explicit flat_set(container_type cont, const key_compare& comp = key_compare());
template<class Alloc>
flat_set(const container_type& cont, const Alloc& a);
template<class Alloc>
flat_set(const container_type& cont, const key_compare& comp, const Alloc& a);
template<class Alloc>
flat_set(sorted_unique_t s, const container_type& cont, const Alloc& a);
template<class Alloc>
flat_set(sorted_unique_t s, const container_type& cont,
const key_compare& comp, const Alloc& a);
template<class Alloc>
explicit flat_set(const Alloc& a);
template<class Alloc>
flat_set(const key_compare& comp, const Alloc& a);
template<class Alloc>
flat_set(const flat_set&, const Alloc& a);
template<class Alloc>
flat_set(flat_set&&, const Alloc& a);
template<class InputIterator, class Alloc>
flat_set(InputIterator first, InputIterator last, const Alloc& a);
template<class InputIterator, class Alloc>
flat_set(InputIterator first, InputIterator last, const key_compare& comp, const Alloc& a);
template<class InputIterator, class Alloc>
flat_set(sorted_unique_t, InputIterator first, InputIterator last, const Alloc& a);
template<class InputIterator, class Alloc>
flat_set(sorted_unique_t, InputIterator first, InputIterator last,
const key_compare& comp, const Alloc& a);
template<container-compatible-range<value_type> R, class Alloc>
flat_set(from_range_t, R&& rg, const Alloc& a);
template<container-compatible-range<value_type> R, class Alloc>
flat_set(from_range_t, R&& rg, const key_compare& comp, const Alloc& a);
template<class Alloc>
flat_set(initializer_list<value_type> il, const Alloc& a);
template<class Alloc>
flat_set(initializer_list<value_type> il, const key_compare& comp, const Alloc& a);
template<class Alloc>
flat_set(sorted_unique_t, initializer_list<value_type> il, const Alloc& a);
template<class Alloc>
flat_set(sorted_unique_t, initializer_list<value_type> il,
const key_compare& comp, const Alloc& a);
template<class K> pair<iterator, bool> insert(K&& x);
template<class K> iterator insert(const_iterator hint, K&& x);
template<class InputIterator>
void insert(InputIterator first, InputIterator last);
template<class InputIterator>
void insert(sorted_unique_t, InputIterator first, InputIterator last);
template<container-compatible-range<value_type> R>
void insert_range(R&& rg);
void swap(flat_set& y) noexcept;
container_type extract() &&;
void replace(container_type&& cont);
template<class Key, class Compare, class KeyContainer, class Predicate>
typename flat_set<Key, Compare, KeyContainer>::size_type
erase_if(flat_set<Key, Compare, KeyContainer>& c, Predicate pred);