+ /**
+ * Determine whether a given roundingIncrement should be ignored for formatting
+ * based on the current maxFrac value (maximum fraction digits). For example a
+ * roundingIncrement of 0.01 should be ignored if maxFrac is 1, but not if maxFrac
+ * is 2 or more. Note that roundingIncrements are rounded up in significance, so
+ * a roundingIncrement of 0.006 is treated like 0.01 for this determination, i.e.
+ * it should not be ignored if maxFrac is 2 or more (but a roundingIncrement of
+ * 0.005 is treated like 0.001 for significance).
+ *
+ * This test is needed for both NumberPropertyMapper::oldToNew and
+ * PatternStringUtils::propertiesToPatternString. In Java it cannot be
+ * exported by NumberPropertyMapper (package provate) so it is in
+ * PatternStringUtils, do the same in C.
+ *
+ * @param roundIncr
+ * Pointer to roundingIncrement to be checked. Must be non-zero.
+ * If function returns false, this value may be updated to round
+ * to the digits significant for maxFrac.
+ * @param maxFrac
+ * The current maximum fraction digits value.
+ * @return true if roundIncr should be ignored for formatting.
+ */
+ static bool ignoreRoundingIncrement(double* roundIncrPtr, int32_t maxFrac);
+