Chinese (Simplified Han script) (Boost Unordered - en to zh_Hans translation catalogue (303 entries)

en: Class Template unordered_node_map
zh_Hans: 类模板 unordered_node_map

en: `boost::unordered_node_map` — A node-based, open-addressing unordered associative container that associates unique keys with another value.
zh_Hans: `boost::unordered_node_map` — 一个基于节点的、开放寻址的无序关联容器，将唯一键与对应值相关联。

en: `boost::unordered_node_map` uses an open-addressing layout like `boost::unordered_flat_map`, but, being node-based, it provides pointer stability and node handling functionalities. Its performance lies between those of `boost::unordered_map` and `boost::unordered_flat_map`.
zh_Hans: `boost::unordered_node_map` 使用与 `boost::unordered_flat_map` 类似的开放寻址布局，但由于其基于节点的特性，它提供了指针稳定性和节点处理功能。其性能介于 `boost::unordered_map` 和 `boost::unordered_flat_map` 之间。

en: As a result of its using open addressing, the interface of `boost::unordered_node_map` deviates in a number of aspects from that of `boost::unordered_map`/`std::unordered_map`:
zh_Hans: 由于使用开放寻址，`boost::unordered_node_map` 的接口在多个方面与 `boost::unordered_map`/`std::unordered_map` 有所不同：

en: - `begin()` is not constant-time. - There is no API for bucket handling (except `bucket_count`). - The maximum load factor of the container is managed internally and can't be set by the user.
zh_Hans: - `begin()` 不是常数时间复杂度操作。 - 未提供用于桶管理的 API（除 `bucket_count` 外）。 - 容器的最大负载因子由内部管理，用户无法进行设置。

en: Other than this, `boost::unordered_node_map` is mostly a drop-in replacement of standard unordered associative containers.
zh_Hans: 除此之外，`boost::unordered_node_map` 基本上可以作为标准无序关联容器的即时代替品。

en: Synopsis
zh_Hans: 概要

en: Description
zh_Hans: 描述

en: *Template Parameters*
zh_Hans: *模板参数*

en: _Key_
zh_Hans: _键_

en: into the container from any `std::pair` object convertible to it, and it also must be https://en.cppreference.com/w/cpp/named_req/Erasable[Erasable^] from the container.
zh_Hans: 从任何可转换为 `std::pair` 的对象构造并插入容器，并且还必须可以从容器中 https://en.cppreference.com/w/cpp/named_req/Erasable[可擦除^]。

en: A unary function object type that acts a hash function for a `Key`. It takes a single argument of type `Key` and returns a value of type `std::size_t`.
zh_Hans: 一个一元函数对象类型，用作 `Key` 的哈希函数。它接受一个 `Key` 类型的参数，并返回一个 `std::size_t` 类型的值。

en: A binary function object that induces an equivalence relation on values of type `Key`. It takes two arguments of type `Key` and returns a value of type `bool`.
zh_Hans: 一个二元函数对象，用于在 `Key` 类型的值上诱导出等价关系。它接受两个 `Key` 类型的参数，并返回一个 `bool` 类型的值。

en: _Allocator_
zh_Hans: 分配器

en: An allocator whose value type is the same as the container's value type.
zh_Hans: 一个分配器，其值类型与容器的值类型相同。

en: Allocators using https://en.cppreference.com/w/cpp/named_req/Allocator#Fancy_pointers[fancy pointers] are supported.
zh_Hans: 支持使用 https://en.cppreference.com/w/cpp/named_req/Allocator#Fancy_pointers[异形指针] 的分配器。

en: The element nodes of the container are held into an internal _bucket array_. A node is inserted into a bucket determined by the hash code of its element, but if the bucket is already occupied (a _collision_), an available one in the vicinity of the original position is used.
zh_Hans: 容器的元素节点被保存在内部的 _桶数组_ 中。节点根据其元素的哈希码被插入到对应的桶中，但如果该桶已被占用（发生 _冲突_），则会使用原始位置附近的一个可用桶。

en: The size of the bucket array can be automatically increased by a call to `insert`/`emplace`, or as a result of calling `rehash`/`reserve`. The _load factor_ of the container (number of elements divided by number of buckets) is never greater than `max_load_factor()`, except possibly for small sizes where the implementation may decide to allow for higher loads.
zh_Hans: 桶数组的大小可以通过调用 `insert`/`emplace` 自动增加，或者作为调用 `rehash`/`reserve` 的结果。容器的 _负载因子_（元素数量除以桶数量）永远不会大于 `max_load_factor()`，但在容器规模较小时，实现可能会允许更高的负载。

en: If `link:../../../../../container_hash/doc/html/hash.html#ref_hash_is_avalanchinghash[hash_is_avalanching]<Hash>::value` is `true`, the hash function is used as-is; otherwise, a bit-mixing post-processing stage is added to increase the quality of hashing at the expense of extra computational cost.
zh_Hans: 如果 `link:../../../../../container_hash/doc/html/hash.html#ref_hash_is_avalanching[hash_is_avalanching]<hash>::value` 为 `true`，则哈希函数将按原样使用；否则，会增加一个位混合后处理阶段，以牺牲额外的计算成本为代价来提高哈希质量。</hash>

en: Configuration Macros
zh_Hans: 配置宏

en: Globally define this macro to enable xref:reference/stats.adoc#stats[statistics calculation] for the container. Note that this option decreases the overall performance of many operations.
zh_Hans: 全局定义此宏可为容器启用 xref:reference/stats.adoc#stats[统计计算]。请注意，此选项会降低许多操作的整体性能。

en: Typedefs
zh_Hans: 类型定义

en: An iterator whose value type is `value_type`.
zh_Hans: 一种迭代器，其值类型为 `value_type` 。

[ctx: :347]
en: The iterator category is at least a forward iterator.
zh_Hans: 迭代器类别至少为前向迭代器。

en: Convertible to `const_iterator`.
zh_Hans: 可转换为 `const_iterator`。

en: A constant iterator whose value type is `value_type`.
zh_Hans: 一个常量迭代器，其值类型为 `value_type` 。

[ctx: :360]
en: The iterator category is at least a forward iterator.
zh_Hans: 迭代器类别至少为前向迭代器。

en: A class for holding extracted container elements, modelling https://en.cppreference.com/w/cpp/container/node_handle[NodeHandle].
zh_Hans: 一个用于存放被提取容器元素的类，符合 https://en.cppreference.com/w/cpp/container/node_handle[NodeHandle] 模型。

en: A specialization of an internal class template:
zh_Hans: 内部类模板的特化：

en: with `Iterator` = `iterator` and `NodeType` = `node_type`.
zh_Hans: 其中 `Iterator` = `iterator`，`NodeType` = `node_type`。

en: Constructors
zh_Hans: 构造函数

en: Default Constructor
zh_Hans: 默认构造函数

en: Constructs an empty container using `hasher()` as the hash function, `key_equal()` as the key equality predicate and `allocator_type()` as the allocator.
zh_Hans: 使用 `hasher()` 作为哈希函数，`key_equal()` 作为键相等谓词，`allocator_type()` 作为分配器，构造一个空容器。

[ctx: :407]
en: Postconditions:;; `size() == 0` Requires:;; If the defaults are used, `hasher`, `key_equal` and `allocator_type` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
zh_Hans: 后置条件：`size() == 0`  
    要求：如果使用默认值，则 `hasher`、`key_equal` 和 `allocator_type` 需要满足 https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[可默认构造^]。

en: Bucket Count Constructor
zh_Hans: 桶数构造函数

en: ```c++ explicit unordered_node_map(size_type n, const hasher& hf = hasher(), const key_equal& eql = key_equal(), const allocator_type& a = allocator_type()); ```
zh_Hans: ```c++ explicit unordered_node_map(size_type n, const hasher&amp; hf = hasher(), const key_equal&amp; eql = key_equal(), const allocator_type&amp; a = allocator_type()); ```

en: Constructs an empty container with at least `n` buckets, using `hf` as the hash function, `eql` as the key equality predicate, and `a` as the allocator.
zh_Hans: 构造一个至少包含 `n` 个桶的空容器，使用 `hf` 作为哈希函数，`eql` 作为键相等谓词，`a` 作为分配器。

[ctx: :424]
en: Postconditions:;; `size() == 0` Requires:;; If the defaults are used, `hasher`, `key_equal` and `allocator_type` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
zh_Hans: 后置条件：`size() == 0`  
    要求：如果使用默认值，则 `hasher`、`key_equal` 和 `allocator_type` 需要满足 https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[可默认构造^]。

en: Iterator Range Constructor
zh_Hans: 迭代器范围构造函数

en: Constructs an empty container with at least `n` buckets, using `hf` as the hash function, `eql` as the key equality predicate and `a` as the allocator, and inserts the elements from `[f, l)` into it.
zh_Hans: 构造一个至少包含 `n` 个桶的空容器，使用 `hf` 作为哈希函数，`eql` 作为键相等谓词，`a` 作为分配器，并将 `[f, l)` 范围内的元素插入其中。

[ctx: :443]
en: Requires:;; If the defaults are used, `hasher`, `key_equal` and `allocator_type` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
zh_Hans: 要求：如果使用默认值，则 `hasher`、`key_equal` 和 `allocator_type` 需要满足 https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[可默认构造^]。

en: Copy Constructor
zh_Hans: 复制构造函数

en: ```c++ unordered_node_map(unordered_node_map const& other); ```
zh_Hans: ```c++ unordered_node_map(unordered_node_map const&amp; other); ```

en: The copy constructor. Copies the contained elements, hash function, predicate and allocator.
zh_Hans: 拷贝构造函数。拷贝所包含的元素、哈希函数、谓词和分配器。

en: If `Allocator::select_on_container_copy_construction` exists and has the right signature, the allocator will be constructed from its result.
zh_Hans: 如果 `Allocator::select_on_container_copy_construction` 存在且具有正确的签名，则分配器将根据其结果进行构造。

en: Move Constructor
zh_Hans: 移动构造函数

en: ```c++ unordered_node_map(unordered_node_map&& other); ```
zh_Hans: ```c++ unordered_node_map(unordered_node_map&amp;&amp; other); ```

en: The move constructor. The internal bucket array of `other` is transferred directly to the new container. The hash function, predicate and allocator are moved-constructed from `other`. If statistics are xref:unordered_node_map_boost_unordered_enable_stats[enabled], transfers the internal statistical information from `other` and calls `other.reset_stats()`.
zh_Hans: 移动构造函数。`other` 的内部桶数组会被直接转移给新容器。哈希函数、谓词和分配器通过移动构造从 `other` 获得。如果启用了统计信息（详见 xref:unordered_node_map_boost_unordered_enable_stats[`BOOST_UNORDERED_ENABLE_STATS`]），则会从 `other` 转移内部的统计信息，并调用 `other.reset_stats()`。

en: Iterator Range Constructor with Allocator
zh_Hans: 带分配器的迭代器范围构造函数

en: ```c++ template<class InputIterator> unordered_node_map(InputIterator f, InputIterator l, const allocator_type& a); ```
zh_Hans: ```c++ template<class inputiterator=""> unordered_node_map(InputIterator f, InputIterator l, const allocator_type&amp; a); ```</class>

en: Constructs an empty container using `a` as the allocator, with the default hash function and key equality predicate and inserts the elements from `[f, l)` into it.
zh_Hans: 使用 `a` 作为分配器，以默认哈希函数和键相等谓词构造一个空容器，并将 `[f, l)` 范围内的元素插入其中。

[ctx: :479]
en: Requires:;; `hasher`, `key_equal` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
zh_Hans: 要求：`hasher`、`key_equal` 需要满足 https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[可默认构造^]。

en: Allocator Constructor
zh_Hans: 分配器构造函数

en: ```c++ explicit unordered_node_map(Allocator const& a); ```
zh_Hans: ```c++ explicit unordered_node_map(Allocator const&amp; a); ```

en: Constructs an empty container, using allocator `a`.
zh_Hans: 使用分配器 `a` 构造一个空容器。

en: Copy Constructor with Allocator
zh_Hans: 带分配器的拷贝构造函数

en: ```c++ unordered_node_map(unordered_node_map const& other, Allocator const& a); ```
zh_Hans: ```c++ unordered_node_map(unordered_node_map const&amp; other, Allocator const&amp; a); ```

en: Constructs a container, copying ``other``'s contained elements, hash function, and predicate, but using allocator `a`.
zh_Hans: 构造一个容器，拷贝 `other` 所包含的元素、哈希函数和谓词，但使用分配器 `a`。

en: Move Constructor with Allocator
zh_Hans: 带分配器的移动构造函数

en: ```c++ unordered_node_map(unordered_node_map&& other, Allocator const& a); ```
zh_Hans: ```c++ unordered_node_map(unordered_node_map&amp;&amp; other, Allocator const&amp; a); ```

en: If `a == other.get_allocator()`, the element nodes of `other` are transferred directly to the new container; otherwise, elements are moved-constructed from those of `other`. The hash function and predicate are moved-constructed from `other`, and the allocator is copy-constructed from `a`. If statistics are xref:unordered_node_map_boost_unordered_enable_stats[enabled], transfers the internal statistical information from `other` iff `a == other.get_allocator()`, and always calls `other.reset_stats()`.
zh_Hans: 如果 `a == other.get_allocator()`，则 `other` 的元素节点会直接转移给新容器；否则，元素将从 `other` 中的元素通过移动构造获得。哈希函数和谓词通过移动构造从 `other` 获得，而分配器则通过拷贝构造从 `a` 获得。如果启用了统计信息（详见 xref:unordered_node_map_boost_unordered_enable_stats[`BOOST_UNORDERED_ENABLE_STATS`]），则当 `a == other.get_allocator()` 时，会从 `other` 转移内部的统计信息，并且始终会调用 `other.reset_stats()`。

en: Move Constructor from concurrent_node_map
zh_Hans: 从 `concurrent_node_map` 的移动构造函数

en: ```c++ unordered_node_map(concurrent_node_map<Key, T, Hash, Pred, Allocator>&& other); ```
zh_Hans: ```c++ unordered_node_map(concurrent_node_map<key, t,="" hash,="" pred,="" allocator="">&amp;&amp; other); ```</key,>

en: Move construction from a xref:#concurrent_node_map[`concurrent_node_map`]. The internal bucket array of `other` is transferred directly to the new container. The hash function, predicate and allocator are moved-constructed from `other`. If statistics are xref:unordered_node_map_boost_unordered_enable_stats[enabled], transfers the internal statistical information from `other` and calls `other.reset_stats()`.
zh_Hans: 从 xref:#concurrent_node_map[`concurrent_node_map`] 进行移动构造。`other` 的内部桶数组直接转移给新容器。哈希函数、谓词和分配器通过移动构造从 `other` 获得。如果启用了统计信息（详见 xref:unordered_node_map_boost_unordered_enable_stats[`BOOST_UNORDERED_ENABLE_STATS`]），则从 `other` 转移内部的统计信息，并调用 `other.reset_stats()`。

en: Complexity:;; Constant time. Concurrency:;; Blocking on `other`.
zh_Hans: 复杂度：常数时间。  
    并发性：在 `other` 上阻塞。

en: Initializer List Constructor
zh_Hans: 初始化列表构造函数

en: Constructs an empty container with at least `n` buckets, using `hf` as the hash function, `eql` as the key equality predicate and `a`, and inserts the elements from `il` into it.
zh_Hans: 构造一个至少包含 `n` 个桶的空容器，使用 `hf` 作为哈希函数，`eql` 作为键相等谓词和 `a`，并将 `il` 中的元素插入其中。

[ctx: :546]
en: Requires:;; If the defaults are used, `hasher`, `key_equal` and `allocator_type` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
zh_Hans: 要求：如果使用默认值，则 `hasher`、`key_equal` 和 `allocator_type` 需要满足 https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[可默认构造^]。

en: Bucket Count Constructor with Allocator
zh_Hans: 带分配器的桶数构造函数

en: ```c++ unordered_node_map(size_type n, allocator_type const& a); ```
zh_Hans: ```c++ unordered_node_map(size_type n, allocator_type const&amp; a); ```

en: Constructs an empty container with at least `n` buckets, using `hf` as the hash function, the default hash function and key equality predicate and `a` as the allocator.
zh_Hans: 构造一个至少包含 `n` 个桶的空容器，使用 `hf` 作为哈希函数，使用默认的哈希函数和键相等谓词，并以 `a` 作为分配器。

en: Postconditions:;; `size() == 0` Requires:;; `hasher` and `key_equal` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
zh_Hans: 后置条件：`size() == 0`  
    要求：`hasher` 和 `key_equal` 需要满足 https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[可默认构造^]。

en: Bucket Count Constructor with Hasher and Allocator
zh_Hans: 带哈希函数和分配器的桶数构造函数

en: ```c++ unordered_node_map(size_type n, hasher const& hf, allocator_type const& a); ```
zh_Hans: ```c++ unordered_node_map(size_type n, hasher const&amp; hf, allocator_type const&amp; a); ```

en: Constructs an empty container with at least `n` buckets, using `hf` as the hash function, the default key equality predicate and `a` as the allocator.
zh_Hans: 构造一个至少包含 `n` 个桶的空容器，使用 `hf` 作为哈希函数，使用默认的键相等谓词，并以 `a` 作为分配器。

en: Postconditions:;; `size() == 0` Requires:;; `key_equal` needs to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
zh_Hans: 后置条件：`size() == 0` 要求：`key_equal` 需满足 https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[可默认构造^] 要求。

en: Iterator Range Constructor with Bucket Count and Allocator
zh_Hans: 带桶数和分配器的迭代器范围构造函数

en: Constructs an empty container with at least `n` buckets, using `a` as the allocator and default hash function and key equality predicate, and inserts the elements from `[f, l)` into it.
zh_Hans: 构造一个至少包含 `n` 个桶的空容器，使用 `a` 作为分配器以及默认的哈希函数和键相等谓词，并将 `[f, l)` 范围内的元素插入其中。

[ctx: :586]
en: Requires:;; `hasher`, `key_equal` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
zh_Hans: 要求：`hasher`、`key_equal` 需要满足 https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[可默认构造^]。

en: Iterator Range Constructor with Bucket Count and Hasher
zh_Hans: 带桶数和哈希函数的迭代器范围构造函数

en: Constructs an empty container with at least `n` buckets, using `hf` as the hash function, `a` as the allocator, with the default key equality predicate, and inserts the elements from `[f, l)` into it.
zh_Hans: 构造一个至少包含 `n` 个桶的空容器，使用 `hf` 作为哈希函数，`a` 作为分配器，使用默认的键相等谓词，并将 `[f, l)` 范围内的元素插入其中。

[ctx: :601]
en: Requires:;; `key_equal` needs to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
zh_Hans: 要求;; `key_equal` 需满足 https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[可默认构造] 要求。

en: initializer_list Constructor with Allocator
zh_Hans: 带分配器的初始化列表构造函数

en: ```c++ unordered_node_map(std::initializer_list<value_type> il, const allocator_type& a); ```
zh_Hans: ```c++ unordered_node_map(std::initializer_list<value_type> il, const allocator_type&amp; a); ```</value_type>

en: Constructs an empty container using `a` and default hash function and key equality predicate, and inserts the elements from `il` into it.
zh_Hans: 使用 `a` 以及默认的哈希函数和键相等谓词构造一个空容器，并将 `il` 中的元素插入其中。

[ctx: :614]
en: Requires:;; `hasher` and `key_equal` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
zh_Hans: 要求：`hasher` 和 `key_equal` 需要满足 https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[可默认构造^]。

en: initializer_list Constructor with Bucket Count and Allocator
zh_Hans: 带桶数和分配器的初始化列表构造函数

en: ```c++ unordered_node_map(std::initializer_list<value_type> il, size_type n, const allocator_type& a); ```
zh_Hans: ```c++ unordered_node_map(std::initializer_list<value_type> il, size_type n, const allocator_type&amp; a); ```</value_type>

en: Constructs an empty container with at least `n` buckets, using `a` and default hash function and key equality predicate, and inserts the elements from `il` into it.
zh_Hans: 使用 `a` 以及默认的哈希函数和键相等谓词，构造一个至少包含 `n` 个桶的空容器，并将 `il` 中的元素插入其中。

[ctx: :627]
en: Requires:;; `hasher` and `key_equal` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
zh_Hans: 要求：`hasher` 和 `key_equal` 需要满足 https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[可默认构造^]。

en: initializer_list Constructor with Bucket Count and Hasher and Allocator
zh_Hans: 带桶数、哈希函数和分配器的初始化列表构造函数

en: ```c++ unordered_node_map(std::initializer_list<value_type> il, size_type n, const hasher& hf, const allocator_type& a); ```
zh_Hans: ```c++ unordered_node_map(std::initializer_list<value_type> il, size_type n, const hasher&amp; hf, const allocator_type&amp; a); ```</value_type>

en: Constructs an empty container with at least `n` buckets, using `hf` as the hash function, `a` as the allocator and default key equality predicate,and inserts the elements from `il` into it.
zh_Hans: 构造一个至少包含 `n` 个桶的空容器，使用 `hf` 作为哈希函数，`a` 作为分配器，使用默认的键相等谓词，并将 `il` 中的元素插入其中。

[ctx: :641]
en: Requires:;; `key_equal` needs to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
zh_Hans: 要求：`key_equal` 需要满足 https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[可默认构造^]。

en: Destructor
zh_Hans: 析构函数

en: Note:;; The destructor is applied to every element, and all memory is deallocated
zh_Hans: 注意：析构函数会应用于每个元素，并且所有内存都会被释放。

en: Assignment
zh_Hans: 赋值操作

en: Copy Assignment
zh_Hans: 拷贝赋值

en: ```c++ unordered_node_map& operator=(unordered_node_map const& other); ```
zh_Hans: ```c++ unordered_node_map&amp; operator=(unordered_node_map const&amp; other); ```

en: The assignment operator. Destroys previously existing elements, copy-assigns the hash function and predicate from `other`, copy-assigns the allocator from `other` if `Alloc::propagate_on_container_copy_assignment` exists and `Alloc::propagate_on_container_copy_assignment::value` is `true`, and finally inserts copies of the elements of `other`.
zh_Hans: 赋值运算符。销毁之前存在的元素，从 `other` 拷贝赋值哈希函数和谓词，如果 `Alloc::propagate_on_container_copy_assignment` 存在且 `Alloc::propagate_on_container_copy_assignment::value` 为 `true`，则从 `other` 拷贝赋值分配器，最后插入 `other` 中元素的副本。

[ctx: :669]
en: Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/CopyInsertable[CopyInsertable^]
zh_Hans: 要求：`value_type` 满足 https://en.cppreference.com/w/cpp/named_req/CopyInsertable[可拷贝插入^]。

en: Move Assignment
zh_Hans: 移动赋值

en: ```c++ unordered_node_map& operator=(unordered_node_map&& other) noexcept((boost::allocator_traits<Allocator>::is_always_equal::value || boost::allocator_traits<Allocator>::propagate_on_container_move_assignment::value) && std::is_same<pointer, value_type*>::value); ``` The move assignment operator. Destroys previously existing elements, swaps the hash function and predicate from `other`, and move-assigns the allocator from `other` if `Alloc::propagate_on_container_move_assignment` exists and `Alloc::propagate_on_container_move_assignment::value` is `true`. If at this point the allocator is equal to `other.get_allocator()`, the internal bucket array of `other` is transferred directly to the new container; otherwise, inserts move-constructed copies of the elements of `other`. If statistics are xref:unordered_node_map_boost_unordered_enable_stats[enabled], transfers the internal statistical information from `other` iff the final allocator is equal to `other.get_allocator()`, and always calls `other.reset_stats()`.
zh_Hans: ```c++
    unordered_node_map&amp; operator=(unordered_node_map&amp;&amp; other) noexcept((boost::allocator_traits<allocator>::is_always_equal::value || boost::allocator_traits<allocator>::propagate_on_container_move_assignment::value) &amp;&amp; std::is_same<pointer, value_type*="">::value);
    ```
    移动赋值运算符。销毁之前存在的元素，交换来自 `other` 的哈希函数和谓词，并且如果 `Alloc::propagate_on_container_move_assignment` 存在且 `Alloc::propagate_on_container_move_assignment::value` 为 `true`，则从 `other` 移动赋值分配器。如果此时分配器与 `other.get_allocator()` 相等，则 `other` 的内部桶数组直接转移给当前容器；否则，插入从 `other` 元素移动构造而来的副本。如果启用了统计信息（详见 xref:unordered_node_map_boost_unordered_enable_stats[`BOOST_UNORDERED_ENABLE_STATS`]），则当最终分配器与 `other.get_allocator()` 相等时，从 `other` 转移内部的统计信息，并且始终会调用 `other.reset_stats()`。</pointer,></allocator></allocator>

en: Initializer List Assignment
zh_Hans: 初始化列表赋值

en: ```c++ unordered_node_map& operator=(std::initializer_list<value_type> il); ```
zh_Hans: ```c++ unordered_node_map&amp; operator=(std::initializer_list<value_type> il); ```</value_type>

en: Assign from values in initializer list. All previously existing elements are destroyed.
zh_Hans: 从初始化列表中的值进行赋值。所有之前存在的元素都会被销毁。

[ctx: :698]
en: Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/CopyInsertable[CopyInsertable^]
zh_Hans: 要求：`value_type` 满足 https://en.cppreference.com/w/cpp/named_req/CopyInsertable[可拷贝插入^]。

en: Iterators
zh_Hans: 迭代器

en: Returns:;; An iterator referring to the first element of the container, or if the container is empty the past-the-end value for the container. Complexity:;; O(`bucket_count()`)
zh_Hans: 返回：指向容器第一个元素的迭代器，如果容器为空则返回容器的尾后迭代器。  
    复杂度：O(`bucket_count()`)

en: Returns:;; An iterator which refers to the past-the-end value for the container.
zh_Hans: 返回：指向容器尾后值的迭代器。

en: Returns:;; A `const_iterator` referring to the first element of the container, or if the container is empty the past-the-end value for the container. Complexity:;; O(`bucket_count()`)
zh_Hans: 返回：指向容器第一个元素的 `const_iterator`，如果容器为空则返回容器的尾后值。  
    复杂度：O(`bucket_count()`)

en: Returns:;; A `const_iterator` which refers to the past-the-end value for the container.
zh_Hans: 返回：指向容器尾后值的 `const_iterator`。

en: Size and Capacity
zh_Hans: 大小与容量

en: empty
zh_Hans: 空

en: size
zh_Hans: 大小

en: Returns:;; `size()` of the largest possible container.
zh_Hans: 返回：可能的最大容器的 `size()`。

en: Modifiers
zh_Hans: 修改器

en: emplace
zh_Hans: 原地构造

en: ```c++ template<class... Args> std::pair<iterator, bool> emplace(Args&&... args); ```
zh_Hans: ```c++ template<class... args=""> std::pair<iterator, bool=""> emplace(Args&amp;&amp;... args); ```</iterator,></class...>

[ctx: :788]
en: Inserts an object, constructed with the arguments `args`, in the container if and only if there is no element in the container with an equivalent key.
zh_Hans: 当且仅当容器中没有具有等价键的元素时，才插入一个使用参数 `args` 构造的对象。

[ctx: :791]
en: Requires:;; `value_type` is constructible from `args`. Returns:;; The `bool` component of the return type is `true` if an insert took place. + + If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key. Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. + + If `args...` is of the form `k,v`, it delays constructing the whole object until it is certain that an element should be inserted, using only the `k` argument to check. This optimization happens when `key_type` is move constructible or when the `k` argument is a `key_type`.
zh_Hans: 要求：`value_type` 可从 `args` 构造。  
    返回：返回类型的 `bool` 分量为 `true` 表示发生了插入。  
    如果发生了插入，则迭代器指向新插入的元素；否则，指向具有等价键的元素。  
    抛出：如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：可能使迭代器失效，但仅当插入导致负载大于最大负载时才会发生。  
    
    如果 `args...` 的形式为 `k,v`，则该函数会延迟构造整个对象，直到确定应该插入元素为止，仅使用 `k` 参数进行检查。当 `key_type` 可移动构造或 `k` 参数本身就是 `key_type` 类型时，此优化生效。

en: ```c++ template<class... Args> iterator emplace_hint(const_iterator position, Args&&... args); ```
zh_Hans: ```c++ template<class... args=""> iterator emplace_hint(const_iterator position, Args&amp;&amp;... args); ```</class...>

[ctx: :807]
en: Inserts an object, constructed with the arguments `args`, in the container if and only if there is no element in the container with an equivalent key.
zh_Hans: 当且仅当容器中没有具有等价键的元素时，才插入一个使用参数 `args` 构造的对象。

en: `position` is a suggestion to where the element should be inserted. This implementation ignores it.
zh_Hans: `position` 是关于元素插入位置的建议。此实现会忽略该建议。

[ctx: :812]
en: Requires:;; `value_type` is constructible from `args`. Returns:;; The `bool` component of the return type is `true` if an insert took place. + + If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key. Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. + + If `args...` is of the form `k,v`, it delays constructing the whole object until it is certain that an element should be inserted, using only the `k` argument to check. This optimization happens when `key_type` is move constructible or when the `k` argument is a `key_type`.
zh_Hans: 要求：`value_type` 可从 `args` 构造。  
    返回：返回类型的 `bool` 分量为 `true` 表示发生了插入。  
    如果发生了插入，则迭代器指向新插入的元素；否则，指向具有等价键的元素。  
    抛出：如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：可能使迭代器失效，但仅当插入导致负载大于最大负载时才会发生。  
    
    如果 `args...` 的形式为 `k,v`，则该函数会延迟构造整个对象，直到确定应该插入元素为止，仅使用 `k` 参数进行检查。当 `key_type` 可移动构造或 `k` 参数本身就是 `key_type` 类型时，此优化生效。

en: Copy Insert
zh_Hans: 复制插入

en: ```c++ std::pair<iterator, bool> insert(const value_type& obj); std::pair<iterator, bool> insert(const init_type& obj); ```
zh_Hans: ```c++ std::pair<iterator, bool=""> insert(const value_type&amp; obj); std::pair<iterator, bool=""> insert(const init_type&amp; obj); ```</iterator,></iterator,>

[ctx: :829]
en: Inserts `obj` in the container if and only if there is no element in the container with an equivalent key.
zh_Hans: 当且仅当容器中没有具有等价键的元素时，才将 `obj` 插入容器。

en: Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/CopyInsertable[CopyInsertable^]. Returns:;; The `bool` component of the return type is `true` if an insert took place. + + If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key. Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. + + A call of the form `insert(x)`, where `x` is equally convertible to both `const value_type&` and `const init_type&`, is not ambiguous and selects the `init_type` overload.
zh_Hans: 要求：`value_type` 满足 https://en.cppreference.com/w/cpp/named_req/CopyInsertable[可拷贝插入^]。  
    返回：返回类型的 `bool` 分量为 `true` 表示发生了插入。  
    如果发生了插入，则迭代器指向新插入的元素；否则，指向具有等价键的元素。  
    抛出：如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：可能使迭代器失效，但仅当插入导致负载大于最大负载时才会发生。  
    
    形式为 `insert(x)` 的调用，如果 `x` 可以同等转换为 `const value_type&amp;` 和 `const init_type&amp;`，则不会产生歧义，并且会选择 `init_type` 重载。

en: Move Insert
zh_Hans: 移动插入

en: ```c++ std::pair<iterator, bool> insert(value_type&& obj); std::pair<iterator, bool> insert(init_type&& obj); ```
zh_Hans: ```c++ std::pair<iterator, bool=""> insert(value_type&amp;&amp; obj); std::pair<iterator, bool=""> insert(init_type&amp;&amp; obj); ```</iterator,></iterator,>

[ctx: :849]
en: Inserts `obj` in the container if and only if there is no element in the container with an equivalent key.
zh_Hans: 当且仅当容器中没有具有等价键的元素时，才将 `obj` 插入容器。

en: Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/MoveInsertable[MoveInsertable^]. Returns:;; The `bool` component of the return type is `true` if an insert took place. + + If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key. Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. + + A call of the form `insert(x)`, where `x` is equally convertible to both `value_type&&` and `init_type&&`, is not ambiguous and selects the `init_type` overload.
zh_Hans: 要求：`value_type` 满足 https://en.cppreference.com/w/cpp/named_req/MoveInsertable[可移动插入^]。  
    返回：返回类型的 `bool` 分量为 `true` 表示发生了插入。  
    如果发生了插入，则迭代器指向新插入的元素；否则，指向具有等价键的元素。  
    抛出：如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：可能使迭代器失效，但仅当插入导致负载大于最大负载时才会发生。  
    
    形式为 `insert(x)` 的调用，如果 `x` 可以同等转换为 `value_type&amp;&amp;` 和 `init_type&amp;&amp;`，则不会产生歧义，并且会选择 `init_type` 重载。

en: Copy Insert with Hint
zh_Hans: 带提示的复制插入

en: ```c++ iterator insert(const_iterator hint, const value_type& obj); iterator insert(const_iterator hint, const init_type& obj); ``` Inserts `obj` in the container if and only if there is no element in the container with an equivalent key.
zh_Hans: ```c++
    iterator insert(const_iterator hint, const value_type&amp; obj);
    iterator insert(const_iterator hint, const init_type&amp; obj);
    ```
    当且仅当容器中没有具有等价键的元素时，才将 `obj` 插入容器。

[ctx: :870]
en: `hint` is a suggestion to where the element should be inserted. This implementation ignores it.
zh_Hans: `hint` 是关于元素插入位置的建议。此实现会忽略该建议。

en: Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/CopyInsertable[CopyInsertable^]. Returns:;; The `bool` component of the return type is `true` if an insert took place. + + If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key. Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. + + A call of the form `insert(hint, x)`, where `x` is equally convertible to both `const value_type&` and `const init_type&`, is not ambiguous and selects the `init_type` overload.
zh_Hans: 要求：`value_type` 满足 https://en.cppreference.com/w/cpp/named_req/CopyInsertable[可拷贝插入^]。  
    返回：返回类型的 `bool` 分量为 `true` 表示发生了插入。  
    如果发生了插入，则迭代器指向新插入的元素；否则，指向具有等价键的元素。  
    抛出：如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：可能使迭代器失效，但仅当插入导致负载大于最大负载时才会发生。  
    
    形式为 `insert(hint, x)` 的调用，如果 `x` 可以同等转换为 `const value_type&amp;` 和 `const init_type&amp;`，则不会产生歧义，并且会选择 `init_type` 重载。

en: Move Insert with Hint
zh_Hans: 带提示的移动插入

en: ```c++ iterator insert(const_iterator hint, value_type&& obj); iterator insert(const_iterator hint, init_type&& obj); ```
zh_Hans: ```c++ iterator insert(const_iterator hint, value_type&amp;&amp; obj); iterator insert(const_iterator hint, init_type&amp;&amp; obj); ```

[ctx: :890]
en: Inserts `obj` in the container if and only if there is no element in the container with an equivalent key.
zh_Hans: 当且仅当容器中没有具有等价键的元素时，才将 `obj` 插入容器。

[ctx: :892]
en: `hint` is a suggestion to where the element should be inserted. This implementation ignores it.
zh_Hans: `hint` 是关于元素插入位置的建议。此实现会忽略该建议。

en: Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/MoveInsertable[MoveInsertable^]. Returns:;; The `bool` component of the return type is `true` if an insert took place. + + If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key. Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. + + A call of the form `insert(hint, x)`, where `x` is equally convertible to both `value_type&&` and `init_type&&`, is not ambiguous and selects the `init_type` overload.
zh_Hans: 要求：`value_type` 满足 https://en.cppreference.com/w/cpp/named_req/MoveInsertable[可移动插入^]。  
    返回：返回类型的 `bool` 分量为 `true` 表示发生了插入。  
    如果发生了插入，则迭代器指向新插入的元素；否则，指向具有等价键的元素。  
    抛出：如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：可能使迭代器失效，但仅当插入导致负载大于最大负载时才会发生。  
    
    形式为 `insert(hint, x)` 的调用，如果 `x` 可以同等转换为 `value_type&amp;&amp;` 和 `init_type&amp;&amp;`，则不会产生歧义，并且会选择 `init_type` 重载。

en: Insert Iterator Range
zh_Hans: 迭代器范围插入

en: ```c++ template<class InputIterator> void insert(InputIterator first, InputIterator last); ```
zh_Hans: ```c++ template<class inputiterator=""> void insert(InputIterator first, InputIterator last); ```</class>

[ctx: :911]
en: Inserts a range of elements into the container. Elements are inserted if and only if there is no element in the container with an equivalent key.
zh_Hans: 将一个范围内的元素插入容器中。当且仅当容器中没有具有等价键的元素时，才会插入这些元素。

en: Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/EmplaceConstructible[EmplaceConstructible^] into the container from `*first`. Throws:;; When inserting a single element, if an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load.
zh_Hans: 要求：`value_type` 可以从 `*first` 出发在容器中进行 https://en.cppreference.com/w/cpp/named_req/EmplaceConstructible[可原位构造^]。  
    抛出：当插入单个元素时，如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：可能使迭代器失效，但仅当插入导致负载大于最大负载时才会发生。

en: Insert Initializer List
zh_Hans: 初始化列表插入

en: ```c++ void insert(std::initializer_list<value_type>); ```
zh_Hans: ```c++ void insert(std::initializer_list<value_type>); ```</value_type>

[ctx: :925]
en: Inserts a range of elements into the container. Elements are inserted if and only if there is no element in the container with an equivalent key.
zh_Hans: 将一个范围内的元素插入容器中。当且仅当容器中没有具有等价键的元素时，才会插入这些元素。

en: Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/CopyInsertable[CopyInsertable^] into the container. Throws:;; When inserting a single element, if an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load.
zh_Hans: 要求：`value_type` 可以在容器中进行 https://en.cppreference.com/w/cpp/named_req/CopyInsertable[可拷贝插入^]。  
    抛出：当插入单个元素时，如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：可能使迭代器失效，但仅当插入导致负载大于最大负载时才会发生。

en: Insert Node
zh_Hans: 节点插入

en: ```c++ insert_return_type insert(node_type&& nh); ```
zh_Hans: ```c++ insert_return_type insert(node_type&amp;&amp; nh); ```

en: If `nh` is not empty, inserts the associated element in the container if and only if there is no element in the container with a key equivalent to `nh.key()`. `nh` is empty when the function returns.
zh_Hans: 如果 `nh` 非空，则当且仅当容器中没有键与 `nh.key()` 等价的元素时，才将关联的元素插入容器。函数返回时 `nh` 变为空。

en: Returns:;; An `insert_return_type` object constructed from `position`, `inserted` and `node`: +
zh_Hans: 返回：一个 `insert_return_type` 对象，由 `position`、`inserted` 和 `node` 构造而成。

en: If `nh` is empty, `inserted` is `false`, `position` is `end()`, and `node` is empty.
zh_Hans: 若 `nh` 为空，则 `inserted` 为 `false` ， `position` 为 `end()` ，且 `node` 为空。

en: Otherwise if the insertion took place, `inserted` is true, `position` points to the inserted element, and `node` is empty.
zh_Hans: 否则，若插入操作发生，则 `inserted` 为 `true` ， `position` 指向被插入的元素，且 `node` 为空。

en: If the insertion failed, `inserted` is false, `node` has the previous value of `nh`, and `position` points to an element with a key equivalent to `nh.key()`.
zh_Hans: 若插入操作失败，则 `inserted` 为 `false` ， `node` 保留 `nh` 的原始值，且 `position` 指向与 `nh.key()` 等效的元素。

en: Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; Behavior is undefined if `nh` is not empty and the allocators of `nh` and the container are not equal.
zh_Hans: 若 `nh` 非空，则当且仅当容器中不存在键等价于 `nh.key()` 的元素时，插入其关联元素。函数返回时 `nh` 为空。

en: Insert Node with Hint
zh_Hans: 带提示的节点插入

en: ```c++ iterator insert(const_iterator hint, node_type&& nh); ```
zh_Hans: ```c++ iterator insert(const_iterator hint, node_type&amp;&amp; nh); ```

en: If `nh` is not empty, inserts the associated element in the container if and only if there is no element in the container with a key equivalent to `nh.key()`. `nh` becomes empty if insertion took place, otherwise it is not changed.
zh_Hans: 如果 `nh` 非空，则当且仅当容器中没有键与 `nh.key()` 等价的元素时，才将关联的元素插入容器。如果插入发生，则 `nh` 变为空；否则 `nh` 不变。

[ctx: :960]
en: `hint` is a suggestion to where the element should be inserted. This implementation ignores it.
zh_Hans: `hint` 是关于元素插入位置的建议。此实现会忽略该建议。

en: Returns:;; The iterator returned is `end()` if `nh` is empty. If insertion took place, then the iterator points to the newly inserted element; otherwise, it points to the element with equivalent key. Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; Behavior is undefined if `nh` is not empty and the allocators of `nh` and the container are not equal.
zh_Hans: 返回：如果 `nh` 为空，则返回的迭代器为 `end()`。如果插入发生，则迭代器指向新插入的元素；否则，指向具有等价键的元素。  
    抛出：如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：如果 `nh` 非空且 `nh` 与容器的分配器不相等，则行为未定义。

en: ```c++ template<class... Args> std::pair<iterator, bool> try_emplace(const key_type& k, Args&&... args); template<class... Args> std::pair<iterator, bool> try_emplace(key_type&& k, Args&&... args); template<class K, class... Args> std::pair<iterator, bool> try_emplace(K&& k, Args&&... args); ```
zh_Hans: ```c++
    template<class... args="">
    std::pair<iterator, bool=""> try_emplace(const key_type&amp; k, Args&amp;&amp;... args);
    template<class... args="">
    std::pair<iterator, bool=""> try_emplace(key_type&amp;&amp; k, Args&amp;&amp;... args);
    template<class k,="" class...="" args="">
    std::pair<iterator, bool=""> try_emplace(K&amp;&amp; k, Args&amp;&amp;... args);
    ```</iterator,></class></iterator,></class...></iterator,></class...>

[ctx: :980]
en: Inserts a new element into the container if there is no existing element with key `k` contained within it.
zh_Hans: 如果容器中不存在键为 `k` 的元素，则插入一个新元素。

[ctx: :982]
en: If there is an existing element with key `k` this function does nothing.
zh_Hans: 如果已存在键为 `k` 的元素，则该函数不执行任何操作。

en: Returns:;; The `bool` component of the return type is `true` if an insert took place. + + If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key. Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; This function is similiar to xref:#unordered_node_map_emplace[emplace], with the difference that no `value_type` is constructed if there is an element with an equivalent key; otherwise, the construction is of the form: + + -- ```c++
zh_Hans: 返回：返回类型的 `bool` 分量为 `true` 表示发生了插入。  
    如果发生了插入，则迭代器指向新插入的元素；否则，指向具有等价键的元素。  
    抛出：如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：此函数类似于 xref:#unordered_node_map_emplace[emplace]，区别在于如果存在具有等价键的元素，则不构造 `value_type`；否则，构造形式为：  
    
    ```c++

[ctx: :995]
en: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<Key>(k)), std::forward_as_tuple(std::forward<Args>(args)...))
zh_Hans: ```c++
    value_type(std::piecewise_construct,
              std::forward_as_tuple(std::forward<key>(k)),
              std::forward_as_tuple(std::forward<args>(args)...))
    ```</args></key>

[ctx: :1000]
en: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<K>(k)), std::forward_as_tuple(std::forward<Args>(args)...)) ```
zh_Hans: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<k>(k)), std::forward_as_tuple(std::forward<args>(args)...)) ```</args></k>

en: unlike xref:#unordered_node_map_emplace[emplace], which simply forwards all arguments to ``value_type``'s constructor.
zh_Hans: 与 xref:#unordered_node_map_emplace[emplace] 不同，后者只是将所有参数直接转发给 `value_type` 的构造函数。

[ctx: :1007]
en: Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load.
zh_Hans: 可能使迭代器失效，但仅当插入导致负载大于最大负载时才会发生。

[ctx: :1009]
en: The `template<class K, class\... Args>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs and neither `iterator` nor `const_iterator` are implicitly convertible from `K`. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
zh_Hans: `template<class k,="" args="">` 重载仅在 `Hash::is_transparent` 和 `Pred::is_transparent` 是有效的成员 typedef，且 `iterator` 和 `const_iterator` 都不能从 `K` 隐式转换时参与重载决议。库假定 `Hash` 可同时使用 `K` 和 `Key` 调用，且 `Pred` 是透明的。这支持了异构查找，从而避免了实例化 `Key` 类型对象的开销。</class>

en: try_emplace with Hint
zh_Hans: 带提示的 try_emplace

en: ```c++ template<class... Args> iterator try_emplace(const_iterator hint, const key_type& k, Args&&... args); template<class... Args> iterator try_emplace(const_iterator hint, key_type&& k, Args&&... args); template<class K, class... Args> iterator try_emplace(const_iterator hint, K&& k, Args&&... args); ```
zh_Hans: ```c++ template<class... args=""> iterator try_emplace(const_iterator hint, const key_type&amp; k, Args&amp;&amp;... args); template<class... args=""> iterator try_emplace(const_iterator hint, key_type&amp;&amp; k, Args&amp;&amp;... args); template<class k,="" class...="" args=""> iterator try_emplace(const_iterator hint, K&amp;&amp; k, Args&amp;&amp;... args); ```</class></class...></class...>

[ctx: :1025]
en: Inserts a new element into the container if there is no existing element with key `k` contained within it.
zh_Hans: 如果容器中不存在键为 `k` 的元素，则插入一个新元素。

[ctx: :1027]
en: If there is an existing element with key `k` this function does nothing.
zh_Hans: 如果已存在键为 `k` 的元素，则该函数不执行任何操作。

en: `hint` is a suggestion to where the element should be inserted.  This implementation ignores it.
zh_Hans: `hint` 是关于元素插入位置的建议。此实现会忽略该建议。

en: Returns:;; If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key. Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; This function is similiar to xref:#unordered_node_map_emplace_hint[emplace_hint], with the difference that no `value_type` is constructed if there is an element with an equivalent key; otherwise, the construction is of the form: + + -- ```c++
zh_Hans: 返回：如果发生了插入，则迭代器指向新插入的元素；否则，指向具有等价键的元素。  
    抛出：如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：此函数类似于 xref:#unordered_node_map_emplace_hint[emplace_hint]，区别在于如果存在具有等价键的元素，则不构造 `value_type`；否则，构造形式为：  
    
    ```c++

[ctx: :1040]
en: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<Key>(k)), std::forward_as_tuple(std::forward<Args>(args)...))
zh_Hans: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<key>(k)), std::forward_as_tuple(std::forward<args>(args)...))</args></key>

[ctx: :1045]
en: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<K>(k)), std::forward_as_tuple(std::forward<Args>(args)...)) ```
zh_Hans: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<k>(k)), std::forward_as_tuple(std::forward<args>(args)...)) ```</args></k>

en: unlike xref:#unordered_node_map_emplace_hint[emplace_hint], which simply forwards all arguments to ``value_type``'s constructor.
zh_Hans: 与 xref:#unordered_node_map_emplace_hint[emplace_hint] 不同，后者只是将所有参数直接转发给 `value_type` 的构造函数。

[ctx: :1052]
en: Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load.
zh_Hans: 可能使迭代器失效，但仅当插入导致负载大于最大负载时才会发生。

[ctx: :1054]
en: The `template<class K, class\... Args>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs and neither `iterator` nor `const_iterator` are implicitly convertible from `K`. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
zh_Hans: `template<class k,="" args="">` 重载仅在 `Hash::is_transparent` 和 `Pred::is_transparent` 是有效的成员 typedef，且 `iterator` 和 `const_iterator` 都不能从 `K` 隐式转换时参与重载决议。库假定 `Hash` 可同时使用 `K` 和 `Key` 调用，且 `Pred` 是透明的。这支持了异构查找，从而避免了实例化 `Key` 类型对象的开销。</class>

en: ```c++ template<class M> std::pair<iterator, bool> insert_or_assign(const key_type& k, M&& obj); template<class M> std::pair<iterator, bool> insert_or_assign(key_type&& k, M&& obj); template<class K, class M> std::pair<iterator, bool> insert_or_assign(K&& k, M&& obj); ```
zh_Hans: ```c++
    template<class m="">
    std::pair<iterator, bool=""> insert_or_assign(const key_type&amp; k, M&amp;&amp; obj);
    template<class m="">
    std::pair<iterator, bool=""> insert_or_assign(key_type&amp;&amp; k, M&amp;&amp; obj);
    template<class k,="" class="" m="">
    std::pair<iterator, bool=""> insert_or_assign(K&amp;&amp; k, M&amp;&amp; obj);
    ```</iterator,></class></iterator,></class></iterator,></class>

[ctx: :1070]
en: Inserts a new element into the container or updates an existing one by assigning to the contained value.
zh_Hans: 向容器中插入一个新元素，或通过赋值更新现有元素的值。

[ctx: :1072]
en: If there is an element with key `k`, then it is updated by assigning `std::forward<M>(obj)`.
zh_Hans: 如果存在键为 `k` 的元素，则通过赋值 `std::forward<m>(obj)` 来更新它。</m>

[ctx: :1074]
en: If there is no such element, it is added to the container as: ```c++
zh_Hans: 如果不存在这样的元素，则将其添加到容器中，形式为：  
    ```c++

[ctx: :1077]
en: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<Key>(k)), std::forward_as_tuple(std::forward<M>(obj)))
zh_Hans: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<key>(k)), std::forward_as_tuple(std::forward<m>(obj)))</m></key>

[ctx: :1082]
en: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<K>(k)), std::forward_as_tuple(std::forward<M>(obj))) ```
zh_Hans: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<k>(k)), std::forward_as_tuple(std::forward<m>(obj))) ```</m></k>

en: Returns:;; The `bool` component of the return type is `true` if an insert took place. + + If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key. Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load.  + + The `template<class K, class M>` only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
zh_Hans: 返回：返回类型的 `bool` 分量为 `true` 表示发生了插入。  
    如果发生了插入，则迭代器指向新插入的元素；否则，指向具有等价键的元素。  
    抛出：如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：可能使迭代器失效，但仅当插入导致负载大于最大负载时才会发生。  
    
    `template<class k,="" class="" m="">` 仅在 `Hash::is_transparent` 和 `Pred::is_transparent` 是有效的成员 typedef 时参与重载决议。库假定 `Hash` 可同时使用 `K` 和 `Key` 调用，且 `Pred` 是透明的。这支持了异构查找，从而避免了实例化 `Key` 类型对象的开销。</class>

en: insert_or_assign with Hint
zh_Hans: 带提示位置的 insert_or_assign

en: ```c++ template<class M> iterator insert_or_assign(const_iterator hint, const key_type& k, M&& obj); template<class M> iterator insert_or_assign(const_iterator hint, key_type&& k, M&& obj); template<class K, class M> iterator insert_or_assign(const_iterator hint, K&& k, M&& obj); ```
zh_Hans: ```c++ template<class m=""> iterator insert_or_assign(const_iterator hint, const key_type&amp; k, M&amp;&amp; obj); template<class m=""> iterator insert_or_assign(const_iterator hint, key_type&amp;&amp; k, M&amp;&amp; obj); template<class k,="" class="" m=""> iterator insert_or_assign(const_iterator hint, K&amp;&amp; k, M&amp;&amp; obj); ```</class></class></class>

[ctx: :1108]
en: Inserts a new element into the container or updates an existing one by assigning to the contained value.
zh_Hans: 向容器中插入一个新元素，或通过赋值更新现有元素的值。

[ctx: :1110]
en: If there is an element with key `k`, then it is updated by assigning `std::forward<M>(obj)`.
zh_Hans: 如果存在键为 `k` 的元素，则通过赋值 `std::forward<m>(obj)` 来更新它。</m>

[ctx: :1112]
en: If there is no such element, it is added to the container as: ```c++
zh_Hans: 如果不存在这样的元素，则将其添加到容器中，形式为：  
    ```c++

[ctx: :1115]
en: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<Key>(k)), std::forward_as_tuple(std::forward<M>(obj)))
zh_Hans: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<key>(k)), std::forward_as_tuple(std::forward<m>(obj)))</m></key>

[ctx: :1120]
en: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<K>(k)), std::forward_as_tuple(std::forward<M>(obj))) ```
zh_Hans: value_type(std::piecewise_construct, std::forward_as_tuple(std::forward<k>(k)), std::forward_as_tuple(std::forward<m>(obj))) ```</m></k>

[ctx: :1125]
en: `hint` is a suggestion to where the element should be inserted. This implementation ignores it.
zh_Hans: `hint` 是关于元素插入位置的建议。此实现会忽略该建议。

en: Returns:;; If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key. Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. + + The `template<class K, class M>` only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
zh_Hans: 返回：如果发生了插入，则迭代器指向新插入的元素；否则，指向具有等价键的元素。  
    抛出：如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：可能使迭代器失效，但仅当插入导致负载大于最大负载时才会发生。  
    
    `template<class k,="" class="" m="">` 仅在 `Hash::is_transparent` 和 `Pred::is_transparent` 是有效的成员 typedef 时参与重载决议。库假定 `Hash` 可同时使用 `K` 和 `Key` 调用，且 `Pred` 是透明的。这支持了异构查找，从而避免了实例化 `Key` 类型对象的开销。</class>

en: Erase by Position
zh_Hans: 按位置擦除

en: Erase the element pointed to by `position`.
zh_Hans: 擦除由 `position` 指向的元素。

en: Returns:;; An opaque object implicitly convertible to the `iterator` or `const_iterator` immediately following `position` prior to the erasure. Throws:;; Nothing. Notes:;; The opaque object returned must only be discarded or immediately converted to `iterator` or `const_iterator`.
zh_Hans: 返回：一个不透明对象，可隐式转换为 `position` 在被擦除之前紧后位置的 `iterator` 或 `const_iterator`。  
    抛出：不抛出任何异常。  
    注意：返回的不透明对象只能被丢弃或立即转换为 `iterator` 或 `const_iterator`。

en: Erase by Key
zh_Hans: 通过键擦除

en: ```c++ size_type erase(const key_type& k); template<class K> size_type erase(K&& k); ```
zh_Hans: ```c++ size_type erase(const key_type&amp; k); template<class k=""> size_type erase(K&amp;&amp; k); ```</class>

en: Erase all elements with key equivalent to `k`.
zh_Hans: 擦除所有键与 `k` 等价的元素。

en: Returns:;; The number of elements erased. Throws:;; Only throws an exception if it is thrown by `hasher` or `key_equal`. Notes:;; The `template<class K>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs and neither `iterator` nor `const_iterator` are implicitly convertible from `K`. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
zh_Hans: 返回：被擦除的元素数量。  
    抛出：仅当 `hasher` 或 `key_equal` 抛出异常时才会抛出。  
    注意：`template<class k="">` 重载仅在 `Hash::is_transparent` 和 `Pred::is_transparent` 是有效的成员 typedef，且 `iterator` 和 `const_iterator` 都不能从 `K` 隐式转换时参与重载决议。库假定 `Hash` 可同时使用 `K` 和 `Key` 调用，且 `Pred` 是透明的。这支持了异构查找，从而避免了实例化 `Key` 类型对象的开销。</class>

en: Erase Range
zh_Hans: 范围擦除

en: Returns:;; The iterator following the erased elements - i.e. `last`. Throws:;; Nothing in this implementation (neither the `hasher` nor the `key_equal` objects are called).
zh_Hans: 返回：被擦除元素之后的迭代器——即 `last`。  
    抛出：在此实现中不抛出任何异常（既不调用 `hasher` 也不调用 `key_equal` 对象）。

en: swap
zh_Hans: 交换

en: ```c++ void swap(unordered_node_map& other) noexcept(boost::allocator_traits<Allocator>::is_always_equal::value || boost::allocator_traits<Allocator>::propagate_on_container_swap::value); ```
zh_Hans: ```c++ void swap(unordered_node_map&amp; other) noexcept(boost::allocator_traits<allocator>::is_always_equal::value || boost::allocator_traits<allocator>::propagate_on_container_swap::value); ```</allocator></allocator>

en: Swaps the contents of the container with the parameter.
zh_Hans: 交换容器的内容与参数的内容。

[ctx: :1193]
en: If `Allocator::propagate_on_container_swap` is declared and `Allocator::propagate_on_container_swap::value` is `true` then the containers' allocators are swapped. Otherwise, swapping with unequal allocators results in undefined behavior.
zh_Hans: 如果 `Allocator::propagate_on_container_swap` 被声明且 `Allocator::propagate_on_container_swap::value` 为 `true`，则交换容器的分配器。否则，使用不相等的分配器进行交换将导致未定义行为。

en: Throws:;; Nothing unless `key_equal` or `hasher` throw on swapping.
zh_Hans: 抛出：除非 `key_equal` 或 `hasher` 在交换时抛出异常，否则不抛出任何异常。

en: Extract by Position
zh_Hans: 通过位置提取

en: Extracts the element pointed to by `position`.
zh_Hans: 提取 `position` 所指向的元素。

en: Returns:;; A `node_type` object holding the extracted element. Throws:;; Nothing.
zh_Hans: 返回：一个持有被提取元素的 `node_type` 对象。  
    抛出：不抛出任何异常。

en: Extract by Key
zh_Hans: 通过键提取

en: ```c++ node_type extract(const key_type& k); template<class K> node_type extract(K&& k); ```
zh_Hans: ```c++ node_type extract(const key_type&amp; k); template<class k=""> node_type extract(K&amp;&amp; k); ```</class>

en: Extracts the element with key equivalent to `k`, if it exists.
zh_Hans: 提取键与 `k` 等价的元素（如果存在）。

en: Returns:;; A `node_type` object holding the extracted element, or empty if no element was extracted. Throws:;; Only throws an exception if it is thrown by `hasher` or `key_equal`. Notes:;; The `template<class K>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
zh_Hans: 返回：一个持有被提取元素的 `node_type` 对象；如果未提取到任何元素，则返回空。  
    抛出：仅当 `hasher` 或 `key_equal` 抛出异常时才会抛出。  
    注意：`template<class k="">` 重载仅在 `Hash::is_transparent` 和 `Pred::is_transparent` 是有效的成员 typedef 时参与重载决议。库假定 `Hash` 可同时使用 `K` 和 `Key` 调用，且 `Pred` 是透明的。这支持了异构查找，从而避免了实例化 `Key` 类型对象的开销。</class>

en: Move-constructs an `init_value` `x` from the element pointed to by `position`, erases the element and returns `x`.
zh_Hans: 从 `position` 指向的元素移动构造一个 `init_value` 对象 `x`，擦除该元素并返回 `x`。

en: clear
zh_Hans: 清空

en: Erases all elements in the container.
zh_Hans: 擦除容器中的所有元素。

en: Postconditions:;; `size() == 0`, `max_load() >= max_load_factor() * bucket_count()`
zh_Hans: 后置条件：`size() == 0`，`max_load() &gt;= max_load_factor() * bucket_count()`

en: merge
zh_Hans: 合并

en: ```c++ template<class H2, class P2> void merge(unordered_node_map<Key, T, H2, P2, Allocator>& source); template<class H2, class P2> void merge(unordered_node_map<Key, T, H2, P2, Allocator>&& source); ```
zh_Hans: ```c++ template<class h2,="" class="" p2=""> void merge(unordered_node_map<key, t,="" h2,="" p2,="" allocator="">&amp; source); template<class h2,="" class="" p2=""> void merge(unordered_node_map<key, t,="" h2,="" p2,="" allocator="">&amp;&amp; source); ```</key,></class></key,></class>

en: Transfers all the element nodes from `source` whose key is not already present in `*this`.
zh_Hans: 从 `source` 转移所有键在 `*this` 中尚未存在的元素节点。

en: Requires:;; `this\->get_allocator() == source.get_allocator()`. Notes:;; Invalidates iterators to the elements transferred. If the resulting size of `*this` is greater than its original maximum load, invalidates all iterators associated to `*this`.
zh_Hans: 要求：`this-&gt;get_allocator() == source.get_allocator()`。  
    注意：会使被转移元素的迭代器失效。如果 `*this` 的结果大小大于其原始最大负载，则会使与 `*this` 关联的所有迭代器失效。

en: Observers
zh_Hans: 观察器

en: Returns:;; The container's allocator.
zh_Hans: 返回：容器的分配器。

en: hash_function
zh_Hans: 哈希函数

en: Returns:;; The container's hash function.
zh_Hans: 返回：容器的哈希函数。

en: Returns:;; The container's key equality predicate
zh_Hans: 返回：容器的键相等谓词。

en: Lookup
zh_Hans: 查找

en: ```c++ iterator         find(const key_type& k); const_iterator   find(const key_type& k) const; template<class K> iterator       find(const K& k);
zh_Hans: ```c++ iterator         find(const key_type&amp; k); const_iterator   find(const key_type&amp; k) const; template<class k=""> iterator       find(const K&amp; k);</class>

en: Returns:;; An iterator pointing to an element with key equivalent to `k`, or `end()` if no such element exists. Notes:;; The `template<class K>` overloads only participate in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
zh_Hans: 返回：指向键与 `k` 等价的元素的迭代器；如果不存在这样的元素，则返回 `end()`。  
    注意：`template<class k="">` 重载仅在 `Hash::is_transparent` 和 `Pred::is_transparent` 是有效的成员 typedef 时参与重载决议。库假定 `Hash` 可同时使用 `K` 和 `Key` 调用，且 `Pred` 是透明的。这支持了异构查找，从而避免了实例化 `Key` 类型对象的开销。</class>

en: ```c++ size_type        count(const key_type& k) const; template<class K> size_type      count(const K& k) const; ```
zh_Hans: ```c++ size_type        count(const key_type&amp; k) const; template<class k=""> size_type      count(const K&amp; k) const; ```</class>

en: Returns:;; The number of elements with key equivalent to `k`. Notes:;; The `template<class K>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
zh_Hans: 返回：键与 `k` 等价的元素数量。  
    注意：`template<class k="">` 重载仅在 `Hash::is_transparent` 和 `Pred::is_transparent` 是有效的成员 typedef 时参与重载决议。库假定 `Hash` 可同时使用 `K` 和 `Key` 调用，且 `Pred` 是透明的。这支持了异构查找，从而避免了实例化 `Key` 类型对象的开销。</class>

en: contains
zh_Hans: 包含

en: ```c++ bool             contains(const key_type& k) const; template<class K> bool           contains(const K& k) const; ```
zh_Hans: ```c++ bool             contains(const key_type&amp; k) const; template<class k=""> bool           contains(const K&amp; k) const; ```</class>

en: Returns:;; A boolean indicating whether or not there is an element with key equal to `key` in the container Notes:;; The `template<class K>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
zh_Hans: 返回：一个布尔值，指示容器中是否存在键等于 `key` 的元素。  
    注意：`template<class k="">` 重载仅在 `Hash::is_transparent` 和 `Pred::is_transparent` 是有效的成员 typedef 时参与重载决议。库假定 `Hash` 可同时使用 `K` 和 `Key` 调用，且 `Pred` 是透明的。这支持了异构查找，从而避免了实例化 `Key` 类型对象的开销。</class>

en: ```c++ std::pair<iterator, iterator>               equal_range(const key_type& k); std::pair<const_iterator, const_iterator>   equal_range(const key_type& k) const; template<class K> std::pair<iterator, iterator>             equal_range(const K& k); template<class K> std::pair<const_iterator, const_iterator> equal_range(const K& k) const; ```
zh_Hans: ```c++ std::pair<iterator, iterator="">               equal_range(const key_type&amp; k); std::pair<const_iterator, const_iterator="">   equal_range(const key_type&amp; k) const; template<class k=""> std::pair<iterator, iterator="">             equal_range(const K&amp; k); template<class k=""> std::pair<const_iterator, const_iterator=""> equal_range(const K&amp; k) const; ```</const_iterator,></class></iterator,></class></const_iterator,></iterator,>

en: Returns:;; A range containing all elements with key equivalent to `k`. If the container doesn't contain any such elements, returns `std::make_pair(b.end(), b.end())`. Notes:;; The `template<class K>` overloads only participate in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
zh_Hans: 返回：包含所有键与 `k` 等价的元素的范围。如果容器不包含任何此类元素，则返回 `std::make_pair(b.end(), b.end())`。  
    注意：`template<class k="">` 重载仅在 `Hash::is_transparent` 和 `Pred::is_transparent` 是有效的成员 typedef 时参与重载决议。库假定 `Hash` 可同时使用 `K` 和 `Key` 调用，且 `Pred` 是透明的。这支持了异构查找，从而避免了实例化 `Key` 类型对象的开销。</class>

en: ```c++ mapped_type& operator[](const key_type& k); mapped_type& operator[](key_type&& k); template<class K> mapped_type& operator[](K&& k); ```
zh_Hans: ```c++ mapped_type&amp; operator[](const key_type&amp; k); mapped_type&amp; operator[](key_type&amp;&amp; k); template<class k=""> mapped_type&amp; operator[](K&amp;&amp; k); ```</class>

en: Effects:;; If the container does not already contain an element with a key equivalent to `k`, inserts the value `std::pair<key_type const, mapped_type>(k, mapped_type())`. Returns:;; A reference to `x.second` where `x` is the element already in the container, or the newly inserted element with a key equivalent to `k`. Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect. Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. + + The `template<class K>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
zh_Hans: 效果：如果容器中不存在键与 `k` 等价的元素，则插入值 `std::pair<key_type const,="" mapped_type="">(k, mapped_type())`。  
    返回：对 `x.second` 的引用，其中 `x` 是容器中已存在的元素，或是新插入的键与 `k` 等价的元素。  
    抛出：如果除调用 `hasher` 之外的操作抛出异常，则该函数无效果。  
    注意：可能使迭代器失效，但仅当插入导致负载大于最大负载时才会发生。  
    
    `template<class k="">` 重载仅在 `Hash::is_transparent` 和 `Pred::is_transparent` 是有效的成员 typedef 时参与重载决议。库假定 `Hash` 可同时使用 `K` 和 `Key` 调用，且 `Pred` 是透明的。这支持了异构查找，从而避免了实例化 `Key` 类型对象的开销。</class></key_type>

en: ```c++ mapped_type& at(const key_type& k); const mapped_type& at(const key_type& k) const; template<class K> mapped_type& at(const K& k); template<class K> const mapped_type& at(const K& k) const; ```
zh_Hans: ```c++ mapped_type&amp; at(const key_type&amp; k); const mapped_type&amp; at(const key_type&amp; k) const; template<class k=""> mapped_type&amp; at(const K&amp; k); template<class k=""> const mapped_type&amp; at(const K&amp; k) const; ```</class></class>

en: Returns:;; A reference to `x.second` where `x` is the (unique) element whose key is equivalent to `k`. Throws:;; An exception object of type `std::out_of_range` if no such element is present. Notes:;; The `template<class K>` overloads only participate in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
zh_Hans: 返回：对 `x.second` 的引用，其中 `x` 是键与 `k` 等价的（唯一）元素。  
    抛出：如果不存在这样的元素，则抛出 `std::out_of_range` 类型的异常对象。  
    注意：`template<class k="">` 重载仅在 `Hash::is_transparent` 和 `Pred::is_transparent` 是有效的成员 typedef 时参与重载决议。库假定 `Hash` 可同时使用 `K` 和 `Key` 调用，且 `Pred` 是透明的。这支持了异构查找，从而避免了实例化 `Key` 类型对象的开销。</class>

en: Bucket Interface
zh_Hans: 桶接口

en: Returns:;; The size of the bucket array.
zh_Hans: 返回：桶数组的大小。

en: Hash Policy
zh_Hans: 哈希策略

en: load_factor
zh_Hans: 负载因子

en: Returns:;; `static_cast<float>(size())/static_cast<float>(bucket_count())`, or `0` if `bucket_count() == 0`.
zh_Hans: 返回：`static_cast<float>(size())/static_cast<float>(bucket_count())`，如果 `bucket_count() == 0` 则返回 `0`。</float></float>

en: Returns:;; Returns the container's maximum load factor.
zh_Hans: 返回：容器的最大负载因子。

en: Set max_load_factor
zh_Hans: 设置最大负载因子

en: Effects:;; Does nothing, as the user is not allowed to change this parameter. Kept for compatibility with `boost::unordered_map`.
zh_Hans: 效果：不执行任何操作，因为用户不允许更改此参数。保留此函数是为了与 `boost::unordered_map` 保持兼容。

en: Returns:;; The maximum number of elements the container can hold without rehashing, assuming that no further elements will be erased. Note:;; After construction, rehash or clearance, the container's maximum load is at least `max_load_factor() * bucket_count()`. This number may decrease on erasure under high-load conditions.
zh_Hans: 返回：容器在不触发重哈希的情况下能够容纳的最大元素数量（假设不再有元素被擦除）。  
    注意：在构造、重哈希或清空操作之后，容器的最大负载至少为 `max_load_factor() * bucket_count()`。在高负载条件下，该数值可能会因元素擦除而减小。

en: rehash
zh_Hans: 重哈希

en: Changes if necessary the size of the bucket array so that there are at least `n` buckets, and so that the load factor is less than or equal to the maximum load factor. When applicable, this will either grow or shrink the `bucket_count()` associated with the container.
zh_Hans: 必要时更改桶数组的大小，使其至少包含 `n` 个桶，并且使得负载因子小于或等于最大负载因子。在适用的情况下，这将增大或缩小与容器关联的 `bucket_count()`。

en: When `size() == 0`, `rehash(0)` will deallocate the underlying buckets array. If the provided Allocator uses fancy pointers, a default allocation is subsequently performed.
zh_Hans: 当 `size() == 0` 时，`rehash(0)` 将释放底层的桶数组。如果提供的分配器使用异形指针，则会随后执行一次默认分配。

[ctx: :1459]
en: Invalidates iterators and changes the order of elements.
zh_Hans: 使迭代器失效并改变元素的顺序。

[ctx: :1462]
en: Throws:;; The function has no effect if an exception is thrown, unless it is thrown by the container's hash function or comparison function.
zh_Hans: 抛出：如果抛出异常（除非是由容器的哈希函数或比较函数抛出的），则该函数无效果。

en: reserve
zh_Hans: 保留

en: Equivalent to `a.rehash(ceil(n / a.max_load_factor()))`.
zh_Hans: 等价于 `a.rehash(ceil(n / a.max_load_factor()))`。

en: Similar to `rehash`, this function can be used to grow or shrink the number of buckets in the container.
zh_Hans: 与 `rehash` 类似，此函数可用于增大或缩小容器中的桶数量。

[ctx: :1475]
en: Invalidates iterators and changes the order of elements.
zh_Hans: 使迭代器失效并改变元素的顺序。

[ctx: :1478]
en: Throws:;; The function has no effect if an exception is thrown, unless it is thrown by the container's hash function or comparison function.
zh_Hans: 抛出：如果抛出异常（除非是由容器的哈希函数或比较函数抛出的），则该函数无效果。

en: Statistics
zh_Hans: 统计信息

en: Returns:;; A statistical description of the insertion and lookup operations performed by the container so far. Notes:;; Only available if xref:reference/stats.adoc#stats[statistics calculation] is xref:unordered_node_map_boost_unordered_enable_stats[enabled].
zh_Hans: 返回：容器迄今为止所执行插入和查找操作的统计描述。  
    注意：仅在 xref:reference/stats.adoc#stats[统计计算] 通过 xref:unordered_node_map_boost_unordered_enable_stats[`BOOST_UNORDERED_ENABLE_STATS`] 启用时才可用。

en: Effects:;; Sets to zero the internal statistics kept by the container. Notes:;; Only available if xref:reference/stats.adoc#stats[statistics calculation] is xref:unordered_node_map_boost_unordered_enable_stats[enabled].
zh_Hans: 效果：将容器内部维护的统计信息归零。  
    注意：仅在 xref:reference/stats.adoc#stats[统计计算] 通过 xref:unordered_node_map_boost_unordered_enable_stats[`BOOST_UNORDERED_ENABLE_STATS`] 启用时才可用。

en: Deduction Guides
zh_Hans: 推导指引

en: A deduction guide will not participate in overload resolution if any of the following are true:
zh_Hans: 如果以下任何一条件为真，则推导指引将不参与重载决议：

en: - It has an `InputIterator` template parameter and a type that does not qualify as an input iterator is deduced for that parameter. - It has an `Allocator` template parameter and a type that does not qualify as an allocator is deduced for that parameter. - It has a `Hash` template parameter and an integral type or a type that qualifies as an allocator is deduced for that parameter. - It has a `Pred` template parameter and a type that qualifies as an allocator is deduced for that parameter.
zh_Hans: - 它具有一个 `InputIterator` 模板参数，并且为该参数推导出的类型不符合输入迭代器的要求。
    - 它具有一个 `Allocator` 模板参数，并且为该参数推导出的类型不符合分配器的要求。
    - 它具有一个 `Hash` 模板参数，并且为该参数推导出的类型是整数类型或符合分配器的要求。
    - 它具有一个 `Pred` 模板参数，并且为该参数推导出的类型符合分配器的要求。

en: A `size_­type` parameter type in a deduction guide refers to the `size_­type` member type of the container type deduced by the deduction guide. Its default value coincides with the default value of the constructor selected.
zh_Hans: 推导指引中的 `size_type` 参数类型指的是由该推导指引所推导出的容器类型的 `size_type` 成员类型。其默认值与所选构造函数的默认值一致。

en: __iter-value-type__
zh_Hans: _iter-value-type_

en: Equality Comparisons
zh_Hans: 相等性比较

en: ```c++ template<class Key, class T, class Hash, class Pred, class Alloc> bool operator==(const unordered_node_map<Key, T, Hash, Pred, Alloc>& x, const unordered_node_map<Key, T, Hash, Pred, Alloc>& y); ```
zh_Hans: ```c++ template<class key,="" class="" t,="" hash,="" pred,="" alloc=""> bool operator==(const unordered_node_map<key, t,="" hash,="" pred,="" alloc="">&amp; x, const unordered_node_map<key, t,="" hash,="" pred,="" alloc="">&amp; y); ```</key,></key,></class>

en: Return `true` if `x.size() == y.size()` and for every element in `x`, there is an element in `y` with the same key, with an equal value (using `operator==` to compare the value types).
zh_Hans: 若 `x.size() == y.size()` 且对于 `x` 中的每个元素，在 `y` 中均存在一个具有相同键且值相等（使用 `operator==` 比较值类型）的元素，则返回 `true`。

[ctx: :1563]
en: Notes:;; Behavior is undefined if the two containers don't have equivalent equality predicates.
zh_Hans: 注意：如果两个容器不具有等价的相等谓词，则行为未定义。

en: ```c++ template<class Key, class T, class Hash, class Pred, class Alloc> bool operator!=(const unordered_node_map<Key, T, Hash, Pred, Alloc>& x, const unordered_node_map<Key, T, Hash, Pred, Alloc>& y); ```
zh_Hans: ```c++ template<class key,="" class="" t,="" hash,="" pred,="" alloc=""> bool operator!=(const unordered_node_map<key, t,="" hash,="" pred,="" alloc="">&amp; x, const unordered_node_map<key, t,="" hash,="" pred,="" alloc="">&amp; y); ```</key,></key,></class>

en: Return `false` if `x.size() == y.size()` and for every element in `x`, there is an element in `y` with the same key, with an equal value (using `operator==` to compare the value types).
zh_Hans: 若 `x.size() == y.size()` 且对于 `x` 中的每个元素，在 `y` 中均存在一个具有相同键且值相等（使用 `operator==` 比较值类型）的元素，则返回 `false`。

[ctx: :1577]
en: Notes:;; Behavior is undefined if the two containers don't have equivalent equality predicates.
zh_Hans: 注意：如果两个容器不具有等价的相等谓词，则行为未定义。

en: Swap
zh_Hans: 交换

en: ```c++ template<class Key, class T, class Hash, class Pred, class Alloc> void swap(unordered_node_map<Key, T, Hash, Pred, Alloc>& x, unordered_node_map<Key, T, Hash, Pred, Alloc>& y) noexcept(noexcept(x.swap(y))); ```
zh_Hans: ```c++ template<class key,="" class="" t,="" hash,="" pred,="" alloc=""> void swap(unordered_node_map<key, t,="" hash,="" pred,="" alloc="">&amp; x, unordered_node_map<key, t,="" hash,="" pred,="" alloc="">&amp; y) noexcept(noexcept(x.swap(y))); ```</key,></key,></class>

en: Swaps the contents of `x` and `y`.
zh_Hans: 交换 `x` 和 `y` 的内容。

[ctx: :1589]
en: If `Allocator::propagate_on_container_swap` is declared and `Allocator::propagate_on_container_swap::value` is `true` then the containers' allocators are swapped. Otherwise, swapping with unequal allocators results in undefined behavior.
zh_Hans: 如果 `Allocator::propagate_on_container_swap` 被声明且 `Allocator::propagate_on_container_swap::value` 为 `true`，则交换容器的分配器。否则，使用不相等的分配器进行交换将导致未定义行为。

en: Effects:;; `x.swap(y)` Throws:;; Nothing unless `key_equal` or `hasher` throw on swapping.
zh_Hans: 效果：`x.swap(y)`  
    抛出：除非 `key_equal` 或 `hasher` 在交换时抛出异常，否则不抛出任何异常。

en: ```c++ template<class K, class T, class H, class P, class A, class Predicate> typename unordered_node_map<K, T, H, P, A>::size_type erase_if(unordered_node_map<K, T, H, P, A>& c, Predicate pred); ```
zh_Hans: ```c++ template<class k,="" class="" t,="" h,="" p,="" a,="" predicate=""> typename unordered_node_map<k, t,="" h,="" p,="" a="">::size_type erase_if(unordered_node_map<k, t,="" h,="" p,="" a="">&amp; c, Predicate pred); ```</k,></k,></class>

en: Traverses the container `c` and removes all elements for which the supplied predicate returns `true`.
zh_Hans: 遍历容器 `c`，并移除所有使给定谓词返回 `true` 的元素。

en: Returns:;; The number of erased elements. Notes:;; Equivalent to: + + ```c++ auto original_size = c.size(); for (auto i = c.begin(), last = c.end(); i != last; ) { if (pred(*i)) { i = c.erase(i); } else { ++i; } } return original_size - c.size(); ``` + Note that the references passed to `pred` are non-const.
zh_Hans: 返回：被擦除的元素数量。  
    注意：等价于：  
    ```c++
    auto original_size = c.size();
    for (auto i = c.begin(), last = c.end(); i != last; ) {
        if (pred(*i)) {
            i = c.erase(i);
        } else {
            ++i;
        }
    }
    return original_size - c.size();
    ```  
    注意，传递给 `pred` 的引用是非常量的。

en: Serialization
zh_Hans: 序列化

en: ``unordered_node_map``s can be archived/retrieved by means of link:../../../../../serialization/index.html[Boost.Serialization^] using the API provided by this library. Both regular and XML archives are supported.
zh_Hans: `unordered_node_map` 可以通过本库提供的 API，借助 link:../../../../../serialization/index.html[Boost.Serialization^] 进行归档/恢复。支持常规归档和 XML 归档。

en: Saving an unordered_node_map to an archive
zh_Hans: 将 unordered_node_map 保存到归档中

en: Saves all the elements of an `unordered_node_map` `x` to an archive (XML archive) `ar`.
zh_Hans: 将 `unordered_node_map` `x` 的所有元素保存到归档（XML 归档） `ar` 。

en: Requires:;; `std::remove_const<key_type>::type` and `std::remove_const<mapped_type>::type` are serializable (XML serializable), and they do support Boost.Serialization `save_construct_data`/`load_construct_data` protocol (automatically suported by https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^] types).
zh_Hans: 要求：`std::remove_const<key_type>::type` 和 `std::remove_const<mapped_type>::type` 必须是可序列化的（对于 XML 归档需支持 XML 序列化），并且它们必须支持 Boost.Serialization 的 `save_construct_data`/`load_construct_data` 协议（该协议由满足 https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[可默认构造^] 的类型自动支持）。</mapped_type></key_type>

en: Loading an unordered_node_map from an archive
zh_Hans: 从归档中加载 unordered_node_map

en: Deletes all preexisting elements of an `unordered_node_map` `x` and inserts from an archive (XML archive) `ar` restored copies of the elements of the original `unordered_node_map` `other` saved to the storage read by `ar`.
zh_Hans: 删除 `unordered_node_map` 容器 `x` 中所有已存在的元素，并从归档（XML 归档）`ar` 中插入从原始 `unordered_node_map` 容器 `other` 保存到 `ar` 所读取存储中的元素恢复出的副本。

en: Requires:;; `key_type` and `mapped_type` are constructible from `std::remove_const<key_type>::type&&` and `std::remove_const<mapped_type>::type&&`, respectively. `x.key_equal()` is functionally equivalent to `other.key_equal()`.
zh_Hans: 要求：`key_type` 和 `mapped_type` 必须分别能够从 `std::remove_const<key_type>::type&amp;&amp;` 和 `std::remove_const<mapped_type>::type&amp;&amp;` 构造。`x.key_equal()` 在功能上必须等价于 `other.key_equal()`。</mapped_type></key_type>

en: Saving an iterator/const_iterator to an archive
zh_Hans: 将迭代器/常量迭代器保存到归档

en: Saves the positional information of an `iterator` (`const_iterator`) `it` to an archive (XML archive) `ar`. `it` can be and `end()` iterator.
zh_Hans: 将迭代器（或常量迭代器）`it` 的位置信息保存到归档（XML 归档）`ar` 中。`it` 可以是一个 `end()` 迭代器。

en: Requires:;; The `unordered_node_map` `x` pointed to by `it` has been previously saved to `ar`, and no modifying operations have been issued on `x` between saving of `x` and saving of `it`.
zh_Hans: 要求：`it` 所指向的 `unordered_node_map` 容器 `x` 必须先被保存到 `ar` 中，并且在保存 `x` 和保存 `it` 之间，不能对 `x` 执行任何修改操作。

en: Loading an iterator/const_iterator from an archive
zh_Hans: 从归档加载迭代器/常量迭代器

en: Makes an `iterator` (`const_iterator`) `it` point to the restored position of the original `iterator` (`const_iterator`) saved to the storage read by an archive (XML archive) `ar`.
zh_Hans: 使迭代器（或常量迭代器）`it` 指向原始迭代器（或常量迭代器）被保存到归档（XML 归档）`ar` 所读取存储中的位置恢复后的位置。

en: Requires:;; If `x` is the `unordered_node_map` `it` points to, no modifying operations have been issued on `x` between loading of `x` and loading of `it`.
zh_Hans: 要求：如果 `x` 是 `it` 所指向的 `unordered_node_map` 容器，则在加载 `x` 和加载 `it` 之间，不能对 `x` 执行任何修改操作。
