/*D
   MPI_T_event_read - Copy one element of event data to a user-specified buffer

Synopsis:
.vb
int MPI_T_event_read(MPI_T_event_instance event_instance, int element_index,
                     void *buffer)
.ve

Input Parameters:
+ event_instance - event-instance handle provided to the callback function (handle)
- element_index - index into the array of datatypes of the item to be queried (integer)

Output Parameters:
. buffer - pointer to a memory location to store the item data (choice)

.N ThreadSafe

.N Errors
.N MPI_SUCCESS
.N MPI_T_ERR_INVALID
.N MPI_T_ERR_INVALID_HANDLE
.N MPI_T_ERR_NOT_INITIALIZED
.N MPI_ERR_OTHER

D*/

