Trait Covariant
functor
pub trait Covariant<'a, B>: ReParam<B> { fn fmap<F: 'a + Fn(Self::Param) -> B>(self, _: F) -> Self::Output; }
fn fmap<F: 'a + Fn(Self::Param) -> B>(self, _: F) -> Self::Output
impl<'a, A, B> Covariant<'a, B> for Option<A>
impl<'a, X, A, B> Covariant<'a, B> for (X, A)
impl<'a, A, B> Covariant<'a, B> for Box<A>
impl<'a, A, B, E> Covariant<'a, B> for Result<A, E>