std::multiset::equal_range

 

C++

Language

Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms 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

span (C++20)

 

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::contains (C++20)

multiset::equal_range

multiset::lower_bound

multiset::upper_bound

Observers

multiset::key_comp

multiset::value_comp

Deduction guides(C++17)

 

std::pair<iterator,iterator> equal_range( const Key& key );	(1)
std::pair<const_iterator,const_iterator> equal_range( const Key& key ) const;	(2)
template< class K > std::pair<iterator,iterator> equal_range( const K& x );	(3)	(since C++14)
template< class K > std::pair<const_iterator,const_iterator> equal_range( const K& x ) const;	(4)	(since C++14)

Returns a range containing all elements with the given key in the container. The range is defined by two iterators, one pointing to the first element that is not less than key and another pointing to the first element greater than key. Alternatively, the first iterator may be obtained with lower_bound(), and the second with upper_bound().

1,2) Compares the keys to key.

3,4) Compares the keys 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 to compare the elements to
x	-	alternative value that can be compared to Key

Return value

std::pair containing a pair of iterators defining the wanted range: the first pointing to the first element that is not less than key and the second pointing to the first element greater than key.

If there are no elements not less than key, past-the-end (see end()) iterator is returned as the first element. Similarly if there are no elements greater than key, past-the-end iterator is returned as the second element.

Since emplace and unhinted insert always insert at the upper bound, the order of equivalent elements in the equal range is the order of insertion unless hinted insert or emplace_hint was used to insert an element at a different position.

(since C++11)

Complexity

Logarithmic in the size of the container.

See also

find	finds element with specific key (public member function)
upper_bound	returns an iterator to the first element greater than the given key (public member function)
lower_bound	returns an iterator to the first element not less than the given key (public member function)