NAME

       MPI_Type_struct - Creates a struct data type -- use of this routine is deprecated.

SYNTAX

C Syntax

       #include <mpi.h>
       int MPI_Type_struct(int count, int *array_of_blocklengths,
            MPI_Aint *array_of_displacements, MPI_Datatype *array_of_types,
            MPI_Datatype *newtype)

Fortran Syntax

       INCLUDE 'mpif.h'
       MPI_TYPE_STRUCT(COUNT, ARRAY_OF_BLOCKLENGTHS,
                 ARRAY_OF_DISPLACEMENTS, ARRAY_OF_TYPES,
                 NEWTYPE, IERROR)
            INTEGER   COUNT, ARRAY_OF_BLOCKLENGTHS(*)
            INTEGER   ARRAY_OF_DISPLACEMENTS(*)
            INTEGER   ARRAY_OF_TYPES(*), NEWTYPE, IERROR

INPUT PARAMETERS

       count     Number  of  blocks  (integer)   also number of entries in arrays array_of_types,
                 array_of_displacements, and array_of_blocklengths.

       array_of_blocklengths
                 Number of elements in each block (array).

       array_of_displacements
                 Byte displacement of each block (array).

       array_of_types
                 Type of elements in each block (array of handles to datatype objects).

OUTPUT PARAMETERS

       newtype   New datatype (handle).

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       Note that use of this routine  is  deprecated  as  of  MPI-2.  Use  MPI_Type_create_struct
       instead.

       This deprecated routine is not available in C++.

       MPI_Type_struct   is   the   most   general   type  constructor.  It  further  generalizes
       MPI_Type_hindexed in that it allows each block to consist  of  replications  of  different
       datatypes.

       Example: Let type1 have type map

           {(double, 0), (char, 8)}

       with  extent 16. Let B = (2, 1, 3), D = (0, 16, 26), and T = (MPI_FLOAT, type1, MPI_CHAR).
       Then a call to MPI_Type_struct(3, B, D, T, newtype) returns a datatype with type map

           {(float, 0), (float,4), (double, 16), (char, 24),
           (char, 26), (char, 27), (char, 28)}

       That is, two copies of MPI_FLOAT starting at 0, followed by one copy of type1 starting  at
       16, followed by three copies of MPI_CHAR, starting at 26. (We assume that a float occupies
       4 bytes.)

       For more information, see section 3.12.1 of the MPI-1.1 Standard.

NOTES

       If an upperbound is set explicitly by using the MPI  datatype  MPI_UB,  the  corresponding
       index must be positive.

       The  MPI-1 Standard originally made vague statements about padding and alignment; this was
       intended to allow the simple definition of structures that could  be  sent  with  a  count
       greater than one. For example,
           struct {int a; char b;} foo;
       may have
           sizeof(foo) = sizeof(int) + sizeof(char);
       defining  the  extent  of  a datatype as including an epsilon, which would have allowed an
       implementation  to  make  the  extent  an  MPI  datatype  for  this  structure  equal   to
       2*sizeof(int).  However,  since  different  systems  might  define  different  paddings, a
       clarification to the standard made epsilon zero. Thus, if you define a structure  datatype
       and  wish to send or receive multiple items, you should explicitly include an MPI_UB entry
       as the last member of the structure.  For example, the following code can be used for  the
       structure foo:

           blen[0] = 1; indices[0] = 0; oldtypes[0] = MPI_INT;
           blen[1] = 1; indices[1] = &foo.b - &foo; oldtypes[1] = MPI_CHAR;
           blen[2] = 1; indices[2] = sizeof(foo); oldtypes[2] = MPI_UB;
           MPI_Type_struct( 3, blen, indices, oldtypes, &newtype );

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.

SEE ALSO

       MPI_Type_create_struct
       MPI_Type_create_hindexed