Type Alias CovariantOver 

pub type CovariantOver<T> = PhantomData<fn() -> T>;

Mark a type as covariant.

This marker does not “own” the type, i.e. T does not get dropped when the containing type is dropped. If T could be dropped, use Owns instead.

See the crate root documentation for details on variance.

Aliased Type

pub struct CovariantOver<T>;