operator==,!=(std::unordered_multiset)

 

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)

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::unordered_multiset

Member functions

unordered_multiset::unordered_multiset

unordered_multiset::~unordered_multiset

unordered_multiset::operator=

unordered_multiset::get_allocator

Iterators

unordered_multiset::beginunordered_multiset::cbegin

unordered_multiset::endunordered_multiset::cend

Capacity

unordered_multiset::erase

unordered_multiset::size

unordered_multiset::max_size

Modifiers

unordered_multiset::clear

unordered_multiset::insert

unordered_multiset::emplace

unordered_multiset::emplace_hint

unordered_multiset::erase

unordered_multiset::swap

Lookup

unordered_multiset::count

unordered_multiset::find

unordered_multiset::equal_range

Bucket interface

unordered_multiset::begin2

unordered_multiset::end2

unordered_multiset::bucket_count

unordered_multiset::max_bucket_count

unordered_multiset::bucket_size

unordered_multiset::bucket

Hash policy

unordered_multiset::load_factor

unordered_multiset::max_load_factor

unordered_multiset::rehash

unordered_multiset::reserve

Observers

unordered_multiset::hash_function

unordered_multiset::key_eq

 

template< class Key, class Hash, class KeyEqual, class Allocator > bool operator==( const unordered_multiset<Key,Hash,KeyEqual,Allocator>& lhs,                  const unordered_multiset<Key,Hash,KeyEqual,Allocator>& rhs );	(1)
template< class Key, class Hash, class KeyEqual, class Allocator > bool operator!=( const unordered_multiset<Key,Hash,KeyEqual,Allocator>& lhs,                  const unordered_multiset<Key,Hash,KeyEqual,Allocator>& rhs );	(2)

Compares the contents of two unordered containers.

The contents of two unordered containers lhs and rhs are equal if the following conditions hold:

• lhs.size() == rhs.size()
• each group of equivalent keys [lhs_eq1, lhs_eq2) obtained from lhs.equal_range(lhs_eq1) has a corresponding group of equivalent keys in the other container [rhs_eq1, rhs_eq2) obtained from rhs.equal_range(rhs_eq1), that has the following properties:

• std::distance(lhs_eq1, lhs_eq2) == std::distance(rhs_eq1, rhs_eq2).
• std::is_permutation(lhs_eq1, lhs_eq2, rhs_eq1) == true.

The behavior is undefined if Key is not EqualityComparable.

The behavior is also undefined if Hash and KeyEqual do not have the same behavior on lhs and rhs or if the equality comparison operator for Key is not a refinement of the partition into equivalent-key groups introduced by KeyEqual (that is, if two keys that compare equal fall into different partitions)

Parameters

lhs, rhs

-

unordered containers to compare

Return value

1) true if the contents of the containers are equal, false otherwise

2) true if the contents of the containers are not equal, false otherwise

Complexity

ΣS_i² comparisons of the keys in the average case, where S is the size of the ith equivalent key group. N² comparisons of the keys in the worst case, where N is the size of the container.