bsl::unordered_set

Synopsis

Declared in <bslstl_unorderedset.h>

template<
    class KEY,
    class HASH = bsl::hash<KEY>,
    class EQUAL = bsl::equal_to<KEY>,
    class ALLOCATOR = bsl::allocator<KEY>>
class unordered_set;

Description

This class: * supports a complete set of value-semantic operations

except for BDEX serialization * is exception-neutral (agnostic except for the at method) * is alias-safe * is const thread-safe For terminology see {bsldoc_glossary}.

Type Aliases

Name	Description
`allocator_type`	This `typedef` is an alias to the (template parameter) `ALLOCATOR`.
`const_iterator`	This `typedef` is an alias to `iterator`.
`const_local_iterator`	This `typedef` is an alias to `local_iterator`.
`const_pointer`	This `typedef` is an alias to the allocator const-pointer type.
`const_reference`	This `typedef` is an alias to `const value_type&`.
`difference_type`	This `typedef` is an alias to the allocator difference type.
`hasher`	This `typedef` is an alias to the (template parameter) `HASH` type.
`iterator`	This `typedef` is an alias to the hash-table iterator type.
`key_equal`	This `typedef` is an alias to the (template parameter) `EQUAL` type.
`key_type`	This `typedef` is an alias to the (template parameter) `KEY` type.
`local_iterator`	This `typedef` is an alias for `local_iterator`.
`pointer`	This `typedef` is an alias to the allocator pointer type.
`reference`	This `typedef` is an alias to `value_type&`.
`size_type`	This `typedef` is an alias to the allocator size type.
`value_type`	This `typedef` is an alias to `key_type`.

Member Functions

Name	Description
`unordered_set` [constructor]	Constructors
`~unordered_set` [destructor]	Destroy this object.
`operator=`	Assignment operators
`begin`	`begin` overloads
`bucket`	Return the bucket index for the specified `key`.
`bucket_count`	Return the number of buckets in the array of buckets maintained by this set.
`bucket_size`	Return the number of elements in the bucket at `index`.
`cbegin`	`cbegin` overloads
`cend`	`cend` overloads
`clear`	Remove all entries from this unordered set. Note that the set is empty after this call, but allocated memory may be retained for future use.
`contains`	`contains` overloads
`count`	Return the number of elements equivalent to `key`.
`emplace`	Emplace a newly constructed element if the key is missing.
`emplace_hint`	Emplace a newly constructed element using `hint` if the key is missing.
`empty`	Return `true` if this set contains no elements, and `false` otherwise.
`end`	`end` overloads
`equal_range`	Return the range of elements equivalent to `key`.
`erase`	`erase` overloads
`find`	Return an iterator to the element equivalent to `key`.
`get_allocator`	Return (a copy of) the allocator used for memory allocation by this unordered set.
`hash_function`	Return (a copy of) the hash unary functor used by this set to generate a hash value (of type `size_t`) for a `key_type` object.
`insert`	`insert` overloads
`insert_range`	Insert values from `range` if their keys are missing.
`key_eq`	Return (a copy of) the key-equality binary functor that returns `true` if the value of two `key_type` objects are equivalent, and `false` otherwise.
`load_factor`	Return the current load factor of this container.
`max_bucket_count`	Return a theoretical upper bound on the number of buckets.
`max_load_factor`	`max_load_factor` overloads
`max_size`	Return a theoretical upper bound on this set's size.
`rehash`	Rehash this set to have at least `numBuckets` buckets.
`reserve`	Reserve capacity for at least `numElements` elements.
`size`	Return the number of elements in this set.
`swap`	Exchange the contents of this set with `other`.
`operator BloombergLP::bslmf::NestedTraitDeclaration<unordered_set, IsBitwiseMoveable, ::BloombergLP::bslmf::IsBitwiseMoveable<HashTable>::value>`	Return the nested trait declaration for `bslmf::IsBitwiseMoveable`.

Deduction Guides

Name	Description
`unordered_set<KEY>`	CTAD guide: deduce `KEY` from initializer_list `value_type`.
`unordered_set<KEY>`	CTAD guide: deduce `KEY` from initializer_list `value_type`.
`unordered_set<KEY>`	CTAD guide: deduce `KEY` from iterator `value_type`.
`unordered_set<KEY>`	CTAD guide: deduce `KEY` from iterator `value_type`.
`unordered_set<KEY, HASH>`	CTAD guide: deduce `KEY` from initializer_list `value_type`.
`unordered_set<KEY, HASH>`	CTAD guide: deduce `KEY` from iterator `value_type`.
`unordered_set<KEY, HASH, EQUAL>`	CTAD guide: deduce `KEY` from initializer_list `value_type`.
`unordered_set<KEY, HASH, EQUAL>`	CTAD guide: deduce `KEY` from iterator `value_type`.
`unordered_set<KEY, HASH, EQUAL, ALLOCATOR>`	CTAD guide: deduce `KEY` from initializer_list `value_type`.
`unordered_set<KEY, HASH, EQUAL, ALLOCATOR>`	CTAD guide: deduce `KEY` from iterator `value_type`.
`unordered_set<KEY, HASH, bsl::equal_to<KEY>, ALLOCATOR>`	CTAD guide: deduce `KEY` from initializer_list `value_type`.
`unordered_set<KEY, HASH, bsl::equal_to<KEY>, ALLOCATOR>`	CTAD guide: deduce `KEY` from iterator `value_type`.
`unordered_set<KEY, bsl::hash<KEY>, bsl::equal_to<KEY>, ALLOCATOR>`	CTAD guide: deduce `KEY` from initializer_list `value_type`.
`unordered_set<KEY, bsl::hash<KEY>, bsl::equal_to<KEY>, ALLOCATOR>`	CTAD guide: deduce `KEY` from initializer_list `value_type`.
`unordered_set<KEY, bsl::hash<KEY>, bsl::equal_to<KEY>, ALLOCATOR>`	CTAD guide: deduce `KEY` from iterator `value_type`.
`unordered_set<KEY, bsl::hash<KEY>, bsl::equal_to<KEY>, ALLOCATOR>`	CTAD guide: deduce `KEY` from iterator `value_type`.

Friends

Name	Description
`bsl::operator==`	Return `true` if the specified `lhs` and `rhs` objects have the same value, and `false` otherwise.

Non-Member Functions

Name	Description
`erase_if`	Erase elements from `s` that satisfy `predicate`.
`operator==`	Return `true` if `lhs` and `rhs` have the same value, and `false` otherwise.
`swap`	Exchange the contents of `a` and `b`.