[#bsl-unordered_multiset-06c]
= xref:bsl.adoc[bsl]::unordered&lowbar;multiset
:relfileprefix: ../
:mrdocs:

This class template implements a value&hyphen;semantic container type holding an unordered multiset of values (of template parameter type `KEY`)&period;

== Synopsis

Declared in `&lt;bslstl&lowbar;unorderedmultiset&period;h&gt;`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
template&lt;
    class KEY,
    class HASH = xref:bsl/hash-06.adoc[bsl::hash&lt;KEY&gt;],
    class EQUAL = xref:bsl/equal_to-0d.adoc[bsl::equal&lowbar;to&lt;KEY&gt;],
    class ALLOCATOR = xref:bsl/allocator-0df.adoc[bsl::allocator&lt;KEY&gt;]&gt;
class unordered&lowbar;multiset;
----

== Description

This class&colon; &ast; supports a complete set of _value&hyphen;semantic_ operations

* except for BDEX serialization &ast; is _exception&hyphen;neutral_ (agnostic except for the `at` method) &ast; is _alias&hyphen;safe_ &ast; is `const` _thread&hyphen;safe_ For terminology see &lcub;`bsldoc&lowbar;glossary`&rcub;&period;

== Type Aliases

[cols="1,4"]
|===
| Name| Description
| xref:bsl/unordered_multiset-06c/allocator_type.adoc[`allocator&lowbar;type`] 
| This `typedef` is an alias to the (template parameter) `ALLOCATOR`&period;
| xref:bsl/unordered_multiset-06c/const_iterator.adoc[`const&lowbar;iterator`] 
| This `typedef` is an alias to `iterator`&period;
| xref:bsl/unordered_multiset-06c/const_local_iterator.adoc[`const&lowbar;local&lowbar;iterator`] 
| This `typedef` is an alias to `local&lowbar;iterator`&period;
| xref:bsl/unordered_multiset-06c/const_pointer.adoc[`const&lowbar;pointer`] 
| This `typedef` is an alias to the allocator const&hyphen;pointer type&period;
| xref:bsl/unordered_multiset-06c/const_reference.adoc[`const&lowbar;reference`] 
| This `typedef` is an alias for `const&lowbar;reference`&period;
| xref:bsl/unordered_multiset-06c/difference_type.adoc[`difference&lowbar;type`] 
| This `typedef` is an alias to the allocator difference type&period;
| xref:bsl/unordered_multiset-06c/hasher.adoc[`hasher`] 
| This `typedef` is an alias to the (template parameter) `HASH` type&period;
| xref:bsl/unordered_multiset-06c/iterator.adoc[`iterator`] 
| This `typedef` is an alias to the hash&hyphen;table iterator type&period;
| xref:bsl/unordered_multiset-06c/key_equal.adoc[`key&lowbar;equal`] 
| This `typedef` is an alias to the (template parameter) `EQUAL` type&period;
| xref:bsl/unordered_multiset-06c/key_type.adoc[`key&lowbar;type`] 
| This `typedef` is an alias to the (template parameter) `KEY` type&period;
| xref:bsl/unordered_multiset-06c/local_iterator.adoc[`local&lowbar;iterator`] 
| This `typedef` is an alias to the hash&hyphen;table local iterator type&period;
| xref:bsl/unordered_multiset-06c/pointer.adoc[`pointer`] 
| This `typedef` is an alias to the allocator pointer type&period;
| xref:bsl/unordered_multiset-06c/reference.adoc[`reference`] 
| This `typedef` is an alias to `value&lowbar;type&amp;`&period;
| xref:bsl/unordered_multiset-06c/size_type.adoc[`size&lowbar;type`] 
| This `typedef` is an alias to the allocator size type&period;
| xref:bsl/unordered_multiset-06c/value_type.adoc[`value&lowbar;type`] 
| This `typedef` is an alias to `key&lowbar;type`&period;
|===


== Member Functions

[cols="1,4"]
|===
| Name| Description
| xref:bsl/unordered_multiset-06c/2constructor-0ab.adoc[`unordered&lowbar;multiset`]         [.small]#[constructor]#
| Constructors
| xref:bsl/unordered_multiset-06c/2destructor.adoc[`&#126;unordered&lowbar;multiset`] [.small]#[destructor]#
| Destroy this object&period;
| xref:bsl/unordered_multiset-06c/operator_assign-0c4.adoc[`operator&equals;`] 
| Assignment operators
| xref:bsl/unordered_multiset-06c/begin-0f2.adoc[`begin`] 
| `begin` overloads
| xref:bsl/unordered_multiset-06c/bucket-0a.adoc[`bucket`] 
| Return the bucket index for the specified `key`&period;
| xref:bsl/unordered_multiset-06c/bucket_count.adoc[`bucket&lowbar;count`] 
| Return the number of buckets in the array of buckets maintained by this unordered multiset&period;
| xref:bsl/unordered_multiset-06c/bucket_size.adoc[`bucket&lowbar;size`] 
| Return the number of elements in the bucket at `index`&period;
| xref:bsl/unordered_multiset-06c/cbegin-02.adoc[`cbegin`] 
| `cbegin` overloads
| xref:bsl/unordered_multiset-06c/cend-0f.adoc[`cend`] 
| `cend` overloads
| xref:bsl/unordered_multiset-06c/clear.adoc[`clear`] 
| Remove all entries from this unordered multiset&period; Note that the container is empty after this call, but allocated memory may be retained for future use&period;
| xref:bsl/unordered_multiset-06c/contains-01.adoc[`contains`] 
| Return whether this unordered multiset contains `key`&period;
| xref:bsl/unordered_multiset-06c/count-00d.adoc[`count`] 
| Return the number of elements equivalent to `key`&period;
| xref:bsl/unordered_multiset-06c/emplace.adoc[`emplace`] 
| Emplace a newly constructed element into this unordered multiset&period;
| xref:bsl/unordered_multiset-06c/emplace_hint.adoc[`emplace&lowbar;hint`] 
| Emplace a newly constructed element near `hint`&period;
| xref:bsl/unordered_multiset-06c/empty.adoc[`empty`] 
| Return `true` if this unordered multiset contains no elements, and `false` otherwise&period;
| xref:bsl/unordered_multiset-06c/end-06.adoc[`end`] 
| `end` overloads
| xref:bsl/unordered_multiset-06c/equal_range-00.adoc[`equal&lowbar;range`] 
| `equal&lowbar;range` overloads
| xref:bsl/unordered_multiset-06c/erase-03.adoc[`erase`] 
| `erase` overloads
| xref:bsl/unordered_multiset-06c/find-0c.adoc[`find`] 
| `find` overloads
| xref:bsl/unordered_multiset-06c/get_allocator.adoc[`get&lowbar;allocator`] 
| Return (a copy of) the allocator used for memory allocation by this unordered multiset&period;
| xref:bsl/unordered_multiset-06c/hash_function.adoc[`hash&lowbar;function`] 
| Return (a copy of) the hash unary functor used by this unordered multiset to generate a hash value (of type `size&lowbar;t`) for a `key&lowbar;type` object&period;
| xref:bsl/unordered_multiset-06c/insert-09.adoc[`insert`] 
| `insert` overloads
| xref:bsl/unordered_multiset-06c/insert_range.adoc[`insert&lowbar;range`] 
| Insert each element from the specified `range`&period;
| xref:bsl/unordered_multiset-06c/key_eq.adoc[`key&lowbar;eq`] 
| Return (a copy of) the key&hyphen;equality binary functor that returns `true` if the value of two `key&lowbar;type` objects are equivalent, and `false` otherwise&period;
| xref:bsl/unordered_multiset-06c/load_factor.adoc[`load&lowbar;factor`] 
| Return the current load factor of this container&period;
| xref:bsl/unordered_multiset-06c/max_bucket_count.adoc[`max&lowbar;bucket&lowbar;count`] 
| Return a theoretical upper bound on the number of buckets&period;
| xref:bsl/unordered_multiset-06c/max_load_factor-04.adoc[`max&lowbar;load&lowbar;factor`] 
| `max&lowbar;load&lowbar;factor` overloads
| xref:bsl/unordered_multiset-06c/max_size.adoc[`max&lowbar;size`] 
| Return a theoretical upper bound on the size of this container&period;
| xref:bsl/unordered_multiset-06c/rehash.adoc[`rehash`] 
| Rehash this container to at least `numBuckets` buckets&period;
| xref:bsl/unordered_multiset-06c/reserve.adoc[`reserve`] 
| Reserve capacity for at least `numElements` without rehashing&period;
| xref:bsl/unordered_multiset-06c/size.adoc[`size`] 
| Return the number of elements in this unordered multiset&period;
| xref:bsl/unordered_multiset-06c/swap.adoc[`swap`] 
| Exchange the contents of this object with those of `other`&period;
| xref:bsl/unordered_multiset-06c/2conversion.adoc[`operator BloombergLP::bslmf::NestedTraitDeclaration&lt;unordered&lowbar;multiset, IsBitwiseMoveable, &colon;&colon;BloombergLP&colon;&colon;bslmf&colon;&colon;IsBitwiseMoveable&lt;HashTable&gt;&colon;&colon;value&gt;`] 
| Nested trait declaration for `bslmf&colon;&colon;IsBitwiseMoveable`&period;
|===


== Deduction Guides

[cols="1,4"]
|===
| Name| Description
| xref:bsl/unordered_multiset-05.adoc[`unordered&lowbar;multiset&lt;KEY&gt;`] 
| CTAD guide&colon; deduce `KEY` from initializer&lowbar;list `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-09e.adoc[`unordered&lowbar;multiset&lt;KEY&gt;`] 
| CTAD guide&colon; deduce `KEY` from initializer&lowbar;list `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-07f.adoc[`unordered&lowbar;multiset&lt;KEY&gt;`] 
| CTAD guide&colon; deduce `KEY` from iterator `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-07a.adoc[`unordered&lowbar;multiset&lt;KEY&gt;`] 
| CTAD guide&colon; deduce `KEY` from iterator `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-063.adoc[`unordered&lowbar;multiset&lt;KEY, HASH&gt;`] 
| CTAD guide&colon; deduce `KEY` from initializer&lowbar;list `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-0d3.adoc[`unordered&lowbar;multiset&lt;KEY, HASH&gt;`] 
| CTAD guide&colon; deduce `KEY` from iterator `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-0a9.adoc[`unordered&lowbar;multiset&lt;KEY, HASH, EQUAL&gt;`] 
| CTAD guide&colon; deduce `KEY` from initializer&lowbar;list `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-091.adoc[`unordered&lowbar;multiset&lt;KEY, HASH, EQUAL&gt;`] 
| CTAD guide&colon; deduce `KEY` from iterator `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-009.adoc[`unordered&lowbar;multiset&lt;KEY, HASH, EQUAL, ALLOCATOR&gt;`] 
| CTAD guide&colon; deduce `KEY` from initializer&lowbar;list `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-0ab.adoc[`unordered&lowbar;multiset&lt;KEY, HASH, EQUAL, ALLOCATOR&gt;`] 
| CTAD guide&colon; deduce `KEY` from iterator `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-00df.adoc[`unordered&lowbar;multiset&lt;KEY, HASH, bsl::equal&lowbar;to&lt;KEY&gt;, ALLOCATOR&gt;`] 
| CTAD guide&colon; deduce `KEY` from initializer&lowbar;list `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-0db.adoc[`unordered&lowbar;multiset&lt;KEY, HASH, bsl::equal&lowbar;to&lt;KEY&gt;, ALLOCATOR&gt;`] 
| CTAD guide&colon; deduce `KEY` from iterator `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-0d0.adoc[`unordered&lowbar;multiset&lt;KEY, bsl::hash&lt;KEY&gt;, bsl::equal&lowbar;to&lt;KEY&gt;, ALLOCATOR&gt;`] 
| CTAD guide&colon; deduce `KEY` from initializer&lowbar;list `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-00d8.adoc[`unordered&lowbar;multiset&lt;KEY, bsl::hash&lt;KEY&gt;, bsl::equal&lowbar;to&lt;KEY&gt;, ALLOCATOR&gt;`] 
| CTAD guide&colon; deduce `KEY` from initializer&lowbar;list `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-0e.adoc[`unordered&lowbar;multiset&lt;KEY, bsl::hash&lt;KEY&gt;, bsl::equal&lowbar;to&lt;KEY&gt;, ALLOCATOR&gt;`] 
| CTAD guide&colon; deduce `KEY` from iterator `value&lowbar;type`&period;
| xref:bsl/unordered_multiset-02.adoc[`unordered&lowbar;multiset&lt;KEY, bsl::hash&lt;KEY&gt;, bsl::equal&lowbar;to&lt;KEY&gt;, ALLOCATOR&gt;`] 
| CTAD guide&colon; deduce `KEY` from iterator `value&lowbar;type`&period;
|===


== Friends

[cols="1,4"]
|===
| Name| Description
| `xref:bsl/operator_eq-0a2.adoc[bsl::operator&equals;&equals;]`
| Return `true` if the specified `lhs` and `rhs` objects have the same value, and `false` otherwise&period;
|===

== Non-Member Functions

[cols="1,4"]
|===
| Name| Description
| xref:bsl/erase_if-074.adoc[`erase&lowbar;if`]
| Erase all elements in `ms` that satisfy `predicate`&period;
| xref:bsl/operator_eq-094.adoc[`operator&equals;&equals;`]
| Return `true` if `lhs` and `rhs` have the same value&period;
| xref:bsl/swap-03d7.adoc[`swap`]
| Exchange the values of the specified `a` and `b` objects&period;
|===


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