#include <initializer_list>
 
namespace std {
 
template <class T, class Allocator = allocator<T> > class forward_list;
 
template <class T, class Allocator>
    bool operator==(const forward_list<T,Allocator>& x, 
                            const forward_list<T,Allocator>& y);
template <class T, class Allocator>
    bool operator< (const forward_list<T,Allocator>& x, 
                    const forward_list<T,Allocator>& y);
template <class T, class Allocator>
    bool operator!=(const forward_list<T,Allocator>& x, 
                        const forward_list<T,Allocator>& y);
template <class T, class Allocator>
    bool operator> (const forward_list<T,Allocator>& x, 
                    const forward_list<T,Allocator>& y);
template <class T, class Allocator>
    bool operator>=(const forward_list<T,Allocator>& x, 
                        const forward_list<T,Allocator>& y);
template <class T, class Allocator>
    bool operator<=(const forward_list<T,Allocator>& x, 
                        const forward_list<T,Allocator>& y);
 
template <class T, class Allocator>
    void swap(forward_list<T,Allocator>& x, forward_list<T,Allocator>& y);
 
}

template <class T, class Allocator = allocator<T> >
class forward_list {
public:
    // types:
    typedef value_type&                                         reference;
    typedef const value_type&                                   const_reference;
    typedef /*implementation-defined*/                          iterator;
    typedef /*implementation-defined*/                          const_iterator; 
    typedef /*implementation-defined*/                          size_type;
    typedef /*implementation-defined*/                          difference_type;
    typedef T                                                   value_type;
    typedef Allocator                                           allocator_type;
    typedef typename allocator_traits<Allocator>::pointer       pointer;
    typedef typename allocator_traits<Allocator>::const_pointer const_pointer;
 
    // construct/copy/destroy:
    explicit forward_list(const Allocator& = Allocator());
    explicit forward_list(size_type n);
    forward_list(size_type n, const T& value,const Allocator& = Allocator());
    template <class InputIterator>
        forward_list(InputIterator first, InputIterator last,
                     const Allocator& = Allocator());
    forward_list(const forward_list<T,Allocator>& x);
    forward_list(forward_list&&);
    forward_list(const forward_list&, const Allocator&);
    forward_list(forward_list&&, const Allocator&);
    forward_list(initializer_list<T>, const Allocator& = Allocator());
 
    ~forward_list();
    forward_list<T,Allocator>& operator=(const forward_list<T,Allocator>& x);
    forward_list<T,Allocator>& operator=(forward_list<T,Allocator>&& x);
    forward_list& operator=(initializer_list<T>);
    template <class InputIterator>
        void assign(InputIterator first, InputIterator last);
    void assign(size_type n, const T& t);
    void assign(initializer_list<T>);
    allocator_type get_allocator() const noexcept;
 
    // iterators:
    iterator                before_begin() noexcept;
    const_iterator          before_begin() const noexcept;
    iterator                begin() noexcept;
    const_iterator          begin() const noexcept;
    iterator                end() noexcept;
    const_iterator          end() const noexcept;
 
    const_iterator          cbegin() noexcept;
    const_iterator          cbefore_begin() const noexcept;
    const_iterator          cend() noexcept;
 
    // capacity:
    size_type max_size() const noexcept;
    bool      empty() const noexcept;
 
    // element access:
    reference       front();
    const_reference front() const;
 
    // modifiers:
    template <class... Args> void emplace_front(Args&&... args);
 
    void push_front(const T& x);
    void push_front(T&& x);
    void pop_front();
 
    template <class... Args> 
        iterator emplace_after(const_iterator position, Args&&... args);
    iterator insert_after(const_iterator position, const T& x);
    iterator insert_after(const_iterator position, T&& x);
 
    iterator insert_after(const_iterator position, size_type n, const T& x);
    template <class InputIterator>
        iterator insert_after(const_iterator position, InputIterator first, 
                              InputIterator last);
    iterator insert_after(const_iterator position, initializer_list<T> il);
 
    iterator erase_after(const_iterator position);
    iterator erase_after(const_iterator position, iterator last);
    void swap(forward_list<T,Allocator>&);
 
    void resize(size_type sz);
    void resize(size_type sz, const value_type& c);
    void clear() noexcept;
 
    // forward_list operations:
    void splice_after(const_iterator position, forward_list<T,Allocator>& x);
    void splice_after(const_iterator position, forward_list<T,Allocator>&& x);
    void splice_after(const_iterator position, forward_list<T,Allocator>& x,
                    const_iterator i);
    void splice_after(const_iterator position, forward_list<T,Allocator>&& x,
                    const_iterator i);
    void splice_after(const_iterator position, forward_list<T,Allocator>& x,
                    const_iterator first, const_iterator last);
    void splice_after(const_iterator position, forward_list<T,Allocator>&& x,
                    const_iterator first, const_iterator last);
 
    void remove(const T& value);
    template <class Predicate> void remove_if(Predicate pred);
 
    void unique();
    template <class BinaryPredicate> void unique(BinaryPredicate binary_pred);
 
    void merge(forward_list<T,Allocator>& x);
    void merge(forward_list<T,Allocator>&& x);
    template <class Compare> void merge(forward_list<T,Allocator>& x, Compare comp);
    template <class Compare> void merge(forward_list<T,Allocator>&& x, Compare comp);
 
    void sort();
    template <class Compare> void sort(Compare comp);
    void reverse() noexcept;
};