.. _mpi_type_ub:


MPI_Type_ub
===========

.. include_body

:ref:`MPI_Type_ub` - Returns the upper bound of a datatype -- |deprecated_favor| :ref:`MPI_Type_get_extent`.


SYNTAX
------


C Syntax
^^^^^^^^

.. code-block:: c

   #include <mpi.h>

   int MPI_Type_ub(MPI_Datatype datatype, MPI_Aint *displacement)


Fortran Syntax
^^^^^^^^^^^^^^

.. code-block:: fortran

   USE MPI
   ! or the older form: INCLUDE 'mpif.h'

   MPI_TYPE_UB(DATATYPE, DISPLACEMENT, IERROR)
   	INTEGER	DATATYPE, DISPLACEMENT, IERROR


INPUT PARAMETER
---------------
* ``datatype``: Datatype (handle).

OUTPUT PARAMETERS
-----------------
* ``displacement``: Displacement of upper bound from origin, in bytes (integer).
* ``ierror``: Fortran only: Error status (integer).

DESCRIPTION
-----------

Note that use of this routine is *deprecated* as of MPI-2. Please use
:ref:`MPI_Type_get_extent` instead.

:ref:`MPI_Type_ub` returns the upper bound of a data type. This will differ
from zero if the type was constructed using MPI_UB. The upper bound will
take into account any alignment considerations.

The "pseudo-datatypes," MPI_LB and MPI_UB, can be used, respectively, to
mark the upper bound (or the lower bound) of a datatype. These
pseudo-datatypes occupy no space (extent (MPI_LB) = extent (MPI_UB) =0.
They do not affect the size or count of a datatype, and do not affect
the context of a message created with this datatype. However, they do
affect the definition of the extent of a datatype and, therefore, affect
the outcome of a replication of this datatype by a datatype constructor.

In general, if

::


       Typemap = {(type(0), disp(0)), ..., (type(n-1), disp(n-1))}

then the lower bound of Typemap is defined to be

::


                     (min(j) disp(j)                          if no entry has
       lb(Typemap) = (                                        basic type lb
                     (min(j) {disp(j) such that type(j) = lb} otherwise

Similarly, the upper bound of Typemap is defined to be

::


                     (max(j) disp(j) + sizeof(type(j) = lb}   if no entry has
       ub(Typemap) = (                                        basic type ub
                     (max(j) {disp(j) such that type(j) = ub} otherwise

Then

::


       extent(Typemap) = ub(Typemap) - lb(Typemap)

If type(i) requires alignment to a byte address that is a multiple of
k(i), then e is the least nonnegative increment needed to round
extent(Typemap) to the next multiple of max(i) k(i).


ERRORS
------

.. include:: ./ERRORS.rst

.. seealso::
   * :ref:`MPI_Type_get_extent`
