std::multiset<Key,Compare,Allocator>::count

 

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std::multiset

Member functions

multiset::multiset multiset::~multiset         multiset::operator= multiset::get_allocator

Iterators multiset::beginmultiset::cbegin (C++11) multiset::endmultiset::cend (C++11) multiset::rbeginmultiset::crbegin (C++11)     multiset::rendmultiset::crend (C++11) Capacity multiset::size multiset::max_size multiset::empty Observers multiset::key_comp multiset::value_comp Modifiers multiset::clear multiset::erase multiset::swap multiset::extract (C++17) multiset::merge (C++17) multiset::insert multiset::insert_range (C++23) multiset::emplace (C++11) multiset::emplace_hint (C++11) Lookup multiset::count multiset::find multiset::contains (C++20) multiset::equal_range multiset::lower_bound multiset::upper_bound

Non-member functions

std::swap(std::multiset) erase_if(std::multiset) (C++20)   operator==operator<=> (C++20) operator!=operator<operator>operator<=operator>= (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)

Deduction guides(C++17)

 

size_type count( const Key& key ) const;	(1)
template< class K > size_type count( const K& x ) const;	(2)	(since C++14)

Returns the number of elements with key that compares equivalent to the specified argument.

1) Returns the number of elements with key key.

2) Returns the number of elements with key that compares equivalent to the value x. This overload participates in overload resolution only if the qualified-id Compare::is_transparent is valid and denotes a type. It allows calling this function without constructing an instance of Key.

Parameters

key	-	key value of the elements to count
x	-	alternative value to compare to the keys

Return value

Number of elements with key that compares equivalent to key or x.

Complexity

Logarithmic in the size of the container plus linear in the number of elements found.

Notes

Feature-test macro	Value	Std	Feature
__cpp_lib_generic_associative_lookup	201304L	(C++14)	Heterogeneous comparison lookup in associative containers; overload (2)

See also

find	finds element with specific key (public member function)
equal_range	returns range of elements matching a specific key (public member function)