bool
mongoc_find_and_modify_opts_set_sort (mongoc_find_and_modify_opts_t *opts,
                                      const bson_t *sort);

void
fam_sort (mongoc_collection_t *collection)
{
   mongoc_find_and_modify_opts_t *opts;
   bson_t *update;
   bson_t sort = BSON_INITIALIZER;
   bson_t reply;
   bson_error_t error;
   bson_t query = BSON_INITIALIZER;
   bool success;
   /* Find all users with the lastname Ibrahimovic */
   BSON_APPEND_UTF8 (&query, "lastname", "Ibrahimovic");
   /* Sort by age (descending) */
   BSON_APPEND_INT32 (&sort, "age", -1);
   /* Bump his goal tally */
   update = BCON_NEW ("$set", "{", "oldest", BCON_BOOL (true), "}");
   opts = mongoc_find_and_modify_opts_new ();
   mongoc_find_and_modify_opts_set_update (opts, update);
   mongoc_find_and_modify_opts_set_sort (opts, &sort);
   success = mongoc_collection_find_and_modify_with_opts (
      collection, &query, opts, &reply, &error);
   if (success) {
      char *str;
      str = bson_as_canonical_extended_json (&reply, NULL);
      printf ("%s\n", str);
      bson_free (str);
   } else {
      fprintf (
         stderr, "Got error: \"%s\" on line %d\n", error.message, __LINE__);
   }
   bson_destroy (&reply);
   bson_destroy (update);
   bson_destroy (&sort);
   bson_destroy (&query);
   mongoc_find_and_modify_opts_destroy (opts);
}

{
   "lastErrorObject" : {"updatedExisting" : true, "n" : 1},
                       "value" : {
                          "_id" : {"$oid" : "56562a99d13e6d86239c7b00"},
                          "age" : 35,
                          "firstname" : "Zlatan",
                          "goals" : 343,
                          "lastname" : "Ibrahimovic",
                          "profession" : "Football player",
                          "position" : "striker",
                          "author" : true
                       },
                                 "ok" : 1
}