iterator lower_bound( const Key& key ); (1)

void push_front( const T& value );

(1)

size_type size() const;

void swap( unordered_set& other );

void splice_after( const_iterator pos, forward_list& other );

size_type bucket( const Key& key ) const;

allocator_type get_allocator() const;

size_type size() const;

template <class... Args> iterator emplace_hint( const_iterator