icuSources/common/uelement.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) 1997-2011, International Business Machines
   6 *   Corporation and others.  All Rights Reserved.
   7 *******************************************************************************
   8 *   file name:  uelement.h
   9 *   encoding:   UTF-8
  10 *   tab size:   8 (not used)
  11 *   indentation:4
  12 *
  13 *   created on: 2011jul04
  14 *   created by: Markus W. Scherer
  15 *
  16 *   Common definitions for UHashTable and UVector.
  17 *   UHashTok moved here from uhash.h and renamed UElement.
  18 *   This allows users of UVector to avoid the confusing #include of uhash.h.
  19 *   uhash.h aliases UElement to UHashTok,
  20 *   so that we need not change all of its code and its users.
  21 */
  22
  23 #ifndef __UELEMENT_H__
  24 #define __UELEMENT_H__
  25
  26 #include "unicode/utypes.h"
  27
  28 U_CDECL_BEGIN
  29
  30 /**
  31  * A UVector element, or a key or value within a UHashtable.
  32  * It may be either a 32-bit integral value or an opaque void* pointer.
  33  * The void* pointer may be smaller than 32 bits (e.g. 24 bits)
  34  * or may be larger (e.g. 64 bits).
  35  *
  36  * Because a UElement is the size of a native pointer or a 32-bit
  37  * integer, we pass it around by value.
  38  */
  39 union UElement {
  40     void*   pointer;
  41     int32_t integer;
  42 };
  43 typedef union UElement UElement;
  44
  45 /**
  46  * An element-equality (boolean) comparison function.
  47  * @param e1 An element (object or integer)
  48  * @param e2 An element (object or integer)
  49  * @return TRUE if the two elements are equal.
  50  */
  51 typedef UBool U_CALLCONV UElementsAreEqual(const UElement e1, const UElement e2);
  52
  53 /**
  54  * An element sorting (three-way) comparison function.
  55  * @param e1 An element (object or integer)
  56  * @param e2 An element (object or integer)
  57  * @return 0 if the two elements are equal, -1 if e1 is < e2, or +1 if e1 is > e2.
  58  */
  59 typedef int8_t U_CALLCONV UElementComparator(UElement e1, UElement e2);
  60
  61 /**
  62  * An element assignment function.  It may copy an integer, copy
  63  * a pointer, or clone a pointer, as appropriate.
  64  * @param dst The element to be assigned to
  65  * @param src The element to assign from
  66  */
  67 typedef void U_CALLCONV UElementAssigner(UElement *dst, UElement *src);
  68
  69 U_CDECL_END
  70
  71 /**
  72  * Comparator function for UnicodeString* keys. Implements UElementsAreEqual.
  73  * @param key1 The string for comparison
  74  * @param key2 The string for comparison
  75  * @return true if key1 and key2 are equal, return false otherwise.
  76  */
  77 U_CAPI UBool U_EXPORT2
  78 uhash_compareUnicodeString(const UElement key1, const UElement key2);
  79
  80 /**
  81  * Comparator function for UnicodeString* keys (case insensitive).
  82  * Make sure to use together with uhash_hashCaselessUnicodeString.
  83  * Implements UElementsAreEqual.
  84  * @param key1 The string for comparison
  85  * @param key2 The string for comparison
  86  * @return true if key1 and key2 are equal, return false otherwise.
  87  */
  88 U_CAPI UBool U_EXPORT2
  89 uhash_compareCaselessUnicodeString(const UElement key1, const UElement key2);
  90
  91 #endif  /* __UELEMENT_H__ */