icuSources/i18n/unicode/reldatefmt.h

   1 // © 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 /*
   4 *****************************************************************************
   5 * Copyright (C) 2014-2016, International Business Machines Corporation and
   6 * others.
   7 * All Rights Reserved.
   8 *****************************************************************************
   9 *
  10 * File RELDATEFMT.H
  11 *****************************************************************************
  12 */
  13
  14 #ifndef __RELDATEFMT_H
  15 #define __RELDATEFMT_H
  16
  17 #include "unicode/utypes.h"
  18
  19 #if U_SHOW_CPLUSPLUS_API
  20
  21 #include "unicode/uobject.h"
  22 #include "unicode/udisplaycontext.h"
  23 #include "unicode/ureldatefmt.h"
  24 #include "unicode/locid.h"
  25 #include "unicode/formattedvalue.h"
  26
  27 /**
  28  * \file
  29  * \brief C++ API: Formats relative dates such as "1 day ago" or "tomorrow"
  30  */
  31
  32 #if !UCONFIG_NO_FORMATTING
  33
  34 /**
  35  * Represents the unit for formatting a relative date. e.g "in 5 days"
  36  * or "in 3 months"
  37  * @stable ICU 53
  38  */
  39 typedef enum UDateRelativeUnit {
  40
  41     /**
  42      * Seconds
  43      * @stable ICU 53
  44      */
  45     UDAT_RELATIVE_SECONDS,
  46
  47     /**
  48      * Minutes
  49      * @stable ICU 53
  50      */
  51     UDAT_RELATIVE_MINUTES,
  52
  53     /**
  54      * Hours
  55      * @stable ICU 53
  56      */
  57     UDAT_RELATIVE_HOURS,
  58
  59     /**
  60      * Days
  61      * @stable ICU 53
  62      */
  63     UDAT_RELATIVE_DAYS,
  64
  65     /**
  66      * Weeks
  67      * @stable ICU 53
  68      */
  69     UDAT_RELATIVE_WEEKS,
  70
  71     /**
  72      * Months
  73      * @stable ICU 53
  74      */
  75     UDAT_RELATIVE_MONTHS,
  76
  77     /**
  78      * Years
  79      * @stable ICU 53
  80      */
  81     UDAT_RELATIVE_YEARS,
  82
  83 #ifndef U_HIDE_DEPRECATED_API
  84     /**
  85      * One more than the highest normal UDateRelativeUnit value.
  86      * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
  87      */
  88     UDAT_RELATIVE_UNIT_COUNT
  89 #endif  // U_HIDE_DEPRECATED_API
  90 } UDateRelativeUnit;
  91
  92 /**
  93  * Represents an absolute unit.
  94  * @stable ICU 53
  95  */
  96 typedef enum UDateAbsoluteUnit {
  97
  98     // Days of week have to remain together and in order from Sunday to
  99     // Saturday.
 100     /**
 101      * Sunday
 102      * @stable ICU 53
 103      */
 104     UDAT_ABSOLUTE_SUNDAY,
 105
 106     /**
 107      * Monday
 108      * @stable ICU 53
 109      */
 110     UDAT_ABSOLUTE_MONDAY,
 111
 112     /**
 113      * Tuesday
 114      * @stable ICU 53
 115      */
 116     UDAT_ABSOLUTE_TUESDAY,
 117
 118     /**
 119      * Wednesday
 120      * @stable ICU 53
 121      */
 122     UDAT_ABSOLUTE_WEDNESDAY,
 123
 124     /**
 125      * Thursday
 126      * @stable ICU 53
 127      */
 128     UDAT_ABSOLUTE_THURSDAY,
 129
 130     /**
 131      * Friday
 132      * @stable ICU 53
 133      */
 134     UDAT_ABSOLUTE_FRIDAY,
 135
 136     /**
 137      * Saturday
 138      * @stable ICU 53
 139      */
 140     UDAT_ABSOLUTE_SATURDAY,
 141
 142     /**
 143      * Day
 144      * @stable ICU 53
 145      */
 146     UDAT_ABSOLUTE_DAY,
 147
 148     /**
 149      * Week
 150      * @stable ICU 53
 151      */
 152     UDAT_ABSOLUTE_WEEK,
 153
 154     /**
 155      * Month
 156      * @stable ICU 53
 157      */
 158     UDAT_ABSOLUTE_MONTH,
 159
 160     /**
 161      * Year
 162      * @stable ICU 53
 163      */
 164     UDAT_ABSOLUTE_YEAR,
 165
 166     /**
 167      * Now
 168      * @stable ICU 53
 169      */
 170     UDAT_ABSOLUTE_NOW,
 171
 172     /**
 173      * Quarter
 174      * @stable ICU 63
 175      */
 176     UDAT_ABSOLUTE_QUARTER,
 177
 178 #ifndef U_HIDE_DRAFT_API
 179     /**
 180      * Hour
 181      * @draft ICU 65
 182      */
 183     UDAT_ABSOLUTE_HOUR,
 184
 185     /**
 186      * Minute
 187      * @draft ICU 65
 188      */
 189     UDAT_ABSOLUTE_MINUTE,
 190 #endif // U_HIDE_DRAFT_API
 191
 192 #ifndef U_HIDE_DEPRECATED_API
 193     /**
 194      * One more than the highest normal UDateAbsoluteUnit value.
 195      * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
 196      */
 197     UDAT_ABSOLUTE_UNIT_COUNT = UDAT_ABSOLUTE_NOW + 4
 198 #endif  // U_HIDE_DEPRECATED_API
 199 } UDateAbsoluteUnit;
 200
 201 /**
 202  * Represents a direction for an absolute unit e.g "Next Tuesday"
 203  * or "Last Tuesday"
 204  * @stable ICU 53
 205  */
 206 typedef enum UDateDirection {
 207
 208     /**
 209      * Two before. Not fully supported in every locale.
 210      * @stable ICU 53
 211      */
 212     UDAT_DIRECTION_LAST_2,
 213
 214     /**
 215      * Last
 216      * @stable ICU 53
 217      */
 218     UDAT_DIRECTION_LAST,
 219
 220     /**
 221      * This
 222      * @stable ICU 53
 223      */
 224     UDAT_DIRECTION_THIS,
 225
 226     /**
 227      * Next
 228      * @stable ICU 53
 229      */
 230     UDAT_DIRECTION_NEXT,
 231
 232     /**
 233      * Two after. Not fully supported in every locale.
 234      * @stable ICU 53
 235      */
 236     UDAT_DIRECTION_NEXT_2,
 237
 238     /**
 239      * Plain, which means the absence of a qualifier.
 240      * @stable ICU 53
 241      */
 242     UDAT_DIRECTION_PLAIN,
 243
 244 #ifndef U_HIDE_DEPRECATED_API
 245     /**
 246      * One more than the highest normal UDateDirection value.
 247      * @deprecated ICU 58 The numeric value may change over time, see ICU ticket #12420.
 248      */
 249     UDAT_DIRECTION_COUNT
 250 #endif  // U_HIDE_DEPRECATED_API
 251 } UDateDirection;
 252
 253 #if !UCONFIG_NO_BREAK_ITERATION
 254
 255 U_NAMESPACE_BEGIN
 256
 257 class BreakIterator;
 258 class RelativeDateTimeCacheData;
 259 class SharedNumberFormat;
 260 class SharedPluralRules;
 261 class SharedBreakIterator;
 262 class NumberFormat;
 263 class UnicodeString;
 264 class FormattedRelativeDateTime;
 265 class FormattedRelativeDateTimeData;
 266
 267 #ifndef U_HIDE_DRAFT_API
 268 /**
 269  * An immutable class containing the result of a relative datetime formatting operation.
 270  *
 271  * Instances of this class are immutable and thread-safe.
 272  *
 273  * Not intended for public subclassing.
 274  *
 275  * @draft ICU 64
 276  */
 277 class U_I18N_API FormattedRelativeDateTime : public UMemory, public FormattedValue {
 278   public:
 279     /**
 280      * Default constructor; makes an empty FormattedRelativeDateTime.
 281      * @draft ICU 64
 282      */
 283     FormattedRelativeDateTime() : fData(nullptr), fErrorCode(U_INVALID_STATE_ERROR) {}
 284
 285     /**
 286      * Move constructor: Leaves the source FormattedRelativeDateTime in an undefined state.
 287      * @draft ICU 64
 288      */
 289     FormattedRelativeDateTime(FormattedRelativeDateTime&& src) U_NOEXCEPT;
 290
 291     /**
 292      * Destruct an instance of FormattedRelativeDateTime.
 293      * @draft ICU 64
 294      */
 295     virtual ~FormattedRelativeDateTime() U_OVERRIDE;
 296
 297     /** Copying not supported; use move constructor instead. */
 298     FormattedRelativeDateTime(const FormattedRelativeDateTime&) = delete;
 299
 300     /** Copying not supported; use move assignment instead. */
 301     FormattedRelativeDateTime& operator=(const FormattedRelativeDateTime&) = delete;
 302
 303     /**
 304      * Move assignment: Leaves the source FormattedRelativeDateTime in an undefined state.
 305      * @draft ICU 64
 306      */
 307     FormattedRelativeDateTime& operator=(FormattedRelativeDateTime&& src) U_NOEXCEPT;
 308
 309     /** @copydoc FormattedValue::toString() */
 310     UnicodeString toString(UErrorCode& status) const U_OVERRIDE;
 311
 312     /** @copydoc FormattedValue::toTempString() */
 313     UnicodeString toTempString(UErrorCode& status) const U_OVERRIDE;
 314
 315     /** @copydoc FormattedValue::appendTo() */
 316     Appendable &appendTo(Appendable& appendable, UErrorCode& status) const U_OVERRIDE;
 317
 318     /** @copydoc FormattedValue::nextPosition() */
 319     UBool nextPosition(ConstrainedFieldPosition& cfpos, UErrorCode& status) const U_OVERRIDE;
 320
 321   private:
 322     FormattedRelativeDateTimeData *fData;
 323     UErrorCode fErrorCode;
 324     explicit FormattedRelativeDateTime(FormattedRelativeDateTimeData *results)
 325         : fData(results), fErrorCode(U_ZERO_ERROR) {}
 326     explicit FormattedRelativeDateTime(UErrorCode errorCode)
 327         : fData(nullptr), fErrorCode(errorCode) {}
 328     friend class RelativeDateTimeFormatter;
 329 };
 330 #endif  /* U_HIDE_DRAFT_API */
 331
 332 /**
 333  * Formats simple relative dates. There are two types of relative dates that
 334  * it handles:
 335  * <ul>
 336  *   <li>relative dates with a quantity e.g "in 5 days"</li>
 337  *   <li>relative dates without a quantity e.g "next Tuesday"</li>
 338  * </ul>
 339  * <p>
 340  * This API is very basic and is intended to be a building block for more
 341  * fancy APIs. The caller tells it exactly what to display in a locale
 342  * independent way. While this class automatically provides the correct plural
 343  * forms, the grammatical form is otherwise as neutral as possible. It is the
 344  * caller's responsibility to handle cut-off logic such as deciding between
 345  * displaying "in 7 days" or "in 1 week." This API supports relative dates
 346  * involving one single unit. This API does not support relative dates
 347  * involving compound units,
 348  * e.g "in 5 days and 4 hours" nor does it support parsing.
 349  * <p>
 350  * This class is mostly thread safe and immutable with the following caveats:
 351  * 1. The assignment operator violates Immutability. It must not be used
 352  *    concurrently with other operations.
 353  * 2. Caller must not hold onto adopted pointers.
 354  * <p>
 355  * This class is not intended for public subclassing.
 356  * <p>
 357  * Here are some examples of use:
 358  * <blockquote>
 359  * <pre>
 360  * UErrorCode status = U_ZERO_ERROR;
 361  * UnicodeString appendTo;
 362  * RelativeDateTimeFormatter fmt(status);
 363  * // Appends "in 1 day"
 364  * fmt.format(
 365  *     1, UDAT_DIRECTION_NEXT, UDAT_RELATIVE_DAYS, appendTo, status);
 366  * // Appends "in 3 days"
 367  * fmt.format(
 368  *     3, UDAT_DIRECTION_NEXT, UDAT_RELATIVE_DAYS, appendTo, status);
 369  * // Appends "3.2 years ago"
 370  * fmt.format(
 371  *     3.2, UDAT_DIRECTION_LAST, UDAT_RELATIVE_YEARS, appendTo, status);
 372  * // Appends "last Sunday"
 373  * fmt.format(UDAT_DIRECTION_LAST, UDAT_ABSOLUTE_SUNDAY, appendTo, status);
 374  * // Appends "this Sunday"
 375  * fmt.format(UDAT_DIRECTION_THIS, UDAT_ABSOLUTE_SUNDAY, appendTo, status);
 376  * // Appends "next Sunday"
 377  * fmt.format(UDAT_DIRECTION_NEXT, UDAT_ABSOLUTE_SUNDAY, appendTo, status);
 378  * // Appends "Sunday"
 379  * fmt.format(UDAT_DIRECTION_PLAIN, UDAT_ABSOLUTE_SUNDAY, appendTo, status);
 380  *
 381  * // Appends "yesterday"
 382  * fmt.format(UDAT_DIRECTION_LAST, UDAT_ABSOLUTE_DAY, appendTo, status);
 383  * // Appends "today"
 384  * fmt.format(UDAT_DIRECTION_THIS, UDAT_ABSOLUTE_DAY, appendTo, status);
 385  * // Appends "tomorrow"
 386  * fmt.format(UDAT_DIRECTION_NEXT, UDAT_ABSOLUTE_DAY, appendTo, status);
 387  * // Appends "now"
 388  * fmt.format(UDAT_DIRECTION_PLAIN, UDAT_ABSOLUTE_NOW, appendTo, status);
 389  *
 390  * </pre>
 391  * </blockquote>
 392  * <p>
 393  * In the future, we may add more forms, such as abbreviated/short forms
 394  * (3 secs ago), and relative day periods ("yesterday afternoon"), etc.
 395  *
 396  * The RelativeDateTimeFormatter class is not intended for public subclassing.
 397  *
 398  * @stable ICU 53
 399  */
 400 class U_I18N_API RelativeDateTimeFormatter : public UObject {
 401 public:
 402
 403     /**
 404      * Create RelativeDateTimeFormatter with default locale.
 405      * @stable ICU 53
 406      */
 407     RelativeDateTimeFormatter(UErrorCode& status);
 408
 409     /**
 410      * Create RelativeDateTimeFormatter with given locale.
 411      * @stable ICU 53
 412      */
 413     RelativeDateTimeFormatter(const Locale& locale, UErrorCode& status);
 414
 415     /**
 416      * Create RelativeDateTimeFormatter with given locale and NumberFormat.
 417      *
 418      * @param locale the locale
 419      * @param nfToAdopt Constructed object takes ownership of this pointer.
 420      *   It is an error for caller to delete this pointer or change its
 421      *   contents after calling this constructor.
 422      * @param status Any error is returned here.
 423      * @stable ICU 53
 424      */
 425     RelativeDateTimeFormatter(
 426         const Locale& locale, NumberFormat *nfToAdopt, UErrorCode& status);
 427
 428     /**
 429      * Create RelativeDateTimeFormatter with given locale, NumberFormat,
 430      * and capitalization context.
 431      *
 432      * @param locale the locale
 433      * @param nfToAdopt Constructed object takes ownership of this pointer.
 434      *   It is an error for caller to delete this pointer or change its
 435      *   contents after calling this constructor. Caller may pass NULL for
 436      *   this argument if they want default number format behavior.
 437      * @param style the format style. The UDAT_RELATIVE bit field has no effect.
 438      * @param capitalizationContext A value from UDisplayContext that pertains to
 439      * capitalization.
 440      * @param status Any error is returned here.
 441      * @stable ICU 54
 442      */
 443     RelativeDateTimeFormatter(
 444             const Locale& locale,
 445             NumberFormat *nfToAdopt,
 446             UDateRelativeDateTimeFormatterStyle style,
 447             UDisplayContext capitalizationContext,
 448             UErrorCode& status);
 449
 450     /**
 451      * Copy constructor.
 452      * @stable ICU 53
 453      */
 454     RelativeDateTimeFormatter(const RelativeDateTimeFormatter& other);
 455
 456     /**
 457      * Assignment operator.
 458      * @stable ICU 53
 459      */
 460     RelativeDateTimeFormatter& operator=(
 461             const RelativeDateTimeFormatter& other);
 462
 463     /**
 464      * Destructor.
 465      * @stable ICU 53
 466      */
 467     virtual ~RelativeDateTimeFormatter();
 468
 469     /**
 470      * Formats a relative date with a quantity such as "in 5 days" or
 471      * "3 months ago"
 472      *
 473      * This method returns a String. To get more information about the
 474      * formatting result, use formatToValue().
 475      *
 476      * @param quantity The numerical amount e.g 5. This value is formatted
 477      * according to this object's NumberFormat object.
 478      * @param direction NEXT means a future relative date; LAST means a past
 479      * relative date. If direction is anything else, this method sets
 480      * status to U_ILLEGAL_ARGUMENT_ERROR.
 481      * @param unit the unit e.g day? month? year?
 482      * @param appendTo The string to which the formatted result will be
 483      *  appended
 484      * @param status ICU error code returned here.
 485      * @return appendTo
 486      * @stable ICU 53
 487      */
 488     UnicodeString& format(
 489             double quantity,
 490             UDateDirection direction,
 491             UDateRelativeUnit unit,
 492             UnicodeString& appendTo,
 493             UErrorCode& status) const;
 494
 495 #ifndef U_HIDE_DRAFT_API
 496     /**
 497      * Formats a relative date with a quantity such as "in 5 days" or
 498      * "3 months ago"
 499      *
 500      * This method returns a FormattedRelativeDateTime, which exposes more
 501      * information than the String returned by format().
 502      *
 503      * @param quantity The numerical amount e.g 5. This value is formatted
 504      * according to this object's NumberFormat object.
 505      * @param direction NEXT means a future relative date; LAST means a past
 506      * relative date. If direction is anything else, this method sets
 507      * status to U_ILLEGAL_ARGUMENT_ERROR.
 508      * @param unit the unit e.g day? month? year?
 509      * @param status ICU error code returned here.
 510      * @return The formatted relative datetime
 511      * @draft ICU 64
 512      */
 513     FormattedRelativeDateTime formatToValue(
 514             double quantity,
 515             UDateDirection direction,
 516             UDateRelativeUnit unit,
 517             UErrorCode& status) const;
 518 #endif  /* U_HIDE_DRAFT_API */
 519
 520     /**
 521      * Formats a relative date without a quantity.
 522      *
 523      * This method returns a String. To get more information about the
 524      * formatting result, use formatToValue().
 525      *
 526      * @param direction NEXT, LAST, THIS, etc.
 527      * @param unit e.g SATURDAY, DAY, MONTH
 528      * @param appendTo The string to which the formatted result will be
 529      *  appended. If the value of direction is documented as not being fully
 530      *  supported in all locales then this method leaves appendTo unchanged if
 531      *  no format string is available.
 532      * @param status ICU error code returned here.
 533      * @return appendTo
 534      * @stable ICU 53
 535      */
 536     UnicodeString& format(
 537             UDateDirection direction,
 538             UDateAbsoluteUnit unit,
 539             UnicodeString& appendTo,
 540             UErrorCode& status) const;
 541
 542 #ifndef U_HIDE_DRAFT_API
 543     /**
 544      * Formats a relative date without a quantity.
 545      *
 546      * This method returns a FormattedRelativeDateTime, which exposes more
 547      * information than the String returned by format().
 548      *
 549      * If the string is not available in the requested locale, the return
 550      * value will be empty (calling toString will give an empty string).
 551      *
 552      * @param direction NEXT, LAST, THIS, etc.
 553      * @param unit e.g SATURDAY, DAY, MONTH
 554      * @param status ICU error code returned here.
 555      * @return The formatted relative datetime
 556      * @draft ICU 64
 557      */
 558     FormattedRelativeDateTime formatToValue(
 559             UDateDirection direction,
 560             UDateAbsoluteUnit unit,
 561             UErrorCode& status) const;
 562 #endif  /* U_HIDE_DRAFT_API */
 563
 564     /**
 565      * Format a combination of URelativeDateTimeUnit and numeric offset
 566      * using a numeric style, e.g. "1 week ago", "in 1 week",
 567      * "5 weeks ago", "in 5 weeks".
 568      *
 569      * This method returns a String. To get more information about the
 570      * formatting result, use formatNumericToValue().
 571      *
 572      * @param offset    The signed offset for the specified unit. This
 573      *                  will be formatted according to this object's
 574      *                  NumberFormat object.
 575      * @param unit      The unit to use when formatting the relative
 576      *                  date, e.g. UDAT_REL_UNIT_WEEK,
 577      *                  UDAT_REL_UNIT_FRIDAY.
 578      * @param appendTo  The string to which the formatted result will be
 579      *                  appended.
 580      * @param status    ICU error code returned here.
 581      * @return          appendTo
 582      * @stable ICU 57
 583      */
 584     UnicodeString& formatNumeric(
 585             double offset,
 586             URelativeDateTimeUnit unit,
 587             UnicodeString& appendTo,
 588             UErrorCode& status) const;
 589
 590 #ifndef U_HIDE_DRAFT_API
 591     /**
 592      * Format a combination of URelativeDateTimeUnit and numeric offset
 593      * using a numeric style, e.g. "1 week ago", "in 1 week",
 594      * "5 weeks ago", "in 5 weeks".
 595      *
 596      * This method returns a FormattedRelativeDateTime, which exposes more
 597      * information than the String returned by formatNumeric().
 598      *
 599      * @param offset    The signed offset for the specified unit. This
 600      *                  will be formatted according to this object's
 601      *                  NumberFormat object.
 602      * @param unit      The unit to use when formatting the relative
 603      *                  date, e.g. UDAT_REL_UNIT_WEEK,
 604      *                  UDAT_REL_UNIT_FRIDAY.
 605      * @param status    ICU error code returned here.
 606      * @return          The formatted relative datetime
 607      * @draft ICU 64
 608      */
 609     FormattedRelativeDateTime formatNumericToValue(
 610             double offset,
 611             URelativeDateTimeUnit unit,
 612             UErrorCode& status) const;
 613 #endif  /* U_HIDE_DRAFT_API */
 614
 615     /**
 616      * Format a combination of URelativeDateTimeUnit and numeric offset
 617      * using a text style if possible, e.g. "last week", "this week",
 618      * "next week", "yesterday", "tomorrow". Falls back to numeric
 619      * style if no appropriate text term is available for the specified
 620      * offset in the object's locale.
 621      *
 622      * This method returns a String. To get more information about the
 623      * formatting result, use formatToValue().
 624      *
 625      * @param offset    The signed offset for the specified unit.
 626      * @param unit      The unit to use when formatting the relative
 627      *                  date, e.g. UDAT_REL_UNIT_WEEK,
 628      *                  UDAT_REL_UNIT_FRIDAY.
 629      * @param appendTo  The string to which the formatted result will be
 630      *                  appended.
 631      * @param status    ICU error code returned here.
 632      * @return          appendTo
 633      * @stable ICU 57
 634      */
 635     UnicodeString& format(
 636             double offset,
 637             URelativeDateTimeUnit unit,
 638             UnicodeString& appendTo,
 639             UErrorCode& status) const;
 640
 641 #ifndef U_HIDE_DRAFT_API
 642     /**
 643      * Format a combination of URelativeDateTimeUnit and numeric offset
 644      * using a text style if possible, e.g. "last week", "this week",
 645      * "next week", "yesterday", "tomorrow". Falls back to numeric
 646      * style if no appropriate text term is available for the specified
 647      * offset in the object's locale.
 648      *
 649      * This method returns a FormattedRelativeDateTime, which exposes more
 650      * information than the String returned by format().
 651      *
 652      * @param offset    The signed offset for the specified unit.
 653      * @param unit      The unit to use when formatting the relative
 654      *                  date, e.g. UDAT_REL_UNIT_WEEK,
 655      *                  UDAT_REL_UNIT_FRIDAY.
 656      * @param status    ICU error code returned here.
 657      * @return          The formatted relative datetime
 658      * @draft ICU 64
 659      */
 660     FormattedRelativeDateTime formatToValue(
 661             double offset,
 662             URelativeDateTimeUnit unit,
 663             UErrorCode& status) const;
 664 #endif  /* U_HIDE_DRAFT_API */
 665
 666     /**
 667      * Combines a relative date string and a time string in this object's
 668      * locale. This is done with the same date-time separator used for the
 669      * default calendar in this locale.
 670      *
 671      * @param relativeDateString the relative date, e.g 'yesterday'
 672      * @param timeString the time e.g '3:45'
 673      * @param appendTo concatenated date and time appended here
 674      * @param status ICU error code returned here.
 675      * @return appendTo
 676      * @stable ICU 53
 677      */
 678     UnicodeString& combineDateAndTime(
 679             const UnicodeString& relativeDateString,
 680             const UnicodeString& timeString,
 681             UnicodeString& appendTo,
 682             UErrorCode& status) const;
 683
 684     /**
 685      * Returns the NumberFormat this object is using.
 686      *
 687      * @stable ICU 53
 688      */
 689     const NumberFormat& getNumberFormat() const;
 690
 691     /**
 692      * Returns the capitalization context.
 693      *
 694      * @stable ICU 54
 695      */
 696     UDisplayContext getCapitalizationContext() const;
 697
 698     /**
 699      * Returns the format style.
 700      *
 701      * @stable ICU 54
 702      */
 703     UDateRelativeDateTimeFormatterStyle getFormatStyle() const;
 704
 705 private:
 706     const RelativeDateTimeCacheData* fCache;
 707     const SharedNumberFormat *fNumberFormat;
 708     const SharedPluralRules *fPluralRules;
 709     UDateRelativeDateTimeFormatterStyle fStyle;
 710     UDisplayContext fContext;
 711     const SharedBreakIterator *fOptBreakIterator;
 712     Locale fLocale;
 713     void init(
 714             NumberFormat *nfToAdopt,
 715             BreakIterator *brkIter,
 716             UErrorCode &status);
 717     UnicodeString& adjustForContext(UnicodeString &) const;
 718     UBool checkNoAdjustForContext(UErrorCode& status) const;
 719
 720     template<typename F, typename... Args>
 721     UnicodeString& doFormat(
 722             F callback,
 723             UnicodeString& appendTo,
 724             UErrorCode& status,
 725             Args... args) const;
 726
 727 #ifndef U_HIDE_DRAFT_API  // for FormattedRelativeDateTime
 728     template<typename F, typename... Args>
 729     FormattedRelativeDateTime doFormatToValue(
 730             F callback,
 731             UErrorCode& status,
 732             Args... args) const;
 733 #endif  // U_HIDE_DRAFT_API
 734
 735     void formatImpl(
 736             double quantity,
 737             UDateDirection direction,
 738             UDateRelativeUnit unit,
 739             FormattedRelativeDateTimeData& output,
 740             UErrorCode& status) const;
 741     void formatAbsoluteImpl(
 742             UDateDirection direction,
 743             UDateAbsoluteUnit unit,
 744             FormattedRelativeDateTimeData& output,
 745             UErrorCode& status) const;
 746     void formatNumericImpl(
 747             double offset,
 748             URelativeDateTimeUnit unit,
 749             FormattedRelativeDateTimeData& output,
 750             UErrorCode& status) const;
 751     void formatRelativeImpl(
 752             double offset,
 753             URelativeDateTimeUnit unit,
 754             FormattedRelativeDateTimeData& output,
 755             UErrorCode& status) const;
 756 };
 757
 758 U_NAMESPACE_END
 759
 760 #endif /* !UCONFIG_NO_BREAK_ITERATION */
 761 #endif /* !UCONFIG_NO_FORMATTING */
 762
 763 #endif /* U_SHOW_CPLUSPLUS_API */
 764
 765 #endif /* __RELDATEFMT_H */