include/functional

// -*- C++ -*-
//===------------------------ functional ----------------------------------===//
//
// 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_FUNCTIONAL
#define _LIBCPP_FUNCTIONAL

/*
 functional synopsis

namespace std
{

template <class Arg, class Result>
struct unary_function
{
 typedef Arg argument_type;
 typedef Result result_type;
};

template <class Arg1, class Arg2, class Result>
struct binary_function
{
 typedef Arg1 first_argument_type;
 typedef Arg2 second_argument_type;
 typedef Result result_type;
};

template <class T>
class reference_wrapper
 : public unary_function<T1, R> // if wrapping a unary functor
 : public binary_function<T1, T2, R> // if wraping a binary functor
{
public:
 // types
 typedef T type;
 typedef see below result_type; // Not always defined

 // construct/copy/destroy
 reference_wrapper(T&) noexcept;
 reference_wrapper(T&&) = delete; // do not bind to temps
 reference_wrapper(const reference_wrapper<T>& x) noexcept;

 // assignment
 reference_wrapper& operator=(const reference_wrapper<T>& x) noexcept;

 // access
 operator T& () const noexcept;
 T& get() const noexcept;

 // invoke
 template <class... ArgTypes>
 typename result_of<T&(ArgTypes&&...)>::type
 operator() (ArgTypes&&...) const;
};

template <class T> reference_wrapper<T> ref(T& t) noexcept;
template <class T> void ref(const T&& t) = delete;
template <class T> reference_wrapper<T> ref(reference_wrapper<T>t) noexcept;

template <class T> reference_wrapper<const T> cref(const T& t) noexcept;
template <class T> void cref(const T&& t) = delete;
template <class T> reference_wrapper<const T> cref(reference_wrapper<T> t) noexcept;

template <class T> // <class T=void> in C++14
struct plus : binary_function<T, T, T>
{
 T operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct minus : binary_function<T, T, T>
{
 T operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct multiplies : binary_function<T, T, T>
{
 T operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct divides : binary_function<T, T, T>
{
 T operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct modulus : binary_function<T, T, T>
{
 T operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct negate : unary_function<T, T>
{
 T operator()(const T& x) const;
};

template <class T> // <class T=void> in C++14
struct equal_to : binary_function<T, T, bool>
{
 bool operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct not_equal_to : binary_function<T, T, bool>
{
 bool operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct greater : binary_function<T, T, bool>
{
 bool operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct less : binary_function<T, T, bool>
{
 bool operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct greater_equal : binary_function<T, T, bool>
{
 bool operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct less_equal : binary_function<T, T, bool>
{
 bool operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct logical_and : binary_function<T, T, bool>
{
 bool operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct logical_or : binary_function<T, T, bool>
{
 bool operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct logical_not : unary_function<T, bool>
{
 bool operator()(const T& x) const;
};

template <class T> // <class T=void> in C++14
struct bit_and : unary_function<T, bool>
{
 bool operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct bit_or : unary_function<T, bool>
{
 bool operator()(const T& x, const T& y) const;
};

template <class T> // <class T=void> in C++14
struct bit_xor : unary_function<T, bool>
{
 bool operator()(const T& x, const T& y) const;
};

template <class T=void> // C++14
struct bit_xor : unary_function<T, bool>
{
 bool operator()(const T& x) const;
};

template <class Predicate>
class unary_negate
 : public unary_function<typename Predicate::argument_type, bool>
{
public:
 explicit unary_negate(const Predicate& pred);
 bool operator()(const typename Predicate::argument_type& x) const;
};

template <class Predicate> unary_negate<Predicate> not1(const Predicate& pred);

template <class Predicate>
class binary_negate
 : public binary_function<typename Predicate::first_argument_type,
 typename Predicate::second_argument_type,
 bool>
{
public:
 explicit binary_negate(const Predicate& pred);
 bool operator()(const typename Predicate::first_argument_type& x,
 const typename Predicate::second_argument_type& y) const;
};

template <class Predicate> binary_negate<Predicate> not2(const Predicate& pred);

template <class F> unspecified not_fn(F&& f); // C++17

template<class T> struct is_bind_expression;
template<class T> struct is_placeholder;

 // See C++14 20.9.9, Function object binders
template <class T> constexpr bool is_bind_expression_v
 = is_bind_expression<T>::value; // C++17
template <class T> constexpr int is_placeholder_v
 = is_placeholder<T>::value; // C++17


template<class Fn, class... BoundArgs>
 unspecified bind(Fn&&, BoundArgs&&...);
template<class R, class Fn, class... BoundArgs>
 unspecified bind(Fn&&, BoundArgs&&...);

namespace placeholders {
 // M is the implementation-defined number of placeholders
 extern unspecified _1;
 extern unspecified _2;
 .
 .
 .
 extern unspecified _Mp;
}

template <class Operation>
class binder1st
 : public unary_function<typename Operation::second_argument_type,
 typename Operation::result_type>
{
protected:
 Operation op;
 typename Operation::first_argument_type value;
public:
 binder1st(const Operation& x, const typename Operation::first_argument_type y);
 typename Operation::result_type operator()( typename Operation::second_argument_type& x) const;
 typename Operation::result_type operator()(const typename Operation::second_argument_type& x) const;
};

template <class Operation, class T>
binder1st<Operation> bind1st(const Operation& op, const T& x);

template <class Operation>
class binder2nd
 : public unary_function<typename Operation::first_argument_type,
 typename Operation::result_type>
{
protected:
 Operation op;
 typename Operation::second_argument_type value;
public:
 binder2nd(const Operation& x, const typename Operation::second_argument_type y);
 typename Operation::result_type operator()( typename Operation::first_argument_type& x) const;
 typename Operation::result_type operator()(const typename Operation::first_argument_type& x) const;
};

template <class Operation, class T>
binder2nd<Operation> bind2nd(const Operation& op, const T& x);

template <class Arg, class Result>
class pointer_to_unary_function : public unary_function<Arg, Result>
{
public:
 explicit pointer_to_unary_function(Result (*f)(Arg));
 Result operator()(Arg x) const;
};

template <class Arg, class Result>
pointer_to_unary_function<Arg,Result> ptr_fun(Result (*f)(Arg));

template <class Arg1, class Arg2, class Result>
class pointer_to_binary_function : public binary_function<Arg1, Arg2, Result>
{
public:
 explicit pointer_to_binary_function(Result (*f)(Arg1, Arg2));
 Result operator()(Arg1 x, Arg2 y) const;
};

template <class Arg1, class Arg2, class Result>
pointer_to_binary_function<Arg1,Arg2,Result> ptr_fun(Result (*f)(Arg1,Arg2));

template<class S, class T>
class mem_fun_t : public unary_function<T*, S>
{
public:
 explicit mem_fun_t(S (T::*p)());
 S operator()(T* p) const;
};

template<class S, class T, class A>
class mem_fun1_t : public binary_function<T*, A, S>
{
public:
 explicit mem_fun1_t(S (T::*p)(A));
 S operator()(T* p, A x) const;
};

template<class S, class T> mem_fun_t<S,T> mem_fun(S (T::*f)());
template<class S, class T, class A> mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A));

template<class S, class T>
class mem_fun_ref_t : public unary_function<T, S>
{
public:
 explicit mem_fun_ref_t(S (T::*p)());
 S operator()(T& p) const;
};

template<class S, class T, class A>
class mem_fun1_ref_t : public binary_function<T, A, S>
{
public:
 explicit mem_fun1_ref_t(S (T::*p)(A));
 S operator()(T& p, A x) const;
};

template<class S, class T> mem_fun_ref_t<S,T> mem_fun_ref(S (T::*f)());
template<class S, class T, class A> mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A));

template <class S, class T>
class const_mem_fun_t : public unary_function<const T*, S>
{
public:
 explicit const_mem_fun_t(S (T::*p)() const);
 S operator()(const T* p) const;
};

template <class S, class T, class A>
class const_mem_fun1_t : public binary_function<const T*, A, S>
{
public:
 explicit const_mem_fun1_t(S (T::*p)(A) const);
 S operator()(const T* p, A x) const;
};

template <class S, class T> const_mem_fun_t<S,T> mem_fun(S (T::*f)() const);
template <class S, class T, class A> const_mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A) const);

template <class S, class T>
class const_mem_fun_ref_t : public unary_function<T, S>
{
public:
 explicit const_mem_fun_ref_t(S (T::*p)() const);
 S operator()(const T& p) const;
};

template <class S, class T, class A>
class const_mem_fun1_ref_t : public binary_function<T, A, S>
{
public:
 explicit const_mem_fun1_ref_t(S (T::*p)(A) const);
 S operator()(const T& p, A x) const;
};

template <class S, class T> const_mem_fun_ref_t<S,T> mem_fun_ref(S (T::*f)() const);
template <class S, class T, class A> const_mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A) const);

template<class R, class T> unspecified mem_fn(R T::*);

class bad_function_call
 : public exception
{
};

template<class> class function; // undefined

template<class R, class... ArgTypes>
class function<R(ArgTypes...)>
 : public unary_function<T1, R> // iff sizeof...(ArgTypes) == 1 and
 // ArgTypes contains T1
 : public binary_function<T1, T2, R> // iff sizeof...(ArgTypes) == 2 and
 // ArgTypes contains T1 and T2
{
public:
 typedef R result_type;

 // construct/copy/destroy:
 function() noexcept;
 function(nullptr_t) noexcept;
 function(const function&);
 function(function&&) noexcept;
 template<class F>
 function(F);
 template<Allocator Alloc>
 function(allocator_arg_t, const Alloc&) noexcept; // removed in C++17
 template<Allocator Alloc>
 function(allocator_arg_t, const Alloc&, nullptr_t) noexcept; // removed in C++17
 template<Allocator Alloc>
 function(allocator_arg_t, const Alloc&, const function&); // removed in C++17
 template<Allocator Alloc>
 function(allocator_arg_t, const Alloc&, function&&); // removed in C++17
 template<class F, Allocator Alloc>
 function(allocator_arg_t, const Alloc&, F); // removed in C++17

 function& operator=(const function&);
 function& operator=(function&&) noexcept;
 function& operator=(nullptr_t) noexcept;
 template<class F>
 function& operator=(F&&);
 template<class F>
 function& operator=(reference_wrapper<F>) noexcept;

 ~function();

 // function modifiers:
 void swap(function&) noexcept;
 template<class F, class Alloc>
 void assign(F&&, const Alloc&); // Removed in C++17

 // function capacity:
 explicit operator bool() const noexcept;

 // function invocation:
 R operator()(ArgTypes...) const;

 // function target access:
 const std::type_info& target_type() const noexcept;
 template <typename T> T* target() noexcept;
 template <typename T> const T* target() const noexcept;
};

// Null pointer comparisons:
template <class R, class ... ArgTypes>
 bool operator==(const function<R(ArgTypes...)>&, nullptr_t) noexcept;

template <class R, class ... ArgTypes>
 bool operator==(nullptr_t, const function<R(ArgTypes...)>&) noexcept;

template <class R, class ... ArgTypes>
 bool operator!=(const function<R(ArgTypes...)>&, nullptr_t) noexcept;

template <class R, class ... ArgTypes>
 bool operator!=(nullptr_t, const function<R(ArgTypes...)>&) noexcept;

// specialized algorithms:
template <class R, class ... ArgTypes>
 void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&) noexcept;

template <class T> struct hash;

template <> struct hash<bool>;
template <> struct hash<char>;
template <> struct hash<signed char>;
template <> struct hash<unsigned char>;
template <> struct hash<char16_t>;
template <> struct hash<char32_t>;
template <> struct hash<wchar_t>;
template <> struct hash<short>;
template <> struct hash<unsigned short>;
template <> struct hash<int>;
template <> struct hash<unsigned int>;
template <> struct hash<long>;
template <> struct hash<long long>;
template <> struct hash<unsigned long>;
template <> struct hash<unsigned long long>;

template <> struct hash<float>;
template <> struct hash<double>;
template <> struct hash<long double>;

template<class T> struct hash<T*>;

} // std

POLICY: For non-variadic implementations, the number of arguments is limited
 to 3. It is hoped that the need for non-variadic implementations
 will be minimal.

*/

#include <__config>
#include <type_traits>
#include <typeinfo>
#include <exception>
#include <memory>
#include <tuple>

#include <__functional_base>

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

_LIBCPP_BEGIN_NAMESPACE_STD

#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY plus : binary_function<_Tp, _Tp, _Tp>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 _Tp operator()(const _Tp& __x, const _Tp& __y) const
 {return __x + __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY plus<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY minus : binary_function<_Tp, _Tp, _Tp>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 _Tp operator()(const _Tp& __x, const _Tp& __y) const
 {return __x - __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY minus<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY multiplies : binary_function<_Tp, _Tp, _Tp>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 _Tp operator()(const _Tp& __x, const _Tp& __y) const
 {return __x * __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY multiplies<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY divides : binary_function<_Tp, _Tp, _Tp>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 _Tp operator()(const _Tp& __x, const _Tp& __y) const
 {return __x / __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY divides<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY modulus : binary_function<_Tp, _Tp, _Tp>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 _Tp operator()(const _Tp& __x, const _Tp& __y) const
 {return __x % __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY modulus<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY negate : unary_function<_Tp, _Tp>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 _Tp operator()(const _Tp& __x) const
 {return -__x;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY negate<void>
{
 template <class _Tp>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_Tp&& __x) const
 _NOEXCEPT_(noexcept(- _VSTD::forward<_Tp>(__x)))
 -> decltype (- _VSTD::forward<_Tp>(__x))
 { return - _VSTD::forward<_Tp>(__x); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY equal_to : binary_function<_Tp, _Tp, bool>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator()(const _Tp& __x, const _Tp& __y) const
 {return __x == __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY equal_to<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY not_equal_to : binary_function<_Tp, _Tp, bool>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator()(const _Tp& __x, const _Tp& __y) const
 {return __x != __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY not_equal_to<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY greater : binary_function<_Tp, _Tp, bool>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator()(const _Tp& __x, const _Tp& __y) const
 {return __x > __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY greater<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


// less in <__functional_base>

#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY greater_equal : binary_function<_Tp, _Tp, bool>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator()(const _Tp& __x, const _Tp& __y) const
 {return __x >= __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY greater_equal<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY less_equal : binary_function<_Tp, _Tp, bool>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator()(const _Tp& __x, const _Tp& __y) const
 {return __x <= __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY less_equal<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY logical_and : binary_function<_Tp, _Tp, bool>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator()(const _Tp& __x, const _Tp& __y) const
 {return __x && __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY logical_and<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY logical_or : binary_function<_Tp, _Tp, bool>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator()(const _Tp& __x, const _Tp& __y) const
 {return __x || __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY logical_or<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY logical_not : unary_function<_Tp, bool>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator()(const _Tp& __x) const
 {return !__x;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY logical_not<void>
{
 template <class _Tp>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_Tp&& __x) const
 _NOEXCEPT_(noexcept(!_VSTD::forward<_Tp>(__x)))
 -> decltype (!_VSTD::forward<_Tp>(__x))
 { return !_VSTD::forward<_Tp>(__x); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY bit_and : binary_function<_Tp, _Tp, _Tp>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 _Tp operator()(const _Tp& __x, const _Tp& __y) const
 {return __x & __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY bit_and<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY bit_or : binary_function<_Tp, _Tp, _Tp>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 _Tp operator()(const _Tp& __x, const _Tp& __y) const
 {return __x | __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY bit_or<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
#else
template <class _Tp>
#endif
struct _LIBCPP_TYPE_VIS_ONLY bit_xor : binary_function<_Tp, _Tp, _Tp>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 _Tp operator()(const _Tp& __x, const _Tp& __y) const
 {return __x ^ __y;}
};

#if _LIBCPP_STD_VER > 11
template <>
struct _LIBCPP_TYPE_VIS_ONLY bit_xor<void>
{
 template <class _T1, class _T2>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_T1&& __t, _T2&& __u) const
 _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u)))
 -> decltype (_VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u))
 { return _VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u); }
 typedef void is_transparent;
};
#endif


#if _LIBCPP_STD_VER > 11
template <class _Tp = void>
struct _LIBCPP_TYPE_VIS_ONLY bit_not : unary_function<_Tp, _Tp>
{
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 _Tp operator()(const _Tp& __x) const
 {return ~__x;}
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY bit_not<void>
{
 template <class _Tp>
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_Tp&& __x) const
 _NOEXCEPT_(noexcept(~_VSTD::forward<_Tp>(__x)))
 -> decltype (~_VSTD::forward<_Tp>(__x))
 { return ~_VSTD::forward<_Tp>(__x); }
 typedef void is_transparent;
};
#endif

template <class _Predicate>
class _LIBCPP_TYPE_VIS_ONLY unary_negate
 : public unary_function<typename _Predicate::argument_type, bool>
{
 _Predicate __pred_;
public:
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 explicit unary_negate(const _Predicate& __pred)
 : __pred_(__pred) {}
 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator()(const typename _Predicate::argument_type& __x) const
 {return !__pred_(__x);}
};

template <class _Predicate>
inline _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
unary_negate<_Predicate>
not1(const _Predicate& __pred) {return unary_negate<_Predicate>(__pred);}

template <class _Predicate>
class _LIBCPP_TYPE_VIS_ONLY binary_negate
 : public binary_function<typename _Predicate::first_argument_type,
 typename _Predicate::second_argument_type,
 bool>
{
 _Predicate __pred_;
public:
 _LIBCPP_INLINE_VISIBILITY explicit _LIBCPP_CONSTEXPR_AFTER_CXX11 
 binary_negate(const _Predicate& __pred) : __pred_(__pred) {}

 _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
 bool operator()(const typename _Predicate::first_argument_type& __x,
 const typename _Predicate::second_argument_type& __y) const
 {return !__pred_(__x, __y);}
};

template <class _Predicate>
inline _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
binary_negate<_Predicate>
not2(const _Predicate& __pred) {return binary_negate<_Predicate>(__pred);}

template <class __Operation>
class _LIBCPP_TYPE_VIS_ONLY binder1st
 : public unary_function<typename __Operation::second_argument_type,
 typename __Operation::result_type>
{
protected:
 __Operation op;
 typename __Operation::first_argument_type value;
public:
 _LIBCPP_INLINE_VISIBILITY binder1st(const __Operation& __x,
 const typename __Operation::first_argument_type __y)
 : op(__x), value(__y) {}
 _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
 (typename __Operation::second_argument_type& __x) const
 {return op(value, __x);}
 _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
 (const typename __Operation::second_argument_type& __x) const
 {return op(value, __x);}
};

template <class __Operation, class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
binder1st<__Operation>
bind1st(const __Operation& __op, const _Tp& __x)
 {return binder1st<__Operation>(__op, __x);}

template <class __Operation>
class _LIBCPP_TYPE_VIS_ONLY binder2nd
 : public unary_function<typename __Operation::first_argument_type,
 typename __Operation::result_type>
{
protected:
 __Operation op;
 typename __Operation::second_argument_type value;
public:
 _LIBCPP_INLINE_VISIBILITY
 binder2nd(const __Operation& __x, const typename __Operation::second_argument_type __y)
 : op(__x), value(__y) {}
 _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
 ( typename __Operation::first_argument_type& __x) const
 {return op(__x, value);}
 _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
 (const typename __Operation::first_argument_type& __x) const
 {return op(__x, value);}
};

template <class __Operation, class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
binder2nd<__Operation>
bind2nd(const __Operation& __op, const _Tp& __x)
 {return binder2nd<__Operation>(__op, __x);}

template <class _Arg, class _Result>
class _LIBCPP_TYPE_VIS_ONLY pointer_to_unary_function
 : public unary_function<_Arg, _Result>
{
 _Result (*__f_)(_Arg);
public:
 _LIBCPP_INLINE_VISIBILITY explicit pointer_to_unary_function(_Result (*__f)(_Arg))
 : __f_(__f) {}
 _LIBCPP_INLINE_VISIBILITY _Result operator()(_Arg __x) const
 {return __f_(__x);}
};

template <class _Arg, class _Result>
inline _LIBCPP_INLINE_VISIBILITY
pointer_to_unary_function<_Arg,_Result>
ptr_fun(_Result (*__f)(_Arg))
 {return pointer_to_unary_function<_Arg,_Result>(__f);}

template <class _Arg1, class _Arg2, class _Result>
class _LIBCPP_TYPE_VIS_ONLY pointer_to_binary_function
 : public binary_function<_Arg1, _Arg2, _Result>
{
 _Result (*__f_)(_Arg1, _Arg2);
public:
 _LIBCPP_INLINE_VISIBILITY explicit pointer_to_binary_function(_Result (*__f)(_Arg1, _Arg2))
 : __f_(__f) {}
 _LIBCPP_INLINE_VISIBILITY _Result operator()(_Arg1 __x, _Arg2 __y) const
 {return __f_(__x, __y);}
};

template <class _Arg1, class _Arg2, class _Result>
inline _LIBCPP_INLINE_VISIBILITY
pointer_to_binary_function<_Arg1,_Arg2,_Result>
ptr_fun(_Result (*__f)(_Arg1,_Arg2))
 {return pointer_to_binary_function<_Arg1,_Arg2,_Result>(__f);}

template<class _Sp, class _Tp>
class _LIBCPP_TYPE_VIS_ONLY mem_fun_t : public unary_function<_Tp*, _Sp>
{
 _Sp (_Tp::*__p_)();
public:
 _LIBCPP_INLINE_VISIBILITY explicit mem_fun_t(_Sp (_Tp::*__p)())
 : __p_(__p) {}
 _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp* __p) const
 {return (__p->*__p_)();}
};

template<class _Sp, class _Tp, class _Ap>
class _LIBCPP_TYPE_VIS_ONLY mem_fun1_t : public binary_function<_Tp*, _Ap, _Sp>
{
 _Sp (_Tp::*__p_)(_Ap);
public:
 _LIBCPP_INLINE_VISIBILITY explicit mem_fun1_t(_Sp (_Tp::*__p)(_Ap))
 : __p_(__p) {}
 _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp* __p, _Ap __x) const
 {return (__p->*__p_)(__x);}
};

template<class _Sp, class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
mem_fun_t<_Sp,_Tp>
mem_fun(_Sp (_Tp::*__f)())
 {return mem_fun_t<_Sp,_Tp>(__f);}

template<class _Sp, class _Tp, class _Ap>
inline _LIBCPP_INLINE_VISIBILITY
mem_fun1_t<_Sp,_Tp,_Ap>
mem_fun(_Sp (_Tp::*__f)(_Ap))
 {return mem_fun1_t<_Sp,_Tp,_Ap>(__f);}

template<class _Sp, class _Tp>
class _LIBCPP_TYPE_VIS_ONLY mem_fun_ref_t : public unary_function<_Tp, _Sp>
{
 _Sp (_Tp::*__p_)();
public:
 _LIBCPP_INLINE_VISIBILITY explicit mem_fun_ref_t(_Sp (_Tp::*__p)())
 : __p_(__p) {}
 _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp& __p) const
 {return (__p.*__p_)();}
};

template<class _Sp, class _Tp, class _Ap>
class _LIBCPP_TYPE_VIS_ONLY mem_fun1_ref_t : public binary_function<_Tp, _Ap, _Sp>
{
 _Sp (_Tp::*__p_)(_Ap);
public:
 _LIBCPP_INLINE_VISIBILITY explicit mem_fun1_ref_t(_Sp (_Tp::*__p)(_Ap))
 : __p_(__p) {}
 _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp& __p, _Ap __x) const
 {return (__p.*__p_)(__x);}
};

template<class _Sp, class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
mem_fun_ref_t<_Sp,_Tp>
mem_fun_ref(_Sp (_Tp::*__f)())
 {return mem_fun_ref_t<_Sp,_Tp>(__f);}

template<class _Sp, class _Tp, class _Ap>
inline _LIBCPP_INLINE_VISIBILITY
mem_fun1_ref_t<_Sp,_Tp,_Ap>
mem_fun_ref(_Sp (_Tp::*__f)(_Ap))
 {return mem_fun1_ref_t<_Sp,_Tp,_Ap>(__f);}

template <class _Sp, class _Tp>
class _LIBCPP_TYPE_VIS_ONLY const_mem_fun_t : public unary_function<const _Tp*, _Sp>
{
 _Sp (_Tp::*__p_)() const;
public:
 _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun_t(_Sp (_Tp::*__p)() const)
 : __p_(__p) {}
 _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp* __p) const
 {return (__p->*__p_)();}
};

template <class _Sp, class _Tp, class _Ap>
class _LIBCPP_TYPE_VIS_ONLY const_mem_fun1_t : public binary_function<const _Tp*, _Ap, _Sp>
{
 _Sp (_Tp::*__p_)(_Ap) const;
public:
 _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun1_t(_Sp (_Tp::*__p)(_Ap) const)
 : __p_(__p) {}
 _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp* __p, _Ap __x) const
 {return (__p->*__p_)(__x);}
};

template <class _Sp, class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
const_mem_fun_t<_Sp,_Tp>
mem_fun(_Sp (_Tp::*__f)() const)
 {return const_mem_fun_t<_Sp,_Tp>(__f);}

template <class _Sp, class _Tp, class _Ap>
inline _LIBCPP_INLINE_VISIBILITY
const_mem_fun1_t<_Sp,_Tp,_Ap>
mem_fun(_Sp (_Tp::*__f)(_Ap) const)
 {return const_mem_fun1_t<_Sp,_Tp,_Ap>(__f);}

template <class _Sp, class _Tp>
class _LIBCPP_TYPE_VIS_ONLY const_mem_fun_ref_t : public unary_function<_Tp, _Sp>
{
 _Sp (_Tp::*__p_)() const;
public:
 _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun_ref_t(_Sp (_Tp::*__p)() const)
 : __p_(__p) {}
 _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp& __p) const
 {return (__p.*__p_)();}
};

template <class _Sp, class _Tp, class _Ap>
class _LIBCPP_TYPE_VIS_ONLY const_mem_fun1_ref_t
 : public binary_function<_Tp, _Ap, _Sp>
{
 _Sp (_Tp::*__p_)(_Ap) const;
public:
 _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun1_ref_t(_Sp (_Tp::*__p)(_Ap) const)
 : __p_(__p) {}
 _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp& __p, _Ap __x) const
 {return (__p.*__p_)(__x);}
};

template <class _Sp, class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
const_mem_fun_ref_t<_Sp,_Tp>
mem_fun_ref(_Sp (_Tp::*__f)() const)
 {return const_mem_fun_ref_t<_Sp,_Tp>(__f);}

template <class _Sp, class _Tp, class _Ap>
inline _LIBCPP_INLINE_VISIBILITY
const_mem_fun1_ref_t<_Sp,_Tp,_Ap>
mem_fun_ref(_Sp (_Tp::*__f)(_Ap) const)
 {return const_mem_fun1_ref_t<_Sp,_Tp,_Ap>(__f);}

////////////////////////////////////////////////////////////////////////////////
// MEMFUN
//==============================================================================

template <class _Tp>
class __mem_fn
 : public __weak_result_type<_Tp>
{
public:
 // types
 typedef _Tp type;
private:
 type __f_;

public:
 _LIBCPP_INLINE_VISIBILITY __mem_fn(type __f) _NOEXCEPT : __f_(__f) {}

#ifndef _LIBCPP_HAS_NO_VARIADICS
 // invoke
 template <class... _ArgTypes>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return<type, _ArgTypes...>::type
 operator() (_ArgTypes&&... __args) const {
 return __invoke(__f_, _VSTD::forward<_ArgTypes>(__args)...);
 }
#else

 template <class _A0>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return0<type, _A0>::type
 operator() (_A0& __a0) const {
 return __invoke(__f_, __a0);
 }

 template <class _A0>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return0<type, _A0 const>::type
 operator() (_A0 const& __a0) const {
 return __invoke(__f_, __a0);
 }

 template <class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return1<type, _A0, _A1>::type
 operator() (_A0& __a0, _A1& __a1) const {
 return __invoke(__f_, __a0, __a1);
 }

 template <class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return1<type, _A0 const, _A1>::type
 operator() (_A0 const& __a0, _A1& __a1) const {
 return __invoke(__f_, __a0, __a1);
 }

 template <class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return1<type, _A0, _A1 const>::type
 operator() (_A0& __a0, _A1 const& __a1) const {
 return __invoke(__f_, __a0, __a1);
 }

 template <class _A0, class _A1>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return1<type, _A0 const, _A1 const>::type
 operator() (_A0 const& __a0, _A1 const& __a1) const {
 return __invoke(__f_, __a0, __a1);
 }

 template <class _A0, class _A1, class _A2>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return2<type, _A0, _A1, _A2>::type
 operator() (_A0& __a0, _A1& __a1, _A2& __a2) const {
 return __invoke(__f_, __a0, __a1, __a2);
 }

 template <class _A0, class _A1, class _A2>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return2<type, _A0 const, _A1, _A2>::type
 operator() (_A0 const& __a0, _A1& __a1, _A2& __a2) const {
 return __invoke(__f_, __a0, __a1, __a2);
 }

 template <class _A0, class _A1, class _A2>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return2<type, _A0, _A1 const, _A2>::type
 operator() (_A0& __a0, _A1 const& __a1, _A2& __a2) const {
 return __invoke(__f_, __a0, __a1, __a2);
 }

 template <class _A0, class _A1, class _A2>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return2<type, _A0, _A1, _A2 const>::type
 operator() (_A0& __a0, _A1& __a1, _A2 const& __a2) const {
 return __invoke(__f_, __a0, __a1, __a2);
 }

 template <class _A0, class _A1, class _A2>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return2<type, _A0 const, _A1 const, _A2>::type
 operator() (_A0 const& __a0, _A1 const& __a1, _A2& __a2) const {
 return __invoke(__f_, __a0, __a1, __a2);
 }

 template <class _A0, class _A1, class _A2>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return2<type, _A0 const, _A1, _A2 const>::type
 operator() (_A0 const& __a0, _A1& __a1, _A2 const& __a2) const {
 return __invoke(__f_, __a0, __a1, __a2);
 }

 template <class _A0, class _A1, class _A2>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return2<type, _A0, _A1 const, _A2 const>::type
 operator() (_A0& __a0, _A1 const& __a1, _A2 const& __a2) const {
 return __invoke(__f_, __a0, __a1, __a2);
 }

 template <class _A0, class _A1, class _A2>
 _LIBCPP_INLINE_VISIBILITY
 typename __invoke_return2<type, _A0 const, _A1 const, _A2 const>::type
 operator() (_A0 const& __a0, _A1 const& __a1, _A2 const& __a2) const {
 return __invoke(__f_, __a0, __a1, __a2);
 }
#endif
};

template<class _Rp, class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
__mem_fn<_Rp _Tp::*>
mem_fn(_Rp _Tp::* __pm) _NOEXCEPT
{
 return __mem_fn<_Rp _Tp::*>(__pm);
}

////////////////////////////////////////////////////////////////////////////////
// FUNCTION
//==============================================================================

// bad_function_call

class _LIBCPP_EXCEPTION_ABI bad_function_call
 : public exception
{
};

_LIBCPP_NORETURN inline _LIBCPP_ALWAYS_INLINE
void __throw_bad_function_call()
{
#ifndef _LIBCPP_NO_EXCEPTIONS
 throw bad_function_call();
#else
_VSTD::abort();
#endif
}

template<class _Fp> class _LIBCPP_TYPE_VIS_ONLY function; // undefined

namespace __function
{

template<class _Rp>
struct __maybe_derive_from_unary_function
{
};

template<class _Rp, class _A1>
struct __maybe_derive_from_unary_function<_Rp(_A1)>
 : public unary_function<_A1, _Rp>
{
};

template<class _Rp>
struct __maybe_derive_from_binary_function
{
};

template<class _Rp, class _A1, class _A2>
struct __maybe_derive_from_binary_function<_Rp(_A1, _A2)>
 : public binary_function<_A1, _A2, _Rp>
{
};

template <class _Fp>
_LIBCPP_INLINE_VISIBILITY
bool __not_null(_Fp const&) { return true; }

template <class _Fp>
_LIBCPP_INLINE_VISIBILITY
bool __not_null(_Fp* __ptr) { return __ptr; }

template <class _Ret, class _Class>
_LIBCPP_INLINE_VISIBILITY
bool __not_null(_Ret _Class::*__ptr) { return __ptr; }

template <class _Fp>
_LIBCPP_INLINE_VISIBILITY
bool __not_null(function<_Fp> const& __f) { return !!__f; }

} // namespace __function

#ifndef _LIBCPP_HAS_NO_VARIADICS

namespace __function {

template<class _Fp> class __base;

template<class _Rp, class ..._ArgTypes>
class __base<_Rp(_ArgTypes...)>
{
 __base(const __base&);
 __base& operator=(const __base&);
public:
 _LIBCPP_INLINE_VISIBILITY __base() {}
 _LIBCPP_INLINE_VISIBILITY virtual ~__base() {}
 virtual __base* __clone() const = 0;
 virtual void __clone(__base*) const = 0;
 virtual void destroy() _NOEXCEPT = 0;
 virtual void destroy_deallocate() _NOEXCEPT = 0;
 virtual _Rp operator()(_ArgTypes&& ...) = 0;
#ifndef _LIBCPP_NO_RTTI
 virtual const void* target(const type_info&) const _NOEXCEPT = 0;
 virtual const std::type_info& target_type() const _NOEXCEPT = 0;
#endif // _LIBCPP_NO_RTTI
};

template<class _FD, class _Alloc, class _FB> class __func;

template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
class __func<_Fp, _Alloc, _Rp(_ArgTypes...)>
 : public __base<_Rp(_ArgTypes...)>
{
 __compressed_pair<_Fp, _Alloc> __f_;
public:
 _LIBCPP_INLINE_VISIBILITY
 explicit __func(_Fp&& __f)
 : __f_(piecewise_construct, _VSTD::forward_as_tuple(_VSTD::move(__f)),
 _VSTD::forward_as_tuple()) {}
 _LIBCPP_INLINE_VISIBILITY
 explicit __func(const _Fp& __f, const _Alloc& __a)
 : __f_(piecewise_construct, _VSTD::forward_as_tuple(__f),
 _VSTD::forward_as_tuple(__a)) {}

 _LIBCPP_INLINE_VISIBILITY
 explicit __func(const _Fp& __f, _Alloc&& __a)
 : __f_(piecewise_construct, _VSTD::forward_as_tuple(__f),
 _VSTD::forward_as_tuple(_VSTD::move(__a))) {}

 _LIBCPP_INLINE_VISIBILITY
 explicit __func(_Fp&& __f, _Alloc&& __a)
 : __f_(piecewise_construct, _VSTD::forward_as_tuple(_VSTD::move(__f)),
 _VSTD::forward_as_tuple(_VSTD::move(__a))) {}
 virtual __base<_Rp(_ArgTypes...)>* __clone() const;
 virtual void __clone(__base<_Rp(_ArgTypes...)>*) const;
 virtual void destroy() _NOEXCEPT;
 virtual void destroy_deallocate() _NOEXCEPT;
 virtual _Rp operator()(_ArgTypes&& ... __arg);
#ifndef _LIBCPP_NO_RTTI
 virtual const void* target(const type_info&) const _NOEXCEPT;
 virtual const std::type_info& target_type() const _NOEXCEPT;
#endif // _LIBCPP_NO_RTTI
};

template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
__base<_Rp(_ArgTypes...)>*
__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::__clone() const
{
 typedef allocator_traits<_Alloc> __alloc_traits;
 typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
 _Ap __a(__f_.second());
 typedef __allocator_destructor<_Ap> _Dp;
 unique_ptr<__func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
 ::new (__hold.get()) __func(__f_.first(), _Alloc(__a));
 return __hold.release();
}

template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
void
__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::__clone(__base<_Rp(_ArgTypes...)>* __p) const
{
 ::new (__p) __func(__f_.first(), __f_.second());
}

template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
void
__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy() _NOEXCEPT
{
 __f_.~__compressed_pair<_Fp, _Alloc>();
}

template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
void
__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy_deallocate() _NOEXCEPT
{
 typedef allocator_traits<_Alloc> __alloc_traits;
 typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
 _Ap __a(__f_.second());
 __f_.~__compressed_pair<_Fp, _Alloc>();
 __a.deallocate(this, 1);
}

template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
_Rp
__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::operator()(_ArgTypes&& ... __arg)
{
 typedef __invoke_void_return_wrapper<_Rp> _Invoker;
 return _Invoker::__call(__f_.first(), _VSTD::forward<_ArgTypes>(__arg)...);
}

#ifndef _LIBCPP_NO_RTTI

template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
const void*
__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::target(const type_info& __ti) const _NOEXCEPT
{
 if (__ti == typeid(_Fp))
 return &__f_.first();
 return (const void*)0;
}

template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
const std::type_info&
__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::target_type() const _NOEXCEPT
{
 return typeid(_Fp);
}

#endif // _LIBCPP_NO_RTTI

} // __function

template<class _Rp, class ..._ArgTypes>
class _LIBCPP_TYPE_VIS_ONLY function<_Rp(_ArgTypes...)>
 : public __function::__maybe_derive_from_unary_function<_Rp(_ArgTypes...)>,
 public __function::__maybe_derive_from_binary_function<_Rp(_ArgTypes...)>
{
 typedef __function::__base<_Rp(_ArgTypes...)> __base;
 typename aligned_storage<3*sizeof(void*)>::type __buf_;
 __base* __f_;

 _LIBCPP_NO_CFI static __base *__as_base(void *p) {
 return reinterpret_cast<__base*>(p);
 }

 template <class _Fp, bool = !is_same<_Fp, function>::value &&
 __invokable<_Fp&, _ArgTypes...>::value>
 struct __callable;
 template <class _Fp>
 struct __callable<_Fp, true>
 {
 static const bool value = is_same<void, _Rp>::value ||
 is_convertible<typename __invoke_of<_Fp&, _ArgTypes...>::type,
 _Rp>::value;
 };
 template <class _Fp>
 struct __callable<_Fp, false>
 {
 static const bool value = false;
 };
public:
 typedef _Rp result_type;

 // construct/copy/destroy:
 _LIBCPP_INLINE_VISIBILITY
 function() _NOEXCEPT : __f_(0) {}
 _LIBCPP_INLINE_VISIBILITY
 function(nullptr_t) _NOEXCEPT : __f_(0) {}
 function(const function&);
 function(function&&) _NOEXCEPT;
 template<class _Fp, class = typename enable_if<
 __callable<_Fp>::value && !is_same<_Fp, function>::value
 >::type>
 function(_Fp);

#if _LIBCPP_STD_VER <= 14
 template<class _Alloc>
 _LIBCPP_INLINE_VISIBILITY
 function(allocator_arg_t, const _Alloc&) _NOEXCEPT : __f_(0) {}
 template<class _Alloc>
 _LIBCPP_INLINE_VISIBILITY
 function(allocator_arg_t, const _Alloc&, nullptr_t) _NOEXCEPT : __f_(0) {}
 template<class _Alloc>
 function(allocator_arg_t, const _Alloc&, const function&);
 template<class _Alloc>
 function(allocator_arg_t, const _Alloc&, function&&);
 template<class _Fp, class _Alloc, class = typename enable_if<__callable<_Fp>::value>::type>
 function(allocator_arg_t, const _Alloc& __a, _Fp __f);
#endif

 function& operator=(const function&);
 function& operator=(function&&) _NOEXCEPT;
 function& operator=(nullptr_t) _NOEXCEPT;
 template<class _Fp>
 typename enable_if
 <
 __callable<typename decay<_Fp>::type>::value &&
 !is_same<typename remove_reference<_Fp>::type, function>::value,
 function&
 >::type
 operator=(_Fp&&);

 ~function();

 // function modifiers:
 void swap(function&) _NOEXCEPT;

#if _LIBCPP_STD_VER <= 14
 template<class _Fp, class _Alloc>
 _LIBCPP_INLINE_VISIBILITY
 void assign(_Fp&& __f, const _Alloc& __a)
 {function(allocator_arg, __a, _VSTD::forward<_Fp>(__f)).swap(*this);}
#endif

 // function capacity:
 _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {return __f_;}

 // deleted overloads close possible hole in the type system
 template<class _R2, class... _ArgTypes2>
 bool operator==(const function<_R2(_ArgTypes2...)>&) const = delete;
 template<class _R2, class... _ArgTypes2>
 bool operator!=(const function<_R2(_ArgTypes2...)>&) const = delete;
public:
 // function invocation:
 _Rp operator()(_ArgTypes...) const;

#ifndef _LIBCPP_NO_RTTI
 // function target access:
 const std::type_info& target_type() const _NOEXCEPT;
 template <typename _Tp> _Tp* target() _NOEXCEPT;
 template <typename _Tp> const _Tp* target() const _NOEXCEPT;
#endif // _LIBCPP_NO_RTTI
};

template<class _Rp, class ..._ArgTypes>
function<_Rp(_ArgTypes...)>::function(const function& __f)
{
 if (__f.__f_ == 0)
 __f_ = 0;
 else if ((void *)__f.__f_ == &__f.__buf_)
 {
 __f_ = __as_base(&__buf_);
 __f.__f_->__clone(__f_);
 }
 else
 __f_ = __f.__f_->__clone();
}

#if _LIBCPP_STD_VER <= 14
template<class _Rp, class ..._ArgTypes>
template <class _Alloc>
function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc&,
 const function& __f)
{
 if (__f.__f_ == 0)
 __f_ = 0;
 else if ((void *)__f.__f_ == &__f.__buf_)
 {
 __f_ = __as_base(&__buf_);
 __f.__f_->__clone(__f_);
 }
 else
 __f_ = __f.__f_->__clone();
}
#endif

template<class _Rp, class ..._ArgTypes>
function<_Rp(_ArgTypes...)>::function(function&& __f) _NOEXCEPT
{
 if (__f.__f_ == 0)
 __f_ = 0;
 else if ((void *)__f.__f_ == &__f.__buf_)
 {
 __f_ = __as_base(&__buf_);
 __f.__f_->__clone(__f_);
 }
 else
 {
 __f_ = __f.__f_;
 __f.__f_ = 0;
 }
}

#if _LIBCPP_STD_VER <= 14
template<class _Rp, class ..._ArgTypes>
template <class _Alloc>
function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc&,
 function&& __f)
{
 if (__f.__f_ == 0)
 __f_ = 0;
 else if ((void *)__f.__f_ == &__f.__buf_)
 {
 __f_ = __as_base(&__buf_);
 __f.__f_->__clone(__f_);
 }
 else
 {
 __f_ = __f.__f_;
 __f.__f_ = 0;
 }
}
#endif

template<class _Rp, class ..._ArgTypes>
template <class _Fp, class>
function<_Rp(_ArgTypes...)>::function(_Fp __f)
 : __f_(0)
{
 if (__function::__not_null(__f))
 {
 typedef __function::__func<_Fp, allocator<_Fp>, _Rp(_ArgTypes...)> _FF;
 if (sizeof(_FF) <= sizeof(__buf_) && is_nothrow_copy_constructible<_Fp>::value)
 {
 __f_ = ::new((void*)&__buf_) _FF(_VSTD::move(__f));
 }
 else
 {
 typedef allocator<_FF> _Ap;
 _Ap __a;
 typedef __allocator_destructor<_Ap> _Dp;
 unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
 ::new (__hold.get()) _FF(_VSTD::move(__f), allocator<_Fp>(__a));
 __f_ = __hold.release();
 }
 }
}

#if _LIBCPP_STD_VER <= 14
template<class _Rp, class ..._ArgTypes>
template <class _Fp, class _Alloc, class>
function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc& __a0, _Fp __f)
 : __f_(0)
{
 typedef allocator_traits<_Alloc> __alloc_traits;
 if (__function::__not_null(__f))
 {
 typedef __function::__func<_Fp, _Alloc, _Rp(_ArgTypes...)> _FF;
 typedef typename __rebind_alloc_helper<__alloc_traits, _FF>::type _Ap;
 _Ap __a(__a0);
 if (sizeof(_FF) <= sizeof(__buf_) && 
 is_nothrow_copy_constructible<_Fp>::value && is_nothrow_copy_constructible<_Ap>::value)
 {
 __f_ = ::new((void*)&__buf_) _FF(_VSTD::move(__f), _Alloc(__a));
 }
 else
 {
 typedef __allocator_destructor<_Ap> _Dp;
 unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
 ::new (__hold.get()) _FF(_VSTD::move(__f), _Alloc(__a));
 __f_ = __hold.release();
 }
 }
}
#endif

template<class _Rp, class ..._ArgTypes>
function<_Rp(_ArgTypes...)>&
function<_Rp(_ArgTypes...)>::operator=(const function& __f)
{
 function(__f).swap(*this);
 return *this;
}

template<class _Rp, class ..._ArgTypes>
function<_Rp(_ArgTypes...)>&
function<_Rp(_ArgTypes...)>::operator=(function&& __f) _NOEXCEPT
{
 if ((void *)__f_ == &__buf_)
 __f_->destroy();
 else if (__f_)
 __f_->destroy_deallocate();
 __f_ = 0;
 if (__f.__f_ == 0)
 __f_ = 0;
 else if ((void *)__f.__f_ == &__f.__buf_)
 {
 __f_ = __as_base(&__buf_);
 __f.__f_->__clone(__f_);
 }
 else
 {
 __f_ = __f.__f_;
 __f.__f_ = 0;
 }
 return *this;
}

template<class _Rp, class ..._ArgTypes>
function<_Rp(_ArgTypes...)>&
function<_Rp(_ArgTypes...)>::operator=(nullptr_t) _NOEXCEPT
{
 if ((void *)__f_ == &__buf_)
 __f_->destroy();
 else if (__f_)
 __f_->destroy_deallocate();
 __f_ = 0;
 return *this;
}

template<class _Rp, class ..._ArgTypes>
template <class _Fp>
typename enable_if
<
 function<_Rp(_ArgTypes...)>::template __callable<typename decay<_Fp>::type>::value &&
 !is_same<typename remove_reference<_Fp>::type, function<_Rp(_ArgTypes...)>>::value,
 function<_Rp(_ArgTypes...)>&
>::type
function<_Rp(_ArgTypes...)>::operator=(_Fp&& __f)
{
 function(_VSTD::forward<_Fp>(__f)).swap(*this);
 return *this;
}

template<class _Rp, class ..._ArgTypes>
function<_Rp(_ArgTypes...)>::~function()
{
 if ((void *)__f_ == &__buf_)
 __f_->destroy();
 else if (__f_)
 __f_->destroy_deallocate();
}

template<class _Rp, class ..._ArgTypes>
void
function<_Rp(_ArgTypes...)>::swap(function& __f) _NOEXCEPT
{
 if ((void *)__f_ == &__buf_ && (void *)__f.__f_ == &__f.__buf_)
 {
 typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
 __base* __t = __as_base(&__tempbuf);
 __f_->__clone(__t);
 __f_->destroy();
 __f_ = 0;
 __f.__f_->__clone(__as_base(&__buf_));
 __f.__f_->destroy();
 __f.__f_ = 0;
 __f_ = __as_base(&__buf_);
 __t->__clone(__as_base(&__f.__buf_));
 __t->destroy();
 __f.__f_ = __as_base(&__f.__buf_);
 }
 else if ((void *)__f_ == &__buf_)
 {
 __f_->__clone(__as_base(&__f.__buf_));
 __f_->destroy();
 __f_ = __f.__f_;
 __f.__f_ = __as_base(&__f.__buf_);
 }
 else if ((void *)__f.__f_ == &__f.__buf_)
 {
 __f.__f_->__clone(__as_base(&__buf_));
 __f.__f_->destroy();
 __f.__f_ = __f_;
 __f_ = __as_base(&__buf_);
 }
 else
 _VSTD::swap(__f_, __f.__f_);
}

template<class _Rp, class ..._ArgTypes>
_Rp
function<_Rp(_ArgTypes...)>::operator()(_ArgTypes... __arg) const
{
 if (__f_ == 0)
 __throw_bad_function_call();
 return (*__f_)(_VSTD::forward<_ArgTypes>(__arg)...);
}

#ifndef _LIBCPP_NO_RTTI

template<class _Rp, class ..._ArgTypes>
const std::type_info&
function<_Rp(_ArgTypes...)>::target_type() const _NOEXCEPT
{
 if (__f_ == 0)
 return typeid(void);
 return __f_->target_type();
}

template<class _Rp, class ..._ArgTypes>
template <typename _Tp>
_Tp*
function<_Rp(_ArgTypes...)>::target() _NOEXCEPT
{
 if (__f_ == 0)
 return (_Tp*)0;
 return (_Tp*)__f_->target(typeid(_Tp));
}

template<class _Rp, class ..._ArgTypes>
template <typename _Tp>
const _Tp*
function<_Rp(_ArgTypes...)>::target() const _NOEXCEPT
{
 if (__f_ == 0)
 return (const _Tp*)0;
 return (const _Tp*)__f_->target(typeid(_Tp));
}

#endif // _LIBCPP_NO_RTTI

template <class _Rp, class... _ArgTypes>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(const function<_Rp(_ArgTypes...)>& __f, nullptr_t) _NOEXCEPT {return !__f;}

template <class _Rp, class... _ArgTypes>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator==(nullptr_t, const function<_Rp(_ArgTypes...)>& __f) _NOEXCEPT {return !__f;}

template <class _Rp, class... _ArgTypes>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(const function<_Rp(_ArgTypes...)>& __f, nullptr_t) _NOEXCEPT {return (bool)__f;}

template <class _Rp, class... _ArgTypes>
inline _LIBCPP_INLINE_VISIBILITY
bool
operator!=(nullptr_t, const function<_Rp(_ArgTypes...)>& __f) _NOEXCEPT {return (bool)__f;}

template <class _Rp, class... _ArgTypes>
inline _LIBCPP_INLINE_VISIBILITY
void
swap(function<_Rp(_ArgTypes...)>& __x, function<_Rp(_ArgTypes...)>& __y) _NOEXCEPT
{return __x.swap(__y);}

#else // _LIBCPP_HAS_NO_VARIADICS

#include <__functional_03>

#endif

////////////////////////////////////////////////////////////////////////////////
// BIND
//==============================================================================

template<class _Tp> struct __is_bind_expression : public false_type {};
template<class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_bind_expression
 : public __is_bind_expression<typename remove_cv<_Tp>::type> {};

#if _LIBCPP_STD_VER > 14
template <class _Tp>
constexpr size_t is_bind_expression_v = is_bind_expression<_Tp>::value;
#endif

template<class _Tp> struct __is_placeholder : public integral_constant<int, 0> {};
template<class _Tp> struct _LIBCPP_TYPE_VIS_ONLY is_placeholder
 : public __is_placeholder<typename remove_cv<_Tp>::type> {};

#if _LIBCPP_STD_VER > 14
template <class _Tp>
constexpr size_t is_placeholder_v = is_placeholder<_Tp>::value;
#endif

namespace placeholders
{

template <int _Np> struct __ph {};

#if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_BIND)
_LIBCPP_FUNC_VIS extern const __ph<1> _1;
_LIBCPP_FUNC_VIS extern const __ph<2> _2;
_LIBCPP_FUNC_VIS extern const __ph<3> _3;
_LIBCPP_FUNC_VIS extern const __ph<4> _4;
_LIBCPP_FUNC_VIS extern const __ph<5> _5;
_LIBCPP_FUNC_VIS extern const __ph<6> _6;
_LIBCPP_FUNC_VIS extern const __ph<7> _7;
_LIBCPP_FUNC_VIS extern const __ph<8> _8;
_LIBCPP_FUNC_VIS extern const __ph<9> _9;
_LIBCPP_FUNC_VIS extern const __ph<10> _10;
#else
constexpr __ph<1> _1{};
constexpr __ph<2> _2{};
constexpr __ph<3> _3{};
constexpr __ph<4> _4{};
constexpr __ph<5> _5{};
constexpr __ph<6> _6{};
constexpr __ph<7> _7{};
constexpr __ph<8> _8{};
constexpr __ph<9> _9{};
constexpr __ph<10> _10{};
#endif // defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_BIND)

} // placeholders

template<int _Np>
struct __is_placeholder<placeholders::__ph<_Np> >
 : public integral_constant<int, _Np> {};


#ifndef _LIBCPP_HAS_NO_VARIADICS

template <class _Tp, class _Uj>
inline _LIBCPP_INLINE_VISIBILITY
_Tp&
__mu(reference_wrapper<_Tp> __t, _Uj&)
{
 return __t.get();
}

template <class _Ti, class ..._Uj, size_t ..._Indx>
inline _LIBCPP_INLINE_VISIBILITY
typename __invoke_of<_Ti&, _Uj...>::type
__mu_expand(_Ti& __ti, tuple<_Uj...>& __uj, __tuple_indices<_Indx...>)
{
 return __ti(_VSTD::forward<_Uj>(_VSTD::get<_Indx>(__uj))...);
}

template <class _Ti, class ..._Uj>
inline _LIBCPP_INLINE_VISIBILITY
typename __lazy_enable_if
<
 is_bind_expression<_Ti>::value,
 __invoke_of<_Ti&, _Uj...>
>::type
__mu(_Ti& __ti, tuple<_Uj...>& __uj)
{
 typedef typename __make_tuple_indices<sizeof...(_Uj)>::type __indices;
 return __mu_expand(__ti, __uj, __indices());
}

template <bool IsPh, class _Ti, class _Uj>
struct __mu_return2 {};

template <class _Ti, class _Uj>
struct __mu_return2<true, _Ti, _Uj>
{
 typedef typename tuple_element<is_placeholder<_Ti>::value - 1, _Uj>::type type;
};

template <class _Ti, class _Uj>
inline _LIBCPP_INLINE_VISIBILITY
typename enable_if
<
 0 < is_placeholder<_Ti>::value,
 typename __mu_return2<0 < is_placeholder<_Ti>::value, _Ti, _Uj>::type
>::type
__mu(_Ti&, _Uj& __uj)
{
 const size_t _Indx = is_placeholder<_Ti>::value - 1;
 return _VSTD::forward<typename tuple_element<_Indx, _Uj>::type>(_VSTD::get<_Indx>(__uj));
}

template <class _Ti, class _Uj>
inline _LIBCPP_INLINE_VISIBILITY
typename enable_if
<
 !is_bind_expression<_Ti>::value &&
 is_placeholder<_Ti>::value == 0 &&
 !__is_reference_wrapper<_Ti>::value,
 _Ti&
>::type
__mu(_Ti& __ti, _Uj&)
{
 return __ti;
}

template <class _Ti, bool IsReferenceWrapper, bool IsBindEx, bool IsPh,
 class _TupleUj>
struct ____mu_return;

template <bool _Invokable, class _Ti, class ..._Uj>
struct ____mu_return_invokable // false
{
 typedef __nat type;
};

template <class _Ti, class ..._Uj>
struct ____mu_return_invokable<true, _Ti, _Uj...>
{
 typedef typename __invoke_of<_Ti&, _Uj...>::type type;
};

template <class _Ti, class ..._Uj>
struct ____mu_return<_Ti, false, true, false, tuple<_Uj...> >
 : public ____mu_return_invokable<__invokable<_Ti&, _Uj...>::value, _Ti, _Uj...>
{
};

template <class _Ti, class _TupleUj>
struct ____mu_return<_Ti, false, false, true, _TupleUj>
{
 typedef typename tuple_element<is_placeholder<_Ti>::value - 1,
 _TupleUj>::type&& type;
};

template <class _Ti, class _TupleUj>
struct ____mu_return<_Ti, true, false, false, _TupleUj>
{
 typedef typename _Ti::type& type;
};

template <class _Ti, class _TupleUj>
struct ____mu_return<_Ti, false, false, false, _TupleUj>
{
 typedef _Ti& type;
};

template <class _Ti, class _TupleUj>
struct __mu_return
 : public ____mu_return<_Ti,
 __is_reference_wrapper<_Ti>::value,
 is_bind_expression<_Ti>::value,
 0 < is_placeholder<_Ti>::value &&
 is_placeholder<_Ti>::value <= tuple_size<_TupleUj>::value,
 _TupleUj>
{
};

template <class _Fp, class _BoundArgs, class _TupleUj>
struct __is_valid_bind_return
{
 static const bool value = false;
};

template <class _Fp, class ..._BoundArgs, class _TupleUj>
struct __is_valid_bind_return<_Fp, tuple<_BoundArgs...>, _TupleUj>
{
 static const bool value = __invokable<_Fp,
 typename __mu_return<_BoundArgs, _TupleUj>::type...>::value;
};

template <class _Fp, class ..._BoundArgs, class _TupleUj>
struct __is_valid_bind_return<_Fp, const tuple<_BoundArgs...>, _TupleUj>
{
 static const bool value = __invokable<_Fp,
 typename __mu_return<const _BoundArgs, _TupleUj>::type...>::value;
};

template <class _Fp, class _BoundArgs, class _TupleUj,
 bool = __is_valid_bind_return<_Fp, _BoundArgs, _TupleUj>::value>
struct __bind_return;

template <class _Fp, class ..._BoundArgs, class _TupleUj>
struct __bind_return<_Fp, tuple<_BoundArgs...>, _TupleUj, true>
{
 typedef typename __invoke_of
 <
 _Fp&,
 typename __mu_return
 <
 _BoundArgs,
 _TupleUj
 >::type...
 >::type type;
};

template <class _Fp, class ..._BoundArgs, class _TupleUj>
struct __bind_return<_Fp, const tuple<_BoundArgs...>, _TupleUj, true>
{
 typedef typename __invoke_of
 <
 _Fp&,
 typename __mu_return
 <
 const _BoundArgs,
 _TupleUj
 >::type...
 >::type type;
};

template <class _Fp, class _BoundArgs, size_t ..._Indx, class _Args>
inline _LIBCPP_INLINE_VISIBILITY
typename __bind_return<_Fp, _BoundArgs, _Args>::type
__apply_functor(_Fp& __f, _BoundArgs& __bound_args, __tuple_indices<_Indx...>,
 _Args&& __args)
{
 return __invoke(__f, __mu(_VSTD::get<_Indx>(__bound_args), __args)...);
}

template<class _Fp, class ..._BoundArgs>
class __bind
 : public __weak_result_type<typename decay<_Fp>::type>
{
protected:
 typedef typename decay<_Fp>::type _Fd;
 typedef tuple<typename decay<_BoundArgs>::type...> _Td;
private:
 _Fd __f_;
 _Td __bound_args_;

 typedef typename __make_tuple_indices<sizeof...(_BoundArgs)>::type __indices;
public:
#ifdef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS

 _LIBCPP_INLINE_VISIBILITY
 __bind(const __bind& __b)
 : __f_(__b.__f_),
 __bound_args_(__b.__bound_args_) {}

 _LIBCPP_INLINE_VISIBILITY
 __bind& operator=(const __bind& __b)
 {
 __f_ = __b.__f_;
 __bound_args_ = __b.__bound_args_;
 return *this;
 }

 _LIBCPP_INLINE_VISIBILITY
 __bind(__bind&& __b)
 : __f_(_VSTD::move(__b.__f_)),
 __bound_args_(_VSTD::move(__b.__bound_args_)) {}

 _LIBCPP_INLINE_VISIBILITY
 __bind& operator=(__bind&& __b)
 {
 __f_ = _VSTD::move(__b.__f_);
 __bound_args_ = _VSTD::move(__b.__bound_args_);
 return *this;
 }

#endif // _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS

 template <class _Gp, class ..._BA,
 class = typename enable_if
 <
 is_constructible<_Fd, _Gp>::value &&
 !is_same<typename remove_reference<_Gp>::type,
 __bind>::value
 >::type>
 _LIBCPP_INLINE_VISIBILITY
 explicit __bind(_Gp&& __f, _BA&& ...__bound_args)
 : __f_(_VSTD::forward<_Gp>(__f)),
 __bound_args_(_VSTD::forward<_BA>(__bound_args)...) {}

 template <class ..._Args>
 _LIBCPP_INLINE_VISIBILITY
 typename __bind_return<_Fd, _Td, tuple<_Args&&...> >::type
 operator()(_Args&& ...__args)
 {
 return __apply_functor(__f_, __bound_args_, __indices(),
 tuple<_Args&&...>(_VSTD::forward<_Args>(__args)...));
 }

 template <class ..._Args>
 _LIBCPP_INLINE_VISIBILITY
 typename __bind_return<const _Fd, const _Td, tuple<_Args&&...> >::type
 operator()(_Args&& ...__args) const
 {
 return __apply_functor(__f_, __bound_args_, __indices(),
 tuple<_Args&&...>(_VSTD::forward<_Args>(__args)...));
 }
};

template<class _Fp, class ..._BoundArgs>
struct __is_bind_expression<__bind<_Fp, _BoundArgs...> > : public true_type {};

template<class _Rp, class _Fp, class ..._BoundArgs>
class __bind_r
 : public __bind<_Fp, _BoundArgs...>
{
 typedef __bind<_Fp, _BoundArgs...> base;
 typedef typename base::_Fd _Fd;
 typedef typename base::_Td _Td;
public:
 typedef _Rp result_type;

#ifdef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS

 _LIBCPP_INLINE_VISIBILITY
 __bind_r(const __bind_r& __b)
 : base(_VSTD::forward<const base&>(__b)) {}

 _LIBCPP_INLINE_VISIBILITY
 __bind_r& operator=(const __bind_r& __b)
 {
 base::operator=(_VSTD::forward<const base&>(__b));
 return *this;
 }

 _LIBCPP_INLINE_VISIBILITY
 __bind_r(__bind_r&& __b)
 : base(_VSTD::forward<base>(__b)) {}

 _LIBCPP_INLINE_VISIBILITY
 __bind_r& operator=(__bind_r&& __b)
 {
 base::operator=(_VSTD::forward<base>(__b));
 return *this;
 }

#endif // _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS

 template <class _Gp, class ..._BA,
 class = typename enable_if
 <
 is_constructible<_Fd, _Gp>::value &&
 !is_same<typename remove_reference<_Gp>::type,
 __bind_r>::value
 >::type>
 _LIBCPP_INLINE_VISIBILITY
 explicit __bind_r(_Gp&& __f, _BA&& ...__bound_args)
 : base(_VSTD::forward<_Gp>(__f),
 _VSTD::forward<_BA>(__bound_args)...) {}

 template <class ..._Args>
 _LIBCPP_INLINE_VISIBILITY
 typename enable_if
 <
 is_convertible<typename __bind_return<_Fd, _Td, tuple<_Args&&...> >::type,
 result_type>::value || is_void<_Rp>::value,
 result_type
 >::type
 operator()(_Args&& ...__args)
 {
 typedef __invoke_void_return_wrapper<_Rp> _Invoker;
 return _Invoker::__call(static_cast<base&>(*this), _VSTD::forward<_Args>(__args)...);
 }

 template <class ..._Args>
 _LIBCPP_INLINE_VISIBILITY
 typename enable_if
 <
 is_convertible<typename __bind_return<const _Fd, const _Td, tuple<_Args&&...> >::type,
 result_type>::value || is_void<_Rp>::value,
 result_type
 >::type
 operator()(_Args&& ...__args) const
 {
 typedef __invoke_void_return_wrapper<_Rp> _Invoker;
 return _Invoker::__call(static_cast<base const&>(*this), _VSTD::forward<_Args>(__args)...);
 }
};

template<class _Rp, class _Fp, class ..._BoundArgs>
struct __is_bind_expression<__bind_r<_Rp, _Fp, _BoundArgs...> > : public true_type {};

template<class _Fp, class ..._BoundArgs>
inline _LIBCPP_INLINE_VISIBILITY
__bind<_Fp, _BoundArgs...>
bind(_Fp&& __f, _BoundArgs&&... __bound_args)
{
 typedef __bind<_Fp, _BoundArgs...> type;
 return type(_VSTD::forward<_Fp>(__f), _VSTD::forward<_BoundArgs>(__bound_args)...);
}

template<class _Rp, class _Fp, class ..._BoundArgs>
inline _LIBCPP_INLINE_VISIBILITY
__bind_r<_Rp, _Fp, _BoundArgs...>
bind(_Fp&& __f, _BoundArgs&&... __bound_args)
{
 typedef __bind_r<_Rp, _Fp, _BoundArgs...> type;
 return type(_VSTD::forward<_Fp>(__f), _VSTD::forward<_BoundArgs>(__bound_args)...);
}

#endif // _LIBCPP_HAS_NO_VARIADICS

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<bool>
 : public unary_function<bool, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(bool __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<char>
 : public unary_function<char, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<signed char>
 : public unary_function<signed char, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(signed char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned char>
 : public unary_function<unsigned char, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(unsigned char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
};

#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<char16_t>
 : public unary_function<char16_t, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(char16_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<char32_t>
 : public unary_function<char32_t, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(char32_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
};

#endif // _LIBCPP_HAS_NO_UNICODE_CHARS

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<wchar_t>
 : public unary_function<wchar_t, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(wchar_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<short>
 : public unary_function<short, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned short>
 : public unary_function<unsigned short, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(unsigned short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<int>
 : public unary_function<int, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned int>
 : public unary_function<unsigned int, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(unsigned int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<long>
 : public unary_function<long, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned long>
 : public unary_function<unsigned long, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(unsigned long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<long long>
 : public __scalar_hash<long long>
{
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<unsigned long long>
 : public __scalar_hash<unsigned long long>
{
};

#ifndef _LIBCPP_HAS_NO_INT128

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<__int128_t>
 : public __scalar_hash<__int128_t>
{
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<__uint128_t>
 : public __scalar_hash<__uint128_t>
{
};

#endif

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<float>
 : public __scalar_hash<float>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(float __v) const _NOEXCEPT
 {
 // -0.0 and 0.0 should return same hash
 if (__v == 0)
 return 0;
 return __scalar_hash<float>::operator()(__v);
 }
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<double>
 : public __scalar_hash<double>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(double __v) const _NOEXCEPT
 {
 // -0.0 and 0.0 should return same hash
 if (__v == 0)
 return 0;
 return __scalar_hash<double>::operator()(__v);
 }
};

template <>
struct _LIBCPP_TYPE_VIS_ONLY hash<long double>
 : public __scalar_hash<long double>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(long double __v) const _NOEXCEPT
 {
 // -0.0 and 0.0 should return same hash
 if (__v == 0)
 return 0;
#if defined(__i386__)
 // Zero out padding bits
 union
 {
 long double __t;
 struct
 {
 size_t __a;
 size_t __b;
 size_t __c;
 size_t __d;
 } __s;
 } __u;
 __u.__s.__a = 0;
 __u.__s.__b = 0;
 __u.__s.__c = 0;
 __u.__s.__d = 0;
 __u.__t = __v;
 return __u.__s.__a ^ __u.__s.__b ^ __u.__s.__c ^ __u.__s.__d;
#elif defined(__x86_64__)
 // Zero out padding bits
 union
 {
 long double __t;
 struct
 {
 size_t __a;
 size_t __b;
 } __s;
 } __u;
 __u.__s.__a = 0;
 __u.__s.__b = 0;
 __u.__t = __v;
 return __u.__s.__a ^ __u.__s.__b;
#else
 return __scalar_hash<long double>::operator()(__v);
#endif
 }
};

#if _LIBCPP_STD_VER > 11

template <class _Tp, bool = is_enum<_Tp>::value>
struct _LIBCPP_TYPE_VIS_ONLY __enum_hash
 : public unary_function<_Tp, size_t>
{
 _LIBCPP_INLINE_VISIBILITY
 size_t operator()(_Tp __v) const _NOEXCEPT
 {
 typedef typename underlying_type<_Tp>::type type;
 return hash<type>{}(static_cast<type>(__v));
 }
};
template <class _Tp>
struct _LIBCPP_TYPE_VIS_ONLY __enum_hash<_Tp, false> {
 __enum_hash() = delete;
 __enum_hash(__enum_hash const&) = delete;
 __enum_hash& operator=(__enum_hash const&) = delete;
};

template <class _Tp>
struct _LIBCPP_TYPE_VIS_ONLY hash : public __enum_hash<_Tp>
{
};
#endif


#if _LIBCPP_STD_VER > 14

#define __cpp_lib_invoke 201411

template <class _Fn, class ..._Args>
result_of_t<_Fn&&(_Args&&...)>
invoke(_Fn&& __f, _Args&&... __args)
 noexcept(noexcept(_VSTD::__invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)...)))
{
 return _VSTD::__invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)...);
}

template <class _DecayFunc>
class _LIBCPP_TYPE_VIS_ONLY __not_fn_imp {
 _DecayFunc __fd;

public:
 __not_fn_imp() = delete;

 template <class ..._Args>
 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_Args&& ...__args) &
 noexcept(noexcept(!_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...)))
 -> decltype( !_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...))
 { return !_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...); }

 template <class ..._Args>
 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_Args&& ...__args) &&
 noexcept(noexcept(!_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...)))
 -> decltype( !_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...))
 { return !_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...); }

 template <class ..._Args>
 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_Args&& ...__args) const&
 noexcept(noexcept(!_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...)))
 -> decltype( !_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...))
 { return !_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...); }


 template <class ..._Args>
 _LIBCPP_INLINE_VISIBILITY
 auto operator()(_Args&& ...__args) const&&
 noexcept(noexcept(!_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...)))
 -> decltype( !_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...))
 { return !_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...); }

private:
 template <class _RawFunc,
 class = enable_if_t<!is_same<decay_t<_RawFunc>, __not_fn_imp>::value>>
 _LIBCPP_INLINE_VISIBILITY
 explicit __not_fn_imp(_RawFunc&& __rf)
 : __fd(_VSTD::forward<_RawFunc>(__rf)) {}

 template <class _RawFunc>
 friend inline _LIBCPP_INLINE_VISIBILITY
 __not_fn_imp<decay_t<_RawFunc>> not_fn(_RawFunc&&);
};

template <class _RawFunc>
inline _LIBCPP_INLINE_VISIBILITY
__not_fn_imp<decay_t<_RawFunc>> not_fn(_RawFunc&& __fn) {
 return __not_fn_imp<decay_t<_RawFunc>>(_VSTD::forward<_RawFunc>(__fn));
}

#endif

// struct hash<T*> in <memory>

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP_FUNCTIONAL