ICU-531.30.tar.gz

[apple/icu.git] / icuSources / common / uarrsort.h

diff --git a/icuSources/common/uarrsort.h b/icuSources/common/uarrsort.h
index b9a580c7e22a84b3d268a0bf9fe4a44a11242a45..aece6da939ac09f3ecd8e83bb84f27e2751bd937 100644 (file)
--- a/icuSources/common/uarrsort.h
+++ b/icuSources/common/uarrsort.h
@@ -1,7 +1,7 @@
 /*
 *******************************************************************************
 *
-*   Copyright (C) 2003, International Business Machines
+*   Copyright (C) 2003-2013, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 *******************************************************************************
@@ -81,4 +81,21 @@ uprv_int32Comparator(const void *context, const void *left, const void *right);
 U_CAPI int32_t U_EXPORT2
 uprv_uint32Comparator(const void *context, const void *left, const void *right);
 
+/**
+ * Much like Java Collections.binarySearch(list, key, comparator).
+ *
+ * Except: Java documents "If the list contains multiple elements equal to
+ * the specified object, there is no guarantee which one will be found."
+ *
+ * This version here will return the largest index of any equal item,
+ * for use in stable sorting.
+ *
+ * @return the index>=0 where the item was found:
+ *         the largest such index, if multiple, for stable sorting;
+ *         or the index<0 for inserting the item at ~index in sorted order
+ */
+U_CAPI int32_t U_EXPORT2
+uprv_stableBinarySearch(char *array, int32_t length, void *item, int32_t itemSize,
+                        UComparator *cmp, const void *context);
+
 #endif