NAME

       MPI_Type_get_true_extent  -  Returns  the  true  lower  bound  and  extent of a data type's corresponding
       typemap, ignoring MPI_UB and MPI_LB markers.

SYNTAX

C Syntax

       #include <mpi.h>
       int MPI_Type_get_true_extent(MPI_Datatype datatype,
            MPI_Aint *true_lb, MPI_Aint *true_extent)

Fortran Syntax (see FORTRAN 77 NOTES)

       INCLUDE 'mpif.h'
       MPI_TYPE_GET_TRUE_EXTENT(DATATYPE, TRUE_LB, TRUE_EXTENT, IERROR)
            INTEGER   DATATYPE, IERROR
            INTEGER(KIND=MPI_ADDRESS_KIND) TRUE_LB, TRUE_EXTENT

C++ Syntax

       #include <mpi.h>
       void MPI::Datatype::Get_true_extent(MPI::Aint& true_lb,
            MPI::Aint& true_extent) const

INPUT PARAMETER

       datatype  Data type for which information is wanted (handle).

OUTPUT PARAMETERS

       true_lb   True lower bound of data type (integer).

       true_extent
                 True size of data type (integer).

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       The true_lb parameter returns the offset of the lowest unit of store that is addressed by the data  type,
       that is, the lower bound of the corresponding typemap, ignoring MPI_LB markers. The true_extent parameter
       returns the true size of the data type, that is, the extent of the corresponding typemap, ignoring MPI_LB
       and MPI_UB markers, and performing no rounding for alignment.

       The true_extent is the minimum number of bytes of memory necessary to hold a data type, uncompressed.

       See Section 4.14.3 of the MPI-2 standard for more detailed definitions of these parameters in relation to
       the typemap.

FORTRAN 77 NOTES

       The  MPI  standard  prescribes portable Fortran syntax for the TRUE_LB and TRUE_EXTENT arguments only for
       Fortran 90. FORTRAN 77 users may use the non-portable syntax

            INTEGER*MPI_ADDRESS_KIND TRUE_LB
       or
            INTEGER*MPI_ADDRESS_KIND TRUE_EXTENT

       where MPI_ADDRESS_KIND is a constant defined in mpif.h and gives the length of the  declared  integer  in
       bytes.

ERRORS

       Almost  all  MPI  routines  return  an  error  value; C routines as the value of the function and Fortran
       routines in the last argument. C++ functions do not return errors. If the default error handler is set to
       MPI::ERRORS_THROW_EXCEPTIONS, then on error the  C++  exception  mechanism  will  be  used  to  throw  an
       MPI:Exception object.

       Before  the  error  value  is  returned,  the current MPI error handler is called. By default, this error
       handler aborts the MPI job, except for I/O function  errors.  The  error  handler  may  be  changed  with
       MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values
       to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.

1.6.5                                             Jun 26, 2013                       MPI_Type_get_true_extent(3)