icuSources/common/uelement.h

   1 /*
   2 *******************************************************************************
   3 *   Copyright (C) 1997-2011, International Business Machines
   4 *   Corporation and others.  All Rights Reserved.
   5 *******************************************************************************
   6 *   file name:  uelement.h
   7 *   encoding:   US-ASCII
   8 *   tab size:   8 (not used)
   9 *   indentation:4
  10 *
  11 *   created on: 2011jul04
  12 *   created by: Markus W. Scherer
  13 *
  14 *   Common definitions for UHashTable and UVector.
  15 *   UHashTok moved here from uhash.h and renamed UElement.
  16 *   This allows users of UVector to avoid the confusing #include of uhash.h.
  17 *   uhash.h aliases UElement to UHashTok,
  18 *   so that we need not change all of its code and its users.
  19 */
  20
  21 #ifndef __UELEMENT_H__
  22 #define __UELEMENT_H__
  23
  24 #include "unicode/utypes.h"
  25
  26 U_CDECL_BEGIN
  27
  28 /**
  29  * A UVector element, or a key or value within a UHashtable.
  30  * It may be either a 32-bit integral value or an opaque void* pointer.
  31  * The void* pointer may be smaller than 32 bits (e.g. 24 bits)
  32  * or may be larger (e.g. 64 bits).
  33  *
  34  * Because a UElement is the size of a native pointer or a 32-bit
  35  * integer, we pass it around by value.
  36  */
  37 union UElement {
  38     void*   pointer;
  39     int32_t integer;
  40 };
  41 typedef union UElement UElement;
  42
  43 /**
  44  * An element-equality (boolean) comparison function.
  45  * @param e1 An element (object or integer)
  46  * @param e2 An element (object or integer)
  47  * @return TRUE if the two elements are equal.
  48  */
  49 typedef UBool U_CALLCONV UElementsAreEqual(const UElement e1, const UElement e2);
  50
  51 /**
  52  * An element sorting (three-way) comparison function.
  53  * @param e1 An element (object or integer)
  54  * @param e2 An element (object or integer)
  55  * @return 0 if the two elements are equal, -1 if e1 is < e2, or +1 if e1 is > e2.
  56  */
  57 typedef int8_t U_CALLCONV UElementComparator(UElement e1, UElement e2);
  58
  59 /**
  60  * An element assignment function.  It may copy an integer, copy
  61  * a pointer, or clone a pointer, as appropriate.
  62  * @param dst The element to be assigned to
  63  * @param src The element to assign from
  64  */
  65 typedef void U_CALLCONV UElementAssigner(UElement *dst, UElement *src);
  66
  67 U_CDECL_END
  68
  69 /**
  70  * Comparator function for UnicodeString* keys. Implements UElementsAreEqual.
  71  * @param key1 The string for comparison
  72  * @param key2 The string for comparison
  73  * @return true if key1 and key2 are equal, return false otherwise.
  74  */
  75 U_CAPI UBool U_EXPORT2
  76 uhash_compareUnicodeString(const UElement key1, const UElement key2);
  77
  78 /**
  79  * Comparator function for UnicodeString* keys (case insensitive).
  80  * Make sure to use together with uhash_hashCaselessUnicodeString.
  81  * Implements UElementsAreEqual.
  82  * @param key1 The string for comparison
  83  * @param key2 The string for comparison
  84  * @return true if key1 and key2 are equal, return false otherwise.
  85  */
  86 U_CAPI UBool U_EXPORT2
  87 uhash_compareCaselessUnicodeString(const UElement key1, const UElement key2);
  88
  89 #endif  /* __UELEMENT_H__ */