.\" -*- nroff -*-
.\" Copyright 2010 Cisco Systems, Inc.  All rights reserved.
.\" Copyright 2006-2008 Sun Microsystems, Inc.
.\" Copyright (c) 1996 Thinking Machines Corporation
.\" $COPYRIGHT$
.TH MPI_Type_free 3 "Dec 18, 2020" "4.1.0" "Open MPI"
.SH NAME
\fBMPI_Type_free\fP \- Frees a data type.

.SH SYNTAX
.ft R
.SH C Syntax
.nf
#include <mpi.h>
int MPI_Type_free(MPI_Datatype *\fIdatatype\fP)

.fi
.SH Fortran Syntax
.nf
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_TYPE_FREE(\fIDATATYPE, IERROR\fP)
	INTEGER	\fIDATATYPE, IERROR\fP

.fi
.SH Fortran 2008 Syntax
.nf
USE mpi_f08
MPI_Type_free(\fIdatatype\fP, \fIierror\fP)
	TYPE(MPI_Datatype), INTENT(INOUT) :: \fIdatatype\fP
	INTEGER, OPTIONAL, INTENT(OUT) :: \fIierror\fP

.fi
.SH C++ Syntax
.nf
#include <mpi.h>
void Datatype::Free()

.fi
.SH INPUT/OUTPUT PARAMETER
.ft R
.TP 1i
datatype
Datatype that is freed (handle).
.sp
.SH OUTPUT PARAMETER
.ft R
.TP 1i
IERROR
Fortran only: Error status (integer).

.SH DESCRIPTION
.ft R
Marks the datatype object associated with datatype for de-allocation and sets datatype to MPI_DATATYPE_NULL. Any communication that is currently using this datatype will complete normally. Derived datatypes that were defined from the freed datatype are not affected.
.sp
Freeing a datatype does not affect any other datatype that was built from the freed datatype. The system behaves as if input datatype arguments to derived datatype constructors are passed by value.

.SH 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.
.sp
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.