Trait PredicateBoxExt

pub trait PredicateBoxExt<Item>: Predicate<Item>
where
    Item: ?Sized,
{
    // Provided method
    fn boxed(self) -> BoxPredicate<Item>
       where Self: Sized + Send + Sync + 'static { ... }
}

Predicate extension for boxing a Predicate.

Provided Methods

fn boxed(self) -> BoxPredicate<Item>

where Self: Sized + Send + Sync + 'static,

Returns a BoxPredicate wrapper around this Predicate type.

Returns a BoxPredicate wrapper around this Predicate type. The BoxPredicate` type has a number of useful properties:

• It stores the inner predicate as a trait object, so the type of BoxPredicate will always be the same even if steps are added or removed from the predicate.
• It is a common type, allowing it to be stored in vectors or other collection types.
• It implements Debug and Display.

Examples

use predicates::prelude::*;

let predicates = vec![
    predicate::always().boxed(),
    predicate::never().boxed(),
];
assert_eq!(true, predicates[0].eval(&4));
assert_eq!(false, predicates[1].eval(&4));

Implementors

impl<P, Item> PredicateBoxExt<Item> for P

where P: Predicate<Item>,