include/memory

// -*- C++ -*-
//===-------------------------- memory ------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_MEMORY
#define _LIBCPP_MEMORY

/*
 memory synopsis

namespace std
{

struct allocator_arg_t { };
inline constexpr allocator_arg_t allocator_arg = allocator_arg_t();

template <class T, class Alloc> struct uses_allocator;

template <class Ptr>
struct pointer_traits
{
 typedef Ptr pointer;
 typedef <details> element_type;
 typedef <details> difference_type;

 template <class U> using rebind = <details>;

 static pointer pointer_to(<details>);
};

template <class T>
struct pointer_traits<T*>
{
 typedef T* pointer;
 typedef T element_type;
 typedef ptrdiff_t difference_type;

 template <class U> using rebind = U*;

 static pointer pointer_to(<details>) noexcept;
};

template <class T> constexpr T* to_address(T* p) noexcept; // C++20
template <class Ptr> auto to_address(const Ptr& p) noexcept; // C++20

template <class Alloc>
struct allocator_traits
{
 typedef Alloc allocator_type;
 typedef typename allocator_type::value_type
 value_type;

 typedef Alloc::pointer | value_type* pointer;
 typedef Alloc::const_pointer
 | pointer_traits<pointer>::rebind<const value_type>
 const_pointer;
 typedef Alloc::void_pointer
 | pointer_traits<pointer>::rebind<void>
 void_pointer;
 typedef Alloc::const_void_pointer
 | pointer_traits<pointer>::rebind<const void>
 const_void_pointer;
 typedef Alloc::difference_type
 | pointer_traits<pointer>::difference_type
 difference_type;
 typedef Alloc::size_type
 | make_unsigned<difference_type>::type
 size_type;
 typedef Alloc::propagate_on_container_copy_assignment
 | false_type propagate_on_container_copy_assignment;
 typedef Alloc::propagate_on_container_move_assignment
 | false_type propagate_on_container_move_assignment;
 typedef Alloc::propagate_on_container_swap
 | false_type propagate_on_container_swap;
 typedef Alloc::is_always_equal
 | is_empty is_always_equal;

 template <class T> using rebind_alloc = Alloc::rebind<U>::other | Alloc<T, Args...>;
 template <class T> using rebind_traits = allocator_traits<rebind_alloc<T>>;

 static pointer allocate(allocator_type& a, size_type n); // [[nodiscard]] in C++20
 static pointer allocate(allocator_type& a, size_type n, const_void_pointer hint); // [[nodiscard]] in C++20

 static void deallocate(allocator_type& a, pointer p, size_type n) noexcept;

 template <class T, class... Args>
 static void construct(allocator_type& a, T* p, Args&&... args);

 template <class T>
 static void destroy(allocator_type& a, T* p);

 static size_type max_size(const allocator_type& a); // noexcept in C++14

 static allocator_type
 select_on_container_copy_construction(const allocator_type& a);
};

template <>
class allocator<void>
{
public:
 typedef void* pointer;
 typedef const void* const_pointer;
 typedef void value_type;

 template <class _Up> struct rebind {typedef allocator<_Up> other;};
};

template <class T>
class allocator
{
public:
 typedef size_t size_type;
 typedef ptrdiff_t difference_type;
 typedef T* pointer;
 typedef const T* const_pointer;
 typedef typename add_lvalue_reference<T>::type reference;
 typedef typename add_lvalue_reference<const T>::type const_reference;
 typedef T value_type;

 template <class U> struct rebind {typedef allocator<U> other;};

 constexpr allocator() noexcept; // constexpr in C++20
 constexpr allocator(const allocator&) noexcept; // constexpr in C++20
 template <class U>
 constexpr allocator(const allocator<U>&) noexcept; // constexpr in C++20
 ~allocator();
 pointer address(reference x) const noexcept;
 const_pointer address(const_reference x) const noexcept;
 pointer allocate(size_type, allocator<void>::const_pointer hint = 0);
 void deallocate(pointer p, size_type n) noexcept;
 size_type max_size() const noexcept;
 template<class U, class... Args>
 void construct(U* p, Args&&... args);
 template <class U>
 void destroy(U* p);
};

template <class T, class U>
bool operator==(const allocator<T>&, const allocator<U>&) noexcept;

template <class T, class U>
bool operator!=(const allocator<T>&, const allocator<U>&) noexcept;

template <class OutputIterator, class T>
class raw_storage_iterator
 : public iterator<output_iterator_tag,
 T, // purposefully not C++03
 ptrdiff_t, // purposefully not C++03
 T*, // purposefully not C++03
 raw_storage_iterator&> // purposefully not C++03
{
public:
 explicit raw_storage_iterator(OutputIterator x);
 raw_storage_iterator& operator*();
 raw_storage_iterator& operator=(const T& element);
 raw_storage_iterator& operator++();
 raw_storage_iterator operator++(int);
};

template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
template <class T> void return_temporary_buffer(T* p) noexcept;

template <class T> T* addressof(T& r) noexcept;
template <class T> T* addressof(const T&& r) noexcept = delete;

template <class InputIterator, class ForwardIterator>
ForwardIterator
uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);

template <class InputIterator, class Size, class ForwardIterator>
ForwardIterator
uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);

template <class ForwardIterator, class T>
void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);

template <class ForwardIterator, class Size, class T>
ForwardIterator
uninitialized_fill_n(ForwardIterator first, Size n, const T& x);

template <class T>
void destroy_at(T* location);

template <class ForwardIterator>
 void destroy(ForwardIterator first, ForwardIterator last);

template <class ForwardIterator, class Size>
 ForwardIterator destroy_n(ForwardIterator first, Size n);

template <class InputIterator, class ForwardIterator>
 ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);

template <class InputIterator, class Size, class ForwardIterator>
 pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);

template <class ForwardIterator>
 void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);

template <class ForwardIterator, class Size>
 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);

template <class ForwardIterator>
 void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);

template <class ForwardIterator, class Size>
 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);

template <class Y> struct auto_ptr_ref {}; // removed in C++17

template<class X>
class auto_ptr // removed in C++17
{
public:
 typedef X element_type;

 explicit auto_ptr(X* p =0) throw();
 auto_ptr(auto_ptr&) throw();
 template<class Y> auto_ptr(auto_ptr<Y>&) throw();
 auto_ptr& operator=(auto_ptr&) throw();
 template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
 auto_ptr& operator=(auto_ptr_ref<X> r) throw();
 ~auto_ptr() throw();

 typename add_lvalue_reference<X>::type operator*() const throw();
 X* operator->() const throw();
 X* get() const throw();
 X* release() throw();
 void reset(X* p =0) throw();

 auto_ptr(auto_ptr_ref<X>) throw();
 template<class Y> operator auto_ptr_ref<Y>() throw();
 template<class Y> operator auto_ptr<Y>() throw();
};

template <class T>
struct default_delete
{
 constexpr default_delete() noexcept = default;
 template <class U> default_delete(const default_delete<U>&) noexcept;

 void operator()(T*) const noexcept;
};

template <class T>
struct default_delete<T[]>
{
 constexpr default_delete() noexcept = default;
 void operator()(T*) const noexcept;
 template <class U> void operator()(U*) const = delete;
};

template <class T, class D = default_delete<T>>
class unique_ptr
{
public:
 typedef see below pointer;
 typedef T element_type;
 typedef D deleter_type;

 // constructors
 constexpr unique_ptr() noexcept;
 explicit unique_ptr(pointer p) noexcept;
 unique_ptr(pointer p, see below d1) noexcept;
 unique_ptr(pointer p, see below d2) noexcept;
 unique_ptr(unique_ptr&& u) noexcept;
 unique_ptr(nullptr_t) noexcept : unique_ptr() { }
 template <class U, class E>
 unique_ptr(unique_ptr<U, E>&& u) noexcept;
 template <class U>
 unique_ptr(auto_ptr<U>&& u) noexcept; // removed in C++17

 // destructor
 ~unique_ptr();

 // assignment
 unique_ptr& operator=(unique_ptr&& u) noexcept;
 template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
 unique_ptr& operator=(nullptr_t) noexcept;

 // observers
 typename add_lvalue_reference<T>::type operator*() const;
 pointer operator->() const noexcept;
 pointer get() const noexcept;
 deleter_type& get_deleter() noexcept;
 const deleter_type& get_deleter() const noexcept;
 explicit operator bool() const noexcept;

 // modifiers
 pointer release() noexcept;
 void reset(pointer p = pointer()) noexcept;
 void swap(unique_ptr& u) noexcept;
};

template <class T, class D>
class unique_ptr<T[], D>
{
public:
 typedef implementation-defined pointer;
 typedef T element_type;
 typedef D deleter_type;

 // constructors
 constexpr unique_ptr() noexcept;
 explicit unique_ptr(pointer p) noexcept;
 unique_ptr(pointer p, see below d) noexcept;
 unique_ptr(pointer p, see below d) noexcept;
 unique_ptr(unique_ptr&& u) noexcept;
 unique_ptr(nullptr_t) noexcept : unique_ptr() { }

 // destructor
 ~unique_ptr();

 // assignment
 unique_ptr& operator=(unique_ptr&& u) noexcept;
 unique_ptr& operator=(nullptr_t) noexcept;

 // observers
 T& operator[](size_t i) const;
 pointer get() const noexcept;
 deleter_type& get_deleter() noexcept;
 const deleter_type& get_deleter() const noexcept;
 explicit operator bool() const noexcept;

 // modifiers
 pointer release() noexcept;
 void reset(pointer p = pointer()) noexcept;
 void reset(nullptr_t) noexcept;
 template <class U> void reset(U) = delete;
 void swap(unique_ptr& u) noexcept;
};

template <class T, class D>
 void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;

template <class T1, class D1, class T2, class D2>
 bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
template <class T1, class D1, class T2, class D2>
 bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
template <class T1, class D1, class T2, class D2>
 bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
template <class T1, class D1, class T2, class D2>
 bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
template <class T1, class D1, class T2, class D2>
 bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
template <class T1, class D1, class T2, class D2>
 bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);

template <class T, class D>
 bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
template <class T, class D>
 bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
template <class T, class D>
 bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
template <class T, class D>
 bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;

template <class T, class D>
 bool operator<(const unique_ptr<T, D>& x, nullptr_t);
template <class T, class D>
 bool operator<(nullptr_t, const unique_ptr<T, D>& y);
template <class T, class D>
 bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
template <class T, class D>
 bool operator<=(nullptr_t, const unique_ptr<T, D>& y);
template <class T, class D>
 bool operator>(const unique_ptr<T, D>& x, nullptr_t);
template <class T, class D>
 bool operator>(nullptr_t, const unique_ptr<T, D>& y);
template <class T, class D>
 bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
template <class T, class D>
 bool operator>=(nullptr_t, const unique_ptr<T, D>& y);

class bad_weak_ptr
 : public std::exception
{
 bad_weak_ptr() noexcept;
};

template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args); // C++14
template<class T> unique_ptr<T> make_unique(size_t n); // C++14
template<class T, class... Args> unspecified make_unique(Args&&...) = delete; // C++14, T == U[N]

template<class E, class T, class Y, class D>
 basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);

template<class T>
class shared_ptr
{
public:
 typedef T element_type;
 typedef weak_ptr<T> weak_type; // C++17

 // constructors:
 constexpr shared_ptr() noexcept;
 template<class Y> explicit shared_ptr(Y* p);
 template<class Y, class D> shared_ptr(Y* p, D d);
 template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
 template <class D> shared_ptr(nullptr_t p, D d);
 template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
 template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
 shared_ptr(const shared_ptr& r) noexcept;
 template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
 shared_ptr(shared_ptr&& r) noexcept;
 template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
 template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
 template<class Y> shared_ptr(auto_ptr<Y>&& r); // removed in C++17
 template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
 shared_ptr(nullptr_t) : shared_ptr() { }

 // destructor:
 ~shared_ptr();

 // assignment:
 shared_ptr& operator=(const shared_ptr& r) noexcept;
 template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
 shared_ptr& operator=(shared_ptr&& r) noexcept;
 template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
 template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
 template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);

 // modifiers:
 void swap(shared_ptr& r) noexcept;
 void reset() noexcept;
 template<class Y> void reset(Y* p);
 template<class Y, class D> void reset(Y* p, D d);
 template<class Y, class D, class A> void reset(Y* p, D d, A a);

 // observers:
 T* get() const noexcept;
 T& operator*() const noexcept;
 T* operator->() const noexcept;
 long use_count() const noexcept;
 bool unique() const noexcept;
 explicit operator bool() const noexcept;
 template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
 template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
};

// shared_ptr comparisons:
template<class T, class U>
 bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
template<class T, class U>
 bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
template<class T, class U>
 bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
template<class T, class U>
 bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
template<class T, class U>
 bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
template<class T, class U>
 bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;

template <class T>
 bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
template <class T>
 bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;
template <class T>
 bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;
template <class T>
 bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;
template <class T>
 bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;
template <class T>
bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
template <class T>
 bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;
template <class T>
 bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;
template <class T>
 bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;
template <class T>
 bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;
template <class T>
 bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;
template <class T>
 bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;

// shared_ptr specialized algorithms:
template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;

// shared_ptr casts:
template<class T, class U>
 shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
template<class T, class U>
 shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
template<class T, class U>
 shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;

// shared_ptr I/O:
template<class E, class T, class Y>
 basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);

// shared_ptr get_deleter:
template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;

template<class T, class... Args>
 shared_ptr<T> make_shared(Args&&... args);
template<class T, class A, class... Args>
 shared_ptr<T> allocate_shared(const A& a, Args&&... args);

template<class T>
class weak_ptr
{
public:
 typedef T element_type;

 // constructors
 constexpr weak_ptr() noexcept;
 template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
 weak_ptr(weak_ptr const& r) noexcept;
 template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
 weak_ptr(weak_ptr&& r) noexcept; // C++14
 template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14

 // destructor
 ~weak_ptr();

 // assignment
 weak_ptr& operator=(weak_ptr const& r) noexcept;
 template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
 template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
 weak_ptr& operator=(weak_ptr&& r) noexcept; // C++14
 template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14

 // modifiers
 void swap(weak_ptr& r) noexcept;
 void reset() noexcept;

 // observers
 long use_count() const noexcept;
 bool expired() const noexcept;
 shared_ptr<T> lock() const noexcept;
 template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
 template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
};

// weak_ptr specialized algorithms:
template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;

// class owner_less:
template<class T> struct owner_less;

template<class T>
struct owner_less<shared_ptr<T>>
 : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
{
 typedef bool result_type;
 bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
 bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
 bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
};

template<class T>
struct owner_less<weak_ptr<T>>
 : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
{
 typedef bool result_type;
 bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
 bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
 bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
};

template <> // Added in C++14
struct owner_less<void>
{
 template <class _Tp, class _Up>
 bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
 template <class _Tp, class _Up>
 bool operator()( shared_ptr<_Tp> const& __x, weak_ptr<_Up> const& __y) const noexcept;
 template <class _Tp, class _Up>
 bool operator()( weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
 template <class _Tp, class _Up>
 bool operator()( weak_ptr<_Tp> const& __x, weak_ptr<_Up> const& __y) const noexcept;

 typedef void is_transparent;
};

template<class T>
class enable_shared_from_this
{
protected:
 constexpr enable_shared_from_this() noexcept;
 enable_shared_from_this(enable_shared_from_this const&) noexcept;
 enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
 ~enable_shared_from_this();
public:
 shared_ptr<T> shared_from_this();
 shared_ptr<T const> shared_from_this() const;
};

template<class T>
 bool atomic_is_lock_free(const shared_ptr<T>* p);
template<class T>
 shared_ptr<T> atomic_load(const shared_ptr<T>* p);
template<class T>
 shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
template<class T>
 void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
template<class T>
 void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
template<class T>
 shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
template<class T>
 shared_ptr<T>
 atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
template<class T>
 bool
 atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
template<class T>
 bool
 atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
template<class T>
 bool
 atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
 shared_ptr<T> w, memory_order success,
 memory_order failure);
template<class T>
 bool
 atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
 shared_ptr<T> w, memory_order success,
 memory_order failure);
// Hash support
template <class T> struct hash;
template <class T, class D> struct hash<unique_ptr<T, D> >;
template <class T> struct hash<shared_ptr<T> >;

template <class T, class Alloc>
 inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;

// Pointer safety
enum class pointer_safety { relaxed, preferred, strict };
void declare_reachable(void *p);
template <class T> T *undeclare_reachable(T *p);
void declare_no_pointers(char *p, size_t n);
void undeclare_no_pointers(char *p, size_t n);
pointer_safety get_pointer_safety() noexcept;

void* align(size_t alignment, size_t size, void*& ptr, size_t& space);

} // std

*/

#include <__config>
#include <type_traits>
#include <typeinfo>
#include <cstddef>
#include <cstdint>
#include <new>
#include <utility>
#include <limits>
#include <iterator>
#include <__functional_base>
#include <iosfwd>
#include <tuple>
#include <stdexcept>
#include <cstring>
#include <cassert>
#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
# include <atomic>
#endif
#include <version>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif

_LIBCPP_PUSH_MACROS
#include <__undef_macros>


_LIBCPP_BEGIN_NAMESPACE_STD

template <class _ValueType>
inline _LIBCPP_INLINE_VISIBILITY
_ValueType __libcpp_relaxed_load(_ValueType const* __value) {
#if !defined(_LIBCPP_HAS_NO_THREADS) && \
 defined(__ATOMIC_RELAXED) && \
 (__has_builtin(__atomic_load_n) || _GNUC_VER >= 407)
 return __atomic_load_n(__value, __ATOMIC_RELAXED);
#else
 return *__value;
#endif
}

template <class _ValueType>
inline _LIBCPP_INLINE_VISIBILITY
_ValueType __libcpp_acquire_load(_ValueType const* __value) {
#if !defined(_LIBCPP_HAS_NO_THREADS) && \
 defined(__ATOMIC_ACQUIRE) && \
 (__has_builtin(__atomic_load_n) || _GNUC_VER >= 407)
 return __atomic_load_n(__value, __ATOMIC_ACQUIRE);
#else
 return *__value;
#endif
}

// addressof moved to <type_traits>

template <class _Tp> class allocator;

template <>
class _LIBCPP_TEMPLATE_VIS allocator<void>
{
public:
 typedef void* pointer;
 typedef const void* const_pointer;
 typedef void value_type;

 template <class _Up> struct rebind {typedef allocator<_Up> other;};
};

template <>
class _LIBCPP_TEMPLATE_VIS allocator<const void>
{
public:
 typedef const void* pointer;
 typedef const void* const_pointer;
 typedef const void value_type;

 template <class _Up> struct rebind {typedef allocator<_Up> other;};
};

// pointer_traits

template <class _Tp, class = void>
struct __has_element_type : false_type {};

template <class _Tp>
struct __has_element_type<_Tp,
 typename __void_t<typename _Tp::element_type>::type> : true_type {};

template <class _Ptr, bool = __has_element_type<_Ptr>::value>
struct __pointer_traits_element_type;

template <class _Ptr>
struct __pointer_traits_element_type<_Ptr, true>
{
 typedef typename _Ptr::element_type type;
};

#ifndef _LIBCPP_HAS_NO_VARIADICS

template <template <class, class...> class _Sp, class _Tp, class ..._Args>
struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, true>
{
 typedef typename _Sp<_Tp, _Args...>::element_type type;
};

template <template <class, class...> class _Sp, class _Tp, class ..._Args>
struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, false>
{
 typedef _Tp type;
};

#else // _LIBCPP_HAS_NO_VARIADICS

template <template <class> class _Sp, class _Tp>
struct __pointer_traits_element_type<_Sp<_Tp>, true>
{
 typedef typename _Sp<_Tp>::element_type type;
};

template <template <class> class _Sp, class _Tp>
struct __pointer_traits_element_type<_Sp<_Tp>, false>
{
 typedef _Tp type;
};

template <template <class, class> class _Sp, class _Tp, class _A0>
struct __pointer_traits_element_type<_Sp<_Tp, _A0>, true>
{
 typedef typename _Sp<_Tp, _A0>::element_type type;
};

template <template <class, class> class _Sp, class _Tp, class _A0>
struct __pointer_traits_element_type<_Sp<_Tp, _A0>, false>
{
 typedef _Tp type;
};

template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, true>
{
 typedef typename _Sp<_Tp, _A0, _A1>::element_type type;
};

template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, false>
{
 typedef _Tp type;
};

template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
 class _A1, class _A2>
struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, true>
{
 typedef typename _Sp<_Tp, _A0, _A1, _A2>::element_type type;
};

template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
 class _A1, class _A2>
struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, false>
{
 typedef _Tp type;
};

#endif // _LIBCPP_HAS_NO_VARIADICS

template <class _Tp, class = void>
struct __has_difference_type : false_type {};

template <class _Tp>
struct __has_difference_type<_Tp,
 typename __void_t<typename _Tp::difference_type>::type> : true_type {};

template <class _Ptr, bool = __has_difference_type<_Ptr>::value>
struct __pointer_traits_difference_type
{
 typedef ptrdiff_t type;
};

template <class _Ptr>
struct __pointer_traits_difference_type<_Ptr, true>
{
 typedef typename _Ptr::difference_type type;
};

template <class _Tp, class _Up>
struct __has_rebind
{
private:
 struct __two {char __lx; char __lxx;};
 template <class _Xp> static __two __test(...);
 template <class _Xp> static char __test(typename _Xp::template rebind<_Up>* = 0);
public:
 static const bool value = sizeof(__test<_Tp>(0)) == 1;
};

template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
struct __pointer_traits_rebind
{
#ifndef _LIBCPP_CXX03_LANG
 typedef typename _Tp::template rebind<_Up> type;
#else
 typedef typename _Tp::template rebind<_Up>::other type;
#endif
};

#ifndef _LIBCPP_HAS_NO_VARIADICS

template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, true>
{
#ifndef _LIBCPP_CXX03_LANG
 typedef typename _Sp<_Tp, _Args...>::template rebind<_Up> type;
#else
 typedef typename _Sp<_Tp, _Args...>::template rebind<_Up>::other type;
#endif
};

template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, false>
{
 typedef _Sp<_Up, _Args...> type;
};

#else // _LIBCPP_HAS_NO_VARIADICS

template <template <class> class _Sp, class _Tp, class _Up>
struct __pointer_traits_rebind<_Sp<_Tp>, _Up, true>
{
#ifndef _LIBCPP_CXX03_LANG
 typedef typename _Sp<_Tp>::template rebind<_Up> type;
#else
 typedef typename _Sp<_Tp>::template rebind<_Up>::other type;
#endif
};

template <template <class> class _Sp, class _Tp, class _Up>
struct __pointer_traits_rebind<_Sp<_Tp>, _Up, false>
{
 typedef _Sp<_Up> type;
};

template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, true>
{
#ifndef _LIBCPP_CXX03_LANG
 typedef typename _Sp<_Tp, _A0>::template rebind<_Up> type;
#else
 typedef typename _Sp<_Tp, _A0>::template rebind<_Up>::other type;
#endif
};

template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, false>
{
 typedef _Sp<_Up, _A0> type;
};

template <template <class, class, class> class _Sp, class _Tp, class _A0,
 class _A1, class _Up>
struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, true>
{
#ifndef _LIBCPP_CXX03_LANG
 typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up> type;
#else
 typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up>::other type;
#endif
};

template <template <class, class, class> class _Sp, class _Tp, class _A0,
 class _A1, class _Up>
struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, false>
{
 typedef _Sp<_Up, _A0, _A1> type;
};

template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
 class _A1, class _A2, class _Up>
struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, true>
{
#ifndef _LIBCPP_CXX03_LANG
 typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up> type;
#else
 typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
#endif
};

template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
 class _A1, class _A2, class _Up>
struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, false>
{
 typedef _Sp<_Up, _A0, _A1, _A2> type;
};

#endif // _LIBCPP_HAS_NO_VARIADICS

template <class _Ptr>
struct _LIBCPP_TEMPLATE_VIS pointer_traits
{
 typedef _Ptr pointer;
 typedef typename __pointer_traits_element_type<pointer>::type element_type;
 typedef typename __pointer_traits_difference_type<pointer>::type difference_type;

#ifndef _LIBCPP_CXX03_LANG
 template <class _Up> using rebind = typename __pointer_traits_rebind<pointer, _Up>::type;
#else
 template <class _Up> struct rebind
 {typedef typename __pointer_traits_rebind<pointer, _Up>::type other;};
#endif // _LIBCPP_CXX03_LANG

private:
 struct __nat {};
public:
 _LIBCPP_INLINE_VISIBILITY
 static pointer pointer_to(typename conditional<is_void<element_type>::value,
 __nat, element_type>::type& __r)
 {return pointer::pointer_to(__r);}
};

template <class _Tp>
struct _LIBCPP_TEMPLATE_VIS pointer_traits<_Tp*>
{
 typedef _Tp* pointer;
 typedef _Tp element_type;
 typedef ptrdiff_t difference_type;

#ifndef _LIBCPP_CXX03_LANG
 template <class _Up> using rebind = _Up*;
#else
 template <class _Up> struct rebind {typedef _Up* other;};
#endif

private:
 struct __nat {};
public:
 _LIBCPP_INLINE_VISIBILITY
 static pointer pointer_to(typename conditional<is_void<element_type>::value,
 __nat, element_type>::type& __r) _NOEXCEPT
 {return _VSTD::addressof(__r);}
};

template <class _From, class _To>
struct __rebind_pointer {
#ifndef _LIBCPP_CXX03_LANG
 typedef typename pointer_traits<_From>::template rebind<_To> type;
#else
 typedef typename pointer_traits<_From>::template rebind<_To>::other type;
#endif
};

// allocator_traits

template <class _Tp, class = void>
struct __has_pointer_type : false_type {};

template <class _Tp>
struct __has_pointer_type<_Tp,
 typename __void_t<typename _Tp::pointer>::type> : true_type {};

namespace __pointer_type_imp
{

template <class _Tp, class _Dp, bool = __has_pointer_type<_Dp>::value>
struct __pointer_type
{
 typedef typename _Dp::pointer type;
};

template <class _Tp, class _Dp>
struct __pointer_type<_Tp, _Dp, false>
{
 typedef _Tp* type;
};

} // __pointer_type_imp

template <class _Tp, class _Dp>
struct __pointer_type
{
 typedef typename __pointer_type_imp::__pointer_type<_Tp, typename remove_reference<_Dp>::type>::type type;
};

template <class _Tp, class = void>
struct __has_const_pointer : false_type {};

template <class _Tp>
struct __has_const_pointer<_Tp,
 typename __void_t<typename _Tp::const_pointer>::type> : true_type {};

template <class _Tp, class _Ptr, class _Alloc, bool = __has_const_pointer<_Alloc>::value>
struct __const_pointer
{
 typedef typename _Alloc::const_pointer type;
};

template <class _Tp, class _Ptr, class _Alloc>
struct __const_pointer<_Tp, _Ptr, _Alloc, false>
{
#ifndef _LIBCPP_CXX03_LANG
 typedef typename pointer_traits<_Ptr>::template rebind<const _Tp> type;
#else
 typedef typename pointer_traits<_Ptr>::template rebind<const _Tp>::other type;
#endif
};

template <class _Tp, class = void>
struct __has_void_pointer : false_type {};

template <class _Tp>
struct __has_void_pointer<_Tp,
 typename __void_t<typename _Tp::void_pointer>::type> : true_type {};

template <class _Ptr, class _Alloc, bool = __has_void_pointer<_Alloc>::value>
struct __void_pointer
{
 typedef typename _Alloc::void_pointer type;
};

template <class _Ptr, class _Alloc>
struct __void_pointer<_Ptr, _Alloc, false>
{
#ifndef _LIBCPP_CXX03_LANG
 typedef typename pointer_traits<_Ptr>::template rebind<void> type;
#else
 typedef typename pointer_traits<_Ptr>::template rebind<void>::other type;
#endif
};

template <class _Tp, class = void>
struct __has_const_void_pointer : false_type {};

template <class _Tp>
struct __has_const_void_pointer<_Tp,
 typename __void_t<typename _Tp::const_void_pointer>::type> : true_type {};

template <class _Ptr, class _Alloc, bool = __has_const_void_pointer<_Alloc>::value>
struct __const_void_pointer
{
 typedef typename _Alloc::const_void_pointer type;
};

template <class _Ptr, class _Alloc>
struct __const_void_pointer<_Ptr, _Alloc, false>
{
#ifndef _LIBCPP_CXX03_LANG
 typedef typename pointer_traits<_Ptr>::template rebind<const void> type;
#else
 typedef typename pointer_traits<_Ptr>::template rebind<const void>::other type;
#endif
};

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
_Tp*
__to_raw_pointer(_Tp* __p) _NOEXCEPT
{
 return __p;
}

#if _LIBCPP_STD_VER <= 17
template <class _Pointer>
inline _LIBCPP_INLINE_VISIBILITY
typename pointer_traits<_Pointer>::element_type*
__to_raw_pointer(_Pointer __p) _NOEXCEPT
{
 return _VSTD::__to_raw_pointer(__p.operator->());
}
#else
template <class _Pointer>
inline _LIBCPP_INLINE_VISIBILITY
auto
__to_raw_pointer(const _Pointer& __p) _NOEXCEPT
-> decltype(pointer_traits<_Pointer>::to_address(__p))
{
 return pointer_traits<_Pointer>::to_address(__p);
}

template <class _Pointer, class... _None>
inline _LIBCPP_INLINE_VISIBILITY
auto
__to_raw_pointer(const _Pointer& __p, _None...) _NOEXCEPT
{
 return _VSTD::__to_raw_pointer(__p.operator->());
}

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY constexpr
_Tp*
to_address(_Tp* __p) _NOEXCEPT
{
 static_assert(!is_function_v<_Tp>, "_Tp is a function type");
 return __p;
}

template <class _Pointer>
inline _LIBCPP_INLINE_VISIBILITY
auto
to_address(const _Pointer& __p) _NOEXCEPT
{
 return _VSTD::__to_raw_pointer(__p);
}
#endif

template <class _Tp, class = void>
struct __has_size_type : false_type {};

template <class _Tp>
struct __has_size_type<_Tp,
 typename __void_t<typename _Tp::size_type>::type> : true_type {};

template <class _Alloc, class _DiffType, bool = __has_size_type<_Alloc>::value>
struct __size_type
{
 typedef typename make_unsigned<_DiffType>::type type;
};

template <class _Alloc, class _DiffType>
struct __size_type<_Alloc, _DiffType, true>
{
 typedef typename _Alloc::size_type type;
};

template <class _Tp, class = void>
struct __has_propagate_on_container_copy_assignment : false_type {};

template <class _Tp>
struct __has_propagate_on_container_copy_assignment<_Tp,
 typename __void_t<typename _Tp::propagate_on_container_copy_assignment>::type>
 : true_type {};

template <class _Alloc, bool = __has_propagate_on_container_copy_assignment<_Alloc>::value>
struct __propagate_on_container_copy_assignment
{
 typedef false_type type;
};

template <class _Alloc>
struct __propagate_on_container_copy_assignment<_Alloc, true>
{
 typedef typename _Alloc::propagate_on_container_copy_assignment type;
};

template <class _Tp, class = void>
struct __has_propagate_on_container_move_assignment : false_type {};

template <class _Tp>
struct __has_propagate_on_container_move_assignment<_Tp,
 typename __void_t<typename _Tp::propagate_on_container_move_assignment>::type>
 : true_type {};

template <class _Alloc, bool = __has_propagate_on_container_move_assignment<_Alloc>::value>
struct __propagate_on_container_move_assignment
{
 typedef false_type type;
};

template <class _Alloc>
struct __propagate_on_container_move_assignment<_Alloc, true>
{
 typedef typename _Alloc::propagate_on_container_move_assignment type;
};

template <class _Tp, class = void>
struct __has_propagate_on_container_swap : false_type {};

template <class _Tp>
struct __has_propagate_on_container_swap<_Tp,
 typename __void_t<typename _Tp::propagate_on_container_swap>::type>
 : true_type {};

template <class _Alloc, bool = __has_propagate_on_container_swap<_Alloc>::value>
struct __propagate_on_container_swap
{
 typedef false_type type;
};

template <class _Alloc>
struct __propagate_on_container_swap<_Alloc, true>
{
 typedef typename _Alloc::propagate_on_container_swap type;
};

template <class _Tp, class = void>
struct __has_is_always_equal : false_type {};

template <class _Tp>
struct __has_is_always_equal<_Tp,
 typename __void_t<typename _Tp::is_always_equal>::type>
 : true_type {};

template <class _Alloc, bool = __has_is_always_equal<_Alloc>::value>
struct __is_always_equal
{
 typedef typename _VSTD::is_empty<_Alloc>::type type;
};

template <class _Alloc>
struct __is_always_equal<_Alloc, true>
{
 typedef typename _Alloc::is_always_equal type;
};

template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
struct __has_rebind_other
{
private:
 struct __two {char __lx; char __lxx;};
 template <class _Xp> static __two __test(...);
 template <class _Xp> static char __test(typename _Xp::template rebind<_Up>::other* = 0);
public:
 static const bool value = sizeof(__test<_Tp>(0)) == 1;
};

template <class _Tp, class _Up>
struct __has_rebind_other<_Tp, _Up, false>
{
 static const bool value = false;
};

template <class _Tp, class _Up, bool = __has_rebind_other<_Tp, _Up>::value>
struct __allocator_traits_rebind
{
 typedef typename _Tp::template rebind<_Up>::other type;
};

#ifndef _LIBCPP_HAS_NO_VARIADICS

template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, true>
{
 typedef typename _Alloc<_Tp, _Args...>::template rebind<_Up>::other type;
};

template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, false>
{
 typedef _Alloc<_Up, _Args...> type;
};

#else // _LIBCPP_HAS_NO_VARIADICS

template <template <class> class _Alloc, class _Tp, class _Up>
struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, true>
{
 typedef typename _Alloc<_Tp>::template rebind<_Up>::other type;
};

template <template <class> class _Alloc, class _Tp, class _Up>
struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, false>
{
 typedef _Alloc<_Up> type;
};

template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, true>
{
 typedef typename _Alloc<_Tp, _A0>::template rebind<_Up>::other type;
};

template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, false>
{
 typedef _Alloc<_Up, _A0> type;
};

template <template <class, class, class> class _Alloc, class _Tp, class _A0,
 class _A1, class _Up>
struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, true>
{
 typedef typename _Alloc<_Tp, _A0, _A1>::template rebind<_Up>::other type;
};

template <template <class, class, class> class _Alloc, class _Tp, class _A0,
 class _A1, class _Up>
struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, false>
{
 typedef _Alloc<_Up, _A0, _A1> type;
};

template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
 class _A1, class _A2, class _Up>
struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, true>
{
 typedef typename _Alloc<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
};

template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
 class _A1, class _A2, class _Up>
struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, false>
{
 typedef _Alloc<_Up, _A0, _A1, _A2> type;
};

#endif // _LIBCPP_HAS_NO_VARIADICS

#ifndef _LIBCPP_CXX03_LANG

template <class _Alloc, class _SizeType, class _ConstVoidPtr>
auto
__has_allocate_hint_test(_Alloc&& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
 -> decltype((void)__a.allocate(__sz, __p), true_type());

template <class _Alloc, class _SizeType, class _ConstVoidPtr>
auto
__has_allocate_hint_test(const _Alloc& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
 -> false_type;

template <class _Alloc, class _SizeType, class _ConstVoidPtr>
struct __has_allocate_hint
 : integral_constant<bool,
 is_same<
 decltype(_VSTD::__has_allocate_hint_test(declval<_Alloc>(),
 declval<_SizeType>(),
 declval<_ConstVoidPtr>())),
 true_type>::value>
{
};

#else // _LIBCPP_CXX03_LANG

template <class _Alloc, class _SizeType, class _ConstVoidPtr>
struct __has_allocate_hint
 : true_type
{
};

#endif // _LIBCPP_CXX03_LANG

#if !defined(_LIBCPP_CXX03_LANG)

template <class _Alloc, class _Tp, class ..._Args>
decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Tp*>(),
 _VSTD::declval<_Args>()...),
 true_type())
__has_construct_test(_Alloc&& __a, _Tp* __p, _Args&& ...__args);

template <class _Alloc, class _Pointer, class ..._Args>
false_type
__has_construct_test(const _Alloc& __a, _Pointer&& __p, _Args&& ...__args);

template <class _Alloc, class _Pointer, class ..._Args>
struct __has_construct
 : integral_constant<bool,
 is_same<
 decltype(_VSTD::__has_construct_test(declval<_Alloc>(),
 declval<_Pointer>(),
 declval<_Args>()...)),
 true_type>::value>
{
};

template <class _Alloc, class _Pointer>
auto
__has_destroy_test(_Alloc&& __a, _Pointer&& __p)
 -> decltype(__a.destroy(__p), true_type());

template <class _Alloc, class _Pointer>
auto
__has_destroy_test(const _Alloc& __a, _Pointer&& __p)
 -> false_type;

template <class _Alloc, class _Pointer>
struct __has_destroy
 : integral_constant<bool,
 is_same<
 decltype(_VSTD::__has_destroy_test(declval<_Alloc>(),
 declval<_Pointer>())),
 true_type>::value>
{
};

template <class _Alloc>
auto
__has_max_size_test(_Alloc&& __a)
 -> decltype(__a.max_size(), true_type());

template <class _Alloc>
auto
__has_max_size_test(const volatile _Alloc& __a)
 -> false_type;

template <class _Alloc>
struct __has_max_size
 : integral_constant<bool,
 is_same<
 decltype(_VSTD::__has_max_size_test(declval<_Alloc&>())),
 true_type>::value>
{
};

template <class _Alloc>
auto
__has_select_on_container_copy_construction_test(_Alloc&& __a)
 -> decltype(__a.select_on_container_copy_construction(), true_type());

template <class _Alloc>
auto
__has_select_on_container_copy_construction_test(const volatile _Alloc& __a)
 -> false_type;

template <class _Alloc>
struct __has_select_on_container_copy_construction
 : integral_constant<bool,
 is_same<
 decltype(_VSTD::__has_select_on_container_copy_construction_test(declval<_Alloc&>())),
 true_type>::value>
{
};

#else // _LIBCPP_CXX03_LANG

#ifndef _LIBCPP_HAS_NO_VARIADICS

template <class _Alloc, class _Pointer, class ..._Args>
struct __has_construct
 : false_type
{
};

#else // _LIBCPP_HAS_NO_VARIADICS

template <class _Alloc, class _Pointer, class _Args>
struct __has_construct
 : false_type
{
};

#endif // _LIBCPP_HAS_NO_VARIADICS

template <class _Alloc, class _Pointer>
struct __has_destroy
 : false_type
{
};

template <class _Alloc>
struct __has_max_size
 : true_type
{
};

template <class _Alloc>
struct __has_select_on_container_copy_construction
 : false_type
{
};

#endif // _LIBCPP_CXX03_LANG

template <class _Alloc, class _Ptr, bool = __has_difference_type<_Alloc>::value>
struct __alloc_traits_difference_type
{
 typedef typename pointer_traits<_Ptr>::difference_type type;
};

template <class _Alloc, class _Ptr>
struct __alloc_traits_difference_type<_Alloc, _Ptr, true>
{
 typedef typename _Alloc::difference_type type;
};

template <class _Alloc>
struct _LIBCPP_TEMPLATE_VIS allocator_traits
{
 typedef _Alloc allocator_type;
 typedef typename allocator_type::value_type value_type;

 typedef typename __pointer_type<value_type, allocator_type>::type pointer;
 typedef typename __const_pointer<value_type, pointer, allocator_type>::type const_pointer;
 typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
 typedef typename __const_void_pointer<pointer, allocator_type>::type const_void_pointer;

 typedef typename __alloc_traits_difference_type<allocator_type, pointer>::type difference_type;
 typedef typename __size_type<allocator_type, difference_type>::type size_type;

 typedef typename __propagate_on_container_copy_assignment<allocator_type>::type
 propagate_on_container_copy_assignment;
 typedef typename __propagate_on_container_move_assignment<allocator_type>::type
 propagate_on_container_move_assignment;
 typedef typename __propagate_on_container_swap<allocator_type>::type
 propagate_on_container_swap;
 typedef typename __is_always_equal<allocator_type>::type
 is_always_equal;

#ifndef _LIBCPP_CXX03_LANG
 template <class _Tp> using rebind_alloc =
 typename __allocator_traits_rebind<allocator_type, _Tp>::type;
 template <class _Tp> using rebind_traits = allocator_traits<rebind_alloc<_Tp>>;
#else // _LIBCPP_CXX03_LANG
 template <class _Tp> struct rebind_alloc
 {typedef typename __allocator_traits_rebind<allocator_type, _Tp>::type other;};
 template <class _Tp> struct rebind_traits
 {typedef allocator_traits<typename rebind_alloc<_Tp>::other> other;};
#endif // _LIBCPP_CXX03_LANG

 _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
 static pointer allocate(allocator_type& __a, size_type __n)
 {return __a.allocate(__n);}
 _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
 static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer __hint)
 {return __allocate(__a, __n, __hint,
 __has_allocate_hint<allocator_type, size_type, const_void_pointer>());}

 _LIBCPP_INLINE_VISIBILITY
 static void deallocate(allocator_type& __a, pointer __p, size_type __n) _NOEXCEPT
 {__a.deallocate(__p, __n);}

#ifndef _LIBCPP_HAS_NO_VARIADICS
 template <class _Tp, class... _Args>
 _LIBCPP_INLINE_VISIBILITY
 static void construct(allocator_type& __a, _Tp* __p, _Args&&... __args)
 {__construct(__has_construct<allocator_type, _Tp*, _Args...>(),
 __a, __p, _VSTD::forward<_Args>(__args)...);}
#else // _LIBCPP_HAS_NO_VARIADICS
 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY
 static void construct(allocator_type&, _Tp* __p)
 {
 ::new ((void*)__p) _Tp();
 }
 template <class _Tp, class _A0>
 _LIBCPP_INLINE_VISIBILITY
 static void construct(allocator_type&, _Tp* __p, const _A0& __a0)
 {
 ::new ((void*)__p) _Tp(__a0);
 }
 template <class _Tp, class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 static void construct(allocator_type&, _Tp* __p, const _A0& __a0,
 const _A1& __a1)
 {
 ::new ((void*)__p) _Tp(__a0, __a1);
 }
 template <class _Tp, class _A0, class _A1, class _A2>
 _LIBCPP_INLINE_VISIBILITY
 static void construct(allocator_type&, _Tp* __p, const _A0& __a0,
 const _A1& __a1, const _A2& __a2)
 {
 ::new ((void*)__p) _Tp(__a0, __a1, __a2);
 }
#endif // _LIBCPP_HAS_NO_VARIADICS

 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY
 static void destroy(allocator_type& __a, _Tp* __p)
 {__destroy(__has_destroy<allocator_type, _Tp*>(), __a, __p);}

 _LIBCPP_INLINE_VISIBILITY
 static size_type max_size(const allocator_type& __a) _NOEXCEPT
 {return __max_size(__has_max_size<const allocator_type>(), __a);}

 _LIBCPP_INLINE_VISIBILITY
 static allocator_type
 select_on_container_copy_construction(const allocator_type& __a)
 {return __select_on_container_copy_construction(
 __has_select_on_container_copy_construction<const allocator_type>(),
 __a);}

 template <class _Ptr>
 _LIBCPP_INLINE_VISIBILITY
 static
 void
 __construct_forward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2)
 {
 for (; __begin1 != __end1; ++__begin1, ++__begin2)
 construct(__a, _VSTD::__to_raw_pointer(__begin2), _VSTD::move_if_noexcept(*__begin1));
 }

 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY
 static
 typename enable_if
 <
 (is_same<allocator_type, allocator<_Tp> >::value
 || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
 is_trivially_move_constructible<_Tp>::value,
 void
 >::type
 __construct_forward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
 {
 ptrdiff_t _Np = __end1 - __begin1;
 if (_Np > 0)
 {
 _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
 __begin2 += _Np;
 }
 }

 template <class _Iter, class _Ptr>
 _LIBCPP_INLINE_VISIBILITY
 static
 void
 __construct_range_forward(allocator_type& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2)
 {
 for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
 construct(__a, _VSTD::__to_raw_pointer(__begin2), *__begin1);
 }

 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY
 static
 typename enable_if
 <
 (is_same<allocator_type, allocator<_Tp> >::value
 || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
 is_trivially_move_constructible<_Tp>::value,
 void
 >::type
 __construct_range_forward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
 {
 typedef typename remove_const<_Tp>::type _Vp;
 ptrdiff_t _Np = __end1 - __begin1;
 if (_Np > 0)
 {
 _VSTD::memcpy(const_cast<_Vp*>(__begin2), __begin1, _Np * sizeof(_Tp));
 __begin2 += _Np;
 }
 }

 template <class _Ptr>
 _LIBCPP_INLINE_VISIBILITY
 static
 void
 __construct_backward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2)
 {
 while (__end1 != __begin1)
 {
 construct(__a, _VSTD::__to_raw_pointer(__end2-1), _VSTD::move_if_noexcept(*--__end1));
 --__end2;
 }
 }

 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY
 static
 typename enable_if
 <
 (is_same<allocator_type, allocator<_Tp> >::value
 || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
 is_trivially_move_constructible<_Tp>::value,
 void
 >::type
 __construct_backward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __end2)
 {
 ptrdiff_t _Np = __end1 - __begin1;
 __end2 -= _Np;
 if (_Np > 0)
 _VSTD::memcpy(__end2, __begin1, _Np * sizeof(_Tp));
 }

private:

 _LIBCPP_INLINE_VISIBILITY
 static pointer __allocate(allocator_type& __a, size_type __n,
 const_void_pointer __hint, true_type)
 {return __a.allocate(__n, __hint);}
 _LIBCPP_INLINE_VISIBILITY
 static pointer __allocate(allocator_type& __a, size_type __n,
 const_void_pointer, false_type)
 {return __a.allocate(__n);}

#ifndef _LIBCPP_HAS_NO_VARIADICS
 template <class _Tp, class... _Args>
 _LIBCPP_INLINE_VISIBILITY
 static void __construct(true_type, allocator_type& __a, _Tp* __p, _Args&&... __args)
 {__a.construct(__p, _VSTD::forward<_Args>(__args)...);}
 template <class _Tp, class... _Args>
 _LIBCPP_INLINE_VISIBILITY
 static void __construct(false_type, allocator_type&, _Tp* __p, _Args&&... __args)
 {
 ::new ((void*)__p) _Tp(_VSTD::forward<_Args>(__args)...);
 }
#endif // _LIBCPP_HAS_NO_VARIADICS

 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY
 static void __destroy(true_type, allocator_type& __a, _Tp* __p)
 {__a.destroy(__p);}
 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY
 static void __destroy(false_type, allocator_type&, _Tp* __p)
 {
 __p->~_Tp();
 }

 _LIBCPP_INLINE_VISIBILITY
 static size_type __max_size(true_type, const allocator_type& __a) _NOEXCEPT
 {return __a.max_size();}
 _LIBCPP_INLINE_VISIBILITY
 static size_type __max_size(false_type, const allocator_type&) _NOEXCEPT
 {return numeric_limits<size_type>::max() / sizeof(value_type);}

 _LIBCPP_INLINE_VISIBILITY
 static allocator_type
 __select_on_container_copy_construction(true_type, const allocator_type& __a)
 {return __a.select_on_container_copy_construction();}
 _LIBCPP_INLINE_VISIBILITY
 static allocator_type
 __select_on_container_copy_construction(false_type, const allocator_type& __a)
 {return __a;}
};

template <class _Traits, class _Tp>
struct __rebind_alloc_helper
{
#ifndef _LIBCPP_CXX03_LANG
 typedef typename _Traits::template rebind_alloc<_Tp> type;
#else
 typedef typename _Traits::template rebind_alloc<_Tp>::other type;
#endif
};

// allocator

template <class _Tp>
class _LIBCPP_TEMPLATE_VIS allocator
{
public:
 typedef size_t size_type;
 typedef ptrdiff_t difference_type;
 typedef _Tp* pointer;
 typedef const _Tp* const_pointer;
 typedef _Tp& reference;
 typedef const _Tp& const_reference;
 typedef _Tp value_type;

 typedef true_type propagate_on_container_move_assignment;
 typedef true_type is_always_equal;

 template <class _Up> struct rebind {typedef allocator<_Up> other;};

 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 allocator() _NOEXCEPT {}

 template <class _Up> 
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 allocator(const allocator<_Up>&) _NOEXCEPT {}

 _LIBCPP_INLINE_VISIBILITY pointer address(reference __x) const _NOEXCEPT
 {return _VSTD::addressof(__x);}
 _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
 {return _VSTD::addressof(__x);}
 _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY 
 pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
 {
 if (__n > max_size())
 __throw_length_error("allocator<T>::allocate(size_t n)"
 " 'n' exceeds maximum supported size");
 return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), __alignof(_Tp)));
 }
 _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type) _NOEXCEPT
 {_VSTD::__libcpp_deallocate((void*)__p, __alignof(_Tp));}
 _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
 {return size_type(~0) / sizeof(_Tp);}
#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
 template <class _Up, class... _Args>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(_Up* __p, _Args&&... __args)
 {
 ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
 }
#else // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p)
 {
 ::new((void*)__p) _Tp();
 }
# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)

 template <class _A0>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p, _A0& __a0)
 {
 ::new((void*)__p) _Tp(__a0);
 }
 template <class _A0>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p, const _A0& __a0)
 {
 ::new((void*)__p) _Tp(__a0);
 }
# endif // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
 template <class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p, _A0& __a0, _A1& __a1)
 {
 ::new((void*)__p) _Tp(__a0, __a1);
 }
 template <class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p, const _A0& __a0, _A1& __a1)
 {
 ::new((void*)__p) _Tp(__a0, __a1);
 }
 template <class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p, _A0& __a0, const _A1& __a1)
 {
 ::new((void*)__p) _Tp(__a0, __a1);
 }
 template <class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p, const _A0& __a0, const _A1& __a1)
 {
 ::new((void*)__p) _Tp(__a0, __a1);
 }
#endif // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
 _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
};

template <class _Tp>
class _LIBCPP_TEMPLATE_VIS allocator<const _Tp>
{
public:
 typedef size_t size_type;
 typedef ptrdiff_t difference_type;
 typedef const _Tp* pointer;
 typedef const _Tp* const_pointer;
 typedef const _Tp& reference;
 typedef const _Tp& const_reference;
 typedef const _Tp value_type;

 typedef true_type propagate_on_container_move_assignment;
 typedef true_type is_always_equal;

 template <class _Up> struct rebind {typedef allocator<_Up> other;};

 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 allocator() _NOEXCEPT {}

 template <class _Up>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 
 allocator(const allocator<_Up>&) _NOEXCEPT {}

 _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
 {return _VSTD::addressof(__x);}
 _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
 {
 if (__n > max_size())
 __throw_length_error("allocator<const T>::allocate(size_t n)"
 " 'n' exceeds maximum supported size");
 return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), __alignof(_Tp)));
 }
 _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type) _NOEXCEPT
 {_VSTD::__libcpp_deallocate((void*) const_cast<_Tp *>(__p), __alignof(_Tp));}
 _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
 {return size_type(~0) / sizeof(_Tp);}
#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
 template <class _Up, class... _Args>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(_Up* __p, _Args&&... __args)
 {
 ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
 }
#else // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p)
 {
 ::new((void*) const_cast<_Tp *>(__p)) _Tp();
 }
# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)

 template <class _A0>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p, _A0& __a0)
 {
 ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
 }
 template <class _A0>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p, const _A0& __a0)
 {
 ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
 }
# endif // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
 template <class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p, _A0& __a0, _A1& __a1)
 {
 ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
 }
 template <class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p, const _A0& __a0, _A1& __a1)
 {
 ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
 }
 template <class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p, _A0& __a0, const _A1& __a1)
 {
 ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
 }
 template <class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 void
 construct(pointer __p, const _A0& __a0, const _A1& __a1)
 {
 ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
 }
#endif // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
 _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
};

template <class _Tp, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
bool operator==(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return true;}

template <class _Tp, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
bool operator!=(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return false;}

template <class _OutputIterator, class _Tp>
class _LIBCPP_TEMPLATE_VIS raw_storage_iterator
 : public iterator<output_iterator_tag,
 _Tp, // purposefully not C++03
 ptrdiff_t, // purposefully not C++03
 _Tp*, // purposefully not C++03
 raw_storage_iterator<_OutputIterator, _Tp>&> // purposefully not C++03
{
private:
 _OutputIterator __x_;
public:
 _LIBCPP_INLINE_VISIBILITY explicit raw_storage_iterator(_OutputIterator __x) : __x_(__x) {}
 _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator*() {return *this;}
 _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(const _Tp& __element)
 {::new(_VSTD::addressof(*__x_)) _Tp(__element); return *this;}
#if _LIBCPP_STD_VER >= 14
 _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(_Tp&& __element)
 {::new(_VSTD::addressof(*__x_)) _Tp(_VSTD::move(__element)); return *this;}
#endif
 _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator++() {++__x_; return *this;}
 _LIBCPP_INLINE_VISIBILITY raw_storage_iterator operator++(int)
 {raw_storage_iterator __t(*this); ++__x_; return __t;}
#if _LIBCPP_STD_VER >= 14
 _LIBCPP_INLINE_VISIBILITY _OutputIterator base() const { return __x_; }
#endif
};

template <class _Tp>
_LIBCPP_NO_CFI
pair<_Tp*, ptrdiff_t>
get_temporary_buffer(ptrdiff_t __n) _NOEXCEPT
{
 pair<_Tp*, ptrdiff_t> __r(0, 0);
 const ptrdiff_t __m = (~ptrdiff_t(0) ^
 ptrdiff_t(ptrdiff_t(1) << (sizeof(ptrdiff_t) * __CHAR_BIT__ - 1)))
 / sizeof(_Tp);
 if (__n > __m)
 __n = __m;
 while (__n > 0)
 {
#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
 if (__is_overaligned_for_new(__alignof(_Tp)))
 {
 std::align_val_t __al =
 std::align_val_t(std::alignment_of<_Tp>::value);
 __r.first = static_cast<_Tp*>(::operator new(
 __n * sizeof(_Tp), __al, nothrow));
 } else {
 __r.first = static_cast<_Tp*>(::operator new(
 __n * sizeof(_Tp), nothrow));
 }
#else
 if (__is_overaligned_for_new(__alignof(_Tp)))
 {
 // Since aligned operator new is unavailable, return an empty
 // buffer rather than one with invalid alignment.
 return __r;
 }

 __r.first = static_cast<_Tp*>(::operator new(__n * sizeof(_Tp), nothrow));
#endif

 if (__r.first)
 {
 __r.second = __n;
 break;
 }
 __n /= 2;
 }
 return __r;
}

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
void return_temporary_buffer(_Tp* __p) _NOEXCEPT
{
 _VSTD::__libcpp_deallocate((void*)__p, __alignof(_Tp));
}

#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
template <class _Tp>
struct auto_ptr_ref
{
 _Tp* __ptr_;
};

template<class _Tp>
class _LIBCPP_TEMPLATE_VIS auto_ptr
{
private:
 _Tp* __ptr_;
public:
 typedef _Tp element_type;

 _LIBCPP_INLINE_VISIBILITY explicit auto_ptr(_Tp* __p = 0) throw() : __ptr_(__p) {}
 _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr& __p) throw() : __ptr_(__p.release()) {}
 template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr<_Up>& __p) throw()
 : __ptr_(__p.release()) {}
 _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr& __p) throw()
 {reset(__p.release()); return *this;}
 template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr<_Up>& __p) throw()
 {reset(__p.release()); return *this;}
 _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr_ref<_Tp> __p) throw()
 {reset(__p.__ptr_); return *this;}
 _LIBCPP_INLINE_VISIBILITY ~auto_ptr() throw() {delete __ptr_;}

 _LIBCPP_INLINE_VISIBILITY _Tp& operator*() const throw()
 {return *__ptr_;}
 _LIBCPP_INLINE_VISIBILITY _Tp* operator->() const throw() {return __ptr_;}
 _LIBCPP_INLINE_VISIBILITY _Tp* get() const throw() {return __ptr_;}
 _LIBCPP_INLINE_VISIBILITY _Tp* release() throw()
 {
 _Tp* __t = __ptr_;
 __ptr_ = 0;
 return __t;
 }
 _LIBCPP_INLINE_VISIBILITY void reset(_Tp* __p = 0) throw()
 {
 if (__ptr_ != __p)
 delete __ptr_;
 __ptr_ = __p;
 }

 _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr_ref<_Tp> __p) throw() : __ptr_(__p.__ptr_) {}
 template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr_ref<_Up>() throw()
 {auto_ptr_ref<_Up> __t; __t.__ptr_ = release(); return __t;}
 template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr<_Up>() throw()
 {return auto_ptr<_Up>(release());}
};

template <>
class _LIBCPP_TEMPLATE_VIS auto_ptr<void>
{
public:
 typedef void element_type;
};
#endif

template <class _Tp, int _Idx,
 bool _CanBeEmptyBase =
 is_empty<_Tp>::value && !__libcpp_is_final<_Tp>::value>
struct __compressed_pair_elem {
 typedef _Tp _ParamT;
 typedef _Tp& reference;
 typedef const _Tp& const_reference;

#ifndef _LIBCPP_CXX03_LANG
 _LIBCPP_INLINE_VISIBILITY constexpr __compressed_pair_elem() : __value_() {}

 template <class _Up, class = typename enable_if<
 !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
 >::type>
 _LIBCPP_INLINE_VISIBILITY
 constexpr explicit
 __compressed_pair_elem(_Up&& __u)
 : __value_(_VSTD::forward<_Up>(__u)){};

 template <class... _Args, size_t... _Indexes>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
 __tuple_indices<_Indexes...>)
 : __value_(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
#else
 _LIBCPP_INLINE_VISIBILITY __compressed_pair_elem() : __value_() {}
 _LIBCPP_INLINE_VISIBILITY
 __compressed_pair_elem(_ParamT __p) : __value_(std::forward<_ParamT>(__p)) {}
#endif

 _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return __value_; }
 _LIBCPP_INLINE_VISIBILITY
 const_reference __get() const _NOEXCEPT { return __value_; }

private:
 _Tp __value_;
};

template <class _Tp, int _Idx>
struct __compressed_pair_elem<_Tp, _Idx, true> : private _Tp {
 typedef _Tp _ParamT;
 typedef _Tp& reference;
 typedef const _Tp& const_reference;
 typedef _Tp __value_type;

#ifndef _LIBCPP_CXX03_LANG
 _LIBCPP_INLINE_VISIBILITY constexpr __compressed_pair_elem() = default;

 template <class _Up, class = typename enable_if<
 !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
 >::type>
 _LIBCPP_INLINE_VISIBILITY
 constexpr explicit
 __compressed_pair_elem(_Up&& __u)
 : __value_type(_VSTD::forward<_Up>(__u)){};

 template <class... _Args, size_t... _Indexes>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
 __tuple_indices<_Indexes...>)
 : __value_type(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
#else
 _LIBCPP_INLINE_VISIBILITY __compressed_pair_elem() : __value_type() {}
 _LIBCPP_INLINE_VISIBILITY
 __compressed_pair_elem(_ParamT __p)
 : __value_type(std::forward<_ParamT>(__p)) {}
#endif

 _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return *this; }
 _LIBCPP_INLINE_VISIBILITY
 const_reference __get() const _NOEXCEPT { return *this; }
};

// Tag used to construct the second element of the compressed pair.
struct __second_tag {};

template <class _T1, class _T2>
class __compressed_pair : private __compressed_pair_elem<_T1, 0>,
 private __compressed_pair_elem<_T2, 1> {
 typedef __compressed_pair_elem<_T1, 0> _Base1;
 typedef __compressed_pair_elem<_T2, 1> _Base2;

 // NOTE: This static assert should never fire because __compressed_pair
 // is *almost never* used in a scenario where it's possible for T1 == T2.
 // (The exception is std::function where it is possible that the function
 // object and the allocator have the same type).
 static_assert((!is_same<_T1, _T2>::value),
 "__compressed_pair cannot be instantated when T1 and T2 are the same type; "
 "The current implementation is NOT ABI-compatible with the previous "
 "implementation for this configuration");

public:
#ifndef _LIBCPP_CXX03_LANG
 template <bool _Dummy = true,
 class = typename enable_if<
 __dependent_type<is_default_constructible<_T1>, _Dummy>::value &&
 __dependent_type<is_default_constructible<_T2>, _Dummy>::value
 >::type
 >
 _LIBCPP_INLINE_VISIBILITY
 constexpr __compressed_pair() {}

 template <class _Tp, typename enable_if<!is_same<typename decay<_Tp>::type,
 __compressed_pair>::value,
 bool>::type = true>
 _LIBCPP_INLINE_VISIBILITY constexpr explicit
 __compressed_pair(_Tp&& __t)
 : _Base1(std::forward<_Tp>(__t)), _Base2() {}

 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY constexpr
 __compressed_pair(__second_tag, _Tp&& __t)
 : _Base1(), _Base2(std::forward<_Tp>(__t)) {}

 template <class _U1, class _U2>
 _LIBCPP_INLINE_VISIBILITY constexpr
 __compressed_pair(_U1&& __t1, _U2&& __t2)
 : _Base1(std::forward<_U1>(__t1)), _Base2(std::forward<_U2>(__t2)) {}

 template <class... _Args1, class... _Args2>
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
 __compressed_pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
 tuple<_Args2...> __second_args)
 : _Base1(__pc, _VSTD::move(__first_args),
 typename __make_tuple_indices<sizeof...(_Args1)>::type()),
 _Base2(__pc, _VSTD::move(__second_args),
 typename __make_tuple_indices<sizeof...(_Args2)>::type()) {}

#else
 _LIBCPP_INLINE_VISIBILITY
 __compressed_pair() {}

 _LIBCPP_INLINE_VISIBILITY explicit
 __compressed_pair(_T1 __t1) : _Base1(_VSTD::forward<_T1>(__t1)) {}

 _LIBCPP_INLINE_VISIBILITY
 __compressed_pair(__second_tag, _T2 __t2)
 : _Base1(), _Base2(_VSTD::forward<_T2>(__t2)) {}

 _LIBCPP_INLINE_VISIBILITY
 __compressed_pair(_T1 __t1, _T2 __t2)
 : _Base1(_VSTD::forward<_T1>(__t1)), _Base2(_VSTD::forward<_T2>(__t2)) {}
#endif

 _LIBCPP_INLINE_VISIBILITY
 typename _Base1::reference first() _NOEXCEPT {
 return static_cast<_Base1&>(*this).__get();
 }

 _LIBCPP_INLINE_VISIBILITY
 typename _Base1::const_reference first() const _NOEXCEPT {
 return static_cast<_Base1 const&>(*this).__get();
 }

 _LIBCPP_INLINE_VISIBILITY
 typename _Base2::reference second() _NOEXCEPT {
 return static_cast<_Base2&>(*this).__get();
 }

 _LIBCPP_INLINE_VISIBILITY
 typename _Base2::const_reference second() const _NOEXCEPT {
 return static_cast<_Base2 const&>(*this).__get();
 }

 _LIBCPP_INLINE_VISIBILITY
 void swap(__compressed_pair& __x)
 _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
 __is_nothrow_swappable<_T2>::value)
 {
 using std::swap;
 swap(first(), __x.first());
 swap(second(), __x.second());
 }
};

template <class _T1, class _T2>
inline _LIBCPP_INLINE_VISIBILITY
void swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y)
 _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
 __is_nothrow_swappable<_T2>::value) {
 __x.swap(__y);
}

// default_delete

template <class _Tp>
struct _LIBCPP_TEMPLATE_VIS default_delete {
 static_assert(!is_function<_Tp>::value,
 "default_delete cannot be instantiated for function types");
#ifndef _LIBCPP_CXX03_LANG
 _LIBCPP_INLINE_VISIBILITY constexpr default_delete() noexcept = default;
#else
 _LIBCPP_INLINE_VISIBILITY default_delete() {}
#endif
 template <class _Up>
 _LIBCPP_INLINE_VISIBILITY
 default_delete(const default_delete<_Up>&,
 typename enable_if<is_convertible<_Up*, _Tp*>::value>::type* =
 0) _NOEXCEPT {}

 _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __ptr) const _NOEXCEPT {
 static_assert(sizeof(_Tp) > 0,
 "default_delete can not delete incomplete type");
 static_assert(!is_void<_Tp>::value,
 "default_delete can not delete incomplete type");
 delete __ptr;
 }
};

template <class _Tp>
struct _LIBCPP_TEMPLATE_VIS default_delete<_Tp[]> {
private:
 template <class _Up>
 struct _EnableIfConvertible
 : enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value> {};

public:
#ifndef _LIBCPP_CXX03_LANG
 _LIBCPP_INLINE_VISIBILITY constexpr default_delete() noexcept = default;
#else
 _LIBCPP_INLINE_VISIBILITY default_delete() {}
#endif

 template <class _Up>
 _LIBCPP_INLINE_VISIBILITY
 default_delete(const default_delete<_Up[]>&,
 typename _EnableIfConvertible<_Up>::type* = 0) _NOEXCEPT {}

 template <class _Up>
 _LIBCPP_INLINE_VISIBILITY
 typename _EnableIfConvertible<_Up>::type
 operator()(_Up* __ptr) const _NOEXCEPT {
 static_assert(sizeof(_Tp) > 0,
 "default_delete can not delete incomplete type");
 static_assert(!is_void<_Tp>::value,
 "default_delete can not delete void type");
 delete[] __ptr;
 }
};



#ifndef _LIBCPP_CXX03_LANG
template <class _Deleter>
struct __unique_ptr_deleter_sfinae {
 static_assert(!is_reference<_Deleter>::value, "incorrect specialization");
 typedef const _Deleter& __lval_ref_type;
 typedef _Deleter&& __good_rval_ref_type;
 typedef true_type __enable_rval_overload;
};

template <class _Deleter>
struct __unique_ptr_deleter_sfinae<_Deleter const&> {
 typedef const _Deleter& __lval_ref_type;
 typedef const _Deleter&& __bad_rval_ref_type;
 typedef false_type __enable_rval_overload;
};

template <class _Deleter>
struct __unique_ptr_deleter_sfinae<_Deleter&> {
 typedef _Deleter& __lval_ref_type;
 typedef _Deleter&& __bad_rval_ref_type;
 typedef false_type __enable_rval_overload;
};
#endif // !defined(_LIBCPP_CXX03_LANG)

template <class _Tp, class _Dp = default_delete<_Tp> >
class _LIBCPP_TEMPLATE_VIS unique_ptr {
public:
 typedef _Tp element_type;
 typedef _Dp deleter_type;
 typedef typename __pointer_type<_Tp, deleter_type>::type pointer;

 static_assert(!is_rvalue_reference<deleter_type>::value,
 "the specified deleter type cannot be an rvalue reference");

private:
 __compressed_pair<pointer, deleter_type> __ptr_;

 struct __nat { int __for_bool_; };

#ifndef _LIBCPP_CXX03_LANG
 typedef __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;

 template <bool _Dummy>
 using _LValRefType =
 typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;

 template <bool _Dummy>
 using _GoodRValRefType =
 typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;

 template <bool _Dummy>
 using _BadRValRefType =
 typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;

 template <bool _Dummy, class _Deleter = typename __dependent_type<
 __identity<deleter_type>, _Dummy>::type>
 using _EnableIfDeleterDefaultConstructible =
 typename enable_if<is_default_constructible<_Deleter>::value &&
 !is_pointer<_Deleter>::value>::type;

 template <class _ArgType>
 using _EnableIfDeleterConstructible =
 typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;

 template <class _UPtr, class _Up>
 using _EnableIfMoveConvertible = typename enable_if<
 is_convertible<typename _UPtr::pointer, pointer>::value &&
 !is_array<_Up>::value
 >::type;

 template <class _UDel>
 using _EnableIfDeleterConvertible = typename enable_if<
 (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
 (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
 >::type;

 template <class _UDel>
 using _EnableIfDeleterAssignable = typename enable_if<
 is_assignable<_Dp&, _UDel&&>::value
 >::type;

public:
 template <bool _Dummy = true,
 class = _EnableIfDeleterDefaultConstructible<_Dummy>>
 _LIBCPP_INLINE_VISIBILITY
 constexpr unique_ptr() noexcept : __ptr_(pointer()) {}

 template <bool _Dummy = true,
 class = _EnableIfDeleterDefaultConstructible<_Dummy>>
 _LIBCPP_INLINE_VISIBILITY
 constexpr unique_ptr(nullptr_t) noexcept : __ptr_(pointer()) {}

 template <bool _Dummy = true,
 class = _EnableIfDeleterDefaultConstructible<_Dummy>>
 _LIBCPP_INLINE_VISIBILITY
 explicit unique_ptr(pointer __p) noexcept : __ptr_(__p) {}

 template <bool _Dummy = true,
 class = _EnableIfDeleterConstructible<_LValRefType<_Dummy>>>
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(pointer __p, _LValRefType<_Dummy> __d) noexcept
 : __ptr_(__p, __d) {}

 template <bool _Dummy = true,
 class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy>>>
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(pointer __p, _GoodRValRefType<_Dummy> __d) noexcept
 : __ptr_(__p, _VSTD::move(__d)) {
 static_assert(!is_reference<deleter_type>::value,
 "rvalue deleter bound to reference");
 }

 template <bool _Dummy = true,
 class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy>>>
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(pointer __p, _BadRValRefType<_Dummy> __d) = delete;

 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(unique_ptr&& __u) noexcept
 : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
 }

 template <class _Up, class _Ep,
 class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
 class = _EnableIfDeleterConvertible<_Ep>
 >
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
 : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {}

#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
 template <class _Up>
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(auto_ptr<_Up>&& __p,
 typename enable_if<is_convertible<_Up*, _Tp*>::value &&
 is_same<_Dp, default_delete<_Tp>>::value,
 __nat>::type = __nat()) _NOEXCEPT
 : __ptr_(__p.release()) {}
#endif

 _LIBCPP_INLINE_VISIBILITY
 unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
 reset(__u.release());
 __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
 return *this;
 }

 template <class _Up, class _Ep,
 class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
 class = _EnableIfDeleterAssignable<_Ep>
 >
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr& operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
 reset(__u.release());
 __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
 return *this;
 }

#else // _LIBCPP_CXX03_LANG
private:
 unique_ptr(unique_ptr&);
 template <class _Up, class _Ep> unique_ptr(unique_ptr<_Up, _Ep>&);

 unique_ptr& operator=(unique_ptr&);
 template <class _Up, class _Ep> unique_ptr& operator=(unique_ptr<_Up, _Ep>&);

public:
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr() : __ptr_(pointer())
 {
 static_assert(!is_pointer<deleter_type>::value,
 "unique_ptr constructed with null function pointer deleter");
 static_assert(is_default_constructible<deleter_type>::value,
 "unique_ptr::deleter_type is not default constructible");
 }
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(nullptr_t) : __ptr_(pointer())
 {
 static_assert(!is_pointer<deleter_type>::value,
 "unique_ptr constructed with null function pointer deleter");
 }
 _LIBCPP_INLINE_VISIBILITY
 explicit unique_ptr(pointer __p)
 : __ptr_(_VSTD::move(__p)) {
 static_assert(!is_pointer<deleter_type>::value,
 "unique_ptr constructed with null function pointer deleter");
 }

 _LIBCPP_INLINE_VISIBILITY
 operator __rv<unique_ptr>() {
 return __rv<unique_ptr>(*this);
 }

 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(__rv<unique_ptr> __u)
 : __ptr_(__u->release(),
 _VSTD::forward<deleter_type>(__u->get_deleter())) {}

 template <class _Up, class _Ep>
 _LIBCPP_INLINE_VISIBILITY
 typename enable_if<
 !is_array<_Up>::value &&
 is_convertible<typename unique_ptr<_Up, _Ep>::pointer,
 pointer>::value &&
 is_assignable<deleter_type&, _Ep&>::value,
 unique_ptr&>::type
 operator=(unique_ptr<_Up, _Ep> __u) {
 reset(__u.release());
 __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
 return *this;
 }

 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(pointer __p, deleter_type __d)
 : __ptr_(_VSTD::move(__p), _VSTD::move(__d)) {}
#endif // _LIBCPP_CXX03_LANG

#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
 template <class _Up>
 _LIBCPP_INLINE_VISIBILITY
 typename enable_if<is_convertible<_Up*, _Tp*>::value &&
 is_same<_Dp, default_delete<_Tp> >::value,
 unique_ptr&>::type
 operator=(auto_ptr<_Up> __p) {
 reset(__p.release());
 return *this;
 }
#endif

 _LIBCPP_INLINE_VISIBILITY
 ~unique_ptr() { reset(); }

 _LIBCPP_INLINE_VISIBILITY
 unique_ptr& operator=(nullptr_t) _NOEXCEPT {
 reset();
 return *this;
 }

 _LIBCPP_INLINE_VISIBILITY
 typename add_lvalue_reference<_Tp>::type
 operator*() const {
 return *__ptr_.first();
 }
 _LIBCPP_INLINE_VISIBILITY
 pointer operator->() const _NOEXCEPT {
 return __ptr_.first();
 }
 _LIBCPP_INLINE_VISIBILITY
 pointer get() const _NOEXCEPT {
 return __ptr_.first();
 }
 _LIBCPP_INLINE_VISIBILITY
 deleter_type& get_deleter() _NOEXCEPT {
 return __ptr_.second();
 }
 _LIBCPP_INLINE_VISIBILITY
 const deleter_type& get_deleter() const _NOEXCEPT {
 return __ptr_.second();
 }
 _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
 return __ptr_.first() != nullptr;
 }

 _LIBCPP_INLINE_VISIBILITY
 pointer release() _NOEXCEPT {
 pointer __t = __ptr_.first();
 __ptr_.first() = pointer();
 return __t;
 }

 _LIBCPP_INLINE_VISIBILITY
 void reset(pointer __p = pointer()) _NOEXCEPT {
 pointer __tmp = __ptr_.first();
 __ptr_.first() = __p;
 if (__tmp)
 __ptr_.second()(__tmp);
 }

 _LIBCPP_INLINE_VISIBILITY
 void swap(unique_ptr& __u) _NOEXCEPT {
 __ptr_.swap(__u.__ptr_);
 }
};


template <class _Tp, class _Dp>
class _LIBCPP_TEMPLATE_VIS unique_ptr<_Tp[], _Dp> {
public:
 typedef _Tp element_type;
 typedef _Dp deleter_type;
 typedef typename __pointer_type<_Tp, deleter_type>::type pointer;

private:
 __compressed_pair<pointer, deleter_type> __ptr_;

 template <class _From>
 struct _CheckArrayPointerConversion : is_same<_From, pointer> {};

 template <class _FromElem>
 struct _CheckArrayPointerConversion<_FromElem*>
 : integral_constant<bool,
 is_same<_FromElem*, pointer>::value ||
 (is_same<pointer, element_type*>::value &&
 is_convertible<_FromElem(*)[], element_type(*)[]>::value)
 >
 {};

#ifndef _LIBCPP_CXX03_LANG
 typedef __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;

 template <bool _Dummy>
 using _LValRefType =
 typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;

 template <bool _Dummy>
 using _GoodRValRefType =
 typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;

 template <bool _Dummy>
 using _BadRValRefType =
 typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;

 template <bool _Dummy, class _Deleter = typename __dependent_type<
 __identity<deleter_type>, _Dummy>::type>
 using _EnableIfDeleterDefaultConstructible =
 typename enable_if<is_default_constructible<_Deleter>::value &&
 !is_pointer<_Deleter>::value>::type;

 template <class _ArgType>
 using _EnableIfDeleterConstructible =
 typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;

 template <class _Pp>
 using _EnableIfPointerConvertible = typename enable_if<
 _CheckArrayPointerConversion<_Pp>::value
 >::type;

 template <class _UPtr, class _Up,
 class _ElemT = typename _UPtr::element_type>
 using _EnableIfMoveConvertible = typename enable_if<
 is_array<_Up>::value &&
 is_same<pointer, element_type*>::value &&
 is_same<typename _UPtr::pointer, _ElemT*>::value &&
 is_convertible<_ElemT(*)[], element_type(*)[]>::value
 >::type;

 template <class _UDel>
 using _EnableIfDeleterConvertible = typename enable_if<
 (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
 (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
 >::type;

 template <class _UDel>
 using _EnableIfDeleterAssignable = typename enable_if<
 is_assignable<_Dp&, _UDel&&>::value
 >::type;

public:
 template <bool _Dummy = true,
 class = _EnableIfDeleterDefaultConstructible<_Dummy>>
 _LIBCPP_INLINE_VISIBILITY
 constexpr unique_ptr() noexcept : __ptr_(pointer()) {}

 template <bool _Dummy = true,
 class = _EnableIfDeleterDefaultConstructible<_Dummy>>
 _LIBCPP_INLINE_VISIBILITY
 constexpr unique_ptr(nullptr_t) noexcept : __ptr_(pointer()) {}

 template <class _Pp, bool _Dummy = true,
 class = _EnableIfDeleterDefaultConstructible<_Dummy>,
 class = _EnableIfPointerConvertible<_Pp>>
 _LIBCPP_INLINE_VISIBILITY
 explicit unique_ptr(_Pp __p) noexcept
 : __ptr_(__p) {}

 template <class _Pp, bool _Dummy = true,
 class = _EnableIfDeleterConstructible<_LValRefType<_Dummy>>,
 class = _EnableIfPointerConvertible<_Pp>>
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(_Pp __p, _LValRefType<_Dummy> __d) noexcept
 : __ptr_(__p, __d) {}

 template <bool _Dummy = true,
 class = _EnableIfDeleterConstructible<_LValRefType<_Dummy>>>
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(nullptr_t, _LValRefType<_Dummy> __d) noexcept
 : __ptr_(nullptr, __d) {}

 template <class _Pp, bool _Dummy = true,
 class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy>>,
 class = _EnableIfPointerConvertible<_Pp>>
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(_Pp __p, _GoodRValRefType<_Dummy> __d) noexcept
 : __ptr_(__p, _VSTD::move(__d)) {
 static_assert(!is_reference<deleter_type>::value,
 "rvalue deleter bound to reference");
 }

 template <bool _Dummy = true,
 class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy>>>
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(nullptr_t, _GoodRValRefType<_Dummy> __d) noexcept
 : __ptr_(nullptr, _VSTD::move(__d)) {
 static_assert(!is_reference<deleter_type>::value,
 "rvalue deleter bound to reference");
 }

 template <class _Pp, bool _Dummy = true,
 class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy>>,
 class = _EnableIfPointerConvertible<_Pp>>
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(_Pp __p, _BadRValRefType<_Dummy> __d) = delete;

 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(unique_ptr&& __u) noexcept
 : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
 }

 _LIBCPP_INLINE_VISIBILITY
 unique_ptr& operator=(unique_ptr&& __u) noexcept {
 reset(__u.release());
 __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
 return *this;
 }

 template <class _Up, class _Ep,
 class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
 class = _EnableIfDeleterConvertible<_Ep>
 >
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
 : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {
 }

 template <class _Up, class _Ep,
 class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
 class = _EnableIfDeleterAssignable<_Ep>
 >
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr&
 operator=(unique_ptr<_Up, _Ep>&& __u) noexcept {
 reset(__u.release());
 __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
 return *this;
 }

#else // _LIBCPP_CXX03_LANG
private:
 template <class _Up> explicit unique_ptr(_Up);

 unique_ptr(unique_ptr&);
 template <class _Up> unique_ptr(unique_ptr<_Up>&);

 unique_ptr& operator=(unique_ptr&);
 template <class _Up> unique_ptr& operator=(unique_ptr<_Up>&);

 template <class _Up>
 unique_ptr(_Up __u,
 typename conditional<
 is_reference<deleter_type>::value, deleter_type,
 typename add_lvalue_reference<const deleter_type>::type>::type,
 typename enable_if<is_convertible<_Up, pointer>::value,
 __nat>::type = __nat());
public:
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr() : __ptr_(pointer()) {
 static_assert(!is_pointer<deleter_type>::value,
 "unique_ptr constructed with null function pointer deleter");
 }
 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(nullptr_t) : __ptr_(pointer()) {
 static_assert(!is_pointer<deleter_type>::value,
 "unique_ptr constructed with null function pointer deleter");
 }

 _LIBCPP_INLINE_VISIBILITY
 explicit unique_ptr(pointer __p) : __ptr_(__p) {
 static_assert(!is_pointer<deleter_type>::value,
 "unique_ptr constructed with null function pointer deleter");
 }

 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(pointer __p, deleter_type __d)
 : __ptr_(__p, _VSTD::forward<deleter_type>(__d)) {}

 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(nullptr_t, deleter_type __d)
 : __ptr_(pointer(), _VSTD::forward<deleter_type>(__d)) {}

 _LIBCPP_INLINE_VISIBILITY
 operator __rv<unique_ptr>() {
 return __rv<unique_ptr>(*this);
 }

 _LIBCPP_INLINE_VISIBILITY
 unique_ptr(__rv<unique_ptr> __u)
 : __ptr_(__u->release(),
 _VSTD::forward<deleter_type>(__u->get_deleter())) {}

 _LIBCPP_INLINE_VISIBILITY
 unique_ptr& operator=(__rv<unique_ptr> __u) {
 reset(__u->release());
 __ptr_.second() = _VSTD::forward<deleter_type>(__u->get_deleter());
 return *this;
 }

#endif // _LIBCPP_CXX03_LANG

public:
 _LIBCPP_INLINE_VISIBILITY
 ~unique_ptr() { reset(); }

 _LIBCPP_INLINE_VISIBILITY
 unique_ptr& operator=(nullptr_t) _NOEXCEPT {
 reset();
 return *this;
 }

 _LIBCPP_INLINE_VISIBILITY
 typename add_lvalue_reference<_Tp>::type
 operator[](size_t __i) const {
 return __ptr_.first()[__i];
 }
 _LIBCPP_INLINE_VISIBILITY
 pointer get() const _NOEXCEPT {
 return __ptr_.first();
 }

 _LIBCPP_INLINE_VISIBILITY
 deleter_type& get_deleter() _NOEXCEPT {
 return __ptr_.second();
 }

 _LIBCPP_INLINE_VISIBILITY
 const deleter_type& get_deleter() const _NOEXCEPT {
 return __ptr_.second();
 }
 _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
 return __ptr_.first() != nullptr;
 }

 _LIBCPP_INLINE_VISIBILITY
 pointer release() _NOEXCEPT {
 pointer __t = __ptr_.first();
 __ptr_.first() = pointer();
 return __t;
 }

 template <class _Pp>
 _LIBCPP_INLINE_VISIBILITY
 typename enable_if<
 _CheckArrayPointerConversion<_Pp>::value
 >::type
 reset(_Pp __p) _NOEXCEPT {
 pointer __tmp = __ptr_.first();
 __ptr_.first() = __p;
 if (__tmp)
 __ptr_.second()(__tmp);
 }

 _LIBCPP_INLINE_VISIBILITY
 void reset(nullptr_t = nullptr) _NOEXCEPT {
 pointer __tmp = __ptr_.first();
 __ptr_.first() = nullptr;
 if (__tmp)
 __ptr_.second()(__tmp);
 }

 _LIBCPP_INLINE_VISIBILITY
 void swap(unique_ptr& __u) _NOEXCEPT {
 __ptr_.swap(__u.__ptr_);
 }

};

template <class _Tp, class _Dp>
inline _LIBCPP_INLINE_VISIBILITY
typename enable_if<
 __is_swappable<_Dp>::value,
 void
>::type
swap(unique_ptr<_Tp, _Dp>& __x, unique_ptr<_Tp, _Dp>& __y) _NOEXCEPT {__x.swap(__y);}

template <class _T1, class _D1, class _T2, class _D2>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __x.get() == __y.get();}

template <class _T1, class _D1, class _T2, class _D2>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x == __y);}

template <class _T1, class _D1, class _T2, class _D2>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator< (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y)
{
 typedef typename unique_ptr<_T1, _D1>::pointer _P1;
 typedef typename unique_ptr<_T2, _D2>::pointer _P2;
 typedef typename common_type<_P1, _P2>::type _Vp;
 return less<_Vp>()(__x.get(), __y.get());
}

template <class _T1, class _D1, class _T2, class _D2>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator> (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __y < __x;}

template <class _T1, class _D1, class _T2, class _D2>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__y < __x);}

template <class _T1, class _D1, class _T2, class _D2>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x < __y);}

template <class _T1, class _D1>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
{
 return !__x;
}

template <class _T1, class _D1>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
{
 return !__x;
}

template <class _T1, class _D1>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
{
 return static_cast<bool>(__x);
}

template <class _T1, class _D1>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
{
 return static_cast<bool>(__x);
}

template <class _T1, class _D1>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<(const unique_ptr<_T1, _D1>& __x, nullptr_t)
{
 typedef typename unique_ptr<_T1, _D1>::pointer _P1;
 return less<_P1>()(__x.get(), nullptr);
}

template <class _T1, class _D1>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<(nullptr_t, const unique_ptr<_T1, _D1>& __x)
{
 typedef typename unique_ptr<_T1, _D1>::pointer _P1;
 return less<_P1>()(nullptr, __x.get());
}

template <class _T1, class _D1>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>(const unique_ptr<_T1, _D1>& __x, nullptr_t)
{
 return nullptr < __x;
}

template <class _T1, class _D1>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>(nullptr_t, const unique_ptr<_T1, _D1>& __x)
{
 return __x < nullptr;
}

template <class _T1, class _D1>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
{
 return !(nullptr < __x);
}

template <class _T1, class _D1>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
{
 return !(__x < nullptr);
}

template <class _T1, class _D1>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
{
 return !(__x < nullptr);
}

template <class _T1, class _D1>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
{
 return !(nullptr < __x);
}

#ifdef _LIBCPP_HAS_NO_RVALUE_REFERENCES

template <class _Tp, class _Dp>
inline _LIBCPP_INLINE_VISIBILITY
unique_ptr<_Tp, _Dp>
move(unique_ptr<_Tp, _Dp>& __t)
{
 return unique_ptr<_Tp, _Dp>(__rv<unique_ptr<_Tp, _Dp> >(__t));
}

#endif

#if _LIBCPP_STD_VER > 11

template<class _Tp>
struct __unique_if
{
 typedef unique_ptr<_Tp> __unique_single;
};

template<class _Tp>
struct __unique_if<_Tp[]>
{
 typedef unique_ptr<_Tp[]> __unique_array_unknown_bound;
};

template<class _Tp, size_t _Np>
struct __unique_if<_Tp[_Np]>
{
 typedef void __unique_array_known_bound;
};

template<class _Tp, class... _Args>
inline _LIBCPP_INLINE_VISIBILITY
typename __unique_if<_Tp>::__unique_single
make_unique(_Args&&... __args)
{
 return unique_ptr<_Tp>(new _Tp(_VSTD::forward<_Args>(__args)...));
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
typename __unique_if<_Tp>::__unique_array_unknown_bound
make_unique(size_t __n)
{
 typedef typename remove_extent<_Tp>::type _Up;
 return unique_ptr<_Tp>(new _Up[__n]());
}

template<class _Tp, class... _Args>
 typename __unique_if<_Tp>::__unique_array_known_bound
 make_unique(_Args&&...) = delete;

#endif // _LIBCPP_STD_VER > 11

template <class _Tp, class _Dp>
#ifdef _LIBCPP_CXX03_LANG
struct _LIBCPP_TEMPLATE_VIS hash<unique_ptr<_Tp, _Dp> >
#else
struct _LIBCPP_TEMPLATE_VIS hash<__enable_hash_helper<
 unique_ptr<_Tp, _Dp>, typename unique_ptr<_Tp, _Dp>::pointer>>
#endif
{
 typedef unique_ptr<_Tp, _Dp> argument_type;
 typedef size_t result_type;
 _LIBCPP_INLINE_VISIBILITY
 result_type operator()(const argument_type& __ptr) const
 {
 typedef typename argument_type::pointer pointer;
 return hash<pointer>()(__ptr.get());
 }
};

struct __destruct_n
{
private:
 size_t __size_;

 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
 {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}

 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
 {}

 _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
 {++__size_;}
 _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
 {}

 _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
 {__size_ = __s;}
 _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
 {}
public:
 _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
 : __size_(__s) {}

 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY void __incr(_Tp*) _NOEXCEPT
 {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}

 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
 {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}

 template <class _Tp>
 _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
 {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
};

template <class _Alloc>
class __allocator_destructor
{
 typedef allocator_traits<_Alloc> __alloc_traits;
public:
 typedef typename __alloc_traits::pointer pointer;
 typedef typename __alloc_traits::size_type size_type;
private:
 _Alloc& __alloc_;
 size_type __s_;
public:
 _LIBCPP_INLINE_VISIBILITY __allocator_destructor(_Alloc& __a, size_type __s)
 _NOEXCEPT
 : __alloc_(__a), __s_(__s) {}
 _LIBCPP_INLINE_VISIBILITY
 void operator()(pointer __p) _NOEXCEPT
 {__alloc_traits::deallocate(__alloc_, __p, __s_);}
};

template <class _InputIterator, class _ForwardIterator>
_ForwardIterator
uninitialized_copy(_InputIterator __f, _InputIterator __l, _ForwardIterator __r)
{
 typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
#ifndef _LIBCPP_NO_EXCEPTIONS
 _ForwardIterator __s = __r;
 try
 {
#endif
 for (; __f != __l; ++__f, (void) ++__r)
 ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
#ifndef _LIBCPP_NO_EXCEPTIONS
 }
 catch (...)
 {
 for (; __s != __r; ++__s)
 __s->~value_type();
 throw;
 }
#endif
 return __r;
}

template <class _InputIterator, class _Size, class _ForwardIterator>
_ForwardIterator
uninitialized_copy_n(_InputIterator __f, _Size __n, _ForwardIterator __r)
{
 typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
#ifndef _LIBCPP_NO_EXCEPTIONS
 _ForwardIterator __s = __r;
 try
 {
#endif
 for (; __n > 0; ++__f, (void) ++__r, (void) --__n)
 ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
#ifndef _LIBCPP_NO_EXCEPTIONS
 }
 catch (...)
 {
 for (; __s != __r; ++__s)
 __s->~value_type();
 throw;
 }
#endif
 return __r;
}

template <class _ForwardIterator, class _Tp>
void
uninitialized_fill(_ForwardIterator __f, _ForwardIterator __l, const _Tp& __x)
{
 typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
#ifndef _LIBCPP_NO_EXCEPTIONS
 _ForwardIterator __s = __f;
 try
 {
#endif
 for (; __f != __l; ++__f)
 ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
#ifndef _LIBCPP_NO_EXCEPTIONS
 }
 catch (...)
 {
 for (; __s != __f; ++__s)
 __s->~value_type();
 throw;
 }
#endif
}

template <class _ForwardIterator, class _Size, class _Tp>
_ForwardIterator
uninitialized_fill_n(_ForwardIterator __f, _Size __n, const _Tp& __x)
{
 typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
#ifndef _LIBCPP_NO_EXCEPTIONS
 _ForwardIterator __s = __f;
 try
 {
#endif
 for (; __n > 0; ++__f, (void) --__n)
 ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
#ifndef _LIBCPP_NO_EXCEPTIONS
 }
 catch (...)
 {
 for (; __s != __f; ++__s)
 __s->~value_type();
 throw;
 }
#endif
 return __f;
}

#if _LIBCPP_STD_VER > 14

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
void destroy_at(_Tp* __loc) {
 _LIBCPP_ASSERT(__loc, "null pointer given to destroy_at");
 __loc->~_Tp();
}

template <class _ForwardIterator>
inline _LIBCPP_INLINE_VISIBILITY
void destroy(_ForwardIterator __first, _ForwardIterator __last) {
 for (; __first != __last; ++__first)
 _VSTD::destroy_at(_VSTD::addressof(*__first));
}

template <class _ForwardIterator, class _Size>
inline _LIBCPP_INLINE_VISIBILITY
_ForwardIterator destroy_n(_ForwardIterator __first, _Size __n) {
 for (; __n > 0; (void)++__first, --__n)
 _VSTD::destroy_at(_VSTD::addressof(*__first));
 return __first;
}

template <class _ForwardIterator>
inline _LIBCPP_INLINE_VISIBILITY
void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last) {
 using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
 auto __idx = __first;
#ifndef _LIBCPP_NO_EXCEPTIONS
 try {
#endif
 for (; __idx != __last; ++__idx)
 ::new((void*)_VSTD::addressof(*__idx)) _Vt;
#ifndef _LIBCPP_NO_EXCEPTIONS
 } catch (...) {
 _VSTD::destroy(__first, __idx);
 throw;
 }
#endif
}

template <class _ForwardIterator, class _Size>
inline _LIBCPP_INLINE_VISIBILITY
_ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
 using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
 auto __idx = __first;
#ifndef _LIBCPP_NO_EXCEPTIONS
 try {
#endif
 for (; __n > 0; (void)++__idx, --__n)
 ::new((void*)_VSTD::addressof(*__idx)) _Vt;
 return __idx;
#ifndef _LIBCPP_NO_EXCEPTIONS
 } catch (...) {
 _VSTD::destroy(__first, __idx);
 throw;
 }
#endif
}


template <class _ForwardIterator>
inline _LIBCPP_INLINE_VISIBILITY
void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last) {
 using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
 auto __idx = __first;
#ifndef _LIBCPP_NO_EXCEPTIONS
 try {
#endif
 for (; __idx != __last; ++__idx)
 ::new((void*)_VSTD::addressof(*__idx)) _Vt();
#ifndef _LIBCPP_NO_EXCEPTIONS
 } catch (...) {
 _VSTD::destroy(__first, __idx);
 throw;
 }
#endif
}

template <class _ForwardIterator, class _Size>
inline _LIBCPP_INLINE_VISIBILITY
_ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
 using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
 auto __idx = __first;
#ifndef _LIBCPP_NO_EXCEPTIONS
 try {
#endif
 for (; __n > 0; (void)++__idx, --__n)
 ::new((void*)_VSTD::addressof(*__idx)) _Vt();
 return __idx;
#ifndef _LIBCPP_NO_EXCEPTIONS
 } catch (...) {
 _VSTD::destroy(__first, __idx);
 throw;
 }
#endif
}


template <class _InputIt, class _ForwardIt>
inline _LIBCPP_INLINE_VISIBILITY
_ForwardIt uninitialized_move(_InputIt __first, _InputIt __last, _ForwardIt __first_res) {
 using _Vt = typename iterator_traits<_ForwardIt>::value_type;
 auto __idx = __first_res;
#ifndef _LIBCPP_NO_EXCEPTIONS
 try {
#endif
 for (; __first != __last; (void)++__idx, ++__first)
 ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
 return __idx;
#ifndef _LIBCPP_NO_EXCEPTIONS
 } catch (...) {
 _VSTD::destroy(__first_res, __idx);
 throw;
 }
#endif
}

template <class _InputIt, class _Size, class _ForwardIt>
inline _LIBCPP_INLINE_VISIBILITY
pair<_InputIt, _ForwardIt>
uninitialized_move_n(_InputIt __first, _Size __n, _ForwardIt __first_res) {
 using _Vt = typename iterator_traits<_ForwardIt>::value_type;
 auto __idx = __first_res;
#ifndef _LIBCPP_NO_EXCEPTIONS
 try {
#endif
 for (; __n > 0; ++__idx, (void)++__first, --__n)
 ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
 return {__first, __idx};
#ifndef _LIBCPP_NO_EXCEPTIONS
 } catch (...) {
 _VSTD::destroy(__first_res, __idx);
 throw;
 }
#endif
}


#endif // _LIBCPP_STD_VER > 14

// NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively)
// should be sufficient for thread safety.
// See https://bugs.llvm.org/show_bug.cgi?id=22803
#if defined(__clang__) && __has_builtin(__atomic_add_fetch) \
 && defined(__ATOMIC_RELAXED) \
 && defined(__ATOMIC_ACQ_REL)
# define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
#elif !defined(__clang__) && defined(_GNUC_VER) && _GNUC_VER >= 407
# define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
#endif

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY _Tp
__libcpp_atomic_refcount_increment(_Tp& __t) _NOEXCEPT
{
#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
 return __atomic_add_fetch(&__t, 1, __ATOMIC_RELAXED);
#else
 return __t += 1;
#endif
}

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY _Tp
__libcpp_atomic_refcount_decrement(_Tp& __t) _NOEXCEPT
{
#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
 return __atomic_add_fetch(&__t, -1, __ATOMIC_ACQ_REL);
#else
 return __t -= 1;
#endif
}

class _LIBCPP_EXCEPTION_ABI bad_weak_ptr
 : public std::exception
{
public:
 virtual ~bad_weak_ptr() _NOEXCEPT;
 virtual const char* what() const _NOEXCEPT;
};

_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
void __throw_bad_weak_ptr()
{
#ifndef _LIBCPP_NO_EXCEPTIONS
 throw bad_weak_ptr();
#else
 _VSTD::abort();
#endif
}

template<class _Tp> class _LIBCPP_TEMPLATE_VIS weak_ptr;

class _LIBCPP_TYPE_VIS __shared_count
{
 __shared_count(const __shared_count&);
 __shared_count& operator=(const __shared_count&);

protected:
 long __shared_owners_;
 virtual ~__shared_count();
private:
 virtual void __on_zero_shared() _NOEXCEPT = 0;

public:
 _LIBCPP_INLINE_VISIBILITY
 explicit __shared_count(long __refs = 0) _NOEXCEPT
 : __shared_owners_(__refs) {}

#if defined(_LIBCPP_BUILDING_LIBRARY) && \
 defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
 void __add_shared() _NOEXCEPT;
 bool __release_shared() _NOEXCEPT;
#else
 _LIBCPP_INLINE_VISIBILITY
 void __add_shared() _NOEXCEPT {
 __libcpp_atomic_refcount_increment(__shared_owners_);
 }
 _LIBCPP_INLINE_VISIBILITY
 bool __release_shared() _NOEXCEPT {
 if (__libcpp_atomic_refcount_decrement(__shared_owners_) == -1) {
 __on_zero_shared();
 return true;
 }
 return false;
 }
#endif
 _LIBCPP_INLINE_VISIBILITY
 long use_count() const _NOEXCEPT {
 return __libcpp_relaxed_load(&__shared_owners_) + 1;
 }
};

class _LIBCPP_TYPE_VIS __shared_weak_count
 : private __shared_count
{
 long __shared_weak_owners_;

public:
 _LIBCPP_INLINE_VISIBILITY
 explicit __shared_weak_count(long __refs = 0) _NOEXCEPT
 : __shared_count(__refs),
 __shared_weak_owners_(__refs) {}
protected:
 virtual ~__shared_weak_count();

public:
#if defined(_LIBCPP_BUILDING_LIBRARY) && \
 defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
 void __add_shared() _NOEXCEPT;
 void __add_weak() _NOEXCEPT;
 void __release_shared() _NOEXCEPT;
#else
 _LIBCPP_INLINE_VISIBILITY
 void __add_shared() _NOEXCEPT {
 __shared_count::__add_shared();
 }
 _LIBCPP_INLINE_VISIBILITY
 void __add_weak() _NOEXCEPT {
 __libcpp_atomic_refcount_increment(__shared_weak_owners_);
 }
 _LIBCPP_INLINE_VISIBILITY
 void __release_shared() _NOEXCEPT {
 if (__shared_count::__release_shared())
 __release_weak();
 }
#endif
 void __release_weak() _NOEXCEPT;
 _LIBCPP_INLINE_VISIBILITY
 long use_count() const _NOEXCEPT {return __shared_count::use_count();}
 __shared_weak_count* lock() _NOEXCEPT;

 // Define the function out only if we build static libc++ without RTTI.
 // Otherwise we may break clients who need to compile their projects with
 // -fno-rtti and yet link against a libc++.dylib compiled
 // without -fno-rtti.
#if !defined(_LIBCPP_NO_RTTI) || !defined(_LIBCPP_BUILD_STATIC)
 virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
#endif
private:
 virtual void __on_zero_shared_weak() _NOEXCEPT = 0;
};

template <class _Tp, class _Dp, class _Alloc>
class __shared_ptr_pointer
 : public __shared_weak_count
{
 __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_;
public:
 _LIBCPP_INLINE_VISIBILITY
 __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a)
 : __data_(__compressed_pair<_Tp, _Dp>(__p, _VSTD::move(__d)), _VSTD::move(__a)) {}

#ifndef _LIBCPP_NO_RTTI
 virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
#endif

private:
 virtual void __on_zero_shared() _NOEXCEPT;
 virtual void __on_zero_shared_weak() _NOEXCEPT;
};

#ifndef _LIBCPP_NO_RTTI

template <class _Tp, class _Dp, class _Alloc>
const void*
__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT
{
 return __t == typeid(_Dp) ? _VSTD::addressof(__data_.first().second()) : nullptr;
}

#endif // _LIBCPP_NO_RTTI

template <class _Tp, class _Dp, class _Alloc>
void
__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT
{
 __data_.first().second()(__data_.first().first());
 __data_.first().second().~_Dp();
}

template <class _Tp, class _Dp, class _Alloc>
void
__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
{
 typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al;
 typedef allocator_traits<_Al> _ATraits;
 typedef pointer_traits<typename _ATraits::pointer> _PTraits;

 _Al __a(__data_.second());
 __data_.second().~_Alloc();
 __a.deallocate(_PTraits::pointer_to(*this), 1);
}

template <class _Tp, class _Alloc>
class __shared_ptr_emplace
 : public __shared_weak_count
{
 __compressed_pair<_Alloc, _Tp> __data_;
public:
#ifndef _LIBCPP_HAS_NO_VARIADICS

 _LIBCPP_INLINE_VISIBILITY
 __shared_ptr_emplace(_Alloc __a)
 : __data_(_VSTD::move(__a)) {}

 template <class ..._Args>
 _LIBCPP_INLINE_VISIBILITY
 __shared_ptr_emplace(_Alloc __a, _Args&& ...__args)
 : __data_(piecewise_construct, _VSTD::forward_as_tuple(__a),
 _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)) {}

#else // _LIBCPP_HAS_NO_VARIADICS

 _LIBCPP_INLINE_VISIBILITY
 __shared_ptr_emplace(_Alloc __a)
 : __data_(__a) {}

 template <class _A0>
 _LIBCPP_INLINE_VISIBILITY
 __shared_ptr_emplace(_Alloc __a, _A0& __a0)
 : __data_(__a, _Tp(__a0)) {}

 template <class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1)
 : __data_(__a, _Tp(__a0, __a1)) {}

 template <class _A0, class _A1, class _A2>
 _LIBCPP_INLINE_VISIBILITY
 __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1, _A2& __a2)
 : __data_(__a, _Tp(__a0, __a1, __a2)) {}

#endif // _LIBCPP_HAS_NO_VARIADICS

private:
 virtual void __on_zero_shared() _NOEXCEPT;
 virtual void __on_zero_shared_weak() _NOEXCEPT;
public:
 _LIBCPP_INLINE_VISIBILITY
 _Tp* get() _NOEXCEPT {return _VSTD::addressof(__data_.second());}
};

template <class _Tp, class _Alloc>
void
__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared() _NOEXCEPT
{
 __data_.second().~_Tp();
}

template <class _Tp, class _Alloc>
void
__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
{
 typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type _Al;
 typedef allocator_traits<_Al> _ATraits;
 typedef pointer_traits<typename _ATraits::pointer> _PTraits;
 _Al __a(__data_.first());
 __data_.first().~_Alloc();
 __a.deallocate(_PTraits::pointer_to(*this), 1);
}

struct __shared_ptr_dummy_rebind_allocator_type;
template <>
class _LIBCPP_TEMPLATE_VIS allocator<__shared_ptr_dummy_rebind_allocator_type>
{
public:
 template <class _Other>
 struct rebind
 {
 typedef allocator<_Other> other;
 };
};

template<class _Tp> class _LIBCPP_TEMPLATE_VIS enable_shared_from_this;

template<class _Tp>
class _LIBCPP_TEMPLATE_VIS shared_ptr
{
public:
 typedef _Tp element_type;

#if _LIBCPP_STD_VER > 14
 typedef weak_ptr<_Tp> weak_type;
#endif
private:
 element_type* __ptr_;
 __shared_weak_count* __cntrl_;

 struct __nat {int __for_bool_;};
public:
 _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT;
 _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT;
 template<class _Yp>
 explicit shared_ptr(_Yp* __p,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
 template<class _Yp, class _Dp>
 shared_ptr(_Yp* __p, _Dp __d,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
 template<class _Yp, class _Dp, class _Alloc>
 shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
 template <class _Dp> shared_ptr(nullptr_t __p, _Dp __d);
 template <class _Dp, class _Alloc> shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a);
 template<class _Yp> _LIBCPP_INLINE_VISIBILITY shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT;
 _LIBCPP_INLINE_VISIBILITY
 shared_ptr(const shared_ptr& __r) _NOEXCEPT;
 template<class _Yp>
 _LIBCPP_INLINE_VISIBILITY
 shared_ptr(const shared_ptr<_Yp>& __r,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat())
 _NOEXCEPT;
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 _LIBCPP_INLINE_VISIBILITY
 shared_ptr(shared_ptr&& __r) _NOEXCEPT;
 template<class _Yp> _LIBCPP_INLINE_VISIBILITY shared_ptr(shared_ptr<_Yp>&& __r,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat())
 _NOEXCEPT;
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 template<class _Yp> explicit shared_ptr(const weak_ptr<_Yp>& __r,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type= __nat());
#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 template<class _Yp>
 shared_ptr(auto_ptr<_Yp>&& __r,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
#else
 template<class _Yp>
 shared_ptr(auto_ptr<_Yp> __r,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
#endif
#endif
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 template <class _Yp, class _Dp>
 shared_ptr(unique_ptr<_Yp, _Dp>&&,
 typename enable_if
 <
 !is_lvalue_reference<_Dp>::value &&
 !is_array<_Yp>::value &&
 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
 __nat
 >::type = __nat());
 template <class _Yp, class _Dp>
 shared_ptr(unique_ptr<_Yp, _Dp>&&,
 typename enable_if
 <
 is_lvalue_reference<_Dp>::value &&
 !is_array<_Yp>::value &&
 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
 __nat
 >::type = __nat());
#else // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 template <class _Yp, class _Dp>
 shared_ptr(unique_ptr<_Yp, _Dp>,
 typename enable_if
 <
 !is_lvalue_reference<_Dp>::value &&
 !is_array<_Yp>::value &&
 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
 __nat
 >::type = __nat());
 template <class _Yp, class _Dp>
 shared_ptr(unique_ptr<_Yp, _Dp>,
 typename enable_if
 <
 is_lvalue_reference<_Dp>::value &&
 !is_array<_Yp>::value &&
 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
 __nat
 >::type = __nat());
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

 ~shared_ptr();

 _LIBCPP_INLINE_VISIBILITY
 shared_ptr& operator=(const shared_ptr& __r) _NOEXCEPT;
 template<class _Yp>
 typename enable_if
 <
 is_convertible<_Yp*, element_type*>::value,
 shared_ptr&
 >::type
 _LIBCPP_INLINE_VISIBILITY
 operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT;
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 _LIBCPP_INLINE_VISIBILITY
 shared_ptr& operator=(shared_ptr&& __r) _NOEXCEPT;
 template<class _Yp>
 typename enable_if
 <
 is_convertible<_Yp*, element_type*>::value,
 shared_ptr<_Tp>&
 >::type
 _LIBCPP_INLINE_VISIBILITY
 operator=(shared_ptr<_Yp>&& __r);
#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
 template<class _Yp>
 _LIBCPP_INLINE_VISIBILITY
 typename enable_if
 <
 !is_array<_Yp>::value &&
 is_convertible<_Yp*, element_type*>::value,
 shared_ptr
 >::type&
 operator=(auto_ptr<_Yp>&& __r);
#endif
#else // _LIBCPP_HAS_NO_RVALUE_REFERENCES
#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
 template<class _Yp>
 _LIBCPP_INLINE_VISIBILITY
 typename enable_if
 <
 !is_array<_Yp>::value &&
 is_convertible<_Yp*, element_type*>::value,
 shared_ptr&
 >::type
 operator=(auto_ptr<_Yp> __r);
#endif
#endif
 template <class _Yp, class _Dp>
 typename enable_if
 <
 !is_array<_Yp>::value &&
 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
 shared_ptr&
 >::type
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 _LIBCPP_INLINE_VISIBILITY
 operator=(unique_ptr<_Yp, _Dp>&& __r);
#else // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 _LIBCPP_INLINE_VISIBILITY
 operator=(unique_ptr<_Yp, _Dp> __r);
#endif

 _LIBCPP_INLINE_VISIBILITY
 void swap(shared_ptr& __r) _NOEXCEPT;
 _LIBCPP_INLINE_VISIBILITY
 void reset() _NOEXCEPT;
 template<class _Yp>
 typename enable_if
 <
 is_convertible<_Yp*, element_type*>::value,
 void
 >::type
 _LIBCPP_INLINE_VISIBILITY
 reset(_Yp* __p);
 template<class _Yp, class _Dp>
 typename enable_if
 <
 is_convertible<_Yp*, element_type*>::value,
 void
 >::type
 _LIBCPP_INLINE_VISIBILITY
 reset(_Yp* __p, _Dp __d);
 template<class _Yp, class _Dp, class _Alloc>
 typename enable_if
 <
 is_convertible<_Yp*, element_type*>::value,
 void
 >::type
 _LIBCPP_INLINE_VISIBILITY
 reset(_Yp* __p, _Dp __d, _Alloc __a);

 _LIBCPP_INLINE_VISIBILITY
 element_type* get() const _NOEXCEPT {return __ptr_;}
 _LIBCPP_INLINE_VISIBILITY
 typename add_lvalue_reference<element_type>::type operator*() const _NOEXCEPT
 {return *__ptr_;}
 _LIBCPP_INLINE_VISIBILITY
 element_type* operator->() const _NOEXCEPT {return __ptr_;}
 _LIBCPP_INLINE_VISIBILITY
 long use_count() const _NOEXCEPT {return __cntrl_ ? __cntrl_->use_count() : 0;}
 _LIBCPP_INLINE_VISIBILITY
 bool unique() const _NOEXCEPT {return use_count() == 1;}
 _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {return get() != 0;}
 template <class _Up>
 _LIBCPP_INLINE_VISIBILITY
 bool owner_before(shared_ptr<_Up> const& __p) const _NOEXCEPT
 {return __cntrl_ < __p.__cntrl_;}
 template <class _Up>
 _LIBCPP_INLINE_VISIBILITY
 bool owner_before(weak_ptr<_Up> const& __p) const _NOEXCEPT
 {return __cntrl_ < __p.__cntrl_;}
 _LIBCPP_INLINE_VISIBILITY
 bool
 __owner_equivalent(const shared_ptr& __p) const
 {return __cntrl_ == __p.__cntrl_;}

#ifndef _LIBCPP_NO_RTTI
 template <class _Dp>
 _LIBCPP_INLINE_VISIBILITY
 _Dp* __get_deleter() const _NOEXCEPT
 {return static_cast<_Dp*>(__cntrl_
 ? const_cast<void *>(__cntrl_->__get_deleter(typeid(_Dp)))
 : nullptr);}
#endif // _LIBCPP_NO_RTTI

#ifndef _LIBCPP_HAS_NO_VARIADICS

 template<class ..._Args>
 static
 shared_ptr<_Tp>
 make_shared(_Args&& ...__args);

 template<class _Alloc, class ..._Args>
 static
 shared_ptr<_Tp>
 allocate_shared(const _Alloc& __a, _Args&& ...__args);

#else // _LIBCPP_HAS_NO_VARIADICS

 static shared_ptr<_Tp> make_shared();

 template<class _A0>
 static shared_ptr<_Tp> make_shared(_A0&);

 template<class _A0, class _A1>
 static shared_ptr<_Tp> make_shared(_A0&, _A1&);

 template<class _A0, class _A1, class _A2>
 static shared_ptr<_Tp> make_shared(_A0&, _A1&, _A2&);

 template<class _Alloc>
 static shared_ptr<_Tp>
 allocate_shared(const _Alloc& __a);

 template<class _Alloc, class _A0>
 static shared_ptr<_Tp>
 allocate_shared(const _Alloc& __a, _A0& __a0);

 template<class _Alloc, class _A0, class _A1>
 static shared_ptr<_Tp>
 allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1);

 template<class _Alloc, class _A0, class _A1, class _A2>
 static shared_ptr<_Tp>
 allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2);

#endif // _LIBCPP_HAS_NO_VARIADICS

private:
 template <class _Yp, bool = is_function<_Yp>::value>
 struct __shared_ptr_default_allocator
 {
 typedef allocator<_Yp> type;
 };

 template <class _Yp>
 struct __shared_ptr_default_allocator<_Yp, true>
 {
 typedef allocator<__shared_ptr_dummy_rebind_allocator_type> type;
 };

 template <class _Yp, class _OrigPtr>
 _LIBCPP_INLINE_VISIBILITY
 typename enable_if<is_convertible<_OrigPtr*,
 const enable_shared_from_this<_Yp>*
 >::value,
 void>::type
 __enable_weak_this(const enable_shared_from_this<_Yp>* __e,
 _OrigPtr* __ptr) _NOEXCEPT
 {
 typedef typename remove_cv<_Yp>::type _RawYp;
 if (__e && __e->__weak_this_.expired())
 {
 __e->__weak_this_ = shared_ptr<_RawYp>(*this,
 const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr)));
 }
 }

 _LIBCPP_INLINE_VISIBILITY void __enable_weak_this(...) _NOEXCEPT {}

 template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
 template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
};


template<class _Tp>
inline
_LIBCPP_CONSTEXPR
shared_ptr<_Tp>::shared_ptr() _NOEXCEPT
 : __ptr_(0),
 __cntrl_(0)
{
}

template<class _Tp>
inline
_LIBCPP_CONSTEXPR
shared_ptr<_Tp>::shared_ptr(nullptr_t) _NOEXCEPT
 : __ptr_(0),
 __cntrl_(0)
{
}

template<class _Tp>
template<class _Yp>
shared_ptr<_Tp>::shared_ptr(_Yp* __p,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
 : __ptr_(__p)
{
 unique_ptr<_Yp> __hold(__p);
 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
 typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, _AllocT > _CntrlBlk;
 __cntrl_ = new _CntrlBlk(__p, default_delete<_Yp>(), _AllocT());
 __hold.release();
 __enable_weak_this(__p, __p);
}

template<class _Tp>
template<class _Yp, class _Dp>
shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
 : __ptr_(__p)
{
#ifndef _LIBCPP_NO_EXCEPTIONS
 try
 {
#endif // _LIBCPP_NO_EXCEPTIONS
 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
 typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
 __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
 __enable_weak_this(__p, __p);
#ifndef _LIBCPP_NO_EXCEPTIONS
 }
 catch (...)
 {
 __d(__p);
 throw;
 }
#endif // _LIBCPP_NO_EXCEPTIONS
}

template<class _Tp>
template<class _Dp>
shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d)
 : __ptr_(0)
{
#ifndef _LIBCPP_NO_EXCEPTIONS
 try
 {
#endif // _LIBCPP_NO_EXCEPTIONS
 typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT;
 typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT > _CntrlBlk;
 __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
#ifndef _LIBCPP_NO_EXCEPTIONS
 }
 catch (...)
 {
 __d(__p);
 throw;
 }
#endif // _LIBCPP_NO_EXCEPTIONS
}

template<class _Tp>
template<class _Yp, class _Dp, class _Alloc>
shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
 : __ptr_(__p)
{
#ifndef _LIBCPP_NO_EXCEPTIONS
 try
 {
#endif // _LIBCPP_NO_EXCEPTIONS
 typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
 typedef __allocator_destructor<_A2> _D2;
 _A2 __a2(__a);
 unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
 ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
 _CntrlBlk(__p, __d, __a);
 __cntrl_ = _VSTD::addressof(*__hold2.release());
 __enable_weak_this(__p, __p);
#ifndef _LIBCPP_NO_EXCEPTIONS
 }
 catch (...)
 {
 __d(__p);
 throw;
 }
#endif // _LIBCPP_NO_EXCEPTIONS
}

template<class _Tp>
template<class _Dp, class _Alloc>
shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a)
 : __ptr_(0)
{
#ifndef _LIBCPP_NO_EXCEPTIONS
 try
 {
#endif // _LIBCPP_NO_EXCEPTIONS
 typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
 typedef __allocator_destructor<_A2> _D2;
 _A2 __a2(__a);
 unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
 ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
 _CntrlBlk(__p, __d, __a);
 __cntrl_ = _VSTD::addressof(*__hold2.release());
#ifndef _LIBCPP_NO_EXCEPTIONS
 }
 catch (...)
 {
 __d(__p);
 throw;
 }
#endif // _LIBCPP_NO_EXCEPTIONS
}

template<class _Tp>
template<class _Yp>
inline
shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r, element_type *__p) _NOEXCEPT
 : __ptr_(__p),
 __cntrl_(__r.__cntrl_)
{
 if (__cntrl_)
 __cntrl_->__add_shared();
}

template<class _Tp>
inline
shared_ptr<_Tp>::shared_ptr(const shared_ptr& __r) _NOEXCEPT
 : __ptr_(__r.__ptr_),
 __cntrl_(__r.__cntrl_)
{
 if (__cntrl_)
 __cntrl_->__add_shared();
}

template<class _Tp>
template<class _Yp>
inline
shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
 _NOEXCEPT
 : __ptr_(__r.__ptr_),
 __cntrl_(__r.__cntrl_)
{
 if (__cntrl_)
 __cntrl_->__add_shared();
}

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES

template<class _Tp>
inline
shared_ptr<_Tp>::shared_ptr(shared_ptr&& __r) _NOEXCEPT
 : __ptr_(__r.__ptr_),
 __cntrl_(__r.__cntrl_)
{
 __r.__ptr_ = 0;
 __r.__cntrl_ = 0;
}

template<class _Tp>
template<class _Yp>
inline
shared_ptr<_Tp>::shared_ptr(shared_ptr<_Yp>&& __r,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
 _NOEXCEPT
 : __ptr_(__r.__ptr_),
 __cntrl_(__r.__cntrl_)
{
 __r.__ptr_ = 0;
 __r.__cntrl_ = 0;
}

#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
template<class _Tp>
template<class _Yp>
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp>&& __r,
#else
shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp> __r,
#endif
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
 : __ptr_(__r.get())
{
 typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
 __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<_Yp>());
 __enable_weak_this(__r.get(), __r.get());
 __r.release();
}
#endif

template<class _Tp>
template <class _Yp, class _Dp>
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
#else
shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
#endif
 typename enable_if
 <
 !is_lvalue_reference<_Dp>::value &&
 !is_array<_Yp>::value &&
 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
 __nat
 >::type)
 : __ptr_(__r.get())
{
#if _LIBCPP_STD_VER > 11
 if (__ptr_ == nullptr)
 __cntrl_ = nullptr;
 else
#endif
 {
 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
 typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
 __cntrl_ = new _CntrlBlk(__r.get(), __r.get_deleter(), _AllocT());
 __enable_weak_this(__r.get(), __r.get());
 }
 __r.release();
}

template<class _Tp>
template <class _Yp, class _Dp>
#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
#else
shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
#endif
 typename enable_if
 <
 is_lvalue_reference<_Dp>::value &&
 !is_array<_Yp>::value &&
 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
 __nat
 >::type)
 : __ptr_(__r.get())
{
#if _LIBCPP_STD_VER > 11
 if (__ptr_ == nullptr)
 __cntrl_ = nullptr;
 else
#endif
 {
 typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
 typedef __shared_ptr_pointer<_Yp*,
 reference_wrapper<typename remove_reference<_Dp>::type>,
 _AllocT > _CntrlBlk;
 __cntrl_ = new _CntrlBlk(__r.get(), ref(__r.get_deleter()), _AllocT());
 __enable_weak_this(__r.get(), __r.get());
 }
 __r.release();
}

#ifndef _LIBCPP_HAS_NO_VARIADICS

template<class _Tp>
template<class ..._Args>
shared_ptr<_Tp>
shared_ptr<_Tp>::make_shared(_Args&& ...__args)
{
 static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in make_shared" );
 typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
 typedef allocator<_CntrlBlk> _A2;
 typedef __allocator_destructor<_A2> _D2;
 _A2 __a2;
 unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
 ::new(__hold2.get()) _CntrlBlk(__a2, _VSTD::forward<_Args>(__args)...);
 shared_ptr<_Tp> __r;
 __r.__ptr_ = __hold2.get()->get();
 __r.__cntrl_ = __hold2.release();
 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
 return __r;
}

template<class _Tp>
template<class _Alloc, class ..._Args>
shared_ptr<_Tp>
shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _Args&& ...__args)
{
 static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in allocate_shared" );
 typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
 typedef __allocator_destructor<_A2> _D2;
 _A2 __a2(__a);
 unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
 ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
 _CntrlBlk(__a, _VSTD::forward<_Args>(__args)...);
 shared_ptr<_Tp> __r;
 __r.__ptr_ = __hold2.get()->get();
 __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
 return __r;
}

#else // _LIBCPP_HAS_NO_VARIADICS

template<class _Tp>
shared_ptr<_Tp>
shared_ptr<_Tp>::make_shared()
{
 static_assert((is_constructible<_Tp>::value), "Can't construct object in make_shared" );
 typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
 typedef allocator<_CntrlBlk> _Alloc2;
 typedef __allocator_destructor<_Alloc2> _D2;
 _Alloc2 __alloc2;
 unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
 ::new(__hold2.get()) _CntrlBlk(__alloc2);
 shared_ptr<_Tp> __r;
 __r.__ptr_ = __hold2.get()->get();
 __r.__cntrl_ = __hold2.release();
 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
 return __r;
}

template<class _Tp>
template<class _A0>
shared_ptr<_Tp>
shared_ptr<_Tp>::make_shared(_A0& __a0)
{
 static_assert((is_constructible<_Tp, _A0>::value), "Can't construct object in make_shared" );
 typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
 typedef allocator<_CntrlBlk> _Alloc2;
 typedef __allocator_destructor<_Alloc2> _D2;
 _Alloc2 __alloc2;
 unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
 ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0);
 shared_ptr<_Tp> __r;
 __r.__ptr_ = __hold2.get()->get();
 __r.__cntrl_ = __hold2.release();
 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
 return __r;
}

template<class _Tp>
template<class _A0, class _A1>
shared_ptr<_Tp>
shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1)
{
 static_assert((is_constructible<_Tp, _A0, _A1>::value), "Can't construct object in make_shared" );
 typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
 typedef allocator<_CntrlBlk> _Alloc2;
 typedef __allocator_destructor<_Alloc2> _D2;
 _Alloc2 __alloc2;
 unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
 ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1);
 shared_ptr<_Tp> __r;
 __r.__ptr_ = __hold2.get()->get();
 __r.__cntrl_ = __hold2.release();
 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
 return __r;
}

template<class _Tp>
template<class _A0, class _A1, class _A2>
shared_ptr<_Tp>
shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
{
 static_assert((is_constructible<_Tp, _A0, _A1, _A2>::value), "Can't construct object in make_shared" );
 typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
 typedef allocator<_CntrlBlk> _Alloc2;
 typedef __allocator_destructor<_Alloc2> _D2;
 _Alloc2 __alloc2;
 unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
 ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1, __a2);
 shared_ptr<_Tp> __r;
 __r.__ptr_ = __hold2.get()->get();
 __r.__cntrl_ = __hold2.release();
 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
 return __r;
}

template<class _Tp>
template<class _Alloc>
shared_ptr<_Tp>
shared_ptr<_Tp>::allocate_shared(const _Alloc& __a)
{
 static_assert((is_constructible<_Tp>::value), "Can't construct object in allocate_shared" );
 typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
 typedef __allocator_destructor<_Alloc2> _D2;
 _Alloc2 __alloc2(__a);
 unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
 ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
 _CntrlBlk(__a);
 shared_ptr<_Tp> __r;
 __r.__ptr_ = __hold2.get()->get();
 __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
 return __r;
}

template<class _Tp>
template<class _Alloc, class _A0>
shared_ptr<_Tp>
shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0)
{
 static_assert((is_constructible<_Tp, _A0>::value), "Can't construct object in allocate_shared" );
 typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
 typedef __allocator_destructor<_Alloc2> _D2;
 _Alloc2 __alloc2(__a);
 unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
 ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
 _CntrlBlk(__a, __a0);
 shared_ptr<_Tp> __r;
 __r.__ptr_ = __hold2.get()->get();
 __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
 return __r;
}

template<class _Tp>
template<class _Alloc, class _A0, class _A1>
shared_ptr<_Tp>
shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
{
 static_assert((is_constructible<_Tp, _A0, _A1>::value), "Can't construct object in allocate_shared" );
 typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
 typedef __allocator_destructor<_Alloc2> _D2;
 _Alloc2 __alloc2(__a);
 unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
 ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
 _CntrlBlk(__a, __a0, __a1);
 shared_ptr<_Tp> __r;
 __r.__ptr_ = __hold2.get()->get();
 __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
 return __r;
}

template<class _Tp>
template<class _Alloc, class _A0, class _A1, class _A2>
shared_ptr<_Tp>
shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
{
 static_assert((is_constructible<_Tp, _A0, _A1, _A2>::value), "Can't construct object in allocate_shared" );
 typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
 typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
 typedef __allocator_destructor<_Alloc2> _D2;
 _Alloc2 __alloc2(__a);
 unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
 ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
 _CntrlBlk(__a, __a0, __a1, __a2);
 shared_ptr<_Tp> __r;
 __r.__ptr_ = __hold2.get()->get();
 __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
 __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
 return __r;
}

#endif // _LIBCPP_HAS_NO_VARIADICS

template<class _Tp>
shared_ptr<_Tp>::~shared_ptr()
{
 if (__cntrl_)
 __cntrl_->__release_shared();
}

template<class _Tp>
inline
shared_ptr<_Tp>&
shared_ptr<_Tp>::operator=(const shared_ptr& __r) _NOEXCEPT
{
 shared_ptr(__r).swap(*this);
 return *this;
}

template<class _Tp>
template<class _Yp>
inline
typename enable_if
<
 is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
 shared_ptr<_Tp>&
>::type
shared_ptr<_Tp>::operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT
{
 shared_ptr(__r).swap(*this);
 return *this;
}

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES

template<class _Tp>
inline
shared_ptr<_Tp>&
shared_ptr<_Tp>::operator=(shared_ptr&& __r) _NOEXCEPT
{
 shared_ptr(_VSTD::move(__r)).swap(*this);
 return *this;
}

template<class _Tp>
template<class _Yp>
inline
typename enable_if
<
 is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
 shared_ptr<_Tp>&
>::type
shared_ptr<_Tp>::operator=(shared_ptr<_Yp>&& __r)
{
 shared_ptr(_VSTD::move(__r)).swap(*this);
 return *this;
}

#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
template<class _Tp>
template<class _Yp>
inline
typename enable_if
<
 !is_array<_Yp>::value &&
 is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
 shared_ptr<_Tp>
>::type&
shared_ptr<_Tp>::operator=(auto_ptr<_Yp>&& __r)
{
 shared_ptr(_VSTD::move(__r)).swap(*this);
 return *this;
}
#endif

template<class _Tp>
template <class _Yp, class _Dp>
inline
typename enable_if
<
 !is_array<_Yp>::value &&
 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
 typename shared_ptr<_Tp>::element_type*>::value,
 shared_ptr<_Tp>&
>::type
shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp>&& __r)
{
 shared_ptr(_VSTD::move(__r)).swap(*this);
 return *this;
}

#else // _LIBCPP_HAS_NO_RVALUE_REFERENCES

#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
template<class _Tp>
template<class _Yp>
inline _LIBCPP_INLINE_VISIBILITY
typename enable_if
<
 !is_array<_Yp>::value &&
 is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
 shared_ptr<_Tp>&
>::type
shared_ptr<_Tp>::operator=(auto_ptr<_Yp> __r)
{
 shared_ptr(__r).swap(*this);
 return *this;
}
#endif

template<class _Tp>
template <class _Yp, class _Dp>
inline _LIBCPP_INLINE_VISIBILITY
typename enable_if
<
 !is_array<_Yp>::value &&
 is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
 typename shared_ptr<_Tp>::element_type*>::value,
 shared_ptr<_Tp>&
>::type
shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp> __r)
{
 shared_ptr(_VSTD::move(__r)).swap(*this);
 return *this;
}

#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

template<class _Tp>
inline
void
shared_ptr<_Tp>::swap(shared_ptr& __r) _NOEXCEPT
{
 _VSTD::swap(__ptr_, __r.__ptr_);
 _VSTD::swap(__cntrl_, __r.__cntrl_);
}

template<class _Tp>
inline
void
shared_ptr<_Tp>::reset() _NOEXCEPT
{
 shared_ptr().swap(*this);
}

template<class _Tp>
template<class _Yp>
inline
typename enable_if
<
 is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
 void
>::type
shared_ptr<_Tp>::reset(_Yp* __p)
{
 shared_ptr(__p).swap(*this);
}

template<class _Tp>
template<class _Yp, class _Dp>
inline
typename enable_if
<
 is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
 void
>::type
shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d)
{
 shared_ptr(__p, __d).swap(*this);
}

template<class _Tp>
template<class _Yp, class _Dp, class _Alloc>
inline
typename enable_if
<
 is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
 void
>::type
shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d, _Alloc __a)
{
 shared_ptr(__p, __d, __a).swap(*this);
}

#ifndef _LIBCPP_HAS_NO_VARIADICS

template<class _Tp, class ..._Args>
inline _LIBCPP_INLINE_VISIBILITY
typename enable_if
<
 !is_array<_Tp>::value,
 shared_ptr<_Tp>
>::type
make_shared(_Args&& ...__args)
{
 return shared_ptr<_Tp>::make_shared(_VSTD::forward<_Args>(__args)...);
}

template<class _Tp, class _Alloc, class ..._Args>
inline _LIBCPP_INLINE_VISIBILITY
typename enable_if
<
 !is_array<_Tp>::value,
 shared_ptr<_Tp>
>::type
allocate_shared(const _Alloc& __a, _Args&& ...__args)
{
 return shared_ptr<_Tp>::allocate_shared(__a, _VSTD::forward<_Args>(__args)...);
}

#else // _LIBCPP_HAS_NO_VARIADICS

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
shared_ptr<_Tp>
make_shared()
{
 return shared_ptr<_Tp>::make_shared();
}

template<class _Tp, class _A0>
inline _LIBCPP_INLINE_VISIBILITY
shared_ptr<_Tp>
make_shared(_A0& __a0)
{
 return shared_ptr<_Tp>::make_shared(__a0);
}

template<class _Tp, class _A0, class _A1>
inline _LIBCPP_INLINE_VISIBILITY
shared_ptr<_Tp>
make_shared(_A0& __a0, _A1& __a1)
{
 return shared_ptr<_Tp>::make_shared(__a0, __a1);
}

template<class _Tp, class _A0, class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
shared_ptr<_Tp>
make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
{
 return shared_ptr<_Tp>::make_shared(__a0, __a1, __a2);
}

template<class _Tp, class _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
shared_ptr<_Tp>
allocate_shared(const _Alloc& __a)
{
 return shared_ptr<_Tp>::allocate_shared(__a);
}

template<class _Tp, class _Alloc, class _A0>
inline _LIBCPP_INLINE_VISIBILITY
shared_ptr<_Tp>
allocate_shared(const _Alloc& __a, _A0& __a0)
{
 return shared_ptr<_Tp>::allocate_shared(__a, __a0);
}

template<class _Tp, class _Alloc, class _A0, class _A1>
inline _LIBCPP_INLINE_VISIBILITY
shared_ptr<_Tp>
allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
{
 return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1);
}

template<class _Tp, class _Alloc, class _A0, class _A1, class _A2>
inline _LIBCPP_INLINE_VISIBILITY
shared_ptr<_Tp>
allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
{
 return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1, __a2);
}

#endif // _LIBCPP_HAS_NO_VARIADICS

template<class _Tp, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
{
 return __x.get() == __y.get();
}

template<class _Tp, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
{
 return !(__x == __y);
}

template<class _Tp, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
{
#if _LIBCPP_STD_VER <= 11
 typedef typename common_type<_Tp*, _Up*>::type _Vp;
 return less<_Vp>()(__x.get(), __y.get());
#else
 return less<>()(__x.get(), __y.get());
#endif

}

template<class _Tp, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
{
 return __y < __x;
}

template<class _Tp, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
{
 return !(__y < __x);
}

template<class _Tp, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
{
 return !(__x < __y);
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
{
 return !__x;
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
{
 return !__x;
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
{
 return static_cast<bool>(__x);
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
{
 return static_cast<bool>(__x);
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
{
 return less<_Tp*>()(__x.get(), nullptr);
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
{
 return less<_Tp*>()(nullptr, __x.get());
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
{
 return nullptr < __x;
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
{
 return __x < nullptr;
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
{
 return !(nullptr < __x);
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
{
 return !(__x < nullptr);
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
{
 return !(__x < nullptr);
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
{
 return !(nullptr < __x);
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
void
swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT
{
 __x.swap(__y);
}

template<class _Tp, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
typename enable_if
<
 !is_array<_Tp>::value && !is_array<_Up>::value,
 shared_ptr<_Tp>
>::type
static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
{
 return shared_ptr<_Tp>(__r, static_cast<_Tp*>(__r.get()));
}

template<class _Tp, class _Up>
inline _LIBCPP_INLINE_VISIBILITY
typename enable_if
<
 !is_array<_Tp>::value && !is_array<_Up>::value,
 shared_ptr<_Tp>
>::type
dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
{
 _Tp* __p = dynamic_cast<_Tp*>(__r.get());
 return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>();
}

template<class _Tp, class _Up>
typename enable_if
<
 is_array<_Tp>::value == is_array<_Up>::value,
 shared_ptr<_Tp>
>::type
const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
{
 typedef typename remove_extent<_Tp>::type _RTp;
 return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get()));
}

#ifndef _LIBCPP_NO_RTTI

template<class _Dp, class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
_Dp*
get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT
{
 return __p.template __get_deleter<_Dp>();
}

#endif // _LIBCPP_NO_RTTI

template<class _Tp>
class _LIBCPP_TEMPLATE_VIS weak_ptr
{
public:
 typedef _Tp element_type;
private:
 element_type* __ptr_;
 __shared_weak_count* __cntrl_;

public:
 _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT;
 template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(shared_ptr<_Yp> const& __r,
 typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
 _NOEXCEPT;
 _LIBCPP_INLINE_VISIBILITY
 weak_ptr(weak_ptr const& __r) _NOEXCEPT;
 template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp> const& __r,
 typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
 _NOEXCEPT;

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 _LIBCPP_INLINE_VISIBILITY
 weak_ptr(weak_ptr&& __r) _NOEXCEPT;
 template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp>&& __r,
 typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
 _NOEXCEPT;
#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 ~weak_ptr();

 _LIBCPP_INLINE_VISIBILITY
 weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT;
 template<class _Yp>
 typename enable_if
 <
 is_convertible<_Yp*, element_type*>::value,
 weak_ptr&
 >::type
 _LIBCPP_INLINE_VISIBILITY
 operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT;

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES

 _LIBCPP_INLINE_VISIBILITY
 weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT;
 template<class _Yp>
 typename enable_if
 <
 is_convertible<_Yp*, element_type*>::value,
 weak_ptr&
 >::type
 _LIBCPP_INLINE_VISIBILITY
 operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT;

#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

 template<class _Yp>
 typename enable_if
 <
 is_convertible<_Yp*, element_type*>::value,
 weak_ptr&
 >::type
 _LIBCPP_INLINE_VISIBILITY
 operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT;

 _LIBCPP_INLINE_VISIBILITY
 void swap(weak_ptr& __r) _NOEXCEPT;
 _LIBCPP_INLINE_VISIBILITY
 void reset() _NOEXCEPT;

 _LIBCPP_INLINE_VISIBILITY
 long use_count() const _NOEXCEPT
 {return __cntrl_ ? __cntrl_->use_count() : 0;}
 _LIBCPP_INLINE_VISIBILITY
 bool expired() const _NOEXCEPT
 {return __cntrl_ == 0 || __cntrl_->use_count() == 0;}
 shared_ptr<_Tp> lock() const _NOEXCEPT;
 template<class _Up>
 _LIBCPP_INLINE_VISIBILITY
 bool owner_before(const shared_ptr<_Up>& __r) const _NOEXCEPT
 {return __cntrl_ < __r.__cntrl_;}
 template<class _Up>
 _LIBCPP_INLINE_VISIBILITY
 bool owner_before(const weak_ptr<_Up>& __r) const _NOEXCEPT
 {return __cntrl_ < __r.__cntrl_;}

 template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
 template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
};

template<class _Tp>
inline
_LIBCPP_CONSTEXPR
weak_ptr<_Tp>::weak_ptr() _NOEXCEPT
 : __ptr_(0),
 __cntrl_(0)
{
}

template<class _Tp>
inline
weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT
 : __ptr_(__r.__ptr_),
 __cntrl_(__r.__cntrl_)
{
 if (__cntrl_)
 __cntrl_->__add_weak();
}

template<class _Tp>
template<class _Yp>
inline
weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r,
 typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
 _NOEXCEPT
 : __ptr_(__r.__ptr_),
 __cntrl_(__r.__cntrl_)
{
 if (__cntrl_)
 __cntrl_->__add_weak();
}

template<class _Tp>
template<class _Yp>
inline
weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r,
 typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
 _NOEXCEPT
 : __ptr_(__r.__ptr_),
 __cntrl_(__r.__cntrl_)
{
 if (__cntrl_)
 __cntrl_->__add_weak();
}

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES

template<class _Tp>
inline
weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT
 : __ptr_(__r.__ptr_),
 __cntrl_(__r.__cntrl_)
{
 __r.__ptr_ = 0;
 __r.__cntrl_ = 0;
}

template<class _Tp>
template<class _Yp>
inline
weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r,
 typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
 _NOEXCEPT
 : __ptr_(__r.__ptr_),
 __cntrl_(__r.__cntrl_)
{
 __r.__ptr_ = 0;
 __r.__cntrl_ = 0;
}

#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

template<class _Tp>
weak_ptr<_Tp>::~weak_ptr()
{
 if (__cntrl_)
 __cntrl_->__release_weak();
}

template<class _Tp>
inline
weak_ptr<_Tp>&
weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT
{
 weak_ptr(__r).swap(*this);
 return *this;
}

template<class _Tp>
template<class _Yp>
inline
typename enable_if
<
 is_convertible<_Yp*, _Tp*>::value,
 weak_ptr<_Tp>&
>::type
weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT
{
 weak_ptr(__r).swap(*this);
 return *this;
}

#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES

template<class _Tp>
inline
weak_ptr<_Tp>&
weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT
{
 weak_ptr(_VSTD::move(__r)).swap(*this);
 return *this;
}

template<class _Tp>
template<class _Yp>
inline
typename enable_if
<
 is_convertible<_Yp*, _Tp*>::value,
 weak_ptr<_Tp>&
>::type
weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT
{
 weak_ptr(_VSTD::move(__r)).swap(*this);
 return *this;
}

#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES

template<class _Tp>
template<class _Yp>
inline
typename enable_if
<
 is_convertible<_Yp*, _Tp*>::value,
 weak_ptr<_Tp>&
>::type
weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT
{
 weak_ptr(__r).swap(*this);
 return *this;
}

template<class _Tp>
inline
void
weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT
{
 _VSTD::swap(__ptr_, __r.__ptr_);
 _VSTD::swap(__cntrl_, __r.__cntrl_);
}

template<class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
void
swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT
{
 __x.swap(__y);
}

template<class _Tp>
inline
void
weak_ptr<_Tp>::reset() _NOEXCEPT
{
 weak_ptr().swap(*this);
}

template<class _Tp>
template<class _Yp>
shared_ptr<_Tp>::shared_ptr(const weak_ptr<_Yp>& __r,
 typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
 : __ptr_(__r.__ptr_),
 __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_)
{
 if (__cntrl_ == 0)
 __throw_bad_weak_ptr();
}

template<class _Tp>
shared_ptr<_Tp>
weak_ptr<_Tp>::lock() const _NOEXCEPT
{
 shared_ptr<_Tp> __r;
 __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_;
 if (__r.__cntrl_)
 __r.__ptr_ = __ptr_;
 return __r;
}

#if _LIBCPP_STD_VER > 14
template <class _Tp = void> struct owner_less;
#else
template <class _Tp> struct owner_less;
#endif

template <class _Tp>
struct _LIBCPP_TEMPLATE_VIS owner_less<shared_ptr<_Tp> >
 : binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool>
{
 typedef bool result_type;
 _LIBCPP_INLINE_VISIBILITY
 bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
 {return __x.owner_before(__y);}
 _LIBCPP_INLINE_VISIBILITY
 bool operator()(shared_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT
 {return __x.owner_before(__y);}
 _LIBCPP_INLINE_VISIBILITY
 bool operator()( weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
 {return __x.owner_before(__y);}
};

template <class _Tp>
struct _LIBCPP_TEMPLATE_VIS owner_less<weak_ptr<_Tp> >
 : binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool>
{
 typedef bool result_type;
 _LIBCPP_INLINE_VISIBILITY
 bool operator()( weak_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT
 {return __x.owner_before(__y);}
 _LIBCPP_INLINE_VISIBILITY
 bool operator()(shared_ptr<_Tp> const& __x, weak_ptr<_Tp> const& __y) const _NOEXCEPT
 {return __x.owner_before(__y);}
 _LIBCPP_INLINE_VISIBILITY
 bool operator()( weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
 {return __x.owner_before(__y);}
};

#if _LIBCPP_STD_VER > 14
template <>
struct _LIBCPP_TEMPLATE_VIS owner_less<void>
{
 template <class _Tp, class _Up>
 _LIBCPP_INLINE_VISIBILITY
 bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
 {return __x.owner_before(__y);}
 template <class _Tp, class _Up>
 _LIBCPP_INLINE_VISIBILITY
 bool operator()( shared_ptr<_Tp> const& __x, weak_ptr<_Up> const& __y) const _NOEXCEPT
 {return __x.owner_before(__y);}
 template <class _Tp, class _Up>
 _LIBCPP_INLINE_VISIBILITY
 bool operator()( weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
 {return __x.owner_before(__y);}
 template <class _Tp, class _Up>
 _LIBCPP_INLINE_VISIBILITY
 bool operator()( weak_ptr<_Tp> const& __x, weak_ptr<_Up> const& __y) const _NOEXCEPT
 {return __x.owner_before(__y);}
 typedef void is_transparent;
};
#endif

template<class _Tp>
class _LIBCPP_TEMPLATE_VIS enable_shared_from_this
{
 mutable weak_ptr<_Tp> __weak_this_;
protected:
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
 enable_shared_from_this() _NOEXCEPT {}
 _LIBCPP_INLINE_VISIBILITY
 enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {}
 _LIBCPP_INLINE_VISIBILITY
 enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT
 {return *this;}
 _LIBCPP_INLINE_VISIBILITY
 ~enable_shared_from_this() {}
public:
 _LIBCPP_INLINE_VISIBILITY
 shared_ptr<_Tp> shared_from_this()
 {return shared_ptr<_Tp>(__weak_this_);}
 _LIBCPP_INLINE_VISIBILITY
 shared_ptr<_Tp const> shared_from_this() const
 {return shared_ptr<const _Tp>(__weak_this_);}

#if _LIBCPP_STD_VER > 14
 _LIBCPP_INLINE_VISIBILITY
 weak_ptr<_Tp> weak_from_this() _NOEXCEPT
 { return __weak_this_; }

 _LIBCPP_INLINE_VISIBILITY
 weak_ptr<const _Tp> weak_from_this() const _NOEXCEPT
 { return __weak_this_; }
#endif // _LIBCPP_STD_VER > 14

 template <class _Up> friend class shared_ptr;
};

template <class _Tp>
struct _LIBCPP_TEMPLATE_VIS hash<shared_ptr<_Tp> >
{
 typedef shared_ptr<_Tp> argument_type;
 typedef size_t result_type;

 _LIBCPP_INLINE_VISIBILITY
 result_type operator()(const argument_type& __ptr) const _NOEXCEPT
 {
 return hash<_Tp*>()(__ptr.get());
 }
};

template<class _CharT, class _Traits, class _Yp>
inline _LIBCPP_INLINE_VISIBILITY
basic_ostream<_CharT, _Traits>&
operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);


#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)

class _LIBCPP_TYPE_VIS __sp_mut
{
 void* __lx;
public:
 void lock() _NOEXCEPT;
 void unlock() _NOEXCEPT;

private:
 _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT;
 __sp_mut(const __sp_mut&);
 __sp_mut& operator=(const __sp_mut&);

 friend _LIBCPP_FUNC_VIS __sp_mut& __get_sp_mut(const void*);
};

_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
__sp_mut& __get_sp_mut(const void*);

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool
atomic_is_lock_free(const shared_ptr<_Tp>*)
{
 return false;
}

template <class _Tp>
_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
shared_ptr<_Tp>
atomic_load(const shared_ptr<_Tp>* __p)
{
 __sp_mut& __m = __get_sp_mut(__p);
 __m.lock();
 shared_ptr<_Tp> __q = *__p;
 __m.unlock();
 return __q;
}

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
shared_ptr<_Tp>
atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order)
{
 return atomic_load(__p);
}

template <class _Tp>
_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
void
atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
{
 __sp_mut& __m = __get_sp_mut(__p);
 __m.lock();
 __p->swap(__r);
 __m.unlock();
}

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
void
atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
{
 atomic_store(__p, __r);
}

template <class _Tp>
_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
shared_ptr<_Tp>
atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
{
 __sp_mut& __m = __get_sp_mut(__p);
 __m.lock();
 __p->swap(__r);
 __m.unlock();
 return __r;
}

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
shared_ptr<_Tp>
atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
{
 return atomic_exchange(__p, __r);
}

template <class _Tp>
_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
bool
atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
{
 shared_ptr<_Tp> __temp;
 __sp_mut& __m = __get_sp_mut(__p);
 __m.lock();
 if (__p->__owner_equivalent(*__v))
 {
 _VSTD::swap(__temp, *__p);
 *__p = __w;
 __m.unlock();
 return true;
 }
 _VSTD::swap(__temp, *__v);
 *__v = *__p;
 __m.unlock();
 return false;
}

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
bool
atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
{
 return atomic_compare_exchange_strong(__p, __v, __w);
}

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
bool
atomic_compare_exchange_strong_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
 shared_ptr<_Tp> __w, memory_order, memory_order)
{
 return atomic_compare_exchange_strong(__p, __v, __w);
}

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
bool
atomic_compare_exchange_weak_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
 shared_ptr<_Tp> __w, memory_order, memory_order)
{
 return atomic_compare_exchange_weak(__p, __v, __w);
}

#endif // !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)

//enum class
#if defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE)
# ifndef _LIBCPP_CXX03_LANG
enum class pointer_safety : unsigned char {
 relaxed,
 preferred,
 strict
};
# endif
#else
struct _LIBCPP_TYPE_VIS pointer_safety
{
 enum __lx
 {
 relaxed,
 preferred,
 strict
 };

 __lx __v_;

 _LIBCPP_INLINE_VISIBILITY
 pointer_safety() : __v_() {}

 _LIBCPP_INLINE_VISIBILITY
 pointer_safety(__lx __v) : __v_(__v) {}
 _LIBCPP_INLINE_VISIBILITY
 operator int() const {return __v_;}
};
#endif

#if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) && \
 defined(_LIBCPP_BUILDING_LIBRARY)
_LIBCPP_FUNC_VIS pointer_safety get_pointer_safety() _NOEXCEPT;
#else
// This function is only offered in C++03 under ABI v1.
# if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) || !defined(_LIBCPP_CXX03_LANG)
inline _LIBCPP_INLINE_VISIBILITY
pointer_safety get_pointer_safety() _NOEXCEPT {
 return pointer_safety::relaxed;
}
# endif
#endif


_LIBCPP_FUNC_VIS void declare_reachable(void* __p);
_LIBCPP_FUNC_VIS void declare_no_pointers(char* __p, size_t __n);
_LIBCPP_FUNC_VIS void undeclare_no_pointers(char* __p, size_t __n);
_LIBCPP_FUNC_VIS void* __undeclare_reachable(void* __p);

template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
_Tp*
undeclare_reachable(_Tp* __p)
{
 return static_cast<_Tp*>(__undeclare_reachable(__p));
}

_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);

// --- Helper for container swap --
template <typename _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
#if _LIBCPP_STD_VER >= 14
 _NOEXCEPT
#else
 _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
#endif
{
 __swap_allocator(__a1, __a2,
 integral_constant<bool, _VSTD::allocator_traits<_Alloc>::propagate_on_container_swap::value>());
}

template <typename _Alloc>
_LIBCPP_INLINE_VISIBILITY
void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
#if _LIBCPP_STD_VER >= 14
 _NOEXCEPT
#else
 _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
#endif
{
 using _VSTD::swap;
 swap(__a1, __a2);
}

template <typename _Alloc>
inline _LIBCPP_INLINE_VISIBILITY
void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}

template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
struct __noexcept_move_assign_container : public integral_constant<bool,
 _Traits::propagate_on_container_move_assignment::value
#if _LIBCPP_STD_VER > 14
 || _Traits::is_always_equal::value
#else
 && is_nothrow_move_assignable<_Alloc>::value
#endif
 > {};


#ifndef _LIBCPP_HAS_NO_VARIADICS
template <class _Tp, class _Alloc>
struct __temp_value {
 typedef allocator_traits<_Alloc> _Traits;

 typename aligned_storage<sizeof(_Tp), alignof(_Tp)>::type __v;
 _Alloc &__a;

 _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
 _Tp & get() { return *__addr(); }

 template<class... _Args>
 _LIBCPP_NO_CFI
 __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
 _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
 _VSTD::forward<_Args>(__args)...);
 }

 ~__temp_value() { _Traits::destroy(__a, __addr()); }
 };
#endif

template<typename _Alloc, typename = void, typename = void>
struct __is_allocator : false_type {};

template<typename _Alloc>
struct __is_allocator<_Alloc,
 typename __void_t<typename _Alloc::value_type>::type,
 typename __void_t<decltype(_VSTD::declval<_Alloc&>().allocate(size_t(0)))>::type
 >
 : true_type {};

_LIBCPP_END_NAMESPACE_STD

_LIBCPP_POP_MACROS

#endif // _LIBCPP_MEMORY