std::unordered_set

 

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unordered_set (C++11)

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std::unordered_set

Member types
Member functions
unordered_set::unordered_set unordered_set::~unordered_set unordered_set::operator= unordered_set::get_allocator Iterators unordered_set::beginunordered_set::cbegin unordered_set::endunordered_set::cend Capacity unordered_set::size unordered_set::max_size unordered_set::empty Modifiers unordered_set::clear unordered_set::erase unordered_set::swap unordered_set::extract (C++17) unordered_set::merge (C++17) unordered_set::insert unordered_set::insert_range (C++23)   unordered_set::emplace unordered_set::emplace_hint	Lookup unordered_set::count unordered_set::find unordered_set::contains (C++20) unordered_set::equal_range Bucket interface unordered_set::begin(size_type)unordered_set::cbegin(size_type) unordered_set::end(size_type)unordered_set::cend(size_type) unordered_set::bucket_count unordered_set::max_bucket_count unordered_set::bucket_size unordered_set::bucket Hash policy unordered_set::load_factor unordered_set::max_load_factor unordered_set::rehash unordered_set::reserve Observers unordered_set::hash_function unordered_set::key_eq
Non-member functions
operator==operator!= (until C++20)	std::swap(std::unordered_set) erase_if(std::unordered_set) (C++20)
Deduction guides (C++17)

 

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 Template:concept, Template:concept, Template:concept.

Member types

Template:cpp/container/dcl list key typeTemplate:cpp/container/dcl list value typeTemplate:cpp/container/dcl list size typeTemplate:cpp/container/dcl list difference typeTemplate:cpp/container/dcl list hasherTemplate:cpp/container/dcl list key equalTemplate:cpp/container/dcl list allocator typeTemplate:cpp/container/dcl list referenceTemplate:cpp/container/dcl list const referenceTemplate:cpp/container/dcl list pointerTemplate:cpp/container/dcl list const pointerTemplate:cpp/container/dcl list iteratorTemplate:cpp/container/dcl list const iteratorTemplate:cpp/container/dcl list local iteratorTemplate:cpp/container/dcl list const local iterator

Member type

Definition

Member functions

Template:cpp/container/dcl list constructorTemplate:cpp/container/dcl list destructorTemplate:cpp/container/dcl list operator=Template:cpp/container/dcl list get allocatorTemplate:cpp/container/dcl list beginTemplate:cpp/container/dcl list endTemplate:cpp/container/dcl list emptyTemplate:cpp/container/dcl list sizeTemplate:cpp/container/dcl list max sizeTemplate:cpp/container/dcl list clearTemplate:cpp/container/dcl list insertTemplate:cpp/container/dcl list emplaceTemplate:cpp/container/dcl list emplace hintTemplate:cpp/container/dcl list eraseTemplate:cpp/container/dcl list swapTemplate:cpp/container/dcl list countTemplate:cpp/container/dcl list findTemplate:cpp/container/dcl list equal rangeTemplate:cpp/container/dcl list begin(int)Template:cpp/container/dcl list end(int)Template:cpp/container/dcl list bucket countTemplate:cpp/container/dcl list max bucket countTemplate:cpp/container/dcl list bucket sizeTemplate:cpp/container/dcl list bucketTemplate:cpp/container/dcl list load factorTemplate:cpp/container/dcl list max load factorTemplate:cpp/container/dcl list rehashTemplate:cpp/container/dcl list reserveTemplate:cpp/container/dcl list hash functionTemplate:cpp/container/dcl list key eq

Iterators

Capacity

Modifiers

Lookup

Bucket interface

Hash policy

Observers

Non-member functions

Template:cpp/container/dcl list operator cmp unordTemplate:cpp/container/dcl list swap2

Notes

The member types iterator and const_iterator may be aliases to the same type. This means defining a pair of function overloads using the two types as parameter types may violate the One Definition Rule. Since iterator is convertible to const_iterator, a single function with a const_iterator as parameter type will work instead.