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

 

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)

 

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_multimap

Member functions

unordered_multimap::unordered_multimap

unordered_multimap::~unordered_multimap

unordered_multimap::operator=

unordered_multimap::get_allocator

Iterators

unordered_multimap::beginunordered_multimap::cbegin

unordered_multimap::endunordered_multimap::cend

Capacity

unordered_multimap::erase

unordered_multimap::size

unordered_multimap::max_size

Modifiers

unordered_multimap::clear

unordered_multimap::insert

unordered_multimap::emplace

unordered_multimap::emplace_hint

unordered_multimap::erase

unordered_multimap::swap

Lookup

unordered_multimap::count

unordered_multimap::find

unordered_multimap::equal_range

Bucket interface

unordered_multimap::begin2

unordered_multimap::end2

unordered_multimap::bucket_count

unordered_multimap::max_bucket_count

unordered_multimap::bucket_size

unordered_multimap::bucket

Hash policy

unordered_multimap::load_factor

unordered_multimap::max_load_factor

unordered_multimap::rehash

unordered_multimap::reserve

Observers

unordered_multimap::hash_function

unordered_multimap::key_eq

 

template< class Key, class T, class Hash, class KeyEqual, class Allocator > void operator==( unordered_multimap<Key,T,Hash,KeyEqual,Allocator> &lhs,                 unordered_multimap<Key,T,Hash,KeyEqual,Allocator> &rhs);	(1)
template< class Key, class T, class Hash, class KeyEqual, class Allocator > void operator!=( unordered_multimap<Key,T,Hash,KeyEqual,Allocator> &lhs,                  unordered_multimap<Key,T,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 or T are 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.