std::unordered_map<Key,T,Hash,KeyEqual,Allocator>::swap
| void swap( unordered_map& other ); | (since C++11) (until C++17) | |
| void swap( unordered_map& other ) noexcept(/* see below */); | (since C++17) | 
Exchanges the contents of the container with those of other. Does not invoke any move, copy, or swap operations on individual elements.
All iterators and references remain valid. The past-the-end iterator is invalidated.
The Hash and KeyEqual objects must be Swappable, and they are exchanged using unqualified calls to non-member swap.
| If std::allocator_traits<allocator_type>::propagate_on_container_swap::valueis true, then the allocators are exchanged using an unqualified call to non-memberswap. Otherwise, they are not swapped (and ifget_allocator() != other.get_allocator(), the behavior is undefined). | (since C++11) | 
Parameters
| other | - | container to exchange the contents with | 
Return value
(none).
Exceptions
| Any exception thrown by the swap of the  | (until C++17) | 
| noexceptspecification:noexcept(std::allocator_traits<Allocator>::is_always_equal::value | (since C++17) | 
Complexity
Constant.
See also
| (C++11) | specializes the std::swapalgorithm(function template) | 
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