std::unordered_set
cppreference.com
<tbody>
</tbody>
| <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.
Member types
| Member type | Definition |
key_type
|
|
value_type
|
Key
|
size_type
|
(unsigned int) ( std::size_t) |
difference_type
|
(signed int) ( std::ptrdiff_t) |
hasher
|
Hash
|
key_equal
|
KeyEqual
|
allocator_type
|
|
reference
|
value_type&
|
const_reference
|
const value_type&
|
pointer
|
std::allocator_traits<Allocator>::pointer
|
const_pointer
|
std::allocator_traits<Allocator>::const_pointer
|
iterator
|
ForwardIterator
|
const_iterator
|
(constant) (iterator) |
local_iterator
|
An iterator type whose category, value, difference, pointer and reference types are the same as iterator. This iteratorcan be used to iterate through a single bucket but not across buckets |
const_local_iterator
|
An iterator type whose category, value, difference, pointer and reference types are the same as const_iterator. This iteratorcan be used to iterate through a single bucket but not across buckets |
Member functions
:cpp/container/dsc begin(int):cpp/container/dsc end(int)unordered_set . (public member function) | |
unordered_set . (public member function) | |
| . (public member function) | |
| . (public member function) | |
Iterators | |
| (iterator) . (public member function) | |
| (iterator) . (public member function) | |
Capacity | |
| . (public member function) | |
| . (public member function) | |
| . (public member function) | |
Modifiers | |
| . (public member function) | |
| . (public member function) | |
| . (public member function) | |
| constructs elements in-place using a hint (public member function) | |
| (public member function) | |
| (public member function) | |
Lookup | |
| . (public member function) | |
| . (public member function) | |
| returns range of elements matching a specific key (public member function) | |
Bucket interface | |
| returns the number of buckets (public member function) | |
| returns the maximum number of buckets (public member function) | |
| returns the number of elements in specific bucket (public member function) | |
| returns the bucket for specific key (public member function) | |
Hash policy | |
| returns average number of elements per bucket (public member function) | |
| manages maximum average number of elements per bucket (public member function) | |
| reserves at least the specified number of buckets. This regenerates the hash table. (public member function) | |
| reserves space for at least the specified number of elements. This regenerates the hash table. (public member function) | |
Observers | |
| returns function used to hash the keys (public member function) | |
| returns the function used to compare keys for equality (public member function) | |
Non-member functions
| compares the values in the unordered_set (function template) | |
| specializes the std::swap algorithm (function template) |
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.