/*D
   MPI_Win_set_attr - Stores attribute value associated with a key

Synopsis:
.vb
int MPI_Win_set_attr(MPI_Win win, int win_keyval, void *attribute_val)
.ve

Input Parameters:
+ win - window to which attribute will be attached (handle)
. win_keyval - key value (integer)
- attribute_val - attribute value (None)

Notes:

The type of the attribute value depends on whether C or Fortran is being used.
In C, an attribute value is a pointer ('void *'); in Fortran, it is an
address-sized integer.

If an attribute is already present, the delete function (specified when the
corresponding keyval was created) will be called.

.N ThreadSafe

.N Fortran

.N Errors
.N MPI_SUCCESS
.N MPI_ERR_KEYVAL
.N MPI_ERR_WIN
.N MPI_ERR_OTHER

D*/

