```c++ concurrent_node_set& operator=(concurrent_node_set&& other) noexcept(boost::allocator_traits<Allocator>::is_always_equal::value || boost::allocator_traits<Allocator>::propagate_on_container_move_assignment::value); ``` The move assignment operator. Destroys previously existing elements, swaps the hash function and predicate from `other`, and move-assigns the allocator from `other` if `Alloc::propagate_on_container_move_assignment` exists and `Alloc::propagate_on_container_move_assignment::value` is `true`. If at this point the allocator is equal to `other.get_allocator()`, the internal bucket array of `other` is transferred directly to `*this`; otherwise, inserts move-constructed copies of the elements of `other`. If statistics are xref:concurrent_node_set_boost_unordered_enable_stats[enabled], transfers the internal statistical information from `other` iff the final allocator is equal to `other.get_allocator()`, and always calls `other.reset_stats()`.
```c++ template<class FwdIterator, class F> size_t visit(FwdIterator first, FwdIterator last, F f); template<class FwdIterator, class F> size_t visit(FwdIterator first, FwdIterator last, F f) const; template<class FwdIterator, class F> size_t cvisit(FwdIterator first, FwdIterator last, F f) const; ```
For each element `k` in the range [`first`, `last`), if there is an element `x` in the container with key equivalent to `k`, invokes `f` with a const reference to `x`.