Enum core::ops::Bound 1.17.0[−][src]
pub enum Bound<T> {
Included(T),
Excluded(T),
Unbounded,
}Expand description
An endpoint of a range of keys.
Examples
Bounds are range endpoints:
use std::ops::Bound::*; use std::ops::RangeBounds; assert_eq!((..100).start_bound(), Unbounded); assert_eq!((1..12).start_bound(), Included(&1)); assert_eq!((1..12).end_bound(), Excluded(&12));Run
Using a tuple of Bounds as an argument to BTreeMap::range.
Note that in most cases, it’s better to use range syntax (1..5) instead.
use std::collections::BTreeMap; use std::ops::Bound::{Excluded, Included, Unbounded}; let mut map = BTreeMap::new(); map.insert(3, "a"); map.insert(5, "b"); map.insert(8, "c"); for (key, value) in map.range((Excluded(3), Included(8))) { println!("{}: {}", key, value); } assert_eq!(Some((&3, &"a")), map.range((Unbounded, Included(5))).next());Run
Variants
An inclusive bound.
An exclusive bound.
An infinite endpoint. Indicates that there is no bound in this direction.
Implementations
Converts from &Bound<T> to Bound<&T>.
Converts from &mut Bound<T> to Bound<&mut T>.
Maps a Bound<T> to a Bound<U> by applying a function to the contained value (including
both Included and Excluded), returning a Bound of the same kind.
Examples
#![feature(bound_map)] use std::ops::Bound::*; let bound_string = Included("Hello, World!"); assert_eq!(bound_string.map(|s| s.len()), Included(13));Run
#![feature(bound_map)] use std::ops::Bound; use Bound::*; let unbounded_string: Bound<String> = Unbounded; assert_eq!(unbounded_string.map(|s| s.len()), Unbounded);Run