Struct HashMap 

pub struct HashMap<K, V, S = RandomState> { /* private fields */ }

哈希映射

Implementations

impl<K: Hash + Eq, V> HashMap<K, V, RandomState>

pub fn new() -> Self

创建新的哈希映射

pub fn with_capacity(capacity: usize) -> Self

使用指定容量创建哈希映射

impl<K, V, S> HashMap<K, V, S>

where K: Hash + Eq, S: BuildHasher,

pub fn with_capacity_and_hasher(capacity: usize, hash_builder: S) -> Self

使用指定容量和哈希生成器创建哈希映射

pub fn len(&self) -> usize

返回映射中的元素数量

pub fn is_empty(&self) -> bool

判断映射是否为空

pub fn clear(&mut self)

清空映射

pub fn get<Q>(&self, key: &Q) -> Option<&V>

where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

获取键对应的值的引用

pub fn get_mut<Q>(&mut self, key: &Q) -> Option<&mut V>

where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

获取键对应的值的可变引用

pub fn insert(&mut self, key: K, value: V) -> Option<V>

插入键值对

pub fn remove<Q>(&mut self, key: &Q) -> Option<V>

where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

删除键对应的值

pub fn contains_key<Q>(&self, key: &Q) -> bool

where K: Borrow<Q>, Q: Hash + Eq + ?Sized,

检查是否包含指定的键

pub fn iter(&self) -> Iter<'_, K, V>

获取迭代器

pub fn iter_mut(&mut self) -> IterMut<'_, K, V>

获取可变迭代器

Trait Implementations

impl<K: Clone, V: Clone, S: Clone> Clone for HashMap<K, V, S>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.