up
495      * to two leading underbars will occur. Example: "en", "de_DE", "en_US_WIN",
496      * "de__POSIX", "fr__MAC", "__MAC", "_MT", "_FR_EURO"
497      * @return      A pointer to "name".
498      * @stable ICU 2.0
499      */
500     inline const char * getName() const;
501 
502     /**
503      * Returns the programmatic name of the entire locale as getName() would return,
504      * but without keywords.
505      * @return      A pointer to "name".
506      * @see getName
507      * @stable ICU 2.8
508      */
509     const char * getBaseName() const;
510 
511     /**
512      * Add the likely subtags for this Locale, per the algorithm described
513      * in the following CLDR technical report:
514      *
515      *   http://www.unicode.org/reports/tr35/#Likely_Subtags
516      *
517      * If this Locale is already in the maximal form, or not valid, or there is
518      * no data available for maximization, the Locale will be unchanged.
519      *
520      * For example, "sh" cannot be maximized, since there is no
521      * reasonable maximization.
522      *
523      * Examples:
524      *
525      * "und_Zzzz" maximizes to "en_Latn_US"
526      *
527      * "en" maximizes to "en_Latn_US"
528      *
529      * "de" maximizes to "de_Latn_DE"
530      *
531      * "sr" maximizes to "sr_Cyrl_RS"
532      *
533      * "zh_Hani" maximizes to "zh_Hani_CN"
534      *
535      * @param status  error information if maximizing this Locale failed.
536      *                If this Locale is not well-formed, the error code is
537      *                U_ILLEGAL_ARGUMENT_ERROR.
538      * @stable ICU 63
539      */
540     void addLikelySubtags(UErrorCode& status);
541 
542     /**
543      * Minimize the subtags for this Locale, per the algorithm described
544      * in the following CLDR technical report:
545      *
546      *   http://www.unicode.org/reports/tr35/#Likely_Subtags
547      *
548      * If this Locale is already in the minimal form, or not valid, or there is
549      * no data available for minimization, the Locale will be unchanged.
550      *
551      * Since the minimization algorithm relies on proper maximization, see the
552      * comments for addLikelySubtags for reasons why there might not be any
553      * data.
554      *
555      * Examples:
556      *
557      * "en_Latn_US" minimizes to "en"
558      *
559      * "de_Latn_US" minimizes to "de"
560      *
561      * "sr_Cyrl_RS" minimizes to "sr"
562      *
563      * "zh_Hant_TW" minimizes to "zh_TW" (The region is preferred to the
564      * script, and minimizing to "zh" would imply "zh_Hans_CN".)
565      *
566      * @param status  error information if maximizing this Locale failed.
567      *                If this Locale is not well-formed, the error code is
568      *                U_ILLEGAL_ARGUMENT_ERROR.
569      * @stable ICU 63
570      */
571     void minimizeSubtags(UErrorCode& status);
572 
573     /**
574      * Canonicalize the locale ID of this object according to CLDR.
575      * @param status the status code
576      * @stable ICU 67
577      * @see createCanonical
578      */
579     void canonicalize(UErrorCode& status);
580 
581     /**
582      * Gets the list of keywords for the specified locale.
583      *
584      * @param status the status code
585      * @return pointer to StringEnumeration class, or nullptr if there are no keywords.
586      * Client must dispose of it by calling delete.
587      * @see getKeywords
588      * @stable ICU 2.8
589      */
590     StringEnumeration * createKeywords(UErrorCode &status) const;
591 
592     /**
593      * Gets the list of Unicode keywords for the specified locale.
594      *
595      * @param status the status code
596      * @return pointer to StringEnumeration class, or nullptr if there are no keywords.
597      * Client must dispose of it by calling delete.
598      * @see getUnicodeKeywords
599      * @stable ICU 63
600      */
601     StringEnumeration * createUnicodeKeywords(UErrorCode &status) const;
602 
603     /**
604      * Gets the set of keywords for this Locale.
605      *
606      * A wrapper to call createKeywords() and write the resulting
607      * keywords as standard strings (or compatible objects) into any kind of
608      * container that can be written to by an STL style output iterator.
609      *
610      * @param iterator  an STL style output iterator to write the keywords to.
611      * @param status    error information if creating set of keywords failed.
612      * @stable ICU 63
613      */
614     template<typename StringClass, typename OutputIterator>
615     inline void getKeywords(OutputIterator iterator, UErrorCode& status) const;
616 
617     /**
618      * Gets the set of Unicode keywords for this Locale.
619      *
620      * A wrapper to call createUnicodeKeywords() and write the resulting
621      * keywords as standard strings (or compatible objects) into any kind of
622      * container that can be written to by an STL style output iterator.
623      *
624      * @param iterator  an STL style output iterator to write the keywords to.
625      * @param status    error information if creating set of keywords failed.
626      * @stable ICU 63
627      */
628     template<typename StringClass, typename OutputIterator>
629     inline void getUnicodeKeywords(OutputIterator iterator, UErrorCode& status) const;
630 
631     /**
632      * Gets the value for a keyword.
633      *
634      * This uses legacy keyword=value pairs, like "collation=phonebook".
635      *
636      * ICU4C doesn't do automatic conversion between legacy and Unicode
637      * keywords and values in getters and setters (as opposed to ICU4J).
638      *
639      * @param keywordName name of the keyword for which we want the value. Case insensitive.
640      * @param buffer The buffer to receive the keyword value.
641      * @param bufferCapacity The capacity of receiving buffer
642      * @param status Returns any error information while performing this operation.
643      * @return the length of the keyword value
644      *
645      * @stable ICU 2.8
646      */
647     int32_t getKeywordValue(const char* keywordName, char *buffer, int32_t bufferCapacity, UErrorCode &status) const;
648 
649     /**
650      * Gets the value for a keyword.
651      *
652      * This uses legacy keyword=value pairs, like "collation=phonebook".
653      *
654      * ICU4C doesn't do automatic conversion between legacy and Unicode
655      * keywords and values in getters and setters (as opposed to ICU4J).
656      *
657      * @param keywordName  name of the keyword for which we want the value.
658      * @param sink         the sink to receive the keyword value.
659      * @param status       error information if getting the value failed.
660      * @stable ICU 63
661      */
662     void getKeywordValue(StringPiece keywordName, ByteSink& sink, UErrorCode& status) const;
663 
664     /**
665      * Gets the value for a keyword.
666      *
667      * This uses legacy keyword=value pairs, like "collation=phonebook".
668      *
669      * ICU4C doesn't do automatic conversion between legacy and Unicode
670      * keywords and values in getters and setters (as opposed to ICU4J).
671      *
672      * @param keywordName  name of the keyword for which we want the value.
673      * @param status       error information if getting the value failed.
674      * @return             the keyword value.
675      * @stable ICU 63
676      */
677     template<typename StringClass>
678     inline StringClass getKeywordValue(StringPiece keywordName, UErrorCode& status) const;
679 
680     /**
681      * Gets the Unicode value for a Unicode keyword.
682      *
683      * This uses Unicode key-value pairs, like "co-phonebk".
684      *
685      * ICU4C doesn't do automatic conversion between legacy and Unicode
686      * keywords and values in getters and setters (as opposed to ICU4J).
687      *
688      * @param keywordName  name of the keyword for which we want the value.
689      * @param sink         the sink to receive the keyword value.
690      * @param status       error information if getting the value failed.
691      * @stable ICU 63
692      */
693     void getUnicodeKeywordValue(StringPiece keywordName, ByteSink& sink, UErrorCode& status) const;
694 
695     /**
696      * Gets the Unicode value for a Unicode keyword.
697      *
698      * This uses Unicode key-value pairs, like "co-phonebk".
699      *
700      * ICU4C doesn't do automatic conversion between legacy and Unicode
701      * keywords and values in getters and setters (as opposed to ICU4J).
702      *
703      * @param keywordName  name of the keyword for which we want the value.
704      * @param status       error information if getting the value failed.
705      * @return             the keyword value.
706      * @stable ICU 63
707      */
708     template<typename StringClass>
709     inline StringClass getUnicodeKeywordValue(StringPiece keywordName, UErrorCode& status) const;
710 
711     /**
712      * Sets or removes the value for a keyword.
713      *
714      * For removing all keywords, use getBaseName(),
715      * and construct a new Locale if it differs from getName().
716      *
717      * This uses legacy keyword=value pairs, like "collation=phonebook".
718      *
719      * ICU4C doesn't do automatic conversion between legacy and Unicode
720      * keywords and values in getters and setters (as opposed to ICU4J).
721      *
722      * @param keywordName name of the keyword to be set. Case insensitive.
723      * @param keywordValue value of the keyword to be set. If 0-length or
724      *  nullptr, will result in the keyword being removed. No error is given if
725      *  that keyword does not exist.
726      * @param status Returns any error information while performing this operation.
727      *
728      * @stable ICU 49
729      */
730     void setKeywordValue(const char* keywordName, const char* keywordValue, UErrorCode &status);
731 
732     /**
733      * Sets or removes the value for a keyword.
734      *
735      * For removing all keywords, use getBaseName(),
736      * and construct a new Locale if it differs from getName().
737      *
738      * This uses legacy keyword=value pairs, like "collation=phonebook".
739      *
740      * ICU4C doesn't do automatic conversion between legacy and Unicode
741      * keywords and values in getters and setters (as opposed to ICU4J).
742      *
743      * @param keywordName name of the keyword to be set.
744      * @param keywordValue value of the keyword to be set. If 0-length or
745      *  nullptr, will result in the keyword being removed. No error is given if
746      *  that keyword does not exist.
747      * @param status Returns any error information while performing this operation.
748      * @stable ICU 63
749      */
750     void setKeywordValue(StringPiece keywordName, StringPiece keywordValue, UErrorCode& status);
751 
752     /**
753      * Sets or removes the Unicode value for a Unicode keyword.
754      *
755      * For removing all keywords, use getBaseName(),
756      * and construct a new Locale if it differs from getName().
757      *
758      * This uses Unicode key-value pairs, like "co-phonebk".
759      *
760      * ICU4C doesn't do automatic conversion between legacy and Unicode
761      * keywords and values in getters and setters (as opposed to ICU4J).
762      *
763      * @param keywordName name of the keyword to be set.
764      * @param keywordValue value of the keyword to be set. If 0-length or
765      *  nullptr, will result in the keyword being removed. No error is given if
766      *  that keyword does not exist.
767      * @param status Returns any error information while performing this operation.
768      * @stable ICU 63
769      */
770     void setUnicodeKeywordValue(StringPiece keywordName, StringPiece keywordValue, UErrorCode& status);
771 
772     /**
773      * returns the locale's three-letter language code, as specified
774      * in ISO draft standard ISO-639-2.
775      * @return      An alias to the code, or an empty string
776      * @stable ICU 2.0
777      */
778     const char * getISO3Language() const;
779 
780     /**
781      * Fills in "name" with the locale's three-letter ISO-3166 country code.
782      * @return      An alias to the code, or an empty string
783      * @stable ICU 2.0
784      */
785     const char * getISO3Country() const;
786 
787     /**
788      * Returns the Windows LCID value corresponding to this locale.
789      * This value is stored in the resource data for the locale as a one-to-four-digit
790      * hexadecimal number.  If the resource is missing, in the wrong format, or
791      * there is no Windows LCID value that corresponds to this locale, returns 0.
792      * @stable ICU 2.0
793      */
794     uint32_t getLCID() const;
795 
796     /**
797      * Returns whether this locale's script is written right-to-left.
798      * If there is no script subtag, then the likely script is used, see uloc_addLikelySubtags().
799      * If no likely script is known, then false is returned.
800      *
801      * A script is right-to-left according to the CLDR script metadata
802      * which corresponds to whether the script's letters have Bidi_Class=R or AL.
803      *
804      * Returns true for "ar" and "en-Hebr", false for "zh" and "fa-Cyrl".
805      *
806      * @return true if the locale's script is written right-to-left
807      * @stable ICU 54
808      */
809     UBool isRightToLeft() const;
810 
811     /**
812      * Fills in "dispLang" with the name of this locale's language in a format suitable for
813      * user display in the default locale.  For example, if the locale's language code is
814      * "fr" and the default locale's language code is "en", this function would set
815      * dispLang to "French".
816      * @param dispLang  Receives the language's display name.
817      * @return          A reference to "dispLang".
818      * @stable ICU 2.0
819      */
820     UnicodeString&  getDisplayLanguage(UnicodeString&   dispLang) const;
821 
822     /**
823      * Fills in "dispLang" with the name of this locale's language in a format suitable for
824      * user display in the locale specified by "displayLocale".  For example, if the locale's
825      * language code is "en" and displayLocale's language code is "fr", this function would set
826      * dispLang to "Anglais".
827      * @param displayLocale  Specifies the locale to be used to display the name.  In other words,
828      *                  if the locale's language code is "en", passing Locale::getFrench() for
829      *                  displayLocale would result in "Anglais", while passing Locale::getGerman()
830      *                  for displayLocale would result in "Englisch".
831      * @param dispLang  Receives the language's display name.
832      * @return          A reference to "dispLang".
833      * @stable ICU 2.0
834      */
835     UnicodeString&  getDisplayLanguage( const   Locale&         displayLocale,
836                                                 UnicodeString&  dispLang) const;
837 
838     /**
839      * Fills in "dispScript" with the name of this locale's script in a format suitable
840      * for user display in the default locale.  For example, if the locale's script code
841      * is "LATN" and the default locale's language code is "en", this function would set
842      * dispScript to "Latin".
843      * @param dispScript    Receives the scripts's display name.
844      * @return              A reference to "dispScript".
845      * @stable ICU 2.8
846      */
847     UnicodeString&  getDisplayScript(          UnicodeString& dispScript) const;
848 
849     /**
850      * Fills in "dispScript" with the name of this locale's country in a format suitable
851      * for user display in the locale specified by "displayLocale".  For example, if the locale's
852      * script code is "LATN" and displayLocale's language code is "en", this function would set
853      * dispScript to "Latin".
854      * @param displayLocale      Specifies the locale to be used to display the name.  In other
855      *                      words, if the locale's script code is "LATN", passing
856      *                      Locale::getFrench() for displayLocale would result in "", while
857      *                      passing Locale::getGerman() for displayLocale would result in
858      *                      "".
859      * @param dispScript    Receives the scripts's display name.
860      * @return              A reference to "dispScript".
861      * @stable ICU 2.8
862      */
863     UnicodeString&  getDisplayScript(  const   Locale&         displayLocale,
864                                                UnicodeString&  dispScript) const;
865 
866     /**
867      * Fills in "dispCountry" with the name of this locale's country in a format suitable
868      * for user display in the default locale.  For example, if the locale's country code
869      * is "FR" and the default locale's language code is "en", this function would set
870      * dispCountry to "France".
871      * @param dispCountry   Receives the country's display name.
872      * @return              A reference to "dispCountry".
873      * @stable ICU 2.0
874      */
875     UnicodeString&  getDisplayCountry(          UnicodeString& dispCountry) const;
876 
877     /**
878      * Fills in "dispCountry" with the name of this locale's country in a format suitable
879      * for user display in the locale specified by "displayLocale".  For example, if the locale's
880      * country code is "US" and displayLocale's language code is "fr", this function would set
881      * dispCountry to "&Eacute;tats-Unis".
882      * @param displayLocale      Specifies the locale to be used to display the name.  In other
883      *                      words, if the locale's country code is "US", passing
884      *                      Locale::getFrench() for displayLocale would result in "&Eacute;tats-Unis", while
885      *                      passing Locale::getGerman() for displayLocale would result in
886      *                      "Vereinigte Staaten".
887      * @param dispCountry   Receives the country's display name.
888      * @return              A reference to "dispCountry".
889      * @stable ICU 2.0
890      */
891     UnicodeString&  getDisplayCountry(  const   Locale&         displayLocale,
892                                                 UnicodeString&  dispCountry) const;
893 
894     /**
895      * Fills in "dispVar" with the name of this locale's variant code in a format suitable
896      * for user display in the default locale.
897      * @param dispVar   Receives the variant's name.
898      * @return          A reference to "dispVar".
899      * @stable ICU 2.0
900      */
901     UnicodeString&  getDisplayVariant(      UnicodeString& dispVar) const;
902 
903     /**
904      * Fills in "dispVar" with the name of this locale's variant code in a format
905      * suitable for user display in the locale specified by "displayLocale".
906      * @param displayLocale  Specifies the locale to be used to display the name.
907      * @param dispVar   Receives the variant's display name.
908      * @return          A reference to "dispVar".
909      * @stable ICU 2.0
910      */
911     UnicodeString&  getDisplayVariant(  const   Locale&         displayLocale,
912                                                 UnicodeString&  dispVar) const;
913 
914     /**
915      * Fills in "name" with the name of this locale in a format suitable for user display
916      * in the default locale.  This function uses getDisplayLanguage(), getDisplayCountry(),
917      * and getDisplayVariant() to do its work, and outputs the display name in the format
918      * "language (country[,variant])".  For example, if the default locale is en_US, then
919      * fr_FR's display name would be "French (France)", and es_MX_Traditional's display name
920      * would be "Spanish (Mexico,Traditional)".
921      * @param name  Receives the locale's display name.
922      * @return      A reference to "name".
923      * @stable ICU 2.0
924      */
925     UnicodeString&  getDisplayName(         UnicodeString&  name) const;
926 
927     /**
928      * Fills in "name" with the name of this locale in a format suitable for user display
929      * in the locale specified by "displayLocale".  This function uses getDisplayLanguage(),
930      * getDisplayCountry(), and getDisplayVariant() to do its work, and outputs the display
931      * name in the format "language (country[,variant])".  For example, if displayLocale is
932      * fr_FR, then en_US's display name would be "Anglais (&Eacute;tats-Unis)", and no_NO_NY's
933      * display name would be "norv&eacute;gien (Norv&egrave;ge,NY)".
934      * @param displayLocale  Specifies the locale to be used to display the name.
935      * @param name      Receives the locale's display name.
936      * @return          A reference to "name".
937      * @stable ICU 2.0
938      */
939     UnicodeString&  getDisplayName( const   Locale&         displayLocale,
940                                             UnicodeString&  name) const;
941 
942     /**
943      * Generates a hash code for the locale.
944      * @stable ICU 2.0
945      */
946     int32_t hashCode() const;
947 
948     /**
949      * Sets the locale to bogus
950      * A bogus locale represents a non-existing locale associated
951      * with services that can be instantiated from non-locale data
952      * in addition to locale (for example, collation can be
953      * instantiated from a locale and from a rule set).
954      * @stable ICU 2.1
955      */
956     void setToBogus();
957 
958     /**
959      * Gets the bogus state. Locale object can be bogus if it doesn't exist
960      * @return false if it is a real locale, true if it is a bogus locale
961      * @stable ICU 2.1
962      */
963     inline UBool isBogus() const;
964 
965     /**
966      * Returns a list of all installed locales.
967      * @param count Receives the number of locales in the list.
968      * @return      A pointer to an array of Locale objects.  This array is the list
969      *              of all locales with installed resource files.  The called does NOT
970      *              get ownership of this list, and must NOT delete it.
971      * @stable ICU 2.0
972      */
973     static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count);
974 
975     /**
976      * Gets a list of all available 2-letter country codes defined in ISO 3166.  This is a
977      * pointer to an array of pointers to arrays of char.  All of these pointers are
978      * owned by ICU-- do not delete them, and do not write through them.  The array is
979      * terminated with a null pointer.
980      * @return a list of all available country codes
981      * @stable ICU 2.0
982      */
983     static const char* const* U_EXPORT2 getISOCountries();
984 
985     /**
986      * Returns a list of all unique language codes defined in ISO 639.
987      * They can be 2 or 3 letter codes, as defined by
988      * <a href="https://www.ietf.org/rfc/bcp/bcp47.html#section-2.2.1">
989      * BCP 47, section 2.2.1</a>. This is a pointer
990      * to an array of pointers to arrays of char.  All of these pointers are owned
991      * by ICU-- do not delete them, and do not write through them.  The array is
992      * terminated with a null pointer.
993      * @return a list of all available language codes
994      * @stable ICU 2.0
995      */
996     static const char* const* U_EXPORT2 getISOLanguages();
997 
998     /**
999      * ICU "poor man's RTTI", returns a UClassID for this class.
1000      *
1001      * @stable ICU 2.2
1002      */
1003     static UClassID U_EXPORT2 getStaticClassID();
1004 
1005     /**
1006      * ICU "poor man's RTTI", returns a UClassID for the actual class.
1007      *
1008      * @stable ICU 2.2
1009      */
1010     virtual UClassID getDynamicClassID() const override;
1011 
1012     /**
1013      * A Locale iterator interface similar to a Java Iterator<Locale>.
1014      * @stable ICU 65
1015      */
1016     class U_COMMON_API Iterator /* not : public UObject because this is an interface/mixin class */ {
1017     public:
1018         /** @stable ICU 65 */
1019         virtual ~Iterator();
1020 
1021         /**
1022          * @return true if next() can be called again.
1023          * @stable ICU 65
1024          */
1025         virtual UBool hasNext() const = 0;
1026 
1027         /**
1028          * @return the next locale.
1029          * @stable ICU 65
1030          */
1031         virtual const Locale &next() = 0;
1032     };
1033 
1034     /**
1035      * A generic Locale iterator implementation over Locale input iterators.
1036      * @stable ICU 65
1037      */
1038     template<typename Iter>
1039     class RangeIterator : public Iterator, public UMemory {
1040     public:
1041         /**
1042          * Constructs an iterator from a begin/end range.
1043          * Each of the iterator parameter values must be an
1044          * input iterator whose value is convertible to const Locale &.
1045          *
1046          * @param begin Start of range.
1047          * @param end Exclusive end of range.
1048          * @stable ICU 65
1049          */
RangeIterator(Iter begin,Iter end)1050         RangeIterator(Iter begin, Iter end) : it_(begin), end_(end) {}
1051 
1052         /**
1053          * @return true if next() can be called again.
1054          * @stable ICU 65
1055          */
hasNext()1056         UBool hasNext() const override { return it_ != end_; }
1057 
1058         /**
1059          * @return the next locale.
1060          * @stable ICU 65
1061          */
next()1062         const Locale &next() override { return *it_++; }
1063 
1064     private:
1065         Iter it_;
1066         const Iter end_;
1067     };
1068 
1069     /**
1070      * A generic Locale iterator implementation over Locale input iterators.
1071      * Calls the converter to convert each *begin to a const Locale &.
1072      * @stable ICU 65
1073      */
1074     template<typename Iter, typename Conv>
1075     class ConvertingIterator : public Iterator, public UMemory {
1076     public:
1077         /**
1078          * Constructs an iterator from a begin/end range.
1079          * Each of the iterator parameter values must be an
1080          * input iterator whose value the converter converts to const Locale &.
1081          *
1082          * @param begin Start of range.
1083          * @param end Exclusive end of range.
1084          * @param converter Converter from *begin to const Locale & or compatible.
1085          * @stable ICU 65
1086          */
ConvertingIterator(Iter begin,Iter end,Conv converter)1087         ConvertingIterator(Iter begin, Iter end, Conv converter) :
1088                 it_(begin), end_(end), converter_(converter) {}
1089 
1090         /**
1091          * @return true if next() can be called again.
1092          * @stable ICU 65
1093          */
hasNext()1094         UBool hasNext() const override { return it_ != end_; }
1095 
1096         /**
1097          * @return the next locale.
1098          * @stable ICU 65
1099          */
next()1100         const Locale &next() override { return converter_(*it_++); }
1101 
1102     private:
1103         Iter it_;
1104         const Iter end_;
1105         Conv converter_;
1106     };
1107 
1108 protected: /* only protected for testing purposes. DO NOT USE. */
1109 #ifndef U_HIDE_INTERNAL_API
1110     /**
1111      * Set this from a single POSIX style locale string.
1112      * @internal
1113      */
1114     void setFromPOSIXID(const char *posixID);
1115     /**
1116      * Minimize the subtags for this Locale, per the algorithm described
1117      * @param favorScript favor to keep script if true, to keep region if false.
1118      * @param status  error information if maximizing this Locale failed.
1119      *                If this Locale is not well-formed, the error code is
1120      *                U_ILLEGAL_ARGUMENT_ERROR.
1121      * @internal
1122      */
1123     void minimizeSubtags(bool favorScript, UErrorCode& status);
1124 #endif  /* U_HIDE_INTERNAL_API */
1125 
1126 private:
1127     /**
1128      * Initialize the locale object with a new name.
1129      * Was deprecated - used in implementation - moved internal
1130      *
1131      * @param cLocaleID The new locale name.
1132      * @param canonicalize whether to call uloc_canonicalize on cLocaleID
1133      */
1134     Locale& init(const char* cLocaleID, UBool canonicalize);
1135 
1136     /*
1137      * Internal constructor to allow construction of a locale object with
1138      *   NO side effects.   (Default constructor tries to get
1139      *   the default locale.)
1140      */
1141     enum ELocaleType {
1142         eBOGUS
1143     };
1144     Locale(ELocaleType);
1145 
1146     /**
1147      * Initialize the locale cache for commonly used locales
1148      */
1149     static Locale* getLocaleCache();
1150 
1151     char language[ULOC_LANG_CAPACITY];
1152     char script[ULOC_SCRIPT_CAPACITY];
1153     char country[ULOC_COUNTRY_CAPACITY];
1154     int32_t variantBegin;
1155     char* fullName;
1156     char fullNameBuffer[ULOC_FULLNAME_CAPACITY];
1157     // name without keywords
1158     char* baseName;
1159     void initBaseName(UErrorCode& status);
1160 
1161     UBool fIsBogus;
1162 
1163     static const Locale &getLocale(int locid);
1164 
1165     /**
1166      * A friend to allow the default locale to be set by either the C or C++ API.
1167      * @internal (private)
1168      */
1169     friend Locale *locale_set_default_internal(const char *, UErrorCode& status);
1170 
1171     /**
1172      * @internal (private)
1173      */
1174     friend void U_CALLCONV locale_available_init();
1175 };
1176 
1177 inline bool
1178 Locale::operator!=(const    Locale&     other) const
1179 {
1180     return !operator==(other);
1181 }
1182 
1183 template<typename StringClass> inline StringClass
toLanguageTag(UErrorCode & status)1184 Locale::toLanguageTag(UErrorCode& status) const
1185 {
1186     if (U_FAILURE(status)) { return {}; }
1187     StringClass result;
1188     StringByteSink<StringClass> sink(&result);
1189     toLanguageTag(sink, status);
1190     return result;
1191 }
1192 
1193 inline const char *
getCountry()1194 Locale::getCountry() const
1195 {
1196     return country;
1197 }
1198 
1199 inline const char *
getLanguage()1200 Locale::getLanguage() const
1201 {
1202     return language;
1203 }
1204 
1205 inline const char *
getScript()1206 Locale::getScript() const
1207 {
1208     return script;
1209 }
1210 
1211 inline const char *
getVariant()1212 Locale::getVariant() const
1213 {
1214     return fIsBogus ? "" : &baseName[variantBegin];
1215 }
1216 
1217 inline const char *
getName()1218 Locale::getName() const
1219 {
1220     return fullName;
1221 }
1222 
1223 template<typename StringClass, typename OutputIterator> inline void
getKeywords(OutputIterator iterator,UErrorCode & status)1224 Locale::getKeywords(OutputIterator iterator, UErrorCode& status) const
1225 {
1226     if (U_FAILURE(status)) { return; }
1227     LocalPointer<StringEnumeration> keys(createKeywords(status));
1228     if (U_FAILURE(status) || keys.isNull()) {
1229         return;
1230     }
1231     for (;;) {
1232         int32_t resultLength;
1233         const char* buffer = keys->next(&resultLength, status);
1234         if (U_FAILURE(status) || buffer == nullptr) {
1235             return;
1236         }
1237         *iterator++ = StringClass(buffer, resultLength);
1238     }
1239 }
1240 
1241 template<typename StringClass, typename OutputIterator> inline void
getUnicodeKeywords(OutputIterator iterator,UErrorCode & status)1242 Locale::getUnicodeKeywords(OutputIterator iterator, UErrorCode& status) const
1243 {
1244     if (U_FAILURE(status)) { return; }
1245     LocalPointer<StringEnumeration> keys(createUnicodeKeywords(status));
1246     if (U_FAILURE(status) || keys.isNull()) {
1247         return;
1248     }
1249     for (;;) {
1250         int32_t resultLength;
1251         const char* buffer = keys->next(&resultLength, status);
1252         if (U_FAILURE(status) || buffer == nullptr) {
1253             return;
1254         }
1255         *iterator++ = StringClass(buffer, resultLength);
1256     }
1257 }
1258 
1259 template<typename StringClass> inline StringClass
getKeywordValue(StringPiece keywordName,UErrorCode & status)1260 Locale::getKeywordValue(StringPiece keywordName, UErrorCode& status) const
1261 {
1262     if (U_FAILURE(status)) { return {}; }
1263     StringClass result;
1264     StringByteSink<StringClass> sink(&result);
1265     getKeywordValue(keywordName, sink, status);
1266     return result;
1267 }
1268 
1269 template<typename StringClass> inline StringClass
getUnicodeKeywordValue(StringPiece keywordName,UErrorCode & status)1270 Locale::getUnicodeKeywordValue(StringPiece keywordName, UErrorCode& status) const
1271 {
1272     if (U_FAILURE(status)) { return {}; }
1273     StringClass result;
1274     StringByteSink<StringClass> sink(&result);
1275     getUnicodeKeywordValue(keywordName, sink, status);
1276     return result;
1277 }
1278 
1279 inline UBool
isBogus()1280 Locale::isBogus() const {
1281     return fIsBogus;
1282 }
1283 
1284 U_NAMESPACE_END
1285 
1286 #endif /* U_SHOW_CPLUSPLUS_API */
1287 
1288 #endif
1289