ICU-12604 BreakIterator, clarify that setText() retains a reference to the supplied text.

X-SVN-Rev: 39143

icu4c/source/common/unicode/brkiter.h

@@ -170,6 +170,11 @@ public:
     /**
      * Change the text over which this operates. The text boundary is
      * reset to the start.
+     *
+     * The BreakIterator will retain a reference to the supplied string.
+     * The caller must not modify or delete the text while the BreakIterator
+     * retains the reference.
+     *
      * @param text The UnicodeString used to change the text.
      * @stable ICU 2.0
      */

icu4c/source/common/unicode/rbbi.h

@@ -375,6 +375,11 @@ public:
     /**
      * Set the iterator to analyze a new piece of text.  This function resets
      * the current iteration position to the beginning of the text.
+     *
+     * The BreakIterator will retain a reference to the supplied string.
+     * The caller must not modify or delete the text while the BreakIterator
+     * retains the reference.
+     *
      * @param newText The text to analyze.
      *  @stable ICU 2.0
      */

icu4c/source/common/unicode/ubrk.h

@@ -72,7 +72,7 @@
  * "Extended Grapheme Clusters", which are groupings of codepoints
  * that should be treated as character-like units for many text operations.
  * Please see Unicode Standard Annex #29, Unicode Text Segmentation,
- * http://www.unicode.org/reports/tr29/ for additional information 
+ * http://www.unicode.org/reports/tr29/ for additional information
  * on grapheme clusters and guidelines on their use.
  * <p>
  * Title boundary analysis locates all positions,
@@ -318,7 +318,11 @@ U_NAMESPACE_END
 #endif
 
 /**
- * Sets an existing iterator to point to a new piece of text
+ * Sets an existing iterator to point to a new piece of text.
+ * The break iterator retains a pointer to the supplied text.
+ * The caller must not modify or delete the text while the BreakIterator
+ * retains the reference.
+ *
  * @param bi The iterator to use
  * @param text The text to be set
  * @param textLength The length of the text