std::unordered_set<Key,Hash,KeyEqual,Allocator>::bucket

 

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std::unordered_set

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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
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operator==operator!= (until C++20)	std::swap(std::unordered_set) erase_if(std::unordered_set) (C++20)
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size_type bucket( const Key& key ) const;	(1)	(since C++11)
template< typename K > size_type bucket( const K& x ) const;	(2)	(since C++26)

1) Returns the index of the bucket for key key. Elements (if any) with keys equivalent to key are always found in this bucket.

2) Returns the index of the bucket for key that compares equivalent to the value x. Elements (if any) with keys that compare equivalent to x are always found in this bucket. This overload participates in overload resolution only if Hash::is_transparent and KeyEqual::is_transparent are valid and each denotes a type. This assumes that such Hash is callable with both K and Key type, and that the KeyEqual is transparent, which, together, allows calling this function without constructing an instance of Key.

The returned value is valid only for instances of the container for which bucket_count() returns the same value (e.g., rehash() invalidates previously obtained value).

The behavior is undefined if bucket_count() is zero.

Parameters

key	-	the value of the key to examine
x	-	a value of any type that can be transparently compared with a key

Return value

Bucket index for the requested key.

Complexity

Constant.

Notes

Feature-test macro	Value	Std	Feature
__cpp_lib_associative_heterogeneous_insertion	202311L	(C++26)	Heterogeneous overloads for the remaining member functions in ordered and unordered associative containers. (2)

See also

bucket_size

returns the number of elements in specific bucket (public member function)