Struct Pred 

pub struct Pred<A>(pub Box<dyn Fn(A) -> bool>);

Predicate as contravariant functor.

Tuple Fields

0: Box<dyn Fn(A) -> bool>

Implementations

impl<A> Pred<A>

pub fn new(f: impl Fn(A) -> bool + 'static) -> Self

Create from closure.

pub fn test(&self, a: A) -> bool

Test the predicate.

impl<A: 'static> Pred<A>

pub fn contramap<B, F: Fn(B) -> A + 'static>(self, f: F) -> Pred<B>

Contramap: apply f before the predicate.