Gecko [ www.floatingcartbutton.com ]

Name	Size	Permission	Date
alphaindex.h	26.43 KB	-rw-r--r--	2026-04-09 08:47
appendable.h	8.54 KB	-rw-r--r--	2026-04-09 08:47
basictz.h	9.99 KB	-rw-r--r--	2026-04-09 08:47
brkiter.h	28.52 KB	-rw-r--r--	2026-04-09 08:47
bytestream.h	11.79 KB	-rw-r--r--	2026-04-09 08:47
bytestrie.h	20.83 KB	-rw-r--r--	2026-04-09 08:47
bytestriebuilder.h	7.44 KB	-rw-r--r--	2026-04-09 08:47
calendar.h	110.47 KB	-rw-r--r--	2026-04-09 08:47
caniter.h	7.47 KB	-rw-r--r--	2026-04-09 08:47
casemap.h	25.42 KB	-rw-r--r--	2026-04-09 08:47
char16ptr.h	10.79 KB	-rw-r--r--	2026-04-09 08:47
chariter.h	23.79 KB	-rw-r--r--	2026-04-09 08:47
choicfmt.h	23.99 KB	-rw-r--r--	2026-04-09 08:47
coleitr.h	13.78 KB	-rw-r--r--	2026-04-09 08:47
coll.h	59.5 KB	-rw-r--r--	2026-04-09 08:47
compactdecimalformat.h	6.88 KB	-rw-r--r--	2026-04-09 08:47
curramt.h	3.67 KB	-rw-r--r--	2026-04-09 08:47
currpinf.h	7.3 KB	-rw-r--r--	2026-04-09 08:47
currunit.h	4.02 KB	-rw-r--r--	2026-04-09 08:47
datefmt.h	41.29 KB	-rw-r--r--	2026-04-09 08:47
dbbi.h	1.19 KB	-rw-r--r--	2026-04-09 08:47
dcfmtsym.h	21.27 KB	-rw-r--r--	2026-04-09 08:47
decimfmt.h	87.45 KB	-rw-r--r--	2026-04-09 08:47
displayoptions.h	7.08 KB	-rw-r--r--	2026-04-09 08:47
docmain.h	7.66 KB	-rw-r--r--	2026-04-09 08:47
dtfmtsym.h	41.04 KB	-rw-r--r--	2026-04-09 08:47
dtintrv.h	3.84 KB	-rw-r--r--	2026-04-09 08:47
dtitvfmt.h	49.2 KB	-rw-r--r--	2026-04-09 08:47
dtitvinf.h	18.54 KB	-rw-r--r--	2026-04-09 08:47
dtptngen.h	29.28 KB	-rw-r--r--	2026-04-09 08:47
dtrule.h	8.66 KB	-rw-r--r--	2026-04-09 08:47
edits.h	20.74 KB	-rw-r--r--	2026-04-09 08:47
enumset.h	2.08 KB	-rw-r--r--	2026-04-09 08:47
errorcode.h	4.84 KB	-rw-r--r--	2026-04-09 08:47
fieldpos.h	8.69 KB	-rw-r--r--	2026-04-09 08:47
filteredbrk.h	5.37 KB	-rw-r--r--	2026-04-09 08:47
fmtable.h	24.36 KB	-rw-r--r--	2026-04-09 08:47
format.h	12.78 KB	-rw-r--r--	2026-04-09 08:47
formattednumber.h	6.25 KB	-rw-r--r--	2026-04-09 08:47
formattedvalue.h	9.75 KB	-rw-r--r--	2026-04-09 08:47
fpositer.h	3.03 KB	-rw-r--r--	2026-04-09 08:47
gender.h	3.35 KB	-rw-r--r--	2026-04-09 08:47
gregocal.h	30.05 KB	-rw-r--r--	2026-04-09 08:47
icudataver.h	1.02 KB	-rw-r--r--	2026-04-09 08:47
icuplug.h	12.1 KB	-rw-r--r--	2026-04-09 08:47
idna.h	12.93 KB	-rw-r--r--	2026-04-09 08:47
listformatter.h	8.59 KB	-rw-r--r--	2026-04-09 08:47
localebuilder.h	11.09 KB	-rw-r--r--	2026-04-09 08:47
localematcher.h	26.86 KB	-rw-r--r--	2026-04-09 08:47
localpointer.h	19.52 KB	-rw-r--r--	2026-04-09 08:47
locdspnm.h	7.12 KB	-rw-r--r--	2026-04-09 08:47
locid.h	53.98 KB	-rw-r--r--	2026-04-09 08:47
measfmt.h	11.41 KB	-rw-r--r--	2026-04-09 08:47
measunit.h	133.12 KB	-rw-r--r--	2026-04-09 08:47
measure.h	4.63 KB	-rw-r--r--	2026-04-09 08:47
messageformat2.h	21.59 KB	-rw-r--r--	2026-04-09 08:47
messageformat2_arguments.h	3.84 KB	-rw-r--r--	2026-04-09 08:47
messageformat2_data_model.h	96.61 KB	-rw-r--r--	2026-04-09 08:47
messageformat2_data_model_names.h	784 B	-rw-r--r--	2026-04-09 08:47
messageformat2_formattable.h	39.37 KB	-rw-r--r--	2026-04-09 08:47
messageformat2_function_registry.h	18.07 KB	-rw-r--r--	2026-04-09 08:47
messagepattern.h	33.79 KB	-rw-r--r--	2026-04-09 08:47
msgfmt.h	44.94 KB	-rw-r--r--	2026-04-09 08:47
normalizer2.h	34.68 KB	-rw-r--r--	2026-04-09 08:47
normlzr.h	30.79 KB	-rw-r--r--	2026-04-09 08:47
nounit.h	2.24 KB	-rw-r--r--	2026-04-09 08:47
numberformatter.h	90.72 KB	-rw-r--r--	2026-04-09 08:47
numberrangeformatter.h	25.68 KB	-rw-r--r--	2026-04-09 08:47
numfmt.h	50.16 KB	-rw-r--r--	2026-04-09 08:47
numsys.h	7.22 KB	-rw-r--r--	2026-04-09 08:47
parseerr.h	3.08 KB	-rw-r--r--	2026-04-09 08:47
parsepos.h	5.56 KB	-rw-r--r--	2026-04-09 08:47
platform.h	27.19 KB	-rw-r--r--	2026-04-09 08:47
plurfmt.h	25.46 KB	-rw-r--r--	2026-04-09 08:47
plurrule.h	20.63 KB	-rw-r--r--	2026-04-09 08:47
ptypes.h	2.16 KB	-rw-r--r--	2026-04-09 08:47
putil.h	6.32 KB	-rw-r--r--	2026-04-09 08:47
rbbi.h	31.73 KB	-rw-r--r--	2026-04-09 08:47
rbnf.h	57.19 KB	-rw-r--r--	2026-04-09 08:47
rbtz.h	15.75 KB	-rw-r--r--	2026-04-09 08:47
regex.h	83.83 KB	-rw-r--r--	2026-04-09 08:47
region.h	9.2 KB	-rw-r--r--	2026-04-09 08:47
reldatefmt.h	22.69 KB	-rw-r--r--	2026-04-09 08:47
rep.h	9.38 KB	-rw-r--r--	2026-04-09 08:47
resbund.h	18.02 KB	-rw-r--r--	2026-04-09 08:47
schriter.h	6.09 KB	-rw-r--r--	2026-04-09 08:47
scientificnumberformatter.h	6.44 KB	-rw-r--r--	2026-04-09 08:47
search.h	22.21 KB	-rw-r--r--	2026-04-09 08:47
selfmt.h	14.35 KB	-rw-r--r--	2026-04-09 08:47
simpleformatter.h	12.6 KB	-rw-r--r--	2026-04-09 08:47
simplenumberformatter.h	8.87 KB	-rw-r--r--	2026-04-09 08:47
simpletz.h	45.62 KB	-rw-r--r--	2026-04-09 08:47
smpdtfmt.h	57.57 KB	-rw-r--r--	2026-04-09 08:47
sortkey.h	11.13 KB	-rw-r--r--	2026-04-09 08:47
std_string.h	1.05 KB	-rw-r--r--	2026-04-09 08:47
strenum.h	9.96 KB	-rw-r--r--	2026-04-09 08:47
stringoptions.h	5.79 KB	-rw-r--r--	2026-04-09 08:47
stringpiece.h	10.29 KB	-rw-r--r--	2026-04-09 08:47
stringtriebuilder.h	15.53 KB	-rw-r--r--	2026-04-09 08:47
stsearch.h	21.43 KB	-rw-r--r--	2026-04-09 08:47
symtable.h	4.28 KB	-rw-r--r--	2026-04-09 08:47
tblcoll.h	38.79 KB	-rw-r--r--	2026-04-09 08:47
timezone.h	45.59 KB	-rw-r--r--	2026-04-09 08:47
tmunit.h	3.37 KB	-rw-r--r--	2026-04-09 08:47
tmutamt.h	4.9 KB	-rw-r--r--	2026-04-09 08:47
tmutfmt.h	7.42 KB	-rw-r--r--	2026-04-09 08:47
translit.h	65.81 KB	-rw-r--r--	2026-04-09 08:47
tzfmt.h	44.76 KB	-rw-r--r--	2026-04-09 08:47
tznames.h	16.85 KB	-rw-r--r--	2026-04-09 08:47
tzrule.h	34.81 KB	-rw-r--r--	2026-04-09 08:47
tztrans.h	6.11 KB	-rw-r--r--	2026-04-09 08:47
ubidi.h	89.61 KB	-rw-r--r--	2026-04-09 08:47
ubiditransform.h	12.71 KB	-rw-r--r--	2026-04-09 08:47
ubrk.h	24.43 KB	-rw-r--r--	2026-04-09 08:47
ucal.h	63.95 KB	-rw-r--r--	2026-04-09 08:47
ucasemap.h	15.27 KB	-rw-r--r--	2026-04-09 08:47
ucat.h	5.35 KB	-rw-r--r--	2026-04-09 08:47
uchar.h	152.33 KB	-rw-r--r--	2026-04-09 08:47
ucharstrie.h	22.59 KB	-rw-r--r--	2026-04-09 08:47
ucharstriebuilder.h	7.48 KB	-rw-r--r--	2026-04-09 08:47
uchriter.h	13.24 KB	-rw-r--r--	2026-04-09 08:47
uclean.h	11.21 KB	-rw-r--r--	2026-04-09 08:47
ucnv.h	83.34 KB	-rw-r--r--	2026-04-09 08:47
ucnv_cb.h	6.58 KB	-rw-r--r--	2026-04-09 08:47
ucnv_err.h	20.98 KB	-rw-r--r--	2026-04-09 08:47
ucnvsel.h	6.24 KB	-rw-r--r--	2026-04-09 08:47
ucol.h	67.35 KB	-rw-r--r--	2026-04-09 08:47
ucoleitr.h	9.82 KB	-rw-r--r--	2026-04-09 08:47
uconfig.h	12.56 KB	-rw-r--r--	2026-04-09 08:47
ucpmap.h	5.54 KB	-rw-r--r--	2026-04-09 08:47
ucptrie.h	22.51 KB	-rw-r--r--	2026-04-09 08:47
ucsdet.h	14.69 KB	-rw-r--r--	2026-04-09 08:47
ucurr.h	16.72 KB	-rw-r--r--	2026-04-09 08:47
udat.h	62.66 KB	-rw-r--r--	2026-04-09 08:47
udata.h	15.63 KB	-rw-r--r--	2026-04-09 08:47
udateintervalformat.h	11.93 KB	-rw-r--r--	2026-04-09 08:47
udatpg.h	30.13 KB	-rw-r--r--	2026-04-09 08:47
udisplaycontext.h	5.94 KB	-rw-r--r--	2026-04-09 08:47
udisplayoptions.h	8.86 KB	-rw-r--r--	2026-04-09 08:47
uenum.h	7.79 KB	-rw-r--r--	2026-04-09 08:47
ufieldpositer.h	4.41 KB	-rw-r--r--	2026-04-09 08:47
uformattable.h	10.97 KB	-rw-r--r--	2026-04-09 08:47
uformattednumber.h	8.09 KB	-rw-r--r--	2026-04-09 08:47
uformattedvalue.h	12.25 KB	-rw-r--r--	2026-04-09 08:47
ugender.h	2.06 KB	-rw-r--r--	2026-04-09 08:47
uidna.h	34.12 KB	-rw-r--r--	2026-04-09 08:47
uiter.h	22.75 KB	-rw-r--r--	2026-04-09 08:47
uldnames.h	10.48 KB	-rw-r--r--	2026-04-09 08:47
ulistformatter.h	10.78 KB	-rw-r--r--	2026-04-09 08:47
uloc.h	55.38 KB	-rw-r--r--	2026-04-09 08:47
ulocale.h	6.31 KB	-rw-r--r--	2026-04-09 08:47
ulocbuilder.h	16.69 KB	-rw-r--r--	2026-04-09 08:47
ulocdata.h	11.3 KB	-rw-r--r--	2026-04-09 08:47
umachine.h	15.25 KB	-rw-r--r--	2026-04-09 08:47
umisc.h	1.34 KB	-rw-r--r--	2026-04-09 08:47
umsg.h	24.25 KB	-rw-r--r--	2026-04-09 08:47
umutablecptrie.h	8.3 KB	-rw-r--r--	2026-04-09 08:47
unifilt.h	4 KB	-rw-r--r--	2026-04-09 08:47
unifunct.h	4.05 KB	-rw-r--r--	2026-04-09 08:47
unimatch.h	6.1 KB	-rw-r--r--	2026-04-09 08:47
unirepl.h	3.38 KB	-rw-r--r--	2026-04-09 08:47
uniset.h	70.18 KB	-rw-r--r--	2026-04-09 08:47
unistr.h	184.51 KB	-rw-r--r--	2026-04-09 08:47
unorm.h	20.55 KB	-rw-r--r--	2026-04-09 08:47
unorm2.h	25.66 KB	-rw-r--r--	2026-04-09 08:47
unum.h	55.16 KB	-rw-r--r--	2026-04-09 08:47
unumberformatter.h	19.68 KB	-rw-r--r--	2026-04-09 08:47
unumberoptions.h	5.23 KB	-rw-r--r--	2026-04-09 08:47
unumberrangeformatter.h	15.35 KB	-rw-r--r--	2026-04-09 08:47
unumsys.h	7.26 KB	-rw-r--r--	2026-04-09 08:47
uobject.h	10.6 KB	-rw-r--r--	2026-04-09 08:47
upluralrules.h	8.79 KB	-rw-r--r--	2026-04-09 08:47
uregex.h	71.99 KB	-rw-r--r--	2026-04-09 08:47
uregion.h	9.81 KB	-rw-r--r--	2026-04-09 08:47
ureldatefmt.h	16.98 KB	-rw-r--r--	2026-04-09 08:47
urename.h	142.22 KB	-rw-r--r--	2026-04-09 08:47
urep.h	5.38 KB	-rw-r--r--	2026-04-09 08:47
ures.h	36.65 KB	-rw-r--r--	2026-04-09 08:47
uscript.h	28.95 KB	-rw-r--r--	2026-04-09 08:47
usearch.h	39.21 KB	-rw-r--r--	2026-04-09 08:47
uset.h	63.03 KB	-rw-r--r--	2026-04-09 08:47
usetiter.h	9.63 KB	-rw-r--r--	2026-04-09 08:47
ushape.h	18 KB	-rw-r--r--	2026-04-09 08:47
usimplenumberformatter.h	7.31 KB	-rw-r--r--	2026-04-09 08:47
uspoof.h	80 KB	-rw-r--r--	2026-04-09 08:47
usprep.h	8.19 KB	-rw-r--r--	2026-04-09 08:47
ustdio.h	38.58 KB	-rw-r--r--	2026-04-09 08:47
ustream.h	1.89 KB	-rw-r--r--	2026-04-09 08:47
ustring.h	72.16 KB	-rw-r--r--	2026-04-09 08:47
ustringtrie.h	3.15 KB	-rw-r--r--	2026-04-09 08:47
utext.h	58.1 KB	-rw-r--r--	2026-04-09 08:47
utf.h	8.65 KB	-rw-r--r--	2026-04-09 08:47
utf16.h	23.35 KB	-rw-r--r--	2026-04-09 08:47
utf32.h	763 B	-rw-r--r--	2026-04-09 08:47
utf8.h	31.65 KB	-rw-r--r--	2026-04-09 08:47
utf_old.h	45.85 KB	-rw-r--r--	2026-04-09 08:47
utfiterator.h	95.02 KB	-rw-r--r--	2026-04-09 08:47
utfstring.h	4.89 KB	-rw-r--r--	2026-04-09 08:47
utmscale.h	13.78 KB	-rw-r--r--	2026-04-09 08:47
utrace.h	17.18 KB	-rw-r--r--	2026-04-09 08:47
utrans.h	25.54 KB	-rw-r--r--	2026-04-09 08:47
utypes.h	36.73 KB	-rw-r--r--	2026-04-09 08:47
uvernum.h	6.33 KB	-rw-r--r--	2026-04-09 08:47
uversion.h	8.21 KB	-rw-r--r--	2026-04-09 08:47
vtzone.h	20.68 KB	-rw-r--r--	2026-04-09 08:47

Rename

// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
// Copyright (C) 2009-2012, International Business Machines
// Corporation and others. All Rights Reserved.
//
// Copyright 2007 Google Inc. All Rights Reserved.
// Author: sanjay@google.com (Sanjay Ghemawat)
//
// Abstract interface that consumes a sequence of bytes (ByteSink).
//
// Used so that we can write a single piece of code that can operate
// on a variety of output string types.
//
// Various implementations of this interface are provided:
//   ByteSink:
//      CheckedArrayByteSink    Write to a flat array, with bounds checking
//      StringByteSink          Write to an STL string

// This code is a contribution of Google code, and the style used here is
// a compromise between the original Google code and the ICU coding guidelines.
// For example, data types are ICU-ified (size_t,int->int32_t),
// and API comments doxygen-ified, but function names and behavior are
// as in the original, if possible.
// Assertion-style error handling, not available in ICU, was changed to
// parameter "pinning" similar to UnicodeString.
//
// In addition, this is only a partial port of the original Google code,
// limited to what was needed so far. The (nearly) complete original code
// is in the ICU svn repository at icuhtml/trunk/design/strings/contrib
// (see ICU ticket 6765, r25517).

#ifndef __BYTESTREAM_H__
#define __BYTESTREAM_H__

/**
 * \file
 * \brief C++ API: Interface for writing bytes, and implementation classes.
 */

#include "unicode/utypes.h"

#if U_SHOW_CPLUSPLUS_API

#include <type_traits>

#include "unicode/uobject.h"
#include "unicode/std_string.h"

U_NAMESPACE_BEGIN

/**
 * A ByteSink can be filled with bytes.
 * @stable ICU 4.2
 */
class U_COMMON_API ByteSink : public UMemory {
public:
  /**
   * Default constructor.
   * @stable ICU 4.2
   */
  ByteSink() { }
  /**
   * Virtual destructor.
   * @stable ICU 4.2
   */
  virtual ~ByteSink();

/**
   * Append "bytes[0,n-1]" to this.
   * @param bytes the pointer to the bytes
   * @param n the number of bytes; must be non-negative
   * @stable ICU 4.2
   */
  virtual void Append(const char* bytes, int32_t n) = 0;

/**
   * Appends n bytes to this. Same as Append().
   * Call AppendU8() with u8"string literals" which are const char * in C++11
   * but const char8_t * in C++20.
   * If the compiler does support char8_t as a distinct type,
   * then an AppendU8() overload for that is defined and will be chosen.
   *
   * @param bytes the pointer to the bytes
   * @param n the number of bytes; must be non-negative
   * @stable ICU 67
   */
  inline void AppendU8(const char* bytes, int32_t n) {
    Append(bytes, n);
  }

#if defined(__cpp_char8_t) || defined(U_IN_DOXYGEN)
  /**
   * Appends n bytes to this. Same as Append() but for a const char8_t * pointer.
   * Call AppendU8() with u8"string literals" which are const char * in C++11
   * but const char8_t * in C++20.
   * If the compiler does support char8_t as a distinct type,
   * then this AppendU8() overload for that is defined and will be chosen.
   *
   * @param bytes the pointer to the bytes
   * @param n the number of bytes; must be non-negative
   * @stable ICU 67
   */
  inline void AppendU8(const char8_t* bytes, int32_t n) {
    Append(reinterpret_cast<const char*>(bytes), n);
  }
#endif

/**
   * Returns a writable buffer for appending and writes the buffer's capacity to
   * *result_capacity. Guarantees *result_capacity>=min_capacity.
   * May return a pointer to the caller-owned scratch buffer which must have
   * scratch_capacity>=min_capacity.
   * The returned buffer is only valid until the next operation
   * on this ByteSink.
   *
   * After writing at most *result_capacity bytes, call Append() with the
   * pointer returned from this function and the number of bytes written.
   * Many Append() implementations will avoid copying bytes if this function
   * returned an internal buffer.
   *
   * Partial usage example:
   *  int32_t capacity;
   *  char* buffer = sink->GetAppendBuffer(..., &capacity);
   *  ... Write n bytes into buffer, with n <= capacity.
   *  sink->Append(buffer, n);
   * In many implementations, that call to Append will avoid copying bytes.
   *
   * If the ByteSink allocates or reallocates an internal buffer, it should use
   * the desired_capacity_hint if appropriate.
   * If a caller cannot provide a reasonable guess at the desired capacity,
   * it should pass desired_capacity_hint=0.
   *
   * If a non-scratch buffer is returned, the caller may only pass
   * a prefix to it to Append().
   * That is, it is not correct to pass an interior pointer to Append().
   *
   * The default implementation always returns the scratch buffer.
   *
   * @param min_capacity required minimum capacity of the returned buffer;
   *                     must be non-negative
   * @param desired_capacity_hint desired capacity of the returned buffer;
   *                              must be non-negative
   * @param scratch default caller-owned buffer
   * @param scratch_capacity capacity of the scratch buffer
   * @param result_capacity pointer to an integer which will be set to the
   *                        capacity of the returned buffer
   * @return a buffer with *result_capacity>=min_capacity
   * @stable ICU 4.2
   */
  virtual char* GetAppendBuffer(int32_t min_capacity,
                                int32_t desired_capacity_hint,
                                char* scratch, int32_t scratch_capacity,
                                int32_t* result_capacity);

/**
   * Flush internal buffers.
   * Some byte sinks use internal buffers or provide buffering
   * and require calling Flush() at the end of the stream.
   * The ByteSink should be ready for further Append() calls after Flush().
   * The default implementation of Flush() does nothing.
   * @stable ICU 4.2
   */
  virtual void Flush();

private:
  ByteSink(const ByteSink &) = delete;
  ByteSink &operator=(const ByteSink &) = delete;
};

// -------------------------------------------------------------
// Some standard implementations

/** 
 * Implementation of ByteSink that writes to a flat byte array,
 * with bounds-checking:
 * This sink will not write more than capacity bytes to outbuf.
 * If more than capacity bytes are Append()ed, then excess bytes are ignored,
 * and Overflowed() will return true.
 * Overflow does not cause a runtime error.
 * @stable ICU 4.2
 */
class U_COMMON_API CheckedArrayByteSink : public ByteSink {
public:
  /**
   * Constructs a ByteSink that will write to outbuf[0..capacity-1].
   * @param outbuf buffer to write to
   * @param capacity size of the buffer
   * @stable ICU 4.2
   */
  CheckedArrayByteSink(char* outbuf, int32_t capacity);
  /**
   * Destructor.
   * @stable ICU 4.2
   */
  virtual ~CheckedArrayByteSink();
  /**
   * Returns the sink to its original state, without modifying the buffer.
   * Useful for reusing both the buffer and the sink for multiple streams.
   * Resets the state to NumberOfBytesWritten()=NumberOfBytesAppended()=0
   * and Overflowed()=false.
   * @return *this
   * @stable ICU 4.6
   */
  virtual CheckedArrayByteSink& Reset();
  /**
   * Append "bytes[0,n-1]" to this.
   * @param bytes the pointer to the bytes
   * @param n the number of bytes; must be non-negative
   * @stable ICU 4.2
   */
  virtual void Append(const char* bytes, int32_t n) override;
  /**
   * Returns a writable buffer for appending and writes the buffer's capacity to
   * *result_capacity. For details see the base class documentation.
   * @param min_capacity required minimum capacity of the returned buffer;
   *                     must be non-negative
   * @param desired_capacity_hint desired capacity of the returned buffer;
   *                              must be non-negative
   * @param scratch default caller-owned buffer
   * @param scratch_capacity capacity of the scratch buffer
   * @param result_capacity pointer to an integer which will be set to the
   *                        capacity of the returned buffer
   * @return a buffer with *result_capacity>=min_capacity
   * @stable ICU 4.2
   */
  virtual char* GetAppendBuffer(int32_t min_capacity,
                                int32_t desired_capacity_hint,
                                char* scratch, int32_t scratch_capacity,
                                int32_t* result_capacity) override;
  /**
   * Returns the number of bytes actually written to the sink.
   * @return number of bytes written to the buffer
   * @stable ICU 4.2
   */
  int32_t NumberOfBytesWritten() const { return size_; }
  /**
   * Returns true if any bytes were discarded, i.e., if there was an
   * attempt to write more than 'capacity' bytes.
   * @return true if more than 'capacity' bytes were Append()ed
   * @stable ICU 4.2
   */
  UBool Overflowed() const { return overflowed_; }
  /**
   * Returns the number of bytes appended to the sink.
   * If Overflowed() then NumberOfBytesAppended()>NumberOfBytesWritten()
   * else they return the same number.
   * @return number of bytes written to the buffer
   * @stable ICU 4.6
   */
  int32_t NumberOfBytesAppended() const { return appended_; }
private:
  char* outbuf_;
  const int32_t capacity_;
  int32_t size_;
  int32_t appended_;
  UBool overflowed_;

CheckedArrayByteSink() = delete;
  CheckedArrayByteSink(const CheckedArrayByteSink &) = delete;
  CheckedArrayByteSink &operator=(const CheckedArrayByteSink &) = delete;
};

namespace prv {
/** @internal */
template<typename StringClass, typename = void>
struct value_type_or_char {
  /** @internal */
  using type = char;
};
/** @internal */
template<typename StringClass>
struct value_type_or_char<StringClass, std::void_t<typename StringClass::value_type>> {
  /** @internal */
  using type = typename StringClass::value_type;
};
/** @internal */
template<typename StringClass>
using value_type_or_char_t = typename value_type_or_char<StringClass>::type;
}

/** 
 * Implementation of ByteSink that writes to a "string".
 * The StringClass is usually instantiated with a std::string or a std::u8string.
 * StringClass must have public member functions reserve(integer type), capacity(), length(), and
 * append(value type, integer type) with the same semantics as those of std::basic_string, and must
 * have an 8-bit value type.  If the value type is not char, it must be a public member type
 * StringClass::value_type.
 * @stable ICU 4.2
 */
template<typename StringClass>
class StringByteSink : public ByteSink {
  using Unit = typename prv::value_type_or_char_t<StringClass>;
 public:
  /**
   * Constructs a ByteSink that will append bytes to the dest string.
   * @param dest pointer to string object to append to
   * @stable ICU 4.2
   */
  StringByteSink(StringClass* dest) : dest_(dest) { }
  /**
   * Constructs a ByteSink that reserves append capacity and will append bytes to the dest string.
   * 
   * @param dest pointer to string object to append to
   * @param initialAppendCapacity capacity beyond dest->length() to be reserve()d
   * @stable ICU 60
   */
  StringByteSink(StringClass* dest, int32_t initialAppendCapacity) : dest_(dest) {
    if (initialAppendCapacity > 0 &&
        static_cast<uint32_t>(initialAppendCapacity) > dest->capacity() - dest->length()) {
      dest->reserve(dest->length() + initialAppendCapacity);
    }
  }
  /**
   * Append "bytes[0,n-1]" to this.
   * @param data the pointer to the bytes
   * @param n the number of bytes; must be non-negative
   * @stable ICU 4.2
   */
  virtual void Append(const char* data, int32_t n) override {
    if constexpr (std::is_same_v<Unit, char>) {
      dest_->append(data, n);
    } else {
      dest_->append(reinterpret_cast<const Unit*>(data), n);
    }
  }
 private:
  StringClass* dest_;

StringByteSink() = delete;
  StringByteSink(const StringByteSink &) = delete;
  StringByteSink &operator=(const StringByteSink &) = delete;
};

U_NAMESPACE_END

#endif /* U_SHOW_CPLUSPLUS_API */

#endif  // __BYTESTREAM_H__