Function value 

pub fn value<T: VarValue>(
    child: impl IntoUiNode,
    value: impl IntoVar<T>,
) -> UiNode

P Values that is selected in the contextual selector.

The widget is_checked when the value is selected, on click and on value update, the selection is updated according to the behavior defined in the contextual selector. If no contextual selector is the widget is never checked.

Note that the value can be any type, but must be one of the types accepted by the contextual selector, type validation happens in run-time, an error is logged if the type is not compatible. Because any type can be used in this property type inference cannot resolve the type automatically and a type annotation is required: value<T> = t;.

This property interacts with the contextual selector, when the widget is clicked or the value variable changes the contextual Selector is used to implement the behavior.