Returns \c true if the FLAC file is writable. If \c false, calls to
FLAC__metadata_simple_iterator_set_block() and
FLAC__metadata_simple_iterator_insert_block_after() will fail.
\param iterator A pointer to an existing iterator.
\assert
\code iterator != NULL \endcode
\retval FLAC__bool
See above.
Returns \c true if the FLAC file is writable. If \c false, calls to FLAC__metadata_simple_iterator_set_block() and FLAC__metadata_simple_iterator_insert_block_after() will fail.
\param iterator A pointer to an existing iterator. \assert \code iterator != NULL \endcode \retval FLAC__bool See above.