\fBMPI_Op_free\fP \- Frees a user-defined combination function handle.
.SH SYNTAX
.ft R
.SH C Syntax
.nf
#include <mpi.h>
int MPI_Op_free(MPI_Op *\fIop\fP)
.SH Fortran Syntax
.nf
INCLUDE 'mpif.h'
MPI_OP_FREE(\fIOP, IERROR\fP)
INTEGER \fIOP, IERROR\fP
.SH C++ Syntax
.nf
#include <mpi.h>
void Op::Free()
.SH INPUT/OUTPUT PARAMETER
.TP 1i
op
Operation (handle).
.SH OUTPUT PARAMETER
.ft R
.TP 1i
IERROR
Fortran only: Error status (integer).
.SH DESCRIPTION
.ft R
Marks a user-defined reduction operation for deallocation and sets \fIop\fP to MPI_OP_NULL.
.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.
