Enum core::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§

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Included(T)

An inclusive bound.

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Excluded(T)

An exclusive bound.

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Unbounded

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

Implementations§

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impl<T> Bound<T>

1.65.0 · source

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

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: FnOnce(T) -> U>(self, f: F) -> Bound<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: Clone> Bound<&T>

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> Clone for Bound<T>

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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> Debug for Bound<T>

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

Formats the value using the given formatter. Read more
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impl<T: Hash> Hash for Bound<T>

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

Feeds this value into the given Hasher. Read more
1.3.0 · source§

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

Feeds a slice of this type into the given Hasher. Read more
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impl<T: PartialEq> PartialEq<Bound<T>> for Bound<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 ==.
1.0.0 · source§

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl<T: Copy> Copy for Bound<T>

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impl<T: Eq> Eq for Bound<T>

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impl<T> StructuralEq for Bound<T>

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impl<T> StructuralPartialEq for Bound<T>

Auto Trait Implementations§

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

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

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

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

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

Blanket Implementations§

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impl<T> Any for Twhere
    T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere
    T: ?Sized,

const: unstable · source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere
    T: ?Sized,

const: unstable · source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

const: unstable · source§

fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere
    U: From<T>,

const: unstable · source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for Twhere
    U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
const: unstable · source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere
    U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
const: unstable · source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.