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std::unordered_multiset::merge

From cppreference.com
 
 
 
 
template<class H2, class P2>
void merge(std::unordered_set<Key, H2, P2, Allocator>& source);
(1) (since C++17)
template<class H2, class P2>
void merge(std::unordered_set<Key, H2, P2, Allocator>&& source);
(2) (since C++17)
template<class H2, class P2>
void merge(std::unordered_multiset<Key, H2, P2, Allocator>& source);
(3) (since C++17)
template<class H2, class P2>
void merge(std::unordered_multiset<Key, H2, P2, Allocator>&& source);
(4) (since C++17)

Attempts to extract ("splice") each element in source and insert it into *this using the hash function and key equality predicate of *this.

No elements are copied or moved, only the internal pointers of the container nodes are repointed. All pointers and references to the transferred elements remain valid, but now refer into *this, not into source. Iterators referring to the transferred elements and all iterators referring to *this are invalidated.

The behavior is undefined if get_allocator() != source.get_allocator().

Contents

[edit] Parameters

source - compatible container to transfer the nodes from

[edit] Return value

(none)

[edit] Exceptions

Does not throw unless equality or hash function throw.

[edit] Complexity

Average case O(N), worst case O(N*size()+N), where N is source.size()


[edit] Example

[edit] See also

(C++17)
extracts nodes from the container
(public member function) [edit]
inserts elements or nodes (since C++17)
(public member function) [edit]