Trait HKT
funlib
pub trait HKT<B> { type A; type M; }
type A
type M
impl<B, C> HKT<C> for Vec<B>
type A = B
type M = Vec<C>
impl<B, C> HKT<C> for Option<B>
type M = Option<C>
impl<B, C> HKT<C> for Box<B>
type M = Box<C>
impl<B, C> HKT<C> for Rc<B>
type M = Rc<C>