Function gtk_source_sys::gtk_source_search_context_backward_async

pub unsafe extern "C" fn gtk_source_search_context_backward_async(
    search: *mut GtkSourceSearchContext, 
    iter: *const GtkTextIter, 
    cancellable: *mut GCancellable, 
    callback: GAsyncReadyCallback, 
    user_data: gpointer
)