Enum std::ops::Bound

1.17.0 · source ·

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

Included(T)

An inclusive bound.

Excluded(T)

An exclusive bound.

Unbounded

An infinite endpoint. Indicates that there is no bound in this direction.

Implementations

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impl<T> Bound<T>

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pub fn as_ref(&self) -> Bound<&T>

🔬 This is a nightly-only experimental API. (bound_as_ref #80996)

Converts from &Bound<T> to Bound<&T>.

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pub fn as_mut(&mut self) -> Bound<&mut T>

🔬 This is a nightly-only experimental API. (bound_as_ref #80996)

Converts from &mut Bound<T> to Bound<&mut T>.

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pub fn map<U, F>(self, f: F) -> Bound<U> where
F: FnOnce(T) -> U,

🔬 This is a nightly-only experimental API. (bound_map #86026)

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

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impl<T> Bound<&T> where
T: Clone,

1.55.0 · source

pub fn cloned(self) -> Bound<T>

Map a Bound<&T> to a Bound<T> by cloning the contents of the bound.

Examples

use std::ops::Bound::*;
use std::ops::RangeBounds;
assert_eq!((1..12).start_bound(), Included(&1));
assert_eq!((1..12).start_bound().cloned(), Included(1));

Run

Trait Implementations

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impl<T> Clone for Bound<T> where
T: Clone,

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fn clone(&self) -> Bound<T>

Returns a copy of the value. Read more

1.0.0 · source

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more

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impl<T> Debug for Bound<T> where
T: Debug,

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fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter. Read more

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impl<T> Hash for Bound<T> where
T: Hash,

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fn hash<__H>(&self, state: &mut __H) where
__H: Hasher,

Feeds this value into the given Hasher. Read more

1.3.0 · source

fn hash_slice<H>(data: &[Self], state: &mut H) where
H: Hasher,

Feeds a slice of this type into the given Hasher. Read more

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impl<T> PartialEq<Bound<T>> for Bound<T> where
T: PartialEq<T>,

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fn eq(&self, other: &Bound<T>) -> bool

This method tests for self and other values to be equal, and is used by ==. Read more

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fn ne(&self, other: &Bound<T>) -> bool

This method tests for !=.

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impl<T> Copy for Bound<T> where
T: Copy,

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impl<T> Eq for Bound<T> where
T: Eq,

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impl<T> StructuralEq for Bound<T>

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impl<T> StructuralPartialEq for Bound<T>