concurrent_unordered_map Class

Article
04/28/2015

The concurrent_unordered_map class is a concurrency-safe container that controls a varying-length sequence of elements of type std::pair<const _Key_type, _Element_type>. The sequence is represented in a way that enables concurrency-safe append, element access, iterator access, and iterator traversal operations.

template <
   typename _Key_type,
   typename _Element_type,
   typename _Hasher = std::tr1::hash<_Key_type>,
   typename _Key_equality = std::equal_to<_Key_type>,
   typename _Allocator_type = std::allocator<std::pair<const _Key_type,
   _Element_type> >
>
, typename _Key_equality = std::equal_to<_Key_type>, typename _Allocator_type = std::allocator<std::pair<const _Key_type, _Element_type> > > class concurrent_unordered_map : public details::_Concurrent_hash< details::_Concurrent_unordered_map_traits<_Key_type, _Element_type, details::_Hash_compare<_Key_type, _Hasher, _Key_equality>, _Allocator_type, false> >;

Parameters

_Key_type
The key type.
_Element_type
The mapped type.
_Hasher
The hash function object type. This argument is optional and the default value is std::tr1::hash<_Key_type**>**.
_Key_equality
The equality comparison function object type. This argument is optional and the default value is std::equal_to<_Key_type**>**.
_Allocator_type
The type that represents the stored allocator object that encapsulates details about the allocation and deallocation of memory for the concurrent unordered map. This argument is optional and the default value is std::allocator<std::pair<_Key_type, _Element_type**>>**.

Members

Public Typedefs

Name	Description
allocator_type	The type of an allocator for managing storage.
const_iterator	The type of a constant iterator for the controlled sequence.
const_local_iterator	The type of a constant bucket iterator for the controlled sequence.
const_pointer	The type of a constant pointer to an element.
const_reference	The type of a constant reference to an element.
difference_type	The type of a signed distance between two elements.
hasher	The type of the hash function.
iterator	The type of an iterator for the controlled sequence.
key_equal	The type of the comparison function.
key_type	The type of an ordering key.
local_iterator	The type of a bucket iterator for the controlled sequence.
mapped_type	The type of a mapped value associated with each key.
pointer	The type of a pointer to an element.
reference	The type of a reference to an element.
size_type	The type of an unsigned distance between two elements.
value_type	The type of an element.

Public Constructors

Name	Description
concurrent_unordered_map::concurrent_unordered_map Constructor	Overloaded. Constructs a concurrent unordered map.

Public Methods

Name	Description
concurrent_unordered_map::at Method	Overloaded. Finds an element in a concurrent_unordered_map with a specified key value.. This method is concurrency-safe.
concurrent_unordered_map::hash_function Method	Gets the stored hash function object.
concurrent_unordered_map::insert Method	Overloaded. Adds elements to the concurrent_unordered_map object.
concurrent_unordered_map::key_eq Method	Gets the stored equality comparison function object.
concurrent_unordered_map::swap Method	Swaps the contents of two concurrent_unordered_map objects. This method is not concurrency-safe.
concurrent_unordered_map::unsafe_erase Method	Overloaded. Removes elements from the concurrent_unordered_map at specified positions. This method is not concurrency-safe.

Public Operators

Name	Description
concurrent_unordered_map::operator[] Operator	Overloaded. Finds or inserts an element with the specified key. This method is concurrency-safe.
concurrent_unordered_map::operator= Operator	Overloaded. Assigns the contents of another concurrent_unordered_map object to this one. This method is not concurrency-safe.

Remarks

For detailed information on the concurrent_unordered_map class, see Parallel Containers and Objects.

Inheritance Hierarchy

_Traits

_Concurrent_hash

concurrent_unordered_map

Requirements

Header: concurrent_unordered_map.h

Namespace: concurrency