+#ifndef U_HIDE_DRAFT_API
+ /**
+ * Constructs a ByteSink that reserves append capacity and will append bytes to the dest string.
+ *
+ * @param dest pointer to string object to append to
+ * @param initialAppendCapacity capacity beyond dest->length() to be reserve()d
+ * @draft ICU 60
+ */
+ StringByteSink(StringClass* dest, int32_t initialAppendCapacity) : dest_(dest) {
+ if (initialAppendCapacity > 0 &&
+ (uint32_t)initialAppendCapacity > (dest->capacity() - dest->length())) {
+ dest->reserve(dest->length() + initialAppendCapacity);
+ }
+ }
+#endif // U_HIDE_DRAFT_API