vertx / io.vertx.reactivex.core / CompositeFuture / map

# map

`open fun <U : Any> map(mapper: Function<CompositeFuture, U>): Future<U>`

Apply a `mapper` function on this future.

When this future succeeds, the `mapper` will be called with the completed value and this mapper returns a value. This value will complete the future returned by this method call.

If the `mapper` throws an exception, the returned future will be failed with this exception.

When this future fails, the failure will be propagated to the returned future and the `mapper` will not be called.

### Parameters

`mapper` - the mapper function

Return
the mapped future