std::map<Key,T,Compare,Allocator>::merge (3) - Linux Manuals

std::map<Key,T,Compare,Allocator>::merge: std::map<Key,T,Compare,Allocator>::merge

NAME

std::map<Key,T,Compare,Allocator>::merge - std::map<Key,T,Compare,Allocator>::merge

Synopsis


template<class C2> (1) (since C++17)
void merge(std::map<Key, T, C2, Allocator>& source);
template<class C2> (2) (since C++17)
void merge(std::map<Key, T, C2, Allocator>&& source);
template<class C2> (3) (since C++17)
void merge(std::multimap<Key, T, C2, Allocator>& source);
template<class C2> (4) (since C++17)
void merge(std::multimap<Key, T, C2, Allocator>&& source);


Attempts to extract ("splice") each element in source and insert it into *this using the comparison object of *this. If there is an element in *this with key equivalent to the key of an element from source, then that element is not extracted from source. 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.
The behavior is undefined if get_allocator() != source.get_allocator().

Parameters


source - compatible container to transfer the nodes from

Return value


(none)

Exceptions


Does not throw unless comparison throws.

Complexity


N*log(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)

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