Trait Filter

pub trait Filter<Item> {
    type Item;

    // Required method
    fn filter<P>(self, predicate: P) -> Option<Item>
       where P: FnOnce(&Self::Item) -> bool;
}

This trait creates a filter method for Option so that it can be filtered on when used in the map_for macro.

Example:

use map_for::{ Filter, FlatMap };
let c = map_for!{
   a <- Some (1);
   if (a%2) == 0;
   b <- Some (2);
   => { a + b } };
assert_eq!(c, None);

Required Associated Types

type Item

Required Methods

fn filter<P>(self, predicate: P) -> Option<Item>

where P: FnOnce(&Self::Item) -> bool,

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<Item> Filter<Item> for Option<Item>

type Item = Item

fn filter<P>(self, predicate: P) -> Option<Item>

where P: FnOnce(&Self::Item) -> bool,

Implementors