std::map::merge
std::map::merge
template<class C2> void merge(std::map<Key, T, C2, Allocator>& source); | (1) | (since C++17) |
template<class C2> void merge(std::map<Key, T, C2, Allocator>&& source); | (2) | (since C++17) |
template<class C2> void merge(std::multimap<Key, T, C2, Allocator>& source); | (3) | (since C++17) |
template<class C2> void merge(std::multimap<Key, T, C2, Allocator>&& source); | (4) | (since C++17) |
Attempts to extract ("splice") each element in source and insert it into *this using the 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
See also
|
(C++17) | extracts nodes from the container (public member function) |
| inserts elements or nodes (since C++17) (public member function) |
© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
http://en.cppreference.com/w/cpp/container/map/merge
