bsl::unordered

Unordered associative container mapping keys to values, allowing duplicates.

Synopsis

Declared in <bslstl_unorderedmultimap.h>

template<
    class KEY,
    class VALUE,
    class HASH = bsl::hash<KEY>,
    class EQUAL = bsl::equal_to<KEY>,
    class ALLOCATOR = bsl::allocator<bsl::pair<KEY const, VALUE>>>
class unordered_multimap;

Description

This class template implements a value‐semantic container type holding a collection of (possibly equivalent) keys (of the template parameter type KEY), each mapped to their associated values (of another template parameter type VALUE).

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 for allocator_type.

const_iterator

This typedef is an alias for const_iterator.

const_local_iterator

This typedef is an alias for const_local_iterator.

const_pointer

This typedef is an alias to AllocatorTraits::const_pointer.

const_reference

This typedef is an alias for const_reference.

difference_type

This typedef is an alias for difference_type.

hasher

This typedef is an alias to the (template parameter) HASH.

iterator

This typedef is an alias for iterator.

key_equal

This typedef is an alias for key_equal.

key_type

This typedef is an alias for key_type.

local_iterator

This typedef is an alias for local_iterator.

mapped_type

This typedef is an alias for mapped_type.

pointer

This typedef is an alias for pointer.

reference

This typedef is an alias to value_type&.

size_type

This typedef is an alias for size_type.

value_type

This typedef is an alias to bsl::pair<const KEY, VALUE>.

Member Functions

Name

Description

unordered_multimap [constructor]

Constructors

~unordered_multimap [destructor]

Destroy this object.

Assignment operators

begin overloads

bucket overloads

Return the number of buckets in the array of buckets maintained by this unordered multimap.

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 multimap. Note that this object will be empty after this call, but allocated memory may be retained for future use.

contains

Return true if this container has an element with key equivalent to key.

count

Return the number of elements with a key equivalent to key.

emplace

Emplace a newly constructed element into this container.

emplace_hint

Emplace a newly constructed element near hint.

empty

Return true if this unordered multimap contains no elements, and false otherwise.

end

end overloads

equal_range

Return an iterator pair covering elements with key equivalent to key.

erase

erase overloads

find

Return an iterator to the first element with key equivalent to key.

get_allocator

Return (a copy of) the allocator used for memory allocation by this unordered multimap.

hash_function

Return (a copy of) the hash unary functor used by this unordered multimap to generate a hash value (of type size_type) for a key_type object.

insert

insert overloads

insert_range

Insert each element from the specified range.

key_eq

Return (a copy of) the key‐equivalence 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 the number of elements.

rehash

Rehash this container to have at least numBuckets buckets.

reserve

Reserve capacity for at least numElements without rehashing.