Name: H5Tget_native_type
Signature:
hid_t H5Tget_native_type( hid_t dtype_id, H5T_direction_t direction )
Purpose:
Returns the native datatype of a specified datatype.
Description:
H5Tget_native_type returns the equivalent native datatype for the datatype specified in dtype_id.

H5Tget_native_type is a high-level function designed primarily to facilitate use of the H5Dread function, for which users otherwise must undertake a multi-step process to determine the native datatype of a dataset prior to reading it into memory. It can be used not only to determine the native datatype for atomic datatypes, but also to determine the native datatypes of the individual components of a compound datatype, an enumerated datatype, an array datatype, or a variable-length datatype. For example, if dtype_id is a compound datatype, the returned datatype identifier will be for a similar compound datatype with each element converted to the corresponding native datatype.

H5Tget_native_type selects the matching native datatype from the following list: 

        H5T_NATIVE_CHAR         
        H5T_NATIVE_SHORT        
        H5T_NATIVE_INT          
        H5T_NATIVE_LONG         
        H5T_NATIVE_LLONG        

        H5T_NATIVE_UCHAR
        H5T_NATIVE_USHORT
        H5T_NATIVE_UINT
        H5T_NATIVE_ULONG
        H5T_NATIVE_ULLONG

        H5T_NATIVE_FLOAT
        H5T_NATIVE_DOUBLE
        H5T_NATIVE_LDOUBLE

The direction parameter indicates the order in which the library searches for a native datatype match. Valid values for direction are as follows:
     H5T_DIR_ASCEND Searches the above list in ascending size of the datatype,
i.e., from top to bottom. (Default)
  H5T_DIR_DESCEND   Searches the above list in descending size of the datatype,
i.e., from bottom to top.

H5Tget_native_type is designed primarily for use with integer and floating point datatypes. String, time, bitfield, opaque, and reference datatypes are returned as a copy of dtype_id.

The identifier returned by H5Tget_native_type should eventually be closed by calling H5Tclose to release resources.

Parameters:
Returns:
Returns the native datatype identifier for the specified dataset datatype if successful; otherwise returns a negative value.
Fortran90 Interface: h5tget_native_type_f 
SUBROUTINE h5tget_native_type_f(dtype_id, direction, native_dtype_id, hdferr)
  IMPLICIT NONE
  INTEGER(HID_T), INTENT(IN) :: dtype_id  
                                    ! Datatype identifier
  INTEGER, INTENT(IN) :: direction  ! Direction of search:
                                    ! H5T_DIR_ASCEND_F = 1 in inscendent order
                                    ! H5T_DIR_DESCEND_F= 2 in descendent order
  INTEGER(HID_T), INTENT(OUT) :: native_dtype_id  
                                    ! The native datatype identifier
  INTEGER, INTENT(OUT) :: hdferr    ! Error code:
                                    ! 0 on success and -1 on failure
END SUBROUTINE h5tget_native_type_f
History: