Enum std::ops::Bound

pub enum Bound<T> {
    Included(T),
    Excluded(T),
    Unbounded,
}

一系列键的端点。

Examples

边界是范围端点:

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));

使用 Bounds 的元组作为 BTreeMap::range 的参数。 请注意，在大多数情况下，最好改用范围语法 (1..5)。

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)

包容性范围。

Excluded(T)

排他性约束。

Unbounded

无限端点。指示此方向没有界限。

Implementations

impl<T> Bound<T>

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

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

从 &Bound<T> 转换为 Bound<&T>。

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

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

从 &mut Bound<T> 转换为 Bound<&mut T>。

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)

映射一个 Bound 通过将函数应用于包含的值 (包括 Included 和 Excluded)，返回相同类型的 Bound。

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);

impl<'_, T> Bound<&'_ T> where
    T: Clone, 

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

Map 通过克隆绑定的内容将 Bound<&T> 更改为 Bound<T>。

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));

Trait Implementations

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

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

返回值的副本。

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

从 source 执行复制分配。

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

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

使用给定的格式化程序格式化该值。

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

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

将该值输入给定的 Hasher。

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

将这种类型的切片送入给定的 Hasher 中。

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

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

此方法测试 self 和 other 值是否相等，并由 == 使用。

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

此方法测试 !=。

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

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

impl<T> StructuralEq for Bound<T>

impl<T> StructuralPartialEq for Bound<T>