libcxx/include/__functional/bind.h - llvm-project - Git at Google

 // -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//

 #ifndef _LIBCPP___FUNCTIONAL_BIND_H
 #define _LIBCPP___FUNCTIONAL_BIND_H

 #include <__config>
 #include <__functional/weak_result_type.h>
 #include <__functional/invoke.h>
 #include <cstddef>
 #include <tuple>
 #include <type_traits>

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

 _LIBCPP_BEGIN_NAMESPACE_STD

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

 #if _LIBCPP_STD_VER > 14
 template <class _Tp>
 inline 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_TEMPLATE_VIS is_placeholder
     : public __is_placeholder<typename remove_cv<_Tp>::type> {};

 #if _LIBCPP_STD_VER > 14
 template <class _Tp>
 inline 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_LIBRARY)
 _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
 /* inline */ constexpr __ph<1>   _1{};
 /* inline */ constexpr __ph<2>   _2{};
 /* inline */ constexpr __ph<3>   _3{};
 /* inline */ constexpr __ph<4>   _4{};
 /* inline */ constexpr __ph<5>   _5{};
 /* inline */ constexpr __ph<6>   _6{};
 /* inline */ constexpr __ph<7>   _7{};
 /* inline */ constexpr __ph<8>   _8{};
 /* inline */ constexpr __ph<9>   _9{};
 /* inline */ constexpr __ph<10> _10{};
 #endif // defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)

 }  // placeholders

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


 #ifndef _LIBCPP_CXX03_LANG

 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 __enable_if_t
 <
     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 _VSTD::__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_impl;

 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_impl<_Ti, false, true, false, tuple<_Uj...> >
     : public __mu_return_invokable<__invokable<_Ti&, _Uj...>::value, _Ti, _Uj...>
 {
 };

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

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

 template <class _Ti, class _TupleUj>
 struct __mu_return
     : public __mu_return_impl<_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 _VSTD::__invoke(__f, _VSTD::__mu(_VSTD::get<_Indx>(__bound_args), __args)...);
 }

 template<class _Fp, class ..._BoundArgs>
 class __bind
 #if _LIBCPP_STD_VER <= 17 || !defined(_LIBCPP_ABI_NO_BINDER_BASES)
     : public __weak_result_type<typename decay<_Fp>::type>
 #endif
 {
 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:
     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 _LIBCPP_CONSTEXPR_AFTER_CXX17
       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 _LIBCPP_CONSTEXPR_AFTER_CXX17
         typename __bind_return<_Fd, _Td, tuple<_Args&&...> >::type
         operator()(_Args&& ...__args)
         {
             return _VSTD::__apply_functor(__f_, __bound_args_, __indices(),
                                   tuple<_Args&&...>(_VSTD::forward<_Args>(__args)...));
         }

     template <class ..._Args>
         _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
         typename __bind_return<const _Fd, const _Td, tuple<_Args&&...> >::type
         operator()(_Args&& ...__args) const
         {
             return _VSTD::__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;


     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 _LIBCPP_CONSTEXPR_AFTER_CXX17
       explicit __bind_r(_Gp&& __f, _BA&& ...__bound_args)
         : base(_VSTD::forward<_Gp>(__f),
                _VSTD::forward<_BA>(__bound_args)...) {}

     template <class ..._Args>
         _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
         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 _LIBCPP_CONSTEXPR_AFTER_CXX17
         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 _LIBCPP_CONSTEXPR_AFTER_CXX17
 __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 _LIBCPP_CONSTEXPR_AFTER_CXX17
 __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_CXX03_LANG

 _LIBCPP_END_NAMESPACE_STD

 #endif // _LIBCPP___FUNCTIONAL_BIND_H
	// -- C++ --
	//===----------------------------------------------------------------------===//
	//
	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
	// See https://llvm.org/LICENSE.txt for license information.
	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
	//
	//===----------------------------------------------------------------------===//

	#ifndef _LIBCPP___FUNCTIONAL_BIND_H
	#define _LIBCPP___FUNCTIONAL_BIND_H

	#include <__config>
	#include <__functional/weak_result_type.h>
	#include <__functional/invoke.h>
	#include <cstddef>
	#include <tuple>
	#include <type_traits>

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

	_LIBCPP_BEGIN_NAMESPACE_STD

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

	#if _LIBCPP_STD_VER > 14
	template <class _Tp>
	inline 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_TEMPLATE_VIS is_placeholder
	: public __is_placeholder<typename remove_cv<_Tp>::type> {};

	#if _LIBCPP_STD_VER > 14
	template <class _Tp>
	inline 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_LIBRARY)
	_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
	/* inline */ constexpr __ph<1> _1{};
	/* inline */ constexpr __ph<2> _2{};
	/* inline */ constexpr __ph<3> _3{};
	/* inline */ constexpr __ph<4> _4{};
	/* inline */ constexpr __ph<5> _5{};
	/* inline */ constexpr __ph<6> _6{};
	/* inline */ constexpr __ph<7> _7{};
	/* inline */ constexpr __ph<8> _8{};
	/* inline */ constexpr __ph<9> _9{};
	/* inline */ constexpr __ph<10> _10{};
	#endif // defined(_LIBCPP_CXX03_LANG) \|\| defined(_LIBCPP_BUILDING_LIBRARY)

	} // placeholders

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


	#ifndef _LIBCPP_CXX03_LANG

	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 __enable_if_t
	<
	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 _VSTD::__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_impl;

	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_impl<_Ti, false, true, false, tuple<_Uj...> >
	: public __mu_return_invokable<__invokable<_Ti&, _Uj...>::value, _Ti, _Uj...>
	{
	};

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

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

	template <class _Ti, class _TupleUj>
	struct __mu_return
	: public __mu_return_impl<_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 _VSTD::__invoke(__f, _VSTD::__mu(_VSTD::get<_Indx>(__bound_args), __args)...);
	}

	template<class _Fp, class ..._BoundArgs>
	class __bind
	#if _LIBCPP_STD_VER <= 17 \|\| !defined(_LIBCPP_ABI_NO_BINDER_BASES)
	: public __weak_result_type<typename decay<_Fp>::type>
	#endif
	{
	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:
	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 _LIBCPP_CONSTEXPR_AFTER_CXX17
	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 _LIBCPP_CONSTEXPR_AFTER_CXX17
	typename __bind_return<_Fd, _Td, tuple<_Args&&...> >::type
	operator()(_Args&& ...__args)
	{
	return _VSTD::__apply_functor(__f_, __bound_args_, __indices(),
	tuple<_Args&&...>(_VSTD::forward<_Args>(__args)...));
	}

	template <class ..._Args>
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
	typename __bind_return<const _Fd, const _Td, tuple<_Args&&...> >::type
	operator()(_Args&& ...__args) const
	{
	return _VSTD::__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;


	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 _LIBCPP_CONSTEXPR_AFTER_CXX17
	explicit __bind_r(_Gp&& __f, _BA&& ...__bound_args)
	: base(_VSTD::forward<_Gp>(__f),
	_VSTD::forward<_BA>(__bound_args)...) {}

	template <class ..._Args>
	_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
	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 _LIBCPP_CONSTEXPR_AFTER_CXX17
	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 _LIBCPP_CONSTEXPR_AFTER_CXX17
	__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 _LIBCPP_CONSTEXPR_AFTER_CXX17
	__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_CXX03_LANG

	_LIBCPP_END_NAMESPACE_STD

	#endif // _LIBCPP___FUNCTIONAL_BIND_H