Trait externalities::Extension [−][src]
Marker trait for types that should be registered as Externalities extension.
As extensions are stored as Box<Any>, this trait should give more confidence that the correct
type is registered and requested.
Required methods
fn as_mut_any(&mut self) -> &mut dyn Any[src]
Return the extension as &mut dyn Any.
This is a trick to make the trait type castable into an Any.