Valid class identifiers, as defined in H5Tpublic.h, are:

• H5T_INTEGER
• H5T_FLOAT
• H5T_TIME
• H5T_STRING
• H5T_BITFIELD
• H5T_OPAQUE
• H5T_COMPOUND
• H5T_REFERENCE
• H5T_ENUM
• H5T_VLEN
• H5T_ARRAY

Note that the library returns H5T_STRING for both fixed-length and variable-length strings.

Note that the time datatype class, H5T_TIME, is not fully supported in the current version of the HDF5 Library.

SUBROUTINE h5tget_class_f(type_id, class, hdferr) 
  IMPLICIT NONE
  INTEGER(HID_T), INTENT(IN) :: type_id  ! Datatype identifier 
  INTEGER, INTENT(OUT) :: class          ! Datatype class, possible values are:
                                         !    H5T_NO_CLASS_F 
                                         !    H5T_INTEGER_F 
                                         !    H5T_FLOAT_F
                                         !    H5T_TIME_F
                                         !    H5T_STRING_F
                                         !    H5T_BITFIELD_F
                                         !    H5T_OPAQUE_F
                                         !    H5T_COMPOUND_F
                                         !    H5T_REFERENCE_F
                                         !    H5T_ENUM_F
  INTEGER, INTENT(OUT) :: hdferr         ! Error code
                                         ! 0 on success and -1 on failure
END SUBROUTINE h5tget_class_f