(C++17) | ||||
| Sequence | ||||
(C++11) | ||||
(C++26) | ||||
(C++26) | ||||
(C++11) | ||||
| Associative | ||||
| Unordered associative | ||||
(C++11) | ||||
(C++11) | ||||
(C++11) | ||||
(C++11) | ||||
| Adaptors | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
| Views | ||||
(C++20) | ||||
(C++23) | ||||
| Tables | ||||
| Iterator invalidation | ||||
| Member function table | ||||
| Non-member function table |
std::unordered_multimap| Member types | ||||||
| Member functions | ||||||
| Non-member functions | ||||||
| ||||||
| Deduction guides(C++17) | ||||||
template<class Key,class T,class Hash,class KeyEqual,class Alloc> bool operator==(conststd::unordered_multimap<Key, T, Hash, KeyEqual, Alloc>& lhs, | (1) | |
template<class Key,class T,class Hash,class KeyEqual,class Alloc> bool operator!=(conststd::unordered_multimap<Key, T, Hash, KeyEqual, Alloc>& lhs, | (2) | (until C++20) |
Compares the contents of two unordered containers.
The contents of two unordered containerslhs andrhs are equal if the following conditions hold:
[lhs_eq1, lhs_eq2) obtained fromlhs.equal_range(lhs_eq1) has a corresponding group of equivalent elements in the other container[rhs_eq1, rhs_eq2) obtained fromrhs.equal_range(rhs_eq1), that has the following properties:The behavior is undefined ifKey orT are notEqualityComparable.
The behavior is also undefined ifhash_function() andkey_eq() do(until C++20)key_eq() does(since C++20) not have the same behavior onlhs andrhs or ifoperator== forKey is not a refinement of the partition into equivalent-key groups introduced bykey_eq() (that is, if two elements that compare equal usingoperator== fall into different partitions).
The | (since C++20) |
| lhs, rhs | - | unordered containers to compare |
Proportional toΣSi2 calls tooperator== onvalue_type, calls to the predicate returned bykey_eq, and calls to the hasher returned byhash_function in the average case, whereS is the size of theith equivalent key group. Proportional toN2 in the worst case, whereN is the size of the container. Average case becomes proportional toN if the elements within each equivalent key group are arranged in the same order (happens when the containers are copies of each other).
