Learn the number of types defined in a group, and their IDs.
function nf90_inq_typeids(ncid, ntypes, typeids)
integer, intent(in) :: ncid
integer, intent(out) :: ntypes
integer, intent(out) :: typeids
integer :: nf90_inq_typeids
NCIDNTYPESTYPEIDSNF90_NOERRNF90_BADID