The widget layer of densa: a retained widget tree with flexbox layout, pointer and keyboard events, focus and themes, independent of any window or GPU API
/// Identifies a widget in a [`Ui`](crate::Ui).
////// An id stays valid until its widget is removed. A removed widget's slot can hold another
/// widget later, under another generation, so an old id never reaches the new widget.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]pubstructWidgetId{pub(crate)index:u32,
pub(crate)generation:u32,
}implWidgetId{pub(crate)fnslot(self)->usize{self.index asusize}}