pub unsafe extern "C" fn g_output_stream_writev_async(
    stream: *mut GOutputStream,
    vectors: *const GOutputVector,
    n_vectors: size_t,
    io_priority: c_int,
    cancellable: *mut GCancellable,
    callback: GAsyncReadyCallback,
    user_data: gpointer
)
Available on crate feature v2_60 only.