typename Key

is the type to be inserted in the set, which is also the key_type

typename Compare = std::less<Key>

is the comparison functor used to order keys

typename Allocator = new_allocator<Key>

is the allocator to be used to allocate memory for this container

explicit flat_set();

Effects: Default constructs an empty container.

Complexity: Constant.

explicit flat_set(const Compare & comp, 
                  const allocator_type & a = allocator_type());

Effects: Constructs an empty container using the specified comparison object and allocator.

Complexity: Constant.

explicit flat_set(const allocator_type & a);

Effects: Constructs an empty container using the specified allocator.

Complexity: Constant.

template<typename InputIterator> 
  flat_set(InputIterator first, InputIterator last, 
           const Compare & comp = Compare(), 
           const allocator_type & a = allocator_type());

Effects: Constructs an empty container using the specified comparison object and allocator, and inserts elements from the range [first ,last ).

Complexity: Linear in N if the range [first ,last ) is already sorted using comp and otherwise N logN, where N is last - first.

template<typename InputIterator> 
  flat_set(InputIterator first, InputIterator last, const allocator_type & a);

Effects: Constructs an empty container using the specified allocator, and inserts elements from the range [first ,last ).

Complexity: Linear in N if the range [first ,last ) is already sorted using comp and otherwise N logN, where N is last - first.

template<typename InputIterator> 
  flat_set(ordered_unique_range_t, InputIterator first, InputIterator last, 
           const Compare & comp = Compare(), 
           const allocator_type & a = allocator_type());

Effects: Constructs an empty container using the specified comparison object and allocator, and inserts elements from the ordered unique range [first ,last). This function is more efficient than the normal range creation for ordered ranges.

Requires: [first ,last) must be ordered according to the predicate and must be unique values.

Complexity: Linear in N.

Note: Non-standard extension.

flat_set(std::initializer_list< value_type > il, 
         const Compare & comp = Compare(), 
         const allocator_type & a = allocator_type());

Effects: Constructs an empty container using the specified comparison object and allocator, and inserts elements from the range [il.begin(), il.end()).

Complexity: Linear in N if the range [il.begin(), il.end()) is already sorted using comp and otherwise N logN, where N is il.begin() - il.end().

flat_set(std::initializer_list< value_type > il, const allocator_type & a);

Effects: Constructs an empty container using the specified allocator, and inserts elements from the range [il.begin(), il.end()).

Complexity: Linear in N if the range [il.begin(), il.end()) is already sorted using comp and otherwise N logN, where N is il.begin() - il.end().

flat_set(ordered_unique_range_t, std::initializer_list< value_type > il, 
         const Compare & comp = Compare(), 
         const allocator_type & a = allocator_type());

Effects: Constructs an empty container using the specified comparison object and allocator, and inserts elements from the ordered unique range [il.begin(), il.end()). This function is more efficient than the normal range creation for ordered ranges.

Requires: [il.begin(), il.end()) must be ordered according to the predicate and must be unique values.

Complexity: Linear in N.

Note: Non-standard extension.

flat_set(const flat_set & x);

Effects: Copy constructs the container.

Complexity: Linear in x.size().

flat_set(flat_set && x);

Effects: Move constructs thecontainer. Constructs *this using x's resources.

Complexity: Constant.

Postcondition: x is emptied.

flat_set(const flat_set & x, const allocator_type & a);

Effects: Copy constructs a container using the specified allocator.

Complexity: Linear in x.size().

flat_set(flat_set && x, const allocator_type & a);

Effects: Move constructs a container using the specified allocator. Constructs *this using x's resources.

Complexity: Constant if a == x.get_allocator(), linear otherwise

flat_set & operator=(const flat_set & x);

Effects: Makes *this a copy of x.

Complexity: Linear in x.size().

flat_set & operator=(flat_set && x) noexcept(allocator_traits_type::is_always_equal::value &&boost::container::container_detail::is_nothrow_move_assignable< Compare >::value));

Throws: If allocator_traits_type::propagate_on_container_move_assignment is false and (allocation throws or value_type's move constructor throws)

Complexity: Constant if allocator_traits_type:: propagate_on_container_move_assignment is true or this->get>allocator() == x.get_allocator(). Linear otherwise.

flat_set & operator=(std::initializer_list< value_type > il);

Effects: Copy all elements from il to *this.

Complexity: Linear in il.size().

allocator_type get_allocator() const noexcept;

Effects: Returns a copy of the allocator that was passed to the object's constructor.

Complexity: Constant.

stored_allocator_type & get_stored_allocator() noexcept;

Effects: Returns a reference to the internal allocator.

Throws: Nothing

Complexity: Constant.

Note: Non-standard extension.

const stored_allocator_type & get_stored_allocator() const noexcept;

Effects: Returns a reference to the internal allocator.

Throws: Nothing

Complexity: Constant.

Note: Non-standard extension.

iterator begin() noexcept;

Effects: Returns an iterator to the first element contained in the container.

Throws: Nothing.

Complexity: Constant.

const_iterator begin() const noexcept;

Effects: Returns a const_iterator to the first element contained in the container.

Throws: Nothing.

Complexity: Constant.

iterator end() noexcept;

Effects: Returns an iterator to the end of the container.

Throws: Nothing.

Complexity: Constant.

const_iterator end() const noexcept;

Effects: Returns a const_iterator to the end of the container.

Throws: Nothing.

Complexity: Constant.

reverse_iterator rbegin() noexcept;

Effects: Returns a reverse_iterator pointing to the beginning of the reversed container.

Throws: Nothing.

Complexity: Constant.

const_reverse_iterator rbegin() const noexcept;

Effects: Returns a const_reverse_iterator pointing to the beginning of the reversed container.

Throws: Nothing.

Complexity: Constant.

reverse_iterator rend() noexcept;

Effects: Returns a reverse_iterator pointing to the end of the reversed container.

Throws: Nothing.

Complexity: Constant.

const_reverse_iterator rend() const noexcept;

Effects: Returns a const_reverse_iterator pointing to the end of the reversed container.

Throws: Nothing.

Complexity: Constant.

const_iterator cbegin() const noexcept;

Effects: Returns a const_iterator to the first element contained in the container.

Throws: Nothing.

Complexity: Constant.

const_iterator cend() const noexcept;

Effects: Returns a const_iterator to the end of the container.

Throws: Nothing.

Complexity: Constant.

const_reverse_iterator crbegin() const noexcept;

Effects: Returns a const_reverse_iterator pointing to the beginning of the reversed container.

Throws: Nothing.

Complexity: Constant.

const_reverse_iterator crend() const noexcept;

Effects: Returns a const_reverse_iterator pointing to the end of the reversed container.

Throws: Nothing.

Complexity: Constant.

bool empty() const noexcept;

Effects: Returns true if the container contains no elements.

Throws: Nothing.

Complexity: Constant.

size_type size() const noexcept;

Effects: Returns the number of the elements contained in the container.

Throws: Nothing.

Complexity: Constant.

size_type max_size() const noexcept;

Effects: Returns the largest possible size of the container.

Throws: Nothing.

Complexity: Constant.

size_type capacity() const noexcept;

Effects: Number of elements for which memory has been allocated. capacity() is always greater than or equal to size().

Throws: Nothing.

Complexity: Constant.

void reserve(size_type cnt);

Effects: If n is less than or equal to capacity(), this call has no effect. Otherwise, it is a request for allocation of additional memory. If the request is successful, then capacity() is greater than or equal to n; otherwise, capacity() is unchanged. In either case, size() is unchanged.

Throws: If memory allocation allocation throws or Key's copy constructor throws.

Note: If capacity() is less than "cnt", iterators and references to to values might be invalidated.

void shrink_to_fit();

Throws: If memory allocation throws, or Key's copy constructor throws.

Complexity: Linear to size().

template<class... Args> std::pair< iterator, bool > emplace(Args &&... args);

Effects: Inserts an object x of type Key constructed with std::forward<Args>(args)... if and only if there is no element in the container with key equivalent to the key of x.

Returns: The bool component of the returned pair is true if and only if the insertion takes place, and the iterator component of the pair points to the element with key equivalent to the key of x.

Complexity: Logarithmic search time plus linear insertion to the elements with bigger keys than x.

Note: If an element is inserted it might invalidate elements.

template<class... Args> 
  iterator emplace_hint(const_iterator p, Args &&... args);

Effects: Inserts an object of type Key constructed with std::forward<Args>(args)... in the container if and only if there is no element in the container with key equivalent to the key of x. p is a hint pointing to where the insert should start to search.

Returns: An iterator pointing to the element with key equivalent to the key of x.

Complexity: Logarithmic search time (constant if x is inserted right before p) plus insertion linear to the elements with bigger keys than x.

Note: If an element is inserted it might invalidate elements.

std::pair< iterator, bool > insert(const value_type & x);

Effects: Inserts x if and only if there is no element in the container with key equivalent to the key of x.

Returns: The bool component of the returned pair is true if and only if the insertion takes place, and the iterator component of the pair points to the element with key equivalent to the key of x.

Complexity: Logarithmic search time plus linear insertion to the elements with bigger keys than x.

Note: If an element is inserted it might invalidate elements.

std::pair< iterator, bool > insert(value_type && x);

Effects: Inserts a new value_type move constructed from the pair if and only if there is no element in the container with key equivalent to the key of x.

Returns: The bool component of the returned pair is true if and only if the insertion takes place, and the iterator component of the pair points to the element with key equivalent to the key of x.

Complexity: Logarithmic search time plus linear insertion to the elements with bigger keys than x.

Note: If an element is inserted it might invalidate elements.

iterator insert(const_iterator p, const value_type & x);

Effects: Inserts a copy of x in the container if and only if there is no element in the container with key equivalent to the key of x. p is a hint pointing to where the insert should start to search.

Returns: An iterator pointing to the element with key equivalent to the key of x.

Complexity: Logarithmic search time (constant if x is inserted right before p) plus insertion linear to the elements with bigger keys than x.

Note: If an element is inserted it might invalidate elements.

iterator insert(const_iterator p, value_type && x);

Effects: Inserts an element move constructed from x in the container. p is a hint pointing to where the insert should start to search.

Returns: An iterator pointing to the element with key equivalent to the key of x.

Complexity: Logarithmic search time (constant if x is inserted right before p) plus insertion linear to the elements with bigger keys than x.

Note: If an element is inserted it might invalidate elements.

template<typename InputIterator> 
  void insert(InputIterator first, InputIterator last);

Requires: first, last are not iterators into *this.

Effects: inserts each element from the range [first,last) if and only if there is no element with key equivalent to the key of that element.

Complexity: At most N log(size()+N) (N is the distance from first to last) search time plus N*size() insertion time.

Note: If an element is inserted it might invalidate elements.

template<typename InputIterator> 
  void insert(ordered_unique_range_t, InputIterator first, InputIterator last);

Requires: first, last are not iterators into *this and must be ordered according to the predicate and must be unique values.

Effects: inserts each element from the range [first,last) .This function is more efficient than the normal range creation for ordered ranges.

Complexity: At most N log(size()+N) (N is the distance from first to last) search time plus N*size() insertion time.

Note: Non-standard extension. If an element is inserted it might invalidate elements.

void insert(std::initializer_list< value_type > il);

Effects: inserts each element from the range [il.begin(), il.end()) if and only if there is no element with key equivalent to the key of that element.

Complexity: At most N log(size()+N) (N is the distance from il.begin() to il.end()) search time plus N*size() insertion time.

Note: If an element is inserted it might invalidate elements.

void insert(ordered_unique_range_t, std::initializer_list< value_type > il);

Requires: Range [il.begin(), il.end()) must be ordered according to the predicate and must be unique values.

Effects: inserts each element from the range [il.begin(), il.end()) .This function is more efficient than the normal range creation for ordered ranges.

Complexity: At most N log(size()+N) (N is the distance from il.begin() to il.end()) search time plus N*size() insertion time.

Note: Non-standard extension. If an element is inserted it might invalidate elements.

iterator erase(const_iterator p);

Effects: Erases the element pointed to by p.

Returns: Returns an iterator pointing to the element immediately following q prior to the element being erased. If no such element exists, returns end().

Complexity: Linear to the elements with keys bigger than p

Note: Invalidates elements with keys not less than the erased element.

size_type erase(const key_type & x);

Effects: Erases all elements in the container with key equivalent to x.

Returns: Returns the number of erased elements.

Complexity: Logarithmic search time plus erasure time linear to the elements with bigger keys.

iterator erase(const_iterator first, const_iterator last);

Effects: Erases all the elements in the range [first, last).

Returns: Returns last.

Complexity: size()*N where N is the distance from first to last.

Complexity: Logarithmic search time plus erasure time linear to the elements with bigger keys.

void swap(flat_set & x) noexcept(allocator_traits_type::is_always_equal::value &&boost::container::container_detail::is_nothrow_swappable< Compare >::value));

Effects: Swaps the contents of *this and x.

Throws: Nothing.

Complexity: Constant.

void clear() noexcept;

Effects: erase(a.begin(),a.end()).

Postcondition: size() == 0.

Complexity: linear in size().

key_compare key_comp() const;

Effects: Returns the comparison object out of which a was constructed.

Complexity: Constant.

value_compare value_comp() const;

Effects: Returns an object of value_compare constructed out of the comparison object.

Complexity: Constant.

iterator find(const key_type & x);

Returns: An iterator pointing to an element with the key equivalent to x, or end() if such an element is not found.

Complexity: Logarithmic.

const_iterator find(const key_type & x) const;

Returns: A const_iterator pointing to an element with the key equivalent to x, or end() if such an element is not found.

Complexity: Logarithmic.

iterator nth(size_type n) noexcept;

Requires: size() >= n.

Effects: Returns an iterator to the nth element from the beginning of the container. Returns end() if n == size().

Throws: Nothing.

Complexity: Constant.

Note: Non-standard extension

const_iterator nth(size_type n) const noexcept;

Requires: size() >= n.

Effects: Returns a const_iterator to the nth element from the beginning of the container. Returns end() if n == size().

Throws: Nothing.

Complexity: Constant.

Note: Non-standard extension

size_type index_of(iterator p) noexcept;

Requires: size() >= n.

Effects: Returns an iterator to the nth element from the beginning of the container. Returns end() if n == size().

Throws: Nothing.

Complexity: Constant.

Note: Non-standard extension

size_type index_of(const_iterator p) const noexcept;

Requires: begin() <= p <= end().

Effects: Returns the index of the element pointed by p and size() if p == end().

Throws: Nothing.

Complexity: Constant.

Note: Non-standard extension

size_type count(const key_type & x) const;

Returns: The number of elements with key equivalent to x.

Complexity: log(size())+count(k)

iterator lower_bound(const key_type & x);

Returns: An iterator pointing to the first element with key not less than k, or a.end() if such an element is not found.

Complexity: Logarithmic

const_iterator lower_bound(const key_type & x) const;

Returns: A const iterator pointing to the first element with key not less than k, or a.end() if such an element is not found.

Complexity: Logarithmic

iterator upper_bound(const key_type & x);

Returns: An iterator pointing to the first element with key not less than x, or end() if such an element is not found.

Complexity: Logarithmic

const_iterator upper_bound(const key_type & x) const;

Returns: A const iterator pointing to the first element with key not less than x, or end() if such an element is not found.

Complexity: Logarithmic

std::pair< const_iterator, const_iterator > 
equal_range(const key_type & x) const;

Effects: Equivalent to std::make_pair(this->lower_bound(k), this->upper_bound(k)).

Complexity: Logarithmic

std::pair< iterator, iterator > equal_range(const key_type & x);

Effects: Equivalent to std::make_pair(this->lower_bound(k), this->upper_bound(k)).

Complexity: Logarithmic

friend bool operator==(const flat_set & x, const flat_set & y);

Effects: Returns true if x and y are equal

Complexity: Linear to the number of elements in the container.

friend bool operator!=(const flat_set & x, const flat_set & y);

Effects: Returns true if x and y are unequal

Complexity: Linear to the number of elements in the container.

friend bool operator<(const flat_set & x, const flat_set & y);

Effects: Returns true if x is less than y

Complexity: Linear to the number of elements in the container.

friend bool operator>(const flat_set & x, const flat_set & y);

Effects: Returns true if x is greater than y

Complexity: Linear to the number of elements in the container.

friend bool operator<=(const flat_set & x, const flat_set & y);

Effects: Returns true if x is equal or less than y

Complexity: Linear to the number of elements in the container.

friend bool operator>=(const flat_set & x, const flat_set & y);

Effects: Returns true if x is equal or greater than y

Complexity: Linear to the number of elements in the container.

friend void swap(flat_set & x, flat_set & y);

Effects: x.swap(y)

Complexity: Constant.