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      1 // <functional> -*- C++ -*-
      2 
      3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
      4 // 2011 Free Software Foundation, Inc.
      5 //
      6 // This file is part of the GNU ISO C++ Library.  This library is free
      7 // software; you can redistribute it and/or modify it under the
      8 // terms of the GNU General Public License as published by the
      9 // Free Software Foundation; either version 3, or (at your option)
     10 // any later version.
     11 
     12 // This library is distributed in the hope that it will be useful,
     13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
     14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     15 // GNU General Public License for more details.
     16 
     17 // Under Section 7 of GPL version 3, you are granted additional
     18 // permissions described in the GCC Runtime Library Exception, version
     19 // 3.1, as published by the Free Software Foundation.
     20 
     21 // You should have received a copy of the GNU General Public License and
     22 // a copy of the GCC Runtime Library Exception along with this program;
     23 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
     24 // <http://www.gnu.org/licenses/>.
     25 
     26 /*
     27  * Copyright (c) 1997
     28  * Silicon Graphics Computer Systems, Inc.
     29  *
     30  * Permission to use, copy, modify, distribute and sell this software
     31  * and its documentation for any purpose is hereby granted without fee,
     32  * provided that the above copyright notice appear in all copies and
     33  * that both that copyright notice and this permission notice appear
     34  * in supporting documentation.  Silicon Graphics makes no
     35  * representations about the suitability of this software for any
     36  * purpose.  It is provided "as is" without express or implied warranty.
     37  *
     38  */
     39 
     40 /** @file include/functional
     41  *  This is a Standard C++ Library header.
     42  */
     43 
     44 #ifndef _GLIBCXX_FUNCTIONAL
     45 #define _GLIBCXX_FUNCTIONAL 1
     46 
     47 #pragma GCC system_header
     48 
     49 #include <bits/c++config.h>
     50 #include <bits/stl_function.h>
     51 
     52 #ifdef __GXX_EXPERIMENTAL_CXX0X__
     53 
     54 #include <typeinfo>
     55 #include <new>
     56 #include <tuple>
     57 #include <type_traits>
     58 #include <bits/functexcept.h>
     59 #include <bits/functional_hash.h>
     60 
     61 namespace std _GLIBCXX_VISIBILITY(default)
     62 {
     63 _GLIBCXX_BEGIN_NAMESPACE_VERSION
     64 
     65   template<typename _MemberPointer>
     66     class _Mem_fn;
     67   template<typename _Tp, typename _Class>
     68     _Mem_fn<_Tp _Class::*>
     69     mem_fn(_Tp _Class::*);
     70 
     71 _GLIBCXX_HAS_NESTED_TYPE(result_type)
     72 
     73   /// If we have found a result_type, extract it.
     74   template<bool _Has_result_type, typename _Functor>
     75     struct _Maybe_get_result_type
     76     { };
     77 
     78   template<typename _Functor>
     79     struct _Maybe_get_result_type<true, _Functor>
     80     { typedef typename _Functor::result_type result_type; };
     81 
     82   /**
     83    *  Base class for any function object that has a weak result type, as
     84    *  defined in 3.3/3 of TR1.
     85   */
     86   template<typename _Functor>
     87     struct _Weak_result_type_impl
     88     : _Maybe_get_result_type<__has_result_type<_Functor>::value, _Functor>
     89     { };
     90 
     91   /// Retrieve the result type for a function type.
     92   template<typename _Res, typename... _ArgTypes>
     93     struct _Weak_result_type_impl<_Res(_ArgTypes...)>
     94     { typedef _Res result_type; };
     95 
     96   template<typename _Res, typename... _ArgTypes>
     97     struct _Weak_result_type_impl<_Res(_ArgTypes......)>
     98     { typedef _Res result_type; };
     99 
    100   template<typename _Res, typename... _ArgTypes>
    101     struct _Weak_result_type_impl<_Res(_ArgTypes...) const>
    102     { typedef _Res result_type; };
    103 
    104   template<typename _Res, typename... _ArgTypes>
    105     struct _Weak_result_type_impl<_Res(_ArgTypes......) const>
    106     { typedef _Res result_type; };
    107 
    108   template<typename _Res, typename... _ArgTypes>
    109     struct _Weak_result_type_impl<_Res(_ArgTypes...) volatile>
    110     { typedef _Res result_type; };
    111 
    112   template<typename _Res, typename... _ArgTypes>
    113     struct _Weak_result_type_impl<_Res(_ArgTypes......) volatile>
    114     { typedef _Res result_type; };
    115 
    116   template<typename _Res, typename... _ArgTypes>
    117     struct _Weak_result_type_impl<_Res(_ArgTypes...) const volatile>
    118     { typedef _Res result_type; };
    119 
    120   template<typename _Res, typename... _ArgTypes>
    121     struct _Weak_result_type_impl<_Res(_ArgTypes......) const volatile>
    122     { typedef _Res result_type; };
    123 
    124   /// Retrieve the result type for a function reference.
    125   template<typename _Res, typename... _ArgTypes>
    126     struct _Weak_result_type_impl<_Res(&)(_ArgTypes...)>
    127     { typedef _Res result_type; };
    128 
    129   template<typename _Res, typename... _ArgTypes>
    130     struct _Weak_result_type_impl<_Res(&)(_ArgTypes......)>
    131     { typedef _Res result_type; };
    132 
    133   /// Retrieve the result type for a function pointer.
    134   template<typename _Res, typename... _ArgTypes>
    135     struct _Weak_result_type_impl<_Res(*)(_ArgTypes...)>
    136     { typedef _Res result_type; };
    137 
    138   template<typename _Res, typename... _ArgTypes>
    139     struct _Weak_result_type_impl<_Res(*)(_ArgTypes......)>
    140     { typedef _Res result_type; };
    141 
    142   /// Retrieve result type for a member function pointer.
    143   template<typename _Res, typename _Class, typename... _ArgTypes>
    144     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes...)>
    145     { typedef _Res result_type; };
    146 
    147   template<typename _Res, typename _Class, typename... _ArgTypes>
    148     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes......)>
    149     { typedef _Res result_type; };
    150 
    151   /// Retrieve result type for a const member function pointer.
    152   template<typename _Res, typename _Class, typename... _ArgTypes>
    153     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes...) const>
    154     { typedef _Res result_type; };
    155 
    156   template<typename _Res, typename _Class, typename... _ArgTypes>
    157     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes......) const>
    158     { typedef _Res result_type; };
    159 
    160   /// Retrieve result type for a volatile member function pointer.
    161   template<typename _Res, typename _Class, typename... _ArgTypes>
    162     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes...) volatile>
    163     { typedef _Res result_type; };
    164 
    165   template<typename _Res, typename _Class, typename... _ArgTypes>
    166     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes......) volatile>
    167     { typedef _Res result_type; };
    168 
    169   /// Retrieve result type for a const volatile member function pointer.
    170   template<typename _Res, typename _Class, typename... _ArgTypes>
    171     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes...)
    172 				  const volatile>
    173     { typedef _Res result_type; };
    174 
    175   template<typename _Res, typename _Class, typename... _ArgTypes>
    176     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes......)
    177 				  const volatile>
    178     { typedef _Res result_type; };
    179 
    180   /**
    181    *  Strip top-level cv-qualifiers from the function object and let
    182    *  _Weak_result_type_impl perform the real work.
    183   */
    184   template<typename _Functor>
    185     struct _Weak_result_type
    186     : _Weak_result_type_impl<typename remove_cv<_Functor>::type>
    187     { };
    188 
    189   /// Determines if the type _Tp derives from unary_function.
    190   template<typename _Tp>
    191     struct _Derives_from_unary_function : __sfinae_types
    192     {
    193     private:
    194       template<typename _T1, typename _Res>
    195 	static __one __test(const volatile unary_function<_T1, _Res>*);
    196 
    197       // It's tempting to change "..." to const volatile void*, but
    198       // that fails when _Tp is a function type.
    199       static __two __test(...);
    200 
    201     public:
    202       static const bool value = sizeof(__test((_Tp*)0)) == 1;
    203     };
    204 
    205   /// Determines if the type _Tp derives from binary_function.
    206   template<typename _Tp>
    207     struct _Derives_from_binary_function : __sfinae_types
    208     {
    209     private:
    210       template<typename _T1, typename _T2, typename _Res>
    211 	static __one __test(const volatile binary_function<_T1, _T2, _Res>*);
    212 
    213       // It's tempting to change "..." to const volatile void*, but
    214       // that fails when _Tp is a function type.
    215       static __two __test(...);
    216 
    217     public:
    218       static const bool value = sizeof(__test((_Tp*)0)) == 1;
    219     };
    220 
    221   /**
    222    * Invoke a function object, which may be either a member pointer or a
    223    * function object. The first parameter will tell which.
    224    */
    225   template<typename _Functor, typename... _Args>
    226     inline
    227     typename enable_if<
    228 	     (!is_member_pointer<_Functor>::value
    229 	      && !is_function<_Functor>::value
    230 	      && !is_function<typename remove_pointer<_Functor>::type>::value),
    231 	     typename result_of<_Functor(_Args&&...)>::type
    232 	   >::type
    233     __invoke(_Functor& __f, _Args&&... __args)
    234     {
    235       return __f(std::forward<_Args>(__args)...);
    236     }
    237 
    238   template<typename _Functor, typename... _Args>
    239     inline
    240     typename enable_if<
    241              (is_member_pointer<_Functor>::value
    242               && !is_function<_Functor>::value
    243               && !is_function<typename remove_pointer<_Functor>::type>::value),
    244              typename result_of<_Functor(_Args&&...)>::type
    245            >::type
    246     __invoke(_Functor& __f, _Args&&... __args)
    247     {
    248       return mem_fn(__f)(std::forward<_Args>(__args)...);
    249     }
    250 
    251   // To pick up function references (that will become function pointers)
    252   template<typename _Functor, typename... _Args>
    253     inline
    254     typename enable_if<
    255 	     (is_pointer<_Functor>::value
    256 	      && is_function<typename remove_pointer<_Functor>::type>::value),
    257 	     typename result_of<_Functor(_Args&&...)>::type
    258 	   >::type
    259     __invoke(_Functor __f, _Args&&... __args)
    260     {
    261       return __f(std::forward<_Args>(__args)...);
    262     }
    263 
    264   /**
    265    *  Knowing which of unary_function and binary_function _Tp derives
    266    *  from, derives from the same and ensures that reference_wrapper
    267    *  will have a weak result type. See cases below.
    268    */
    269   template<bool _Unary, bool _Binary, typename _Tp>
    270     struct _Reference_wrapper_base_impl;
    271 
    272   // None of the nested argument types.
    273   template<typename _Tp>
    274     struct _Reference_wrapper_base_impl<false, false, _Tp>
    275     : _Weak_result_type<_Tp>
    276     { };
    277 
    278   // Nested argument_type only.
    279   template<typename _Tp>
    280     struct _Reference_wrapper_base_impl<true, false, _Tp>
    281     : _Weak_result_type<_Tp>
    282     {
    283       typedef typename _Tp::argument_type argument_type;
    284     };
    285 
    286   // Nested first_argument_type and second_argument_type only.
    287   template<typename _Tp>
    288     struct _Reference_wrapper_base_impl<false, true, _Tp>
    289     : _Weak_result_type<_Tp>
    290     {
    291       typedef typename _Tp::first_argument_type first_argument_type;
    292       typedef typename _Tp::second_argument_type second_argument_type;
    293     };
    294 
    295   // All the nested argument types.
    296    template<typename _Tp>
    297     struct _Reference_wrapper_base_impl<true, true, _Tp>
    298     : _Weak_result_type<_Tp>
    299     {
    300       typedef typename _Tp::argument_type argument_type;
    301       typedef typename _Tp::first_argument_type first_argument_type;
    302       typedef typename _Tp::second_argument_type second_argument_type;
    303     };
    304 
    305   _GLIBCXX_HAS_NESTED_TYPE(argument_type)
    306   _GLIBCXX_HAS_NESTED_TYPE(first_argument_type)
    307   _GLIBCXX_HAS_NESTED_TYPE(second_argument_type)
    308 
    309   /**
    310    *  Derives from unary_function or binary_function when it
    311    *  can. Specializations handle all of the easy cases. The primary
    312    *  template determines what to do with a class type, which may
    313    *  derive from both unary_function and binary_function.
    314   */
    315   template<typename _Tp>
    316     struct _Reference_wrapper_base
    317     : _Reference_wrapper_base_impl<
    318       __has_argument_type<_Tp>::value,
    319       __has_first_argument_type<_Tp>::value
    320       && __has_second_argument_type<_Tp>::value,
    321       _Tp>
    322     { };
    323 
    324   // - a function type (unary)
    325   template<typename _Res, typename _T1>
    326     struct _Reference_wrapper_base<_Res(_T1)>
    327     : unary_function<_T1, _Res>
    328     { };
    329 
    330   template<typename _Res, typename _T1>
    331     struct _Reference_wrapper_base<_Res(_T1) const>
    332     : unary_function<_T1, _Res>
    333     { };
    334 
    335   template<typename _Res, typename _T1>
    336     struct _Reference_wrapper_base<_Res(_T1) volatile>
    337     : unary_function<_T1, _Res>
    338     { };
    339 
    340   template<typename _Res, typename _T1>
    341     struct _Reference_wrapper_base<_Res(_T1) const volatile>
    342     : unary_function<_T1, _Res>
    343     { };
    344 
    345   // - a function type (binary)
    346   template<typename _Res, typename _T1, typename _T2>
    347     struct _Reference_wrapper_base<_Res(_T1, _T2)>
    348     : binary_function<_T1, _T2, _Res>
    349     { };
    350 
    351   template<typename _Res, typename _T1, typename _T2>
    352     struct _Reference_wrapper_base<_Res(_T1, _T2) const>
    353     : binary_function<_T1, _T2, _Res>
    354     { };
    355 
    356   template<typename _Res, typename _T1, typename _T2>
    357     struct _Reference_wrapper_base<_Res(_T1, _T2) volatile>
    358     : binary_function<_T1, _T2, _Res>
    359     { };
    360 
    361   template<typename _Res, typename _T1, typename _T2>
    362     struct _Reference_wrapper_base<_Res(_T1, _T2) const volatile>
    363     : binary_function<_T1, _T2, _Res>
    364     { };
    365 
    366   // - a function pointer type (unary)
    367   template<typename _Res, typename _T1>
    368     struct _Reference_wrapper_base<_Res(*)(_T1)>
    369     : unary_function<_T1, _Res>
    370     { };
    371 
    372   // - a function pointer type (binary)
    373   template<typename _Res, typename _T1, typename _T2>
    374     struct _Reference_wrapper_base<_Res(*)(_T1, _T2)>
    375     : binary_function<_T1, _T2, _Res>
    376     { };
    377 
    378   // - a pointer to member function type (unary, no qualifiers)
    379   template<typename _Res, typename _T1>
    380     struct _Reference_wrapper_base<_Res (_T1::*)()>
    381     : unary_function<_T1*, _Res>
    382     { };
    383 
    384   // - a pointer to member function type (binary, no qualifiers)
    385   template<typename _Res, typename _T1, typename _T2>
    386     struct _Reference_wrapper_base<_Res (_T1::*)(_T2)>
    387     : binary_function<_T1*, _T2, _Res>
    388     { };
    389 
    390   // - a pointer to member function type (unary, const)
    391   template<typename _Res, typename _T1>
    392     struct _Reference_wrapper_base<_Res (_T1::*)() const>
    393     : unary_function<const _T1*, _Res>
    394     { };
    395 
    396   // - a pointer to member function type (binary, const)
    397   template<typename _Res, typename _T1, typename _T2>
    398     struct _Reference_wrapper_base<_Res (_T1::*)(_T2) const>
    399     : binary_function<const _T1*, _T2, _Res>
    400     { };
    401 
    402   // - a pointer to member function type (unary, volatile)
    403   template<typename _Res, typename _T1>
    404     struct _Reference_wrapper_base<_Res (_T1::*)() volatile>
    405     : unary_function<volatile _T1*, _Res>
    406     { };
    407 
    408   // - a pointer to member function type (binary, volatile)
    409   template<typename _Res, typename _T1, typename _T2>
    410     struct _Reference_wrapper_base<_Res (_T1::*)(_T2) volatile>
    411     : binary_function<volatile _T1*, _T2, _Res>
    412     { };
    413 
    414   // - a pointer to member function type (unary, const volatile)
    415   template<typename _Res, typename _T1>
    416     struct _Reference_wrapper_base<_Res (_T1::*)() const volatile>
    417     : unary_function<const volatile _T1*, _Res>
    418     { };
    419 
    420   // - a pointer to member function type (binary, const volatile)
    421   template<typename _Res, typename _T1, typename _T2>
    422     struct _Reference_wrapper_base<_Res (_T1::*)(_T2) const volatile>
    423     : binary_function<const volatile _T1*, _T2, _Res>
    424     { };
    425 
    426   /**
    427    *  @brief Primary class template for reference_wrapper.
    428    *  @ingroup functors
    429    *  @{
    430    */
    431   template<typename _Tp>
    432     class reference_wrapper
    433     : public _Reference_wrapper_base<typename remove_cv<_Tp>::type>
    434     {
    435       _Tp* _M_data;
    436 
    437     public:
    438       typedef _Tp type;
    439 
    440       reference_wrapper(_Tp& __indata) noexcept
    441       : _M_data(std::__addressof(__indata))
    442       { }
    443 
    444       reference_wrapper(_Tp&&) = delete;
    445 
    446       reference_wrapper(const reference_wrapper<_Tp>& __inref) noexcept
    447       : _M_data(__inref._M_data)
    448       { }
    449 
    450       reference_wrapper&
    451       operator=(const reference_wrapper<_Tp>& __inref) noexcept
    452       {
    453 	_M_data = __inref._M_data;
    454 	return *this;
    455       }
    456 
    457       operator _Tp&() const noexcept
    458       { return this->get(); }
    459 
    460       _Tp&
    461       get() const noexcept
    462       { return *_M_data; }
    463 
    464       template<typename... _Args>
    465 	typename result_of<_Tp&(_Args&&...)>::type
    466 	operator()(_Args&&... __args) const
    467 	{
    468 	  return __invoke(get(), std::forward<_Args>(__args)...);
    469 	}
    470     };
    471 
    472 
    473   /// Denotes a reference should be taken to a variable.
    474   template<typename _Tp>
    475     inline reference_wrapper<_Tp>
    476     ref(_Tp& __t) noexcept
    477     { return reference_wrapper<_Tp>(__t); }
    478 
    479   /// Denotes a const reference should be taken to a variable.
    480   template<typename _Tp>
    481     inline reference_wrapper<const _Tp>
    482     cref(const _Tp& __t) noexcept
    483     { return reference_wrapper<const _Tp>(__t); }
    484 
    485   template<typename _Tp>
    486     void ref(const _Tp&&) = delete;
    487 
    488   template<typename _Tp>
    489     void cref(const _Tp&&) = delete;
    490 
    491   /// Partial specialization.
    492   template<typename _Tp>
    493     inline reference_wrapper<_Tp>
    494     ref(reference_wrapper<_Tp> __t) noexcept
    495     { return ref(__t.get()); }
    496 
    497   /// Partial specialization.
    498   template<typename _Tp>
    499     inline reference_wrapper<const _Tp>
    500     cref(reference_wrapper<_Tp> __t) noexcept
    501     { return cref(__t.get()); }
    502 
    503   // @} group functors
    504 
    505   /**
    506    * Derives from @c unary_function or @c binary_function, or perhaps
    507    * nothing, depending on the number of arguments provided. The
    508    * primary template is the basis case, which derives nothing.
    509    */
    510   template<typename _Res, typename... _ArgTypes>
    511     struct _Maybe_unary_or_binary_function { };
    512 
    513   /// Derives from @c unary_function, as appropriate.
    514   template<typename _Res, typename _T1>
    515     struct _Maybe_unary_or_binary_function<_Res, _T1>
    516     : std::unary_function<_T1, _Res> { };
    517 
    518   /// Derives from @c binary_function, as appropriate.
    519   template<typename _Res, typename _T1, typename _T2>
    520     struct _Maybe_unary_or_binary_function<_Res, _T1, _T2>
    521     : std::binary_function<_T1, _T2, _Res> { };
    522 
    523   /// Implementation of @c mem_fn for member function pointers.
    524   template<typename _Res, typename _Class, typename... _ArgTypes>
    525     class _Mem_fn<_Res (_Class::*)(_ArgTypes...)>
    526     : public _Maybe_unary_or_binary_function<_Res, _Class*, _ArgTypes...>
    527     {
    528       typedef _Res (_Class::*_Functor)(_ArgTypes...);
    529 
    530       template<typename _Tp>
    531 	_Res
    532 	_M_call(_Tp& __object, const volatile _Class *,
    533 		_ArgTypes... __args) const
    534 	{ return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
    535 
    536       template<typename _Tp>
    537 	_Res
    538 	_M_call(_Tp& __ptr, const volatile void *, _ArgTypes... __args) const
    539 	{ return ((*__ptr).*__pmf)(std::forward<_ArgTypes>(__args)...); }
    540 
    541     public:
    542       typedef _Res result_type;
    543 
    544       explicit _Mem_fn(_Functor __pmf) : __pmf(__pmf) { }
    545 
    546       // Handle objects
    547       _Res
    548       operator()(_Class& __object, _ArgTypes... __args) const
    549       { return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
    550 
    551       // Handle pointers
    552       _Res
    553       operator()(_Class* __object, _ArgTypes... __args) const
    554       { return (__object->*__pmf)(std::forward<_ArgTypes>(__args)...); }
    555 
    556       // Handle smart pointers, references and pointers to derived
    557       template<typename _Tp>
    558 	_Res
    559 	operator()(_Tp& __object, _ArgTypes... __args) const
    560 	{
    561 	  return _M_call(__object, &__object,
    562 	      std::forward<_ArgTypes>(__args)...);
    563 	}
    564 
    565     private:
    566       _Functor __pmf;
    567     };
    568 
    569   /// Implementation of @c mem_fn for const member function pointers.
    570   template<typename _Res, typename _Class, typename... _ArgTypes>
    571     class _Mem_fn<_Res (_Class::*)(_ArgTypes...) const>
    572     : public _Maybe_unary_or_binary_function<_Res, const _Class*,
    573 					     _ArgTypes...>
    574     {
    575       typedef _Res (_Class::*_Functor)(_ArgTypes...) const;
    576 
    577       template<typename _Tp>
    578 	_Res
    579 	_M_call(_Tp& __object, const volatile _Class *,
    580 		_ArgTypes... __args) const
    581 	{ return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
    582 
    583       template<typename _Tp>
    584 	_Res
    585 	_M_call(_Tp& __ptr, const volatile void *, _ArgTypes... __args) const
    586 	{ return ((*__ptr).*__pmf)(std::forward<_ArgTypes>(__args)...); }
    587 
    588     public:
    589       typedef _Res result_type;
    590 
    591       explicit _Mem_fn(_Functor __pmf) : __pmf(__pmf) { }
    592 
    593       // Handle objects
    594       _Res
    595       operator()(const _Class& __object, _ArgTypes... __args) const
    596       { return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
    597 
    598       // Handle pointers
    599       _Res
    600       operator()(const _Class* __object, _ArgTypes... __args) const
    601       { return (__object->*__pmf)(std::forward<_ArgTypes>(__args)...); }
    602 
    603       // Handle smart pointers, references and pointers to derived
    604       template<typename _Tp>
    605 	_Res operator()(_Tp& __object, _ArgTypes... __args) const
    606 	{
    607 	  return _M_call(__object, &__object,
    608 	      std::forward<_ArgTypes>(__args)...);
    609 	}
    610 
    611     private:
    612       _Functor __pmf;
    613     };
    614 
    615   /// Implementation of @c mem_fn for volatile member function pointers.
    616   template<typename _Res, typename _Class, typename... _ArgTypes>
    617     class _Mem_fn<_Res (_Class::*)(_ArgTypes...) volatile>
    618     : public _Maybe_unary_or_binary_function<_Res, volatile _Class*,
    619 					     _ArgTypes...>
    620     {
    621       typedef _Res (_Class::*_Functor)(_ArgTypes...) volatile;
    622 
    623       template<typename _Tp>
    624 	_Res
    625 	_M_call(_Tp& __object, const volatile _Class *,
    626 		_ArgTypes... __args) const
    627 	{ return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
    628 
    629       template<typename _Tp>
    630 	_Res
    631 	_M_call(_Tp& __ptr, const volatile void *, _ArgTypes... __args) const
    632 	{ return ((*__ptr).*__pmf)(std::forward<_ArgTypes>(__args)...); }
    633 
    634     public:
    635       typedef _Res result_type;
    636 
    637       explicit _Mem_fn(_Functor __pmf) : __pmf(__pmf) { }
    638 
    639       // Handle objects
    640       _Res
    641       operator()(volatile _Class& __object, _ArgTypes... __args) const
    642       { return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
    643 
    644       // Handle pointers
    645       _Res
    646       operator()(volatile _Class* __object, _ArgTypes... __args) const
    647       { return (__object->*__pmf)(std::forward<_ArgTypes>(__args)...); }
    648 
    649       // Handle smart pointers, references and pointers to derived
    650       template<typename _Tp>
    651 	_Res
    652 	operator()(_Tp& __object, _ArgTypes... __args) const
    653 	{
    654 	  return _M_call(__object, &__object,
    655 	      std::forward<_ArgTypes>(__args)...);
    656 	}
    657 
    658     private:
    659       _Functor __pmf;
    660     };
    661 
    662   /// Implementation of @c mem_fn for const volatile member function pointers.
    663   template<typename _Res, typename _Class, typename... _ArgTypes>
    664     class _Mem_fn<_Res (_Class::*)(_ArgTypes...) const volatile>
    665     : public _Maybe_unary_or_binary_function<_Res, const volatile _Class*,
    666 					     _ArgTypes...>
    667     {
    668       typedef _Res (_Class::*_Functor)(_ArgTypes...) const volatile;
    669 
    670       template<typename _Tp>
    671 	_Res
    672 	_M_call(_Tp& __object, const volatile _Class *,
    673 		_ArgTypes... __args) const
    674 	{ return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
    675 
    676       template<typename _Tp>
    677 	_Res
    678 	_M_call(_Tp& __ptr, const volatile void *, _ArgTypes... __args) const
    679 	{ return ((*__ptr).*__pmf)(std::forward<_ArgTypes>(__args)...); }
    680 
    681     public:
    682       typedef _Res result_type;
    683 
    684       explicit _Mem_fn(_Functor __pmf) : __pmf(__pmf) { }
    685 
    686       // Handle objects
    687       _Res
    688       operator()(const volatile _Class& __object, _ArgTypes... __args) const
    689       { return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
    690 
    691       // Handle pointers
    692       _Res
    693       operator()(const volatile _Class* __object, _ArgTypes... __args) const
    694       { return (__object->*__pmf)(std::forward<_ArgTypes>(__args)...); }
    695 
    696       // Handle smart pointers, references and pointers to derived
    697       template<typename _Tp>
    698 	_Res operator()(_Tp& __object, _ArgTypes... __args) const
    699 	{
    700 	  return _M_call(__object, &__object,
    701 	      std::forward<_ArgTypes>(__args)...);
    702 	}
    703 
    704     private:
    705       _Functor __pmf;
    706     };
    707 
    708 
    709   template<typename _Tp, bool>
    710     struct _Mem_fn_const_or_non
    711     {
    712       typedef const _Tp& type;
    713     };
    714 
    715   template<typename _Tp>
    716     struct _Mem_fn_const_or_non<_Tp, false>
    717     {
    718       typedef _Tp& type;
    719     };
    720 
    721   template<typename _Res, typename _Class>
    722     class _Mem_fn<_Res _Class::*>
    723     {
    724       // This bit of genius is due to Peter Dimov, improved slightly by
    725       // Douglas Gregor.
    726       template<typename _Tp>
    727 	_Res&
    728 	_M_call(_Tp& __object, _Class *) const
    729 	{ return __object.*__pm; }
    730 
    731       template<typename _Tp, typename _Up>
    732 	_Res&
    733 	_M_call(_Tp& __object, _Up * const *) const
    734 	{ return (*__object).*__pm; }
    735 
    736       template<typename _Tp, typename _Up>
    737 	const _Res&
    738 	_M_call(_Tp& __object, const _Up * const *) const
    739 	{ return (*__object).*__pm; }
    740 
    741       template<typename _Tp>
    742 	const _Res&
    743 	_M_call(_Tp& __object, const _Class *) const
    744 	{ return __object.*__pm; }
    745 
    746       template<typename _Tp>
    747 	const _Res&
    748 	_M_call(_Tp& __ptr, const volatile void*) const
    749 	{ return (*__ptr).*__pm; }
    750 
    751       template<typename _Tp> static _Tp& __get_ref();
    752 
    753       template<typename _Tp>
    754 	static __sfinae_types::__one __check_const(_Tp&, _Class*);
    755       template<typename _Tp, typename _Up>
    756 	static __sfinae_types::__one __check_const(_Tp&, _Up * const *);
    757       template<typename _Tp, typename _Up>
    758 	static __sfinae_types::__two __check_const(_Tp&, const _Up * const *);
    759       template<typename _Tp>
    760 	static __sfinae_types::__two __check_const(_Tp&, const _Class*);
    761       template<typename _Tp>
    762 	static __sfinae_types::__two __check_const(_Tp&, const volatile void*);
    763 
    764     public:
    765       template<typename _Tp>
    766 	struct _Result_type
    767 	: _Mem_fn_const_or_non<_Res,
    768 	  (sizeof(__sfinae_types::__two)
    769 	   == sizeof(__check_const<_Tp>(__get_ref<_Tp>(), (_Tp*)0)))>
    770 	{ };
    771 
    772       template<typename _Signature>
    773 	struct result;
    774 
    775       template<typename _CVMem, typename _Tp>
    776 	struct result<_CVMem(_Tp)>
    777 	: public _Result_type<_Tp> { };
    778 
    779       template<typename _CVMem, typename _Tp>
    780 	struct result<_CVMem(_Tp&)>
    781 	: public _Result_type<_Tp> { };
    782 
    783       explicit
    784       _Mem_fn(_Res _Class::*__pm) : __pm(__pm) { }
    785 
    786       // Handle objects
    787       _Res&
    788       operator()(_Class& __object) const
    789       { return __object.*__pm; }
    790 
    791       const _Res&
    792       operator()(const _Class& __object) const
    793       { return __object.*__pm; }
    794 
    795       // Handle pointers
    796       _Res&
    797       operator()(_Class* __object) const
    798       { return __object->*__pm; }
    799 
    800       const _Res&
    801       operator()(const _Class* __object) const
    802       { return __object->*__pm; }
    803 
    804       // Handle smart pointers and derived
    805       template<typename _Tp>
    806 	typename _Result_type<_Tp>::type
    807 	operator()(_Tp& __unknown) const
    808 	{ return _M_call(__unknown, &__unknown); }
    809 
    810     private:
    811       _Res _Class::*__pm;
    812     };
    813 
    814   /**
    815    *  @brief Returns a function object that forwards to the member
    816    *  pointer @a pm.
    817    *  @ingroup functors
    818    */
    819   template<typename _Tp, typename _Class>
    820     inline _Mem_fn<_Tp _Class::*>
    821     mem_fn(_Tp _Class::* __pm)
    822     {
    823       return _Mem_fn<_Tp _Class::*>(__pm);
    824     }
    825 
    826   /**
    827    *  @brief Determines if the given type _Tp is a function object
    828    *  should be treated as a subexpression when evaluating calls to
    829    *  function objects returned by bind(). [TR1 3.6.1]
    830    *  @ingroup binders
    831    */
    832   template<typename _Tp>
    833     struct is_bind_expression
    834     : public false_type { };
    835 
    836   /**
    837    *  @brief Determines if the given type _Tp is a placeholder in a
    838    *  bind() expression and, if so, which placeholder it is. [TR1 3.6.2]
    839    *  @ingroup binders
    840    */
    841   template<typename _Tp>
    842     struct is_placeholder
    843     : public integral_constant<int, 0>
    844     { };
    845 
    846   /** @brief The type of placeholder objects defined by libstdc++.
    847    *  @ingroup binders
    848    */
    849   template<int _Num> struct _Placeholder { };
    850 
    851   _GLIBCXX_END_NAMESPACE_VERSION
    852 
    853   /** @namespace std::placeholders
    854    *  @brief ISO C++11 entities sub-namespace for functional.
    855    *  @ingroup binders
    856    */
    857   namespace placeholders
    858   {
    859   _GLIBCXX_BEGIN_NAMESPACE_VERSION
    860   /* Define a large number of placeholders. There is no way to
    861    * simplify this with variadic templates, because we're introducing
    862    * unique names for each.
    863    */
    864     extern const _Placeholder<1> _1;
    865     extern const _Placeholder<2> _2;
    866     extern const _Placeholder<3> _3;
    867     extern const _Placeholder<4> _4;
    868     extern const _Placeholder<5> _5;
    869     extern const _Placeholder<6> _6;
    870     extern const _Placeholder<7> _7;
    871     extern const _Placeholder<8> _8;
    872     extern const _Placeholder<9> _9;
    873     extern const _Placeholder<10> _10;
    874     extern const _Placeholder<11> _11;
    875     extern const _Placeholder<12> _12;
    876     extern const _Placeholder<13> _13;
    877     extern const _Placeholder<14> _14;
    878     extern const _Placeholder<15> _15;
    879     extern const _Placeholder<16> _16;
    880     extern const _Placeholder<17> _17;
    881     extern const _Placeholder<18> _18;
    882     extern const _Placeholder<19> _19;
    883     extern const _Placeholder<20> _20;
    884     extern const _Placeholder<21> _21;
    885     extern const _Placeholder<22> _22;
    886     extern const _Placeholder<23> _23;
    887     extern const _Placeholder<24> _24;
    888     extern const _Placeholder<25> _25;
    889     extern const _Placeholder<26> _26;
    890     extern const _Placeholder<27> _27;
    891     extern const _Placeholder<28> _28;
    892     extern const _Placeholder<29> _29;
    893   _GLIBCXX_END_NAMESPACE_VERSION
    894   }
    895 
    896   _GLIBCXX_BEGIN_NAMESPACE_VERSION
    897 
    898   /**
    899    *  Partial specialization of is_placeholder that provides the placeholder
    900    *  number for the placeholder objects defined by libstdc++.
    901    *  @ingroup binders
    902    */
    903   template<int _Num>
    904     struct is_placeholder<_Placeholder<_Num> >
    905     : public integral_constant<int, _Num>
    906     { };
    907 
    908   template<int _Num>
    909     struct is_placeholder<const _Placeholder<_Num> >
    910     : public integral_constant<int, _Num>
    911     { };
    912 
    913   /**
    914    * Used by _Safe_tuple_element to indicate that there is no tuple
    915    * element at this position.
    916    */
    917   struct _No_tuple_element;
    918 
    919   /**
    920    * Implementation helper for _Safe_tuple_element. This primary
    921    * template handles the case where it is safe to use @c
    922    * tuple_element.
    923    */
    924   template<std::size_t __i, typename _Tuple, bool _IsSafe>
    925     struct _Safe_tuple_element_impl
    926     : tuple_element<__i, _Tuple> { };
    927 
    928   /**
    929    * Implementation helper for _Safe_tuple_element. This partial
    930    * specialization handles the case where it is not safe to use @c
    931    * tuple_element. We just return @c _No_tuple_element.
    932    */
    933   template<std::size_t __i, typename _Tuple>
    934     struct _Safe_tuple_element_impl<__i, _Tuple, false>
    935     {
    936       typedef _No_tuple_element type;
    937     };
    938 
    939   /**
    940    * Like tuple_element, but returns @c _No_tuple_element when
    941    * tuple_element would return an error.
    942    */
    943  template<std::size_t __i, typename _Tuple>
    944    struct _Safe_tuple_element
    945    : _Safe_tuple_element_impl<__i, _Tuple,
    946 			      (__i < tuple_size<_Tuple>::value)>
    947    { };
    948 
    949   /**
    950    *  Maps an argument to bind() into an actual argument to the bound
    951    *  function object [TR1 3.6.3/5]. Only the first parameter should
    952    *  be specified: the rest are used to determine among the various
    953    *  implementations. Note that, although this class is a function
    954    *  object, it isn't entirely normal because it takes only two
    955    *  parameters regardless of the number of parameters passed to the
    956    *  bind expression. The first parameter is the bound argument and
    957    *  the second parameter is a tuple containing references to the
    958    *  rest of the arguments.
    959    */
    960   template<typename _Arg,
    961 	   bool _IsBindExp = is_bind_expression<_Arg>::value,
    962 	   bool _IsPlaceholder = (is_placeholder<_Arg>::value > 0)>
    963     class _Mu;
    964 
    965   /**
    966    *  If the argument is reference_wrapper<_Tp>, returns the
    967    *  underlying reference. [TR1 3.6.3/5 bullet 1]
    968    */
    969   template<typename _Tp>
    970     class _Mu<reference_wrapper<_Tp>, false, false>
    971     {
    972     public:
    973       typedef _Tp& result_type;
    974 
    975       /* Note: This won't actually work for const volatile
    976        * reference_wrappers, because reference_wrapper::get() is const
    977        * but not volatile-qualified. This might be a defect in the TR.
    978        */
    979       template<typename _CVRef, typename _Tuple>
    980 	result_type
    981 	operator()(_CVRef& __arg, _Tuple&) const volatile
    982 	{ return __arg.get(); }
    983     };
    984 
    985   /**
    986    *  If the argument is a bind expression, we invoke the underlying
    987    *  function object with the same cv-qualifiers as we are given and
    988    *  pass along all of our arguments (unwrapped). [TR1 3.6.3/5 bullet 2]
    989    */
    990   template<typename _Arg>
    991     class _Mu<_Arg, true, false>
    992     {
    993     public:
    994       template<typename _CVArg, typename... _Args>
    995 	auto
    996 	operator()(_CVArg& __arg,
    997 		   tuple<_Args...>& __tuple) const volatile
    998 	-> decltype(__arg(declval<_Args>()...))
    999 	{
   1000 	  // Construct an index tuple and forward to __call
   1001 	  typedef typename _Build_index_tuple<sizeof...(_Args)>::__type
   1002 	    _Indexes;
   1003 	  return this->__call(__arg, __tuple, _Indexes());
   1004 	}
   1005 
   1006     private:
   1007       // Invokes the underlying function object __arg by unpacking all
   1008       // of the arguments in the tuple.
   1009       template<typename _CVArg, typename... _Args, std::size_t... _Indexes>
   1010 	auto
   1011 	__call(_CVArg& __arg, tuple<_Args...>& __tuple,
   1012 	       const _Index_tuple<_Indexes...>&) const volatile
   1013 	-> decltype(__arg(declval<_Args>()...))
   1014 	{
   1015 	  return __arg(std::forward<_Args>(get<_Indexes>(__tuple))...);
   1016 	}
   1017     };
   1018 
   1019   /**
   1020    *  If the argument is a placeholder for the Nth argument, returns
   1021    *  a reference to the Nth argument to the bind function object.
   1022    *  [TR1 3.6.3/5 bullet 3]
   1023    */
   1024   template<typename _Arg>
   1025     class _Mu<_Arg, false, true>
   1026     {
   1027     public:
   1028       template<typename _Signature> class result;
   1029 
   1030       template<typename _CVMu, typename _CVArg, typename _Tuple>
   1031 	class result<_CVMu(_CVArg, _Tuple)>
   1032 	{
   1033 	  // Add a reference, if it hasn't already been done for us.
   1034 	  // This allows us to be a little bit sloppy in constructing
   1035 	  // the tuple that we pass to result_of<...>.
   1036 	  typedef typename _Safe_tuple_element<(is_placeholder<_Arg>::value
   1037 						- 1), _Tuple>::type
   1038 	    __base_type;
   1039 
   1040 	public:
   1041 	  typedef typename add_rvalue_reference<__base_type>::type type;
   1042 	};
   1043 
   1044       template<typename _Tuple>
   1045 	typename result<_Mu(_Arg, _Tuple)>::type
   1046 	operator()(const volatile _Arg&, _Tuple& __tuple) const volatile
   1047 	{
   1048 	  return std::forward<typename result<_Mu(_Arg, _Tuple)>::type>(
   1049 	      ::std::get<(is_placeholder<_Arg>::value - 1)>(__tuple));
   1050 	}
   1051     };
   1052 
   1053   /**
   1054    *  If the argument is just a value, returns a reference to that
   1055    *  value. The cv-qualifiers on the reference are the same as the
   1056    *  cv-qualifiers on the _Mu object. [TR1 3.6.3/5 bullet 4]
   1057    */
   1058   template<typename _Arg>
   1059     class _Mu<_Arg, false, false>
   1060     {
   1061     public:
   1062       template<typename _Signature> struct result;
   1063 
   1064       template<typename _CVMu, typename _CVArg, typename _Tuple>
   1065 	struct result<_CVMu(_CVArg, _Tuple)>
   1066 	{
   1067 	  typedef typename add_lvalue_reference<_CVArg>::type type;
   1068 	};
   1069 
   1070       // Pick up the cv-qualifiers of the argument
   1071       template<typename _CVArg, typename _Tuple>
   1072 	_CVArg&&
   1073 	operator()(_CVArg&& __arg, _Tuple&) const volatile
   1074 	{ return std::forward<_CVArg>(__arg); }
   1075     };
   1076 
   1077   /**
   1078    *  Maps member pointers into instances of _Mem_fn but leaves all
   1079    *  other function objects untouched. Used by tr1::bind(). The
   1080    *  primary template handles the non--member-pointer case.
   1081    */
   1082   template<typename _Tp>
   1083     struct _Maybe_wrap_member_pointer
   1084     {
   1085       typedef _Tp type;
   1086 
   1087       static const _Tp&
   1088       __do_wrap(const _Tp& __x)
   1089       { return __x; }
   1090 
   1091       static _Tp&&
   1092       __do_wrap(_Tp&& __x)
   1093       { return static_cast<_Tp&&>(__x); }
   1094     };
   1095 
   1096   /**
   1097    *  Maps member pointers into instances of _Mem_fn but leaves all
   1098    *  other function objects untouched. Used by tr1::bind(). This
   1099    *  partial specialization handles the member pointer case.
   1100    */
   1101   template<typename _Tp, typename _Class>
   1102     struct _Maybe_wrap_member_pointer<_Tp _Class::*>
   1103     {
   1104       typedef _Mem_fn<_Tp _Class::*> type;
   1105 
   1106       static type
   1107       __do_wrap(_Tp _Class::* __pm)
   1108       { return type(__pm); }
   1109     };
   1110 
   1111   // Specialization needed to prevent "forming reference to void" errors when
   1112   // bind<void>() is called, because argument deduction instantiates
   1113   // _Maybe_wrap_member_pointer<void> outside the immediate context where
   1114   // SFINAE applies.
   1115   template<>
   1116     struct _Maybe_wrap_member_pointer<void>
   1117     {
   1118       typedef void type;
   1119     };
   1120 
   1121   // std::get<I> for volatile-qualified tuples
   1122   template<std::size_t _Ind, typename... _Tp>
   1123     inline auto
   1124     __volget(volatile tuple<_Tp...>& __tuple)
   1125     -> typename tuple_element<_Ind, tuple<_Tp...>>::type volatile&
   1126     { return std::get<_Ind>(const_cast<tuple<_Tp...>&>(__tuple)); }
   1127 
   1128   // std::get<I> for const-volatile-qualified tuples
   1129   template<std::size_t _Ind, typename... _Tp>
   1130     inline auto
   1131     __volget(const volatile tuple<_Tp...>& __tuple)
   1132     -> typename tuple_element<_Ind, tuple<_Tp...>>::type const volatile&
   1133     { return std::get<_Ind>(const_cast<const tuple<_Tp...>&>(__tuple)); }
   1134 
   1135   /// Type of the function object returned from bind().
   1136   template<typename _Signature>
   1137     struct _Bind;
   1138 
   1139    template<typename _Functor, typename... _Bound_args>
   1140     class _Bind<_Functor(_Bound_args...)>
   1141     : public _Weak_result_type<_Functor>
   1142     {
   1143       typedef _Bind __self_type;
   1144       typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
   1145 	_Bound_indexes;
   1146 
   1147       _Functor _M_f;
   1148       tuple<_Bound_args...> _M_bound_args;
   1149 
   1150       // Call unqualified
   1151       template<typename _Result, typename... _Args, std::size_t... _Indexes>
   1152 	_Result
   1153 	__call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
   1154 	{
   1155 	  return _M_f(_Mu<_Bound_args>()
   1156 		      (get<_Indexes>(_M_bound_args), __args)...);
   1157 	}
   1158 
   1159       // Call as const
   1160       template<typename _Result, typename... _Args, std::size_t... _Indexes>
   1161 	_Result
   1162 	__call_c(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
   1163 	{
   1164 	  return _M_f(_Mu<_Bound_args>()
   1165 		      (get<_Indexes>(_M_bound_args), __args)...);
   1166 	}
   1167 
   1168       // Call as volatile
   1169       template<typename _Result, typename... _Args, std::size_t... _Indexes>
   1170 	_Result
   1171 	__call_v(tuple<_Args...>&& __args,
   1172 		 _Index_tuple<_Indexes...>) volatile
   1173 	{
   1174 	  return _M_f(_Mu<_Bound_args>()
   1175 		      (__volget<_Indexes>(_M_bound_args), __args)...);
   1176 	}
   1177 
   1178       // Call as const volatile
   1179       template<typename _Result, typename... _Args, std::size_t... _Indexes>
   1180 	_Result
   1181 	__call_c_v(tuple<_Args...>&& __args,
   1182 		   _Index_tuple<_Indexes...>) const volatile
   1183 	{
   1184 	  return _M_f(_Mu<_Bound_args>()
   1185 		      (__volget<_Indexes>(_M_bound_args), __args)...);
   1186 	}
   1187 
   1188      public:
   1189       template<typename... _Args>
   1190 	explicit _Bind(const _Functor& __f, _Args&&... __args)
   1191 	: _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
   1192 	{ }
   1193 
   1194       template<typename... _Args>
   1195 	explicit _Bind(_Functor&& __f, _Args&&... __args)
   1196 	: _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
   1197 	{ }
   1198 
   1199       _Bind(const _Bind&) = default;
   1200 
   1201       _Bind(_Bind&& __b)
   1202       : _M_f(std::move(__b._M_f)), _M_bound_args(std::move(__b._M_bound_args))
   1203       { }
   1204 
   1205       // Call unqualified
   1206       template<typename... _Args, typename _Result
   1207 	= decltype( std::declval<_Functor>()(
   1208 	      _Mu<_Bound_args>()( std::declval<_Bound_args&>(),
   1209 				  std::declval<tuple<_Args...>&>() )... ) )>
   1210 	_Result
   1211 	operator()(_Args&&... __args)
   1212 	{
   1213 	  return this->__call<_Result>(
   1214 	      std::forward_as_tuple(std::forward<_Args>(__args)...),
   1215 	      _Bound_indexes());
   1216 	}
   1217 
   1218       // Call as const
   1219       template<typename... _Args, typename _Result
   1220 	= decltype( std::declval<typename enable_if<(sizeof...(_Args) >= 0),
   1221 		       typename add_const<_Functor>::type>::type>()(
   1222 	      _Mu<_Bound_args>()( std::declval<const _Bound_args&>(),
   1223 				  std::declval<tuple<_Args...>&>() )... ) )>
   1224 	_Result
   1225 	operator()(_Args&&... __args) const
   1226 	{
   1227 	  return this->__call_c<_Result>(
   1228 	      std::forward_as_tuple(std::forward<_Args>(__args)...),
   1229 	      _Bound_indexes());
   1230 	}
   1231 
   1232       // Call as volatile
   1233       template<typename... _Args, typename _Result
   1234 	= decltype( std::declval<typename enable_if<(sizeof...(_Args) >= 0),
   1235                        typename add_volatile<_Functor>::type>::type>()(
   1236 	      _Mu<_Bound_args>()( std::declval<volatile _Bound_args&>(),
   1237 				  std::declval<tuple<_Args...>&>() )... ) )>
   1238 	_Result
   1239 	operator()(_Args&&... __args) volatile
   1240 	{
   1241 	  return this->__call_v<_Result>(
   1242 	      std::forward_as_tuple(std::forward<_Args>(__args)...),
   1243 	      _Bound_indexes());
   1244 	}
   1245 
   1246       // Call as const volatile
   1247       template<typename... _Args, typename _Result
   1248 	= decltype( std::declval<typename enable_if<(sizeof...(_Args) >= 0),
   1249                        typename add_cv<_Functor>::type>::type>()(
   1250 	      _Mu<_Bound_args>()( std::declval<const volatile _Bound_args&>(),
   1251 				  std::declval<tuple<_Args...>&>() )... ) )>
   1252 	_Result
   1253 	operator()(_Args&&... __args) const volatile
   1254 	{
   1255 	  return this->__call_c_v<_Result>(
   1256 	      std::forward_as_tuple(std::forward<_Args>(__args)...),
   1257 	      _Bound_indexes());
   1258 	}
   1259     };
   1260 
   1261   /// Type of the function object returned from bind<R>().
   1262   template<typename _Result, typename _Signature>
   1263     struct _Bind_result;
   1264 
   1265   template<typename _Result, typename _Functor, typename... _Bound_args>
   1266     class _Bind_result<_Result, _Functor(_Bound_args...)>
   1267     {
   1268       typedef _Bind_result __self_type;
   1269       typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
   1270 	_Bound_indexes;
   1271 
   1272       _Functor _M_f;
   1273       tuple<_Bound_args...> _M_bound_args;
   1274 
   1275       // sfinae types
   1276       template<typename _Res>
   1277 	struct __enable_if_void : enable_if<is_void<_Res>::value, int> { };
   1278       template<typename _Res>
   1279 	struct __disable_if_void : enable_if<!is_void<_Res>::value, int> { };
   1280 
   1281       // Call unqualified
   1282       template<typename _Res, typename... _Args, std::size_t... _Indexes>
   1283 	_Result
   1284 	__call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
   1285 	    typename __disable_if_void<_Res>::type = 0)
   1286 	{
   1287 	  return _M_f(_Mu<_Bound_args>()
   1288 		      (get<_Indexes>(_M_bound_args), __args)...);
   1289 	}
   1290 
   1291       // Call unqualified, return void
   1292       template<typename _Res, typename... _Args, std::size_t... _Indexes>
   1293 	void
   1294 	__call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
   1295 	    typename __enable_if_void<_Res>::type = 0)
   1296 	{
   1297 	  _M_f(_Mu<_Bound_args>()
   1298 	       (get<_Indexes>(_M_bound_args), __args)...);
   1299 	}
   1300 
   1301       // Call as const
   1302       template<typename _Res, typename... _Args, std::size_t... _Indexes>
   1303 	_Result
   1304 	__call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
   1305 	    typename __disable_if_void<_Res>::type = 0) const
   1306 	{
   1307 	  return _M_f(_Mu<_Bound_args>()
   1308 		      (get<_Indexes>(_M_bound_args), __args)...);
   1309 	}
   1310 
   1311       // Call as const, return void
   1312       template<typename _Res, typename... _Args, std::size_t... _Indexes>
   1313 	void
   1314 	__call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
   1315 	    typename __enable_if_void<_Res>::type = 0) const
   1316 	{
   1317 	  _M_f(_Mu<_Bound_args>()
   1318 	       (get<_Indexes>(_M_bound_args),  __args)...);
   1319 	}
   1320 
   1321       // Call as volatile
   1322       template<typename _Res, typename... _Args, std::size_t... _Indexes>
   1323 	_Result
   1324 	__call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
   1325 	    typename __disable_if_void<_Res>::type = 0) volatile
   1326 	{
   1327 	  return _M_f(_Mu<_Bound_args>()
   1328 		      (__volget<_Indexes>(_M_bound_args), __args)...);
   1329 	}
   1330 
   1331       // Call as volatile, return void
   1332       template<typename _Res, typename... _Args, std::size_t... _Indexes>
   1333 	void
   1334 	__call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
   1335 	    typename __enable_if_void<_Res>::type = 0) volatile
   1336 	{
   1337 	  _M_f(_Mu<_Bound_args>()
   1338 	       (__volget<_Indexes>(_M_bound_args), __args)...);
   1339 	}
   1340 
   1341       // Call as const volatile
   1342       template<typename _Res, typename... _Args, std::size_t... _Indexes>
   1343 	_Result
   1344 	__call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
   1345 	    typename __disable_if_void<_Res>::type = 0) const volatile
   1346 	{
   1347 	  return _M_f(_Mu<_Bound_args>()
   1348 		      (__volget<_Indexes>(_M_bound_args), __args)...);
   1349 	}
   1350 
   1351       // Call as const volatile, return void
   1352       template<typename _Res, typename... _Args, std::size_t... _Indexes>
   1353 	void
   1354 	__call(tuple<_Args...>&& __args,
   1355 	       _Index_tuple<_Indexes...>,
   1356 	    typename __enable_if_void<_Res>::type = 0) const volatile
   1357 	{
   1358 	  _M_f(_Mu<_Bound_args>()
   1359 	       (__volget<_Indexes>(_M_bound_args), __args)...);
   1360 	}
   1361 
   1362     public:
   1363       typedef _Result result_type;
   1364 
   1365       template<typename... _Args>
   1366 	explicit _Bind_result(const _Functor& __f, _Args&&... __args)
   1367 	: _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
   1368 	{ }
   1369 
   1370       template<typename... _Args>
   1371 	explicit _Bind_result(_Functor&& __f, _Args&&... __args)
   1372 	: _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
   1373 	{ }
   1374 
   1375       _Bind_result(const _Bind_result&) = default;
   1376 
   1377       _Bind_result(_Bind_result&& __b)
   1378       : _M_f(std::move(__b._M_f)), _M_bound_args(std::move(__b._M_bound_args))
   1379       { }
   1380 
   1381       // Call unqualified
   1382       template<typename... _Args>
   1383 	result_type
   1384 	operator()(_Args&&... __args)
   1385 	{
   1386 	  return this->__call<_Result>(
   1387 	      std::forward_as_tuple(std::forward<_Args>(__args)...),
   1388 	      _Bound_indexes());
   1389 	}
   1390 
   1391       // Call as const
   1392       template<typename... _Args>
   1393 	result_type
   1394 	operator()(_Args&&... __args) const
   1395 	{
   1396 	  return this->__call<_Result>(
   1397 	      std::forward_as_tuple(std::forward<_Args>(__args)...),
   1398 	      _Bound_indexes());
   1399 	}
   1400 
   1401       // Call as volatile
   1402       template<typename... _Args>
   1403 	result_type
   1404 	operator()(_Args&&... __args) volatile
   1405 	{
   1406 	  return this->__call<_Result>(
   1407 	      std::forward_as_tuple(std::forward<_Args>(__args)...),
   1408 	      _Bound_indexes());
   1409 	}
   1410 
   1411       // Call as const volatile
   1412       template<typename... _Args>
   1413 	result_type
   1414 	operator()(_Args&&... __args) const volatile
   1415 	{
   1416 	  return this->__call<_Result>(
   1417 	      std::forward_as_tuple(std::forward<_Args>(__args)...),
   1418 	      _Bound_indexes());
   1419 	}
   1420     };
   1421 
   1422   /**
   1423    *  @brief Class template _Bind is always a bind expression.
   1424    *  @ingroup binders
   1425    */
   1426   template<typename _Signature>
   1427     struct is_bind_expression<_Bind<_Signature> >
   1428     : public true_type { };
   1429 
   1430   /**
   1431    *  @brief Class template _Bind is always a bind expression.
   1432    *  @ingroup binders
   1433    */
   1434   template<typename _Signature>
   1435     struct is_bind_expression<const _Bind<_Signature> >
   1436     : public true_type { };
   1437 
   1438   /**
   1439    *  @brief Class template _Bind is always a bind expression.
   1440    *  @ingroup binders
   1441    */
   1442   template<typename _Signature>
   1443     struct is_bind_expression<volatile _Bind<_Signature> >
   1444     : public true_type { };
   1445 
   1446   /**
   1447    *  @brief Class template _Bind is always a bind expression.
   1448    *  @ingroup binders
   1449    */
   1450   template<typename _Signature>
   1451     struct is_bind_expression<const volatile _Bind<_Signature>>
   1452     : public true_type { };
   1453 
   1454   /**
   1455    *  @brief Class template _Bind_result is always a bind expression.
   1456    *  @ingroup binders
   1457    */
   1458   template<typename _Result, typename _Signature>
   1459     struct is_bind_expression<_Bind_result<_Result, _Signature>>
   1460     : public true_type { };
   1461 
   1462   /**
   1463    *  @brief Class template _Bind_result is always a bind expression.
   1464    *  @ingroup binders
   1465    */
   1466   template<typename _Result, typename _Signature>
   1467     struct is_bind_expression<const _Bind_result<_Result, _Signature>>
   1468     : public true_type { };
   1469 
   1470   /**
   1471    *  @brief Class template _Bind_result is always a bind expression.
   1472    *  @ingroup binders
   1473    */
   1474   template<typename _Result, typename _Signature>
   1475     struct is_bind_expression<volatile _Bind_result<_Result, _Signature>>
   1476     : public true_type { };
   1477 
   1478   /**
   1479    *  @brief Class template _Bind_result is always a bind expression.
   1480    *  @ingroup binders
   1481    */
   1482   template<typename _Result, typename _Signature>
   1483     struct is_bind_expression<const volatile _Bind_result<_Result, _Signature>>
   1484     : public true_type { };
   1485 
   1486   // Trait type used to remove std::bind() from overload set via SFINAE
   1487   // when first argument has integer type, so that std::bind() will
   1488   // not be a better match than ::bind() from the BSD Sockets API.
   1489   template<typename _Tp>
   1490     class __is_socketlike
   1491     {
   1492       typedef typename decay<_Tp>::type _Tp2;
   1493     public:
   1494       static const bool value =
   1495 	is_integral<_Tp2>::value || is_enum<_Tp2>::value;
   1496     };
   1497 
   1498   template<bool _SocketLike, typename _Func, typename... _BoundArgs>
   1499     struct _Bind_helper
   1500     {
   1501       typedef _Maybe_wrap_member_pointer<typename decay<_Func>::type>
   1502 	__maybe_type;
   1503       typedef typename __maybe_type::type __func_type;
   1504       typedef _Bind<__func_type(typename decay<_BoundArgs>::type...)> type;
   1505     };
   1506 
   1507   // Partial specialization for is_socketlike == true, does not define
   1508   // nested type so std::bind() will not participate in overload resolution
   1509   // when the first argument might be a socket file descriptor.
   1510   template<typename _Func, typename... _BoundArgs>
   1511     struct _Bind_helper<true, _Func, _BoundArgs...>
   1512     { };
   1513 
   1514   /**
   1515    *  @brief Function template for std::bind.
   1516    *  @ingroup binders
   1517    */
   1518   template<typename _Func, typename... _BoundArgs>
   1519     inline typename
   1520     _Bind_helper<__is_socketlike<_Func>::value, _Func, _BoundArgs...>::type
   1521     bind(_Func&& __f, _BoundArgs&&... __args)
   1522     {
   1523       typedef _Bind_helper<false, _Func, _BoundArgs...> __helper_type;
   1524       typedef typename __helper_type::__maybe_type __maybe_type;
   1525       typedef typename __helper_type::type __result_type;
   1526       return __result_type(__maybe_type::__do_wrap(std::forward<_Func>(__f)),
   1527 			   std::forward<_BoundArgs>(__args)...);
   1528     }
   1529 
   1530   template<typename _Result, typename _Func, typename... _BoundArgs>
   1531     struct _Bindres_helper
   1532     {
   1533       typedef _Maybe_wrap_member_pointer<typename decay<_Func>::type>
   1534 	__maybe_type;
   1535       typedef typename __maybe_type::type __functor_type;
   1536       typedef _Bind_result<_Result,
   1537 			   __functor_type(typename decay<_BoundArgs>::type...)>
   1538 	type;
   1539     };
   1540 
   1541   /**
   1542    *  @brief Function template for std::bind<R>.
   1543    *  @ingroup binders
   1544    */
   1545   template<typename _Result, typename _Func, typename... _BoundArgs>
   1546     inline
   1547     typename _Bindres_helper<_Result, _Func, _BoundArgs...>::type
   1548     bind(_Func&& __f, _BoundArgs&&... __args)
   1549     {
   1550       typedef _Bindres_helper<_Result, _Func, _BoundArgs...> __helper_type;
   1551       typedef typename __helper_type::__maybe_type __maybe_type;
   1552       typedef typename __helper_type::type __result_type;
   1553       return __result_type(__maybe_type::__do_wrap(std::forward<_Func>(__f)),
   1554 			   std::forward<_BoundArgs>(__args)...);
   1555     }
   1556 
   1557   template<typename _Signature>
   1558     struct _Bind_simple;
   1559 
   1560   template<typename _Callable, typename... _Args>
   1561     struct _Bind_simple<_Callable(_Args...)>
   1562     {
   1563       typedef typename result_of<_Callable(_Args...)>::type result_type;
   1564 
   1565       template<typename... _Args2, typename = typename
   1566                enable_if< sizeof...(_Args) == sizeof...(_Args2)>::type>
   1567         explicit
   1568         _Bind_simple(const _Callable& __callable, _Args2&&... __args)
   1569         : _M_bound(__callable, std::forward<_Args2>(__args)...)
   1570         { }
   1571 
   1572       template<typename... _Args2, typename = typename
   1573                enable_if< sizeof...(_Args) == sizeof...(_Args2)>::type>
   1574         explicit
   1575         _Bind_simple(_Callable&& __callable, _Args2&&... __args)
   1576         : _M_bound(std::move(__callable), std::forward<_Args2>(__args)...)
   1577         { }
   1578 
   1579       _Bind_simple(const _Bind_simple&) = default;
   1580       _Bind_simple(_Bind_simple&&) = default;
   1581 
   1582       result_type
   1583       operator()()
   1584       {
   1585         typedef typename _Build_index_tuple<sizeof...(_Args)>::__type _Indices;
   1586         return _M_invoke(_Indices());
   1587       }
   1588 
   1589     private:
   1590 
   1591       template<std::size_t... _Indices>
   1592         typename result_of<_Callable(_Args...)>::type
   1593         _M_invoke(_Index_tuple<_Indices...>)
   1594         {
   1595 	  // std::bind always forwards bound arguments as lvalues,
   1596 	  // but this type can call functions which only accept rvalues.
   1597           return std::forward<_Callable>(std::get<0>(_M_bound))(
   1598               std::forward<_Args>(std::get<_Indices+1>(_M_bound))...);
   1599         }
   1600 
   1601       std::tuple<_Callable, _Args...> _M_bound;
   1602     };
   1603 
   1604   template<typename _Func, typename... _BoundArgs>
   1605     struct _Bind_simple_helper
   1606     {
   1607       typedef _Maybe_wrap_member_pointer<typename decay<_Func>::type>
   1608         __maybe_type;
   1609       typedef typename __maybe_type::type __func_type;
   1610       typedef _Bind_simple<__func_type(typename decay<_BoundArgs>::type...)>
   1611        	__type;
   1612     };
   1613 
   1614   // Simplified version of std::bind for internal use, without support for
   1615   // unbound arguments, placeholders or nested bind expressions.
   1616   template<typename _Callable, typename... _Args>
   1617     typename _Bind_simple_helper<_Callable, _Args...>::__type
   1618     __bind_simple(_Callable&& __callable, _Args&&... __args)
   1619     {
   1620       typedef _Bind_simple_helper<_Callable, _Args...> __helper_type;
   1621       typedef typename __helper_type::__maybe_type __maybe_type;
   1622       typedef typename __helper_type::__type __result_type;
   1623       return __result_type(
   1624           __maybe_type::__do_wrap( std::forward<_Callable>(__callable)),
   1625           std::forward<_Args>(__args)...);
   1626     }
   1627 
   1628   /**
   1629    *  @brief Exception class thrown when class template function's
   1630    *  operator() is called with an empty target.
   1631    *  @ingroup exceptions
   1632    */
   1633   class bad_function_call : public std::exception
   1634   {
   1635   public:
   1636     virtual ~bad_function_call() noexcept;
   1637   };
   1638 
   1639   /**
   1640    *  Trait identifying "location-invariant" types, meaning that the
   1641    *  address of the object (or any of its members) will not escape.
   1642    *  Also implies a trivial copy constructor and assignment operator.
   1643    */
   1644   template<typename _Tp>
   1645     struct __is_location_invariant
   1646     : integral_constant<bool, (is_pointer<_Tp>::value
   1647 			       || is_member_pointer<_Tp>::value)>
   1648     { };
   1649 
   1650   class _Undefined_class;
   1651 
   1652   union _Nocopy_types
   1653   {
   1654     void*       _M_object;
   1655     const void* _M_const_object;
   1656     void (*_M_function_pointer)();
   1657     void (_Undefined_class::*_M_member_pointer)();
   1658   };
   1659 
   1660   union _Any_data
   1661   {
   1662     void*       _M_access()       { return &_M_pod_data[0]; }
   1663     const void* _M_access() const { return &_M_pod_data[0]; }
   1664 
   1665     template<typename _Tp>
   1666       _Tp&
   1667       _M_access()
   1668       { return *static_cast<_Tp*>(_M_access()); }
   1669 
   1670     template<typename _Tp>
   1671       const _Tp&
   1672       _M_access() const
   1673       { return *static_cast<const _Tp*>(_M_access()); }
   1674 
   1675     _Nocopy_types _M_unused;
   1676     char _M_pod_data[sizeof(_Nocopy_types)];
   1677   };
   1678 
   1679   enum _Manager_operation
   1680   {
   1681     __get_type_info,
   1682     __get_functor_ptr,
   1683     __clone_functor,
   1684     __destroy_functor
   1685   };
   1686 
   1687   // Simple type wrapper that helps avoid annoying const problems
   1688   // when casting between void pointers and pointers-to-pointers.
   1689   template<typename _Tp>
   1690     struct _Simple_type_wrapper
   1691     {
   1692       _Simple_type_wrapper(_Tp __value) : __value(__value) { }
   1693 
   1694       _Tp __value;
   1695     };
   1696 
   1697   template<typename _Tp>
   1698     struct __is_location_invariant<_Simple_type_wrapper<_Tp> >
   1699     : __is_location_invariant<_Tp>
   1700     { };
   1701 
   1702   // Converts a reference to a function object into a callable
   1703   // function object.
   1704   template<typename _Functor>
   1705     inline _Functor&
   1706     __callable_functor(_Functor& __f)
   1707     { return __f; }
   1708 
   1709   template<typename _Member, typename _Class>
   1710     inline _Mem_fn<_Member _Class::*>
   1711     __callable_functor(_Member _Class::* &__p)
   1712     { return mem_fn(__p); }
   1713 
   1714   template<typename _Member, typename _Class>
   1715     inline _Mem_fn<_Member _Class::*>
   1716     __callable_functor(_Member _Class::* const &__p)
   1717     { return mem_fn(__p); }
   1718 
   1719   template<typename _Signature>
   1720     class function;
   1721 
   1722   /// Base class of all polymorphic function object wrappers.
   1723   class _Function_base
   1724   {
   1725   public:
   1726     static const std::size_t _M_max_size = sizeof(_Nocopy_types);
   1727     static const std::size_t _M_max_align = __alignof__(_Nocopy_types);
   1728 
   1729     template<typename _Functor>
   1730       class _Base_manager
   1731       {
   1732       protected:
   1733 	static const bool __stored_locally =
   1734 	(__is_location_invariant<_Functor>::value
   1735 	 && sizeof(_Functor) <= _M_max_size
   1736 	 && __alignof__(_Functor) <= _M_max_align
   1737 	 && (_M_max_align % __alignof__(_Functor) == 0));
   1738 
   1739 	typedef integral_constant<bool, __stored_locally> _Local_storage;
   1740 
   1741 	// Retrieve a pointer to the function object
   1742 	static _Functor*
   1743 	_M_get_pointer(const _Any_data& __source)
   1744 	{
   1745 	  const _Functor* __ptr =
   1746 	    __stored_locally? std::__addressof(__source._M_access<_Functor>())
   1747 	    /* have stored a pointer */ : __source._M_access<_Functor*>();
   1748 	  return const_cast<_Functor*>(__ptr);
   1749 	}
   1750 
   1751 	// Clone a location-invariant function object that fits within
   1752 	// an _Any_data structure.
   1753 	static void
   1754 	_M_clone(_Any_data& __dest, const _Any_data& __source, true_type)
   1755 	{
   1756 	  new (__dest._M_access()) _Functor(__source._M_access<_Functor>());
   1757 	}
   1758 
   1759 	// Clone a function object that is not location-invariant or
   1760 	// that cannot fit into an _Any_data structure.
   1761 	static void
   1762 	_M_clone(_Any_data& __dest, const _Any_data& __source, false_type)
   1763 	{
   1764 	  __dest._M_access<_Functor*>() =
   1765 	    new _Functor(*__source._M_access<_Functor*>());
   1766 	}
   1767 
   1768 	// Destroying a location-invariant object may still require
   1769 	// destruction.
   1770 	static void
   1771 	_M_destroy(_Any_data& __victim, true_type)
   1772 	{
   1773 	  __victim._M_access<_Functor>().~_Functor();
   1774 	}
   1775 
   1776 	// Destroying an object located on the heap.
   1777 	static void
   1778 	_M_destroy(_Any_data& __victim, false_type)
   1779 	{
   1780 	  delete __victim._M_access<_Functor*>();
   1781 	}
   1782 
   1783       public:
   1784 	static bool
   1785 	_M_manager(_Any_data& __dest, const _Any_data& __source,
   1786 		   _Manager_operation __op)
   1787 	{
   1788 	  switch (__op)
   1789 	    {
   1790 #ifdef __GXX_RTTI
   1791 	    case __get_type_info:
   1792 	      __dest._M_access<const type_info*>() = &typeid(_Functor);
   1793 	      break;
   1794 #endif
   1795 	    case __get_functor_ptr:
   1796 	      __dest._M_access<_Functor*>() = _M_get_pointer(__source);
   1797 	      break;
   1798 
   1799 	    case __clone_functor:
   1800 	      _M_clone(__dest, __source, _Local_storage());
   1801 	      break;
   1802 
   1803 	    case __destroy_functor:
   1804 	      _M_destroy(__dest, _Local_storage());
   1805 	      break;
   1806 	    }
   1807 	  return false;
   1808 	}
   1809 
   1810 	static void
   1811 	_M_init_functor(_Any_data& __functor, _Functor&& __f)
   1812 	{ _M_init_functor(__functor, std::move(__f), _Local_storage()); }
   1813 
   1814 	template<typename _Signature>
   1815 	  static bool
   1816 	  _M_not_empty_function(const function<_Signature>& __f)
   1817 	  { return static_cast<bool>(__f); }
   1818 
   1819 	template<typename _Tp>
   1820 	  static bool
   1821 	  _M_not_empty_function(const _Tp*& __fp)
   1822 	  { return __fp; }
   1823 
   1824 	template<typename _Class, typename _Tp>
   1825 	  static bool
   1826 	  _M_not_empty_function(_Tp _Class::* const& __mp)
   1827 	  { return __mp; }
   1828 
   1829 	template<typename _Tp>
   1830 	  static bool
   1831 	  _M_not_empty_function(const _Tp&)
   1832 	  { return true; }
   1833 
   1834       private:
   1835 	static void
   1836 	_M_init_functor(_Any_data& __functor, _Functor&& __f, true_type)
   1837 	{ new (__functor._M_access()) _Functor(std::move(__f)); }
   1838 
   1839 	static void
   1840 	_M_init_functor(_Any_data& __functor, _Functor&& __f, false_type)
   1841 	{ __functor._M_access<_Functor*>() = new _Functor(std::move(__f)); }
   1842       };
   1843 
   1844     template<typename _Functor>
   1845       class _Ref_manager : public _Base_manager<_Functor*>
   1846       {
   1847 	typedef _Function_base::_Base_manager<_Functor*> _Base;
   1848 
   1849     public:
   1850 	static bool
   1851 	_M_manager(_Any_data& __dest, const _Any_data& __source,
   1852 		   _Manager_operation __op)
   1853 	{
   1854 	  switch (__op)
   1855 	    {
   1856 #ifdef __GXX_RTTI
   1857 	    case __get_type_info:
   1858 	      __dest._M_access<const type_info*>() = &typeid(_Functor);
   1859 	      break;
   1860 #endif
   1861 	    case __get_functor_ptr:
   1862 	      __dest._M_access<_Functor*>() = *_Base::_M_get_pointer(__source);
   1863 	      return is_const<_Functor>::value;
   1864 	      break;
   1865 
   1866 	    default:
   1867 	      _Base::_M_manager(__dest, __source, __op);
   1868 	    }
   1869 	  return false;
   1870 	}
   1871 
   1872 	static void
   1873 	_M_init_functor(_Any_data& __functor, reference_wrapper<_Functor> __f)
   1874 	{
   1875 	  // TBD: Use address_of function instead.
   1876 	  _Base::_M_init_functor(__functor, &__f.get());
   1877 	}
   1878       };
   1879 
   1880     _Function_base() : _M_manager(0) { }
   1881 
   1882     ~_Function_base()
   1883     {
   1884       if (_M_manager)
   1885 	_M_manager(_M_functor, _M_functor, __destroy_functor);
   1886     }
   1887 
   1888 
   1889     bool _M_empty() const { return !_M_manager; }
   1890 
   1891     typedef bool (*_Manager_type)(_Any_data&, const _Any_data&,
   1892 				  _Manager_operation);
   1893 
   1894     _Any_data     _M_functor;
   1895     _Manager_type _M_manager;
   1896   };
   1897 
   1898   template<typename _Signature, typename _Functor>
   1899     class _Function_handler;
   1900 
   1901   template<typename _Res, typename _Functor, typename... _ArgTypes>
   1902     class _Function_handler<_Res(_ArgTypes...), _Functor>
   1903     : public _Function_base::_Base_manager<_Functor>
   1904     {
   1905       typedef _Function_base::_Base_manager<_Functor> _Base;
   1906 
   1907     public:
   1908       static _Res
   1909       _M_invoke(const _Any_data& __functor, _ArgTypes... __args)
   1910       {
   1911 	return (*_Base::_M_get_pointer(__functor))(
   1912 	    std::forward<_ArgTypes>(__args)...);
   1913       }
   1914     };
   1915 
   1916   template<typename _Functor, typename... _ArgTypes>
   1917     class _Function_handler<void(_ArgTypes...), _Functor>
   1918     : public _Function_base::_Base_manager<_Functor>
   1919     {
   1920       typedef _Function_base::_Base_manager<_Functor> _Base;
   1921 
   1922      public:
   1923       static void
   1924       _M_invoke(const _Any_data& __functor, _ArgTypes... __args)
   1925       {
   1926 	(*_Base::_M_get_pointer(__functor))(
   1927 	    std::forward<_ArgTypes>(__args)...);
   1928       }
   1929     };
   1930 
   1931   template<typename _Res, typename _Functor, typename... _ArgTypes>
   1932     class _Function_handler<_Res(_ArgTypes...), reference_wrapper<_Functor> >
   1933     : public _Function_base::_Ref_manager<_Functor>
   1934     {
   1935       typedef _Function_base::_Ref_manager<_Functor> _Base;
   1936 
   1937      public:
   1938       static _Res
   1939       _M_invoke(const _Any_data& __functor, _ArgTypes... __args)
   1940       {
   1941 	return __callable_functor(**_Base::_M_get_pointer(__functor))(
   1942 	      std::forward<_ArgTypes>(__args)...);
   1943       }
   1944     };
   1945 
   1946   template<typename _Functor, typename... _ArgTypes>
   1947     class _Function_handler<void(_ArgTypes...), reference_wrapper<_Functor> >
   1948     : public _Function_base::_Ref_manager<_Functor>
   1949     {
   1950       typedef _Function_base::_Ref_manager<_Functor> _Base;
   1951 
   1952      public:
   1953       static void
   1954       _M_invoke(const _Any_data& __functor, _ArgTypes... __args)
   1955       {
   1956 	__callable_functor(**_Base::_M_get_pointer(__functor))(
   1957 	    std::forward<_ArgTypes>(__args)...);
   1958       }
   1959     };
   1960 
   1961   template<typename _Class, typename _Member, typename _Res,
   1962 	   typename... _ArgTypes>
   1963     class _Function_handler<_Res(_ArgTypes...), _Member _Class::*>
   1964     : public _Function_handler<void(_ArgTypes...), _Member _Class::*>
   1965     {
   1966       typedef _Function_handler<void(_ArgTypes...), _Member _Class::*>
   1967 	_Base;
   1968 
   1969      public:
   1970       static _Res
   1971       _M_invoke(const _Any_data& __functor, _ArgTypes... __args)
   1972       {
   1973 	return mem_fn(_Base::_M_get_pointer(__functor)->__value)(
   1974 	    std::forward<_ArgTypes>(__args)...);
   1975       }
   1976     };
   1977 
   1978   template<typename _Class, typename _Member, typename... _ArgTypes>
   1979     class _Function_handler<void(_ArgTypes...), _Member _Class::*>
   1980     : public _Function_base::_Base_manager<
   1981 		 _Simple_type_wrapper< _Member _Class::* > >
   1982     {
   1983       typedef _Member _Class::* _Functor;
   1984       typedef _Simple_type_wrapper<_Functor> _Wrapper;
   1985       typedef _Function_base::_Base_manager<_Wrapper> _Base;
   1986 
   1987      public:
   1988       static bool
   1989       _M_manager(_Any_data& __dest, const _Any_data& __source,
   1990 		 _Manager_operation __op)
   1991       {
   1992 	switch (__op)
   1993 	  {
   1994 #ifdef __GXX_RTTI
   1995 	  case __get_type_info:
   1996 	    __dest._M_access<const type_info*>() = &typeid(_Functor);
   1997 	    break;
   1998 #endif
   1999 	  case __get_functor_ptr:
   2000 	    __dest._M_access<_Functor*>() =
   2001 	      &_Base::_M_get_pointer(__source)->__value;
   2002 	    break;
   2003 
   2004 	  default:
   2005 	    _Base::_M_manager(__dest, __source, __op);
   2006 	  }
   2007 	return false;
   2008       }
   2009 
   2010       static void
   2011       _M_invoke(const _Any_data& __functor, _ArgTypes... __args)
   2012       {
   2013 	mem_fn(_Base::_M_get_pointer(__functor)->__value)(
   2014 	    std::forward<_ArgTypes>(__args)...);
   2015       }
   2016     };
   2017 
   2018   /**
   2019    *  @brief Primary class template for std::function.
   2020    *  @ingroup functors
   2021    *
   2022    *  Polymorphic function wrapper.
   2023    */
   2024   template<typename _Res, typename... _ArgTypes>
   2025     class function<_Res(_ArgTypes...)>
   2026     : public _Maybe_unary_or_binary_function<_Res, _ArgTypes...>,
   2027       private _Function_base
   2028     {
   2029       typedef _Res _Signature_type(_ArgTypes...);
   2030 
   2031       struct _Useless { };
   2032 
   2033     public:
   2034       typedef _Res result_type;
   2035 
   2036       // [3.7.2.1] construct/copy/destroy
   2037 
   2038       /**
   2039        *  @brief Default construct creates an empty function call wrapper.
   2040        *  @post @c !(bool)*this
   2041        */
   2042       function() noexcept
   2043       : _Function_base() { }
   2044 
   2045       /**
   2046        *  @brief Creates an empty function call wrapper.
   2047        *  @post @c !(bool)*this
   2048        */
   2049       function(nullptr_t) noexcept
   2050       : _Function_base() { }
   2051 
   2052       /**
   2053        *  @brief %Function copy constructor.
   2054        *  @param __x A %function object with identical call signature.
   2055        *  @post @c bool(*this) == bool(__x)
   2056        *
   2057        *  The newly-created %function contains a copy of the target of @a
   2058        *  __x (if it has one).
   2059        */
   2060       function(const function& __x);
   2061 
   2062       /**
   2063        *  @brief %Function move constructor.
   2064        *  @param __x A %function object rvalue with identical call signature.
   2065        *
   2066        *  The newly-created %function contains the target of @a __x
   2067        *  (if it has one).
   2068        */
   2069       function(function&& __x) : _Function_base()
   2070       {
   2071 	__x.swap(*this);
   2072       }
   2073 
   2074       // TODO: needs allocator_arg_t
   2075 
   2076       /**
   2077        *  @brief Builds a %function that targets a copy of the incoming
   2078        *  function object.
   2079        *  @param __f A %function object that is callable with parameters of
   2080        *  type @c T1, @c T2, ..., @c TN and returns a value convertible
   2081        *  to @c Res.
   2082        *
   2083        *  The newly-created %function object will target a copy of 
   2084        *  @a __f. If @a __f is @c reference_wrapper<F>, then this function
   2085        *  object will contain a reference to the function object @c
   2086        *  __f.get(). If @a __f is a NULL function pointer or NULL
   2087        *  pointer-to-member, the newly-created object will be empty.
   2088        *
   2089        *  If @a __f is a non-NULL function pointer or an object of type @c
   2090        *  reference_wrapper<F>, this function will not throw.
   2091        */
   2092       template<typename _Functor>
   2093 	function(_Functor __f,
   2094 		 typename enable_if<
   2095 			   !is_integral<_Functor>::value, _Useless>::type
   2096 		   = _Useless());
   2097 
   2098       /**
   2099        *  @brief %Function assignment operator.
   2100        *  @param __x A %function with identical call signature.
   2101        *  @post @c (bool)*this == (bool)x
   2102        *  @returns @c *this
   2103        *
   2104        *  The target of @a __x is copied to @c *this. If @a __x has no
   2105        *  target, then @c *this will be empty.
   2106        *
   2107        *  If @a __x targets a function pointer or a reference to a function
   2108        *  object, then this operation will not throw an %exception.
   2109        */
   2110       function&
   2111       operator=(const function& __x)
   2112       {
   2113 	function(__x).swap(*this);
   2114 	return *this;
   2115       }
   2116 
   2117       /**
   2118        *  @brief %Function move-assignment operator.
   2119        *  @param __x A %function rvalue with identical call signature.
   2120        *  @returns @c *this
   2121        *
   2122        *  The target of @a __x is moved to @c *this. If @a __x has no
   2123        *  target, then @c *this will be empty.
   2124        *
   2125        *  If @a __x targets a function pointer or a reference to a function
   2126        *  object, then this operation will not throw an %exception.
   2127        */
   2128       function&
   2129       operator=(function&& __x)
   2130       {
   2131 	function(std::move(__x)).swap(*this);
   2132 	return *this;
   2133       }
   2134 
   2135       /**
   2136        *  @brief %Function assignment to zero.
   2137        *  @post @c !(bool)*this
   2138        *  @returns @c *this
   2139        *
   2140        *  The target of @c *this is deallocated, leaving it empty.
   2141        */
   2142       function&
   2143       operator=(nullptr_t)
   2144       {
   2145 	if (_M_manager)
   2146 	  {
   2147 	    _M_manager(_M_functor, _M_functor, __destroy_functor);
   2148 	    _M_manager = 0;
   2149 	    _M_invoker = 0;
   2150 	  }
   2151 	return *this;
   2152       }
   2153 
   2154       /**
   2155        *  @brief %Function assignment to a new target.
   2156        *  @param __f A %function object that is callable with parameters of
   2157        *  type @c T1, @c T2, ..., @c TN and returns a value convertible
   2158        *  to @c Res.
   2159        *  @return @c *this
   2160        *
   2161        *  This  %function object wrapper will target a copy of @a
   2162        *  __f. If @a __f is @c reference_wrapper<F>, then this function
   2163        *  object will contain a reference to the function object @c
   2164        *  __f.get(). If @a __f is a NULL function pointer or NULL
   2165        *  pointer-to-member, @c this object will be empty.
   2166        *
   2167        *  If @a __f is a non-NULL function pointer or an object of type @c
   2168        *  reference_wrapper<F>, this function will not throw.
   2169        */
   2170       template<typename _Functor>
   2171 	typename enable_if<!is_integral<_Functor>::value, function&>::type
   2172 	operator=(_Functor&& __f)
   2173 	{
   2174 	  function(std::forward<_Functor>(__f)).swap(*this);
   2175 	  return *this;
   2176 	}
   2177 
   2178       /// @overload
   2179       template<typename _Functor>
   2180 	typename enable_if<!is_integral<_Functor>::value, function&>::type
   2181 	operator=(reference_wrapper<_Functor> __f) noexcept
   2182 	{
   2183 	  function(__f).swap(*this);
   2184 	  return *this;
   2185 	}
   2186 
   2187       // [3.7.2.2] function modifiers
   2188 
   2189       /**
   2190        *  @brief Swap the targets of two %function objects.
   2191        *  @param __x A %function with identical call signature.
   2192        *
   2193        *  Swap the targets of @c this function object and @a __f. This
   2194        *  function will not throw an %exception.
   2195        */
   2196       void swap(function& __x)
   2197       {
   2198 	std::swap(_M_functor, __x._M_functor);
   2199 	std::swap(_M_manager, __x._M_manager);
   2200 	std::swap(_M_invoker, __x._M_invoker);
   2201       }
   2202 
   2203       // TODO: needs allocator_arg_t
   2204       /*
   2205       template<typename _Functor, typename _Alloc>
   2206 	void
   2207 	assign(_Functor&& __f, const _Alloc& __a)
   2208 	{
   2209 	  function(allocator_arg, __a,
   2210 		   std::forward<_Functor>(__f)).swap(*this);
   2211 	}
   2212       */
   2213 
   2214       // [3.7.2.3] function capacity
   2215 
   2216       /**
   2217        *  @brief Determine if the %function wrapper has a target.
   2218        *
   2219        *  @return @c true when this %function object contains a target,
   2220        *  or @c false when it is empty.
   2221        *
   2222        *  This function will not throw an %exception.
   2223        */
   2224       explicit operator bool() const noexcept
   2225       { return !_M_empty(); }
   2226 
   2227       // [3.7.2.4] function invocation
   2228 
   2229       /**
   2230        *  @brief Invokes the function targeted by @c *this.
   2231        *  @returns the result of the target.
   2232        *  @throws bad_function_call when @c !(bool)*this
   2233        *
   2234        *  The function call operator invokes the target function object
   2235        *  stored by @c this.
   2236        */
   2237       _Res operator()(_ArgTypes... __args) const;
   2238 
   2239 #ifdef __GXX_RTTI
   2240       // [3.7.2.5] function target access
   2241       /**
   2242        *  @brief Determine the type of the target of this function object
   2243        *  wrapper.
   2244        *
   2245        *  @returns the type identifier of the target function object, or
   2246        *  @c typeid(void) if @c !(bool)*this.
   2247        *
   2248        *  This function will not throw an %exception.
   2249        */
   2250       const type_info& target_type() const noexcept;
   2251 
   2252       /**
   2253        *  @brief Access the stored target function object.
   2254        *
   2255        *  @return Returns a pointer to the stored target function object,
   2256        *  if @c typeid(Functor).equals(target_type()); otherwise, a NULL
   2257        *  pointer.
   2258        *
   2259        * This function will not throw an %exception.
   2260        */
   2261       template<typename _Functor>       _Functor* target() noexcept;
   2262 
   2263       /// @overload
   2264       template<typename _Functor> const _Functor* target() const noexcept;
   2265 #endif
   2266 
   2267     private:
   2268       typedef _Res (*_Invoker_type)(const _Any_data&, _ArgTypes...);
   2269       _Invoker_type _M_invoker;
   2270   };
   2271 
   2272   // Out-of-line member definitions.
   2273   template<typename _Res, typename... _ArgTypes>
   2274     function<_Res(_ArgTypes...)>::
   2275     function(const function& __x)
   2276     : _Function_base()
   2277     {
   2278       if (static_cast<bool>(__x))
   2279 	{
   2280 	  _M_invoker = __x._M_invoker;
   2281 	  _M_manager = __x._M_manager;
   2282 	  __x._M_manager(_M_functor, __x._M_functor, __clone_functor);
   2283 	}
   2284     }
   2285 
   2286   template<typename _Res, typename... _ArgTypes>
   2287     template<typename _Functor>
   2288       function<_Res(_ArgTypes...)>::
   2289       function(_Functor __f,
   2290 	       typename enable_if<
   2291 			!is_integral<_Functor>::value, _Useless>::type)
   2292       : _Function_base()
   2293       {
   2294 	typedef _Function_handler<_Signature_type, _Functor> _My_handler;
   2295 
   2296 	if (_My_handler::_M_not_empty_function(__f))
   2297 	  {
   2298 	    _M_invoker = &_My_handler::_M_invoke;
   2299 	    _M_manager = &_My_handler::_M_manager;
   2300 	    _My_handler::_M_init_functor(_M_functor, std::move(__f));
   2301 	  }
   2302       }
   2303 
   2304   template<typename _Res, typename... _ArgTypes>
   2305     _Res
   2306     function<_Res(_ArgTypes...)>::
   2307     operator()(_ArgTypes... __args) const
   2308     {
   2309       if (_M_empty())
   2310 	__throw_bad_function_call();
   2311       return _M_invoker(_M_functor, std::forward<_ArgTypes>(__args)...);
   2312     }
   2313 
   2314 #ifdef __GXX_RTTI
   2315   template<typename _Res, typename... _ArgTypes>
   2316     const type_info&
   2317     function<_Res(_ArgTypes...)>::
   2318     target_type() const noexcept
   2319     {
   2320       if (_M_manager)
   2321 	{
   2322 	  _Any_data __typeinfo_result;
   2323 	  _M_manager(__typeinfo_result, _M_functor, __get_type_info);
   2324 	  return *__typeinfo_result._M_access<const type_info*>();
   2325 	}
   2326       else
   2327 	return typeid(void);
   2328     }
   2329 
   2330   template<typename _Res, typename... _ArgTypes>
   2331     template<typename _Functor>
   2332       _Functor*
   2333       function<_Res(_ArgTypes...)>::
   2334       target() noexcept
   2335       {
   2336 	if (typeid(_Functor) == target_type() && _M_manager)
   2337 	  {
   2338 	    _Any_data __ptr;
   2339 	    if (_M_manager(__ptr, _M_functor, __get_functor_ptr)
   2340 		&& !is_const<_Functor>::value)
   2341 	      return 0;
   2342 	    else
   2343 	      return __ptr._M_access<_Functor*>();
   2344 	  }
   2345 	else
   2346 	  return 0;
   2347       }
   2348 
   2349   template<typename _Res, typename... _ArgTypes>
   2350     template<typename _Functor>
   2351       const _Functor*
   2352       function<_Res(_ArgTypes...)>::
   2353       target() const noexcept
   2354       {
   2355 	if (typeid(_Functor) == target_type() && _M_manager)
   2356 	  {
   2357 	    _Any_data __ptr;
   2358 	    _M_manager(__ptr, _M_functor, __get_functor_ptr);
   2359 	    return __ptr._M_access<const _Functor*>();
   2360 	  }
   2361 	else
   2362 	  return 0;
   2363       }
   2364 #endif
   2365 
   2366   // [20.7.15.2.6] null pointer comparisons
   2367 
   2368   /**
   2369    *  @brief Compares a polymorphic function object wrapper against 0
   2370    *  (the NULL pointer).
   2371    *  @returns @c true if the wrapper has no target, @c false otherwise
   2372    *
   2373    *  This function will not throw an %exception.
   2374    */
   2375   template<typename _Res, typename... _Args>
   2376     inline bool
   2377     operator==(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
   2378     { return !static_cast<bool>(__f); }
   2379 
   2380   /// @overload
   2381   template<typename _Res, typename... _Args>
   2382     inline bool
   2383     operator==(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
   2384     { return !static_cast<bool>(__f); }
   2385 
   2386   /**
   2387    *  @brief Compares a polymorphic function object wrapper against 0
   2388    *  (the NULL pointer).
   2389    *  @returns @c false if the wrapper has no target, @c true otherwise
   2390    *
   2391    *  This function will not throw an %exception.
   2392    */
   2393   template<typename _Res, typename... _Args>
   2394     inline bool
   2395     operator!=(const function<_Res(_Args...)>& __f, nullptr_t) noexcept
   2396     { return static_cast<bool>(__f); }
   2397 
   2398   /// @overload
   2399   template<typename _Res, typename... _Args>
   2400     inline bool
   2401     operator!=(nullptr_t, const function<_Res(_Args...)>& __f) noexcept
   2402     { return static_cast<bool>(__f); }
   2403 
   2404   // [20.7.15.2.7] specialized algorithms
   2405 
   2406   /**
   2407    *  @brief Swap the targets of two polymorphic function object wrappers.
   2408    *
   2409    *  This function will not throw an %exception.
   2410    */
   2411   template<typename _Res, typename... _Args>
   2412     inline void
   2413     swap(function<_Res(_Args...)>& __x, function<_Res(_Args...)>& __y)
   2414     { __x.swap(__y); }
   2415 
   2416 _GLIBCXX_END_NAMESPACE_VERSION
   2417 } // namespace std
   2418 
   2419 #endif // __GXX_EXPERIMENTAL_CXX0X__
   2420 
   2421 #endif // _GLIBCXX_FUNCTIONAL
   2422