Derive Macro amethyst_derive::WidgetId

#[derive(WidgetId)]
{
    // Attributes available to this derive:
    #[widget_id]
}

This allows the use of an enum as an ID for the Widgets resource. One variant has to be marked as the default variant with #[widget_id_default] and will be used when a Widgetis added to the resource without an explicit ID. Note that when usingWidgets::add`, this will overwrite an existing widget with the same default id!