std::multiset::count

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Containers library

array (C++11)

vector

deque

forward_list (C++11)

list

set

multiset

map

multimap

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

stack

queue

priority_queue

 

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::empty

multiset::size

multiset::max_size

Modifiers

multiset::clear

multiset::insert

multiset::emplace (C++11)

multiset::emplace_hint (C++11)

multiset::erase

multiset::swap

multiset::extract (C++17)

multiset::merge (C++17)

Lookup

multiset::count

multiset::find

multiset::equal_range

multiset::lower_bound

multiset::upper_bound

Observers

multiset::key_comp

multiset::value_comp

 

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 only participates in overload resolution if the qualified-id Compare::is_transparent is valid and denotes a type. They allow 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 the elements found.

See also

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