class Paragraph;
class Text;
-DocIterator doc_iterator_begin(Buffer const * buf, Inset const * inset = 0);
-DocIterator doc_iterator_end(Buffer const * buf, Inset const * inset = 0);
+DocIterator doc_iterator_begin(Buffer const * buf, Inset const * inset = nullptr);
+DocIterator doc_iterator_end(Buffer const * buf, Inset const * inset = nullptr);
class DocIterator