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std::unordered_set

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< cpp‎ | container
Revision as of 18:27, 9 July 2013 by P12bot (Talk | contribs)

Defined in header <unordered_set>
template<

    class Key,
    class Hash = std::hash<Key>,
    class KeyEqual = std::equal_to<Key>,
    class Allocator = std::allocator<Key>

> class unordered_set;
(since C++11)

Unordered set is an associative container that contains set of unique objects of type Key. Search, insertion, and removal have average constant-time complexity.

std::unordered_set meets the requirements of Container, AllocatorAwareContainer, UnorderedAssociativeContainer.

Contents

Member types

Member type Definition
key_type Key [edit]
value_type Key [edit]
size_type Unsigned integral type (usually std::size_t) [edit]
difference_type Signed integer type (usually std::ptrdiff_t) [edit]
hasher Hash [edit]
key_equal KeyEqual [edit]
allocator_type Allocator [edit]
reference value_type& [edit]
const_reference const value_type& [edit]
pointer std::allocator_traits<Allocator>::pointer [edit]
const_pointer std::allocator_traits<Allocator>::const_pointer [edit]
iterator ForwardIterator [edit]
const_iterator Constant forward iterator [edit]
local_iterator An iterator type whose category, value, difference, pointer and
reference types are the same as iterator. This iterator
can be used to iterate through a single bucket but not across buckets[edit]
const_local_iterator An iterator type whose category, value, difference, pointer and
reference types are the same as const_iterator. This iterator
can be used to iterate through a single bucket but not across buckets[edit]


Member functions

constructs the unordered_set
(public member function) [edit]
destructs the unordered_set
(public member function) [edit]
assigns values to the container
(public member function) [edit]
returns the associated allocator
(public member function) [edit]
Iterators
returns an iterator to the beginning
(public member function) [edit]
returns an iterator to the end
(public member function) [edit]
Capacity
checks whether the container is empty
(public member function) [edit]
returns the number of elements
(public member function) [edit]
returns the maximum possible number of elements
(public member function) [edit]
Modifiers
clears the contents
(public member function) [edit]
inserts elements
(public member function) [edit]
constructs element in-place
(public member function) [edit]
constructs elements in-place using a hint
(public member function) [edit]
erases elements
(public member function) [edit]
swaps the contents
(public member function) [edit]
Lookup
returns the number of elements matching specific key
(public member function) [edit]
finds element with specific key
(public member function) [edit]
returns range of elements matching a specific key
(public member function) [edit]
Bucket interface
returns an iterator to the beginning of the specified bucket
(public member function) [edit]
returns an iterator to the end of the specified bucket
(public member function) [edit]
returns the number of buckets
(public member function) [edit]
returns the maximum number of buckets
(public member function) [edit]
returns the number of elements in specific bucket
(public member function) [edit]
returns the bucket for specific key
(public member function) [edit]
Hash policy
returns average number of elements per bucket
(public member function) [edit]
manages maximum average number of elements per bucket
(public member function) [edit]
reserves at least the specified number of buckets.
This regenerates the hash table.
(public member function) [edit]
reserves space for at least the specified number of elements.
This regenerates the hash table.
(public member function) [edit]
Observers
returns function used to hash the keys
(public member function) [edit]
returns the function used to compare keys for equality
(public member function) [edit]

Non-member functions

compares the values in the unordered_set
(function template) [edit]
specializes the std::swap algorithm
(function template) [edit]

Notes

The member types iterator and const_iterator may be aliases to the same type. Since iterator is convertible to const_iterator, const_iterator should be used in function parameter lists to avoid violations of the One Definition Rule.