Wraps [method@Gio.
IOStream.splice_async].
| stream1 |
a [class@Gio.IOStream] |
| stream2 |
a [class@Gio.IOStream] |
| flags |
splice flags |
| io_priority |
priority for the IO operation |
|
a [class@Dex.Future] that resolves to true or rejects with error. |