explicit flat_set(container_type cont, const key_compare& comp = key_compare());
template<class Allocator>
flat_set(const container_type& cont, const Allocator& a);
template<class Allocator>
flat_set(const container_type& cont, const key_compare& comp, const Allocator& a);
template<class Allocator>
flat_set(sorted_unique_t s, const container_type& cont, const Allocator& a);
template<class Allocator>
flat_set(sorted_unique_t s, const container_type& cont,
const key_compare& comp, const Allocator& a);
template<class Allocator>
flat_set(const key_compare& comp, const Allocator& a);
template<class Allocator>
explicit flat_set(const Allocator& a);
template<class InputIterator, class Allocator>
flat_set(InputIterator first, InputIterator last, const key_compare& comp, const Allocator& a);
template<class InputIterator, class Allocator>
flat_set(InputIterator first, InputIterator last, const Allocator& a);
template<container-compatible-range<value_type> R, class Allocator>
flat_set(from_range_t, R&& rg, const Allocator& a);
template<container-compatible-range<value_type> R, class Allocator>
flat_set(from_range_t, R&& rg, const key_compare& comp, const Allocator& a);
template<class InputIterator, class Allocator>
flat_set(sorted_unique_t, InputIterator first, InputIterator last,
const key_compare& comp, const Allocator& a);
template<class InputIterator, class Allocator>
flat_set(sorted_unique_t, InputIterator first, InputIterator last, const Allocator& a);
template<class Allocator>
flat_set(initializer_list<value_type> il, const key_compare& comp, const Allocator& a);
template<class Allocator>
flat_set(initializer_list<value_type> il, const Allocator& a);
template<class Allocator>
flat_set(sorted_unique_t, initializer_list<value_type> il,
const key_compare& comp, const Allocator& a);
template<class Allocator>
flat_set(sorted_unique_t, initializer_list<value_type> il, const Allocator& a);