pub enum Bound<T> {
Included(T),
Excluded(T),
Unbounded,
}
Expand description
An endpoint of a range of keys.
Examples
Bound
s 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));
Using a tuple of Bound
s 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());
Variants
Included(T)
An inclusive bound.
Excluded(T)
An exclusive bound.
Unbounded
An infinite endpoint. Indicates that there is no bound in this direction.
Implementations
🔬 This is a nightly-only experimental API. (bound_as_ref
)
🔬 This is a nightly-only experimental API. (
bound_as_ref
)Converts from &Bound<T>
to Bound<&T>
.
🔬 This is a nightly-only experimental API. (bound_as_ref
)
🔬 This is a nightly-only experimental API. (
bound_as_ref
)Converts from &mut Bound<T>
to Bound<&mut T>
.
🔬 This is a nightly-only experimental API. (bound_map
)
🔬 This is a nightly-only experimental API. (
bound_map
)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));
#![feature(bound_map)]
use std::ops::Bound;
use Bound::*;
let unbounded_string: Bound<String> = Unbounded;
assert_eq!(unbounded_string.map(|s| s.len()), Unbounded);
Trait Implementations
Auto Trait Implementations
impl<T> RefUnwindSafe for Bound<T> where
T: RefUnwindSafe,
impl<T> UnwindSafe for Bound<T> where
T: UnwindSafe,
Blanket Implementations
Mutably borrows from an owned value. Read more