std::unordered_multimap<Key,T,Hash,KeyEqual,Allocator>::merge (3) - Linux Man Pages

std::unordered_multimap<Key,T,Hash,KeyEqual,Allocator>::merge: std::unordered_multimap<Key,T,Hash,KeyEqual,Allocator>::merge

NAME

std::unordered_multimap<Key,T,Hash,KeyEqual,Allocator>::merge - std::unordered_multimap<Key,T,Hash,KeyEqual,Allocator>::merge

Synopsis


template<class H2, class P2> (1) (since C++17)
void merge(std::unordered_map<Key, T, H2, P2, Allocator>& source);
template<class H2, class P2> (2) (since C++17)
void merge(std::unordered_map<Key, T, H2, P2, Allocator>&& source);
template<class H2, class P2> (3) (since C++17)
void merge(std::unordered_multimap<Key, T, H2, P2, Allocator>& source);
template<class H2, class P2> (4) (since C++17)
void merge(std::unordered_multimap<Key, T, H2, P2, Allocator>&& source);


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().

Parameters


source - compatible container to transfer the nodes from

Return value


(none)

Complexity


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

Example


 This section is incomplete
 Reason: no example

See also


extract extracts nodes from the container
        (public member function)
(C++17)
        inserts elements
        or nodes
insert (since C++17)
        (public member function)