libstdc++-v3/include/std/functional

   1 // <functional> -*- C++ -*-
   2
   3 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
   4 // 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
  62 {
  63 _GLIBCXX_HAS_NESTED_TYPE(result_type)
  64
  65   /// If we have found a result_type, extract it.
  66   template<bool _Has_result_type, typename _Functor>
  67     struct _Maybe_get_result_type
  68     { };
  69
  70   template<typename _Functor>
  71     struct _Maybe_get_result_type<true, _Functor>
  72     { typedef typename _Functor::result_type result_type; };
  73
  74   /**
  75    *  Base class for any function object that has a weak result type, as
  76    *  defined in 3.3/3 of TR1.
  77   */
  78   template<typename _Functor>
  79     struct _Weak_result_type_impl
  80     : _Maybe_get_result_type<__has_result_type<_Functor>::value, _Functor>
  81     { };
  82
  83   /// Retrieve the result type for a function type.
  84   template<typename _Res, typename... _ArgTypes>
  85     struct _Weak_result_type_impl<_Res(_ArgTypes...)>
  86     { typedef _Res result_type; };
  87
  88   template<typename _Res, typename... _ArgTypes>
  89     struct _Weak_result_type_impl<_Res(_ArgTypes......)>
  90     { typedef _Res result_type; };
  91
  92   template<typename _Res, typename... _ArgTypes>
  93     struct _Weak_result_type_impl<_Res(_ArgTypes...) const>
  94     { typedef _Res result_type; };
  95
  96   template<typename _Res, typename... _ArgTypes>
  97     struct _Weak_result_type_impl<_Res(_ArgTypes......) const>
  98     { typedef _Res result_type; };
  99
 100   template<typename _Res, typename... _ArgTypes>
 101     struct _Weak_result_type_impl<_Res(_ArgTypes...) volatile>
 102     { typedef _Res result_type; };
 103
 104   template<typename _Res, typename... _ArgTypes>
 105     struct _Weak_result_type_impl<_Res(_ArgTypes......) volatile>
 106     { typedef _Res result_type; };
 107
 108   template<typename _Res, typename... _ArgTypes>
 109     struct _Weak_result_type_impl<_Res(_ArgTypes...) const volatile>
 110     { typedef _Res result_type; };
 111
 112   template<typename _Res, typename... _ArgTypes>
 113     struct _Weak_result_type_impl<_Res(_ArgTypes......) const volatile>
 114     { typedef _Res result_type; };
 115
 116   /// Retrieve the result type for a function reference.
 117   template<typename _Res, typename... _ArgTypes>
 118     struct _Weak_result_type_impl<_Res(&)(_ArgTypes...)>
 119     { typedef _Res result_type; };
 120
 121   template<typename _Res, typename... _ArgTypes>
 122     struct _Weak_result_type_impl<_Res(&)(_ArgTypes......)>
 123     { typedef _Res result_type; };
 124
 125   /// Retrieve the result type for a function pointer.
 126   template<typename _Res, typename... _ArgTypes>
 127     struct _Weak_result_type_impl<_Res(*)(_ArgTypes...)>
 128     { typedef _Res result_type; };
 129
 130   template<typename _Res, typename... _ArgTypes>
 131     struct _Weak_result_type_impl<_Res(*)(_ArgTypes......)>
 132     { typedef _Res result_type; };
 133
 134   /// Retrieve result type for a member function pointer.
 135   template<typename _Res, typename _Class, typename... _ArgTypes>
 136     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes...)>
 137     { typedef _Res result_type; };
 138
 139   template<typename _Res, typename _Class, typename... _ArgTypes>
 140     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes......)>
 141     { typedef _Res result_type; };
 142
 143   /// Retrieve result type for a const member function pointer.
 144   template<typename _Res, typename _Class, typename... _ArgTypes>
 145     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes...) const>
 146     { typedef _Res result_type; };
 147
 148   template<typename _Res, typename _Class, typename... _ArgTypes>
 149     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes......) const>
 150     { typedef _Res result_type; };
 151
 152   /// Retrieve result type for a volatile member function pointer.
 153   template<typename _Res, typename _Class, typename... _ArgTypes>
 154     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes...) volatile>
 155     { typedef _Res result_type; };
 156
 157   template<typename _Res, typename _Class, typename... _ArgTypes>
 158     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes......) volatile>
 159     { typedef _Res result_type; };
 160
 161   /// Retrieve result type for a const volatile member function pointer.
 162   template<typename _Res, typename _Class, typename... _ArgTypes>
 163     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes...)
 164                                   const volatile>
 165     { typedef _Res result_type; };
 166
 167   template<typename _Res, typename _Class, typename... _ArgTypes>
 168     struct _Weak_result_type_impl<_Res (_Class::*)(_ArgTypes......)
 169                                   const volatile>
 170     { typedef _Res result_type; };
 171
 172   /**
 173    *  Strip top-level cv-qualifiers from the function object and let
 174    *  _Weak_result_type_impl perform the real work.
 175   */
 176   template<typename _Functor>
 177     struct _Weak_result_type
 178     : _Weak_result_type_impl<typename remove_cv<_Functor>::type>
 179     { };
 180
 181   /// Determines if the type _Tp derives from unary_function.
 182   template<typename _Tp>
 183     struct _Derives_from_unary_function : __sfinae_types
 184     {
 185     private:
 186       template<typename _T1, typename _Res>
 187         static __one __test(const volatile unary_function<_T1, _Res>*);
 188
 189       // It's tempting to change "..." to const volatile void*, but
 190       // that fails when _Tp is a function type.
 191       static __two __test(...);
 192
 193     public:
 194       static const bool value = sizeof(__test((_Tp*)0)) == 1;
 195     };
 196
 197   /// Determines if the type _Tp derives from binary_function.
 198   template<typename _Tp>
 199     struct _Derives_from_binary_function : __sfinae_types
 200     {
 201     private:
 202       template<typename _T1, typename _T2, typename _Res>
 203         static __one __test(const volatile binary_function<_T1, _T2, _Res>*);
 204
 205       // It's tempting to change "..." to const volatile void*, but
 206       // that fails when _Tp is a function type.
 207       static __two __test(...);
 208
 209     public:
 210       static const bool value = sizeof(__test((_Tp*)0)) == 1;
 211     };
 212
 213   /// Turns a function type into a function pointer type
 214   template<typename _Tp, bool _IsFunctionType = is_function<_Tp>::value>
 215     struct _Function_to_function_pointer
 216     {
 217       typedef _Tp type;
 218     };
 219
 220   template<typename _Tp>
 221     struct _Function_to_function_pointer<_Tp, true>
 222     {
 223       typedef _Tp* type;
 224     };
 225
 226   /**
 227    * Invoke a function object, which may be either a member pointer or a
 228    * function object. The first parameter will tell which.
 229    */
 230   template<typename _Functor, typename... _Args>
 231     inline
 232     typename enable_if<
 233              (!is_member_pointer<_Functor>::value
 234               && !is_function<_Functor>::value
 235               && !is_function<typename remove_pointer<_Functor>::type>::value),
 236              typename result_of<_Functor(_Args...)>::type
 237            >::type
 238     __invoke(_Functor& __f, _Args&&... __args)
 239     {
 240       return __f(std::forward<_Args>(__args)...);
 241     }
 242
 243   // To pick up function references (that will become function pointers)
 244   template<typename _Functor, typename... _Args>
 245     inline
 246     typename enable_if<
 247              (is_pointer<_Functor>::value
 248               && is_function<typename remove_pointer<_Functor>::type>::value),
 249              typename result_of<_Functor(_Args...)>::type
 250            >::type
 251     __invoke(_Functor __f, _Args&&... __args)
 252     {
 253       return __f(std::forward<_Args>(__args)...);
 254     }
 255
 256   /**
 257    *  Knowing which of unary_function and binary_function _Tp derives
 258    *  from, derives from the same and ensures that reference_wrapper
 259    *  will have a weak result type. See cases below.
 260    */
 261   template<bool _Unary, bool _Binary, typename _Tp>
 262     struct _Reference_wrapper_base_impl;
 263
 264   // Not a unary_function or binary_function, so try a weak result type.
 265   template<typename _Tp>
 266     struct _Reference_wrapper_base_impl<false, false, _Tp>
 267     : _Weak_result_type<_Tp>
 268     { };
 269
 270   // unary_function but not binary_function
 271   template<typename _Tp>
 272     struct _Reference_wrapper_base_impl<true, false, _Tp>
 273     : unary_function<typename _Tp::argument_type,
 274                      typename _Tp::result_type>
 275     { };
 276
 277   // binary_function but not unary_function
 278   template<typename _Tp>
 279     struct _Reference_wrapper_base_impl<false, true, _Tp>
 280     : binary_function<typename _Tp::first_argument_type,
 281                       typename _Tp::second_argument_type,
 282                       typename _Tp::result_type>
 283     { };
 284
 285   // Both unary_function and binary_function. Import result_type to
 286   // avoid conflicts.
 287    template<typename _Tp>
 288     struct _Reference_wrapper_base_impl<true, true, _Tp>
 289     : unary_function<typename _Tp::argument_type,
 290                      typename _Tp::result_type>,
 291       binary_function<typename _Tp::first_argument_type,
 292                       typename _Tp::second_argument_type,
 293                       typename _Tp::result_type>
 294     {
 295       typedef typename _Tp::result_type result_type;
 296     };
 297
 298   /**
 299    *  Derives from unary_function or binary_function when it
 300    *  can. Specializations handle all of the easy cases. The primary
 301    *  template determines what to do with a class type, which may
 302    *  derive from both unary_function and binary_function.
 303   */
 304   template<typename _Tp>
 305     struct _Reference_wrapper_base
 306     : _Reference_wrapper_base_impl<
 307       _Derives_from_unary_function<_Tp>::value,
 308       _Derives_from_binary_function<_Tp>::value,
 309       _Tp>
 310     { };
 311
 312   // - a function type (unary)
 313   template<typename _Res, typename _T1>
 314     struct _Reference_wrapper_base<_Res(_T1)>
 315     : unary_function<_T1, _Res>
 316     { };
 317
 318   template<typename _Res, typename _T1>
 319     struct _Reference_wrapper_base<_Res(_T1) const>
 320     : unary_function<_T1, _Res>
 321     { };
 322
 323   template<typename _Res, typename _T1>
 324     struct _Reference_wrapper_base<_Res(_T1) volatile>
 325     : unary_function<_T1, _Res>
 326     { };
 327
 328   template<typename _Res, typename _T1>
 329     struct _Reference_wrapper_base<_Res(_T1) const volatile>
 330     : unary_function<_T1, _Res>
 331     { };
 332
 333   // - a function type (binary)
 334   template<typename _Res, typename _T1, typename _T2>
 335     struct _Reference_wrapper_base<_Res(_T1, _T2)>
 336     : binary_function<_T1, _T2, _Res>
 337     { };
 338
 339   template<typename _Res, typename _T1, typename _T2>
 340     struct _Reference_wrapper_base<_Res(_T1, _T2) const>
 341     : binary_function<_T1, _T2, _Res>
 342     { };
 343
 344   template<typename _Res, typename _T1, typename _T2>
 345     struct _Reference_wrapper_base<_Res(_T1, _T2) volatile>
 346     : binary_function<_T1, _T2, _Res>
 347     { };
 348
 349   template<typename _Res, typename _T1, typename _T2>
 350     struct _Reference_wrapper_base<_Res(_T1, _T2) const volatile>
 351     : binary_function<_T1, _T2, _Res>
 352     { };
 353
 354   // - a function pointer type (unary)
 355   template<typename _Res, typename _T1>
 356     struct _Reference_wrapper_base<_Res(*)(_T1)>
 357     : unary_function<_T1, _Res>
 358     { };
 359
 360   // - a function pointer type (binary)
 361   template<typename _Res, typename _T1, typename _T2>
 362     struct _Reference_wrapper_base<_Res(*)(_T1, _T2)>
 363     : binary_function<_T1, _T2, _Res>
 364     { };
 365
 366   // - a pointer to member function type (unary, no qualifiers)
 367   template<typename _Res, typename _T1>
 368     struct _Reference_wrapper_base<_Res (_T1::*)()>
 369     : unary_function<_T1*, _Res>
 370     { };
 371
 372   // - a pointer to member function type (binary, no qualifiers)
 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, const)
 379   template<typename _Res, typename _T1>
 380     struct _Reference_wrapper_base<_Res (_T1::*)() const>
 381     : unary_function<const _T1*, _Res>
 382     { };
 383
 384   // - a pointer to member function type (binary, const)
 385   template<typename _Res, typename _T1, typename _T2>
 386     struct _Reference_wrapper_base<_Res (_T1::*)(_T2) const>
 387     : binary_function<const _T1*, _T2, _Res>
 388     { };
 389
 390   // - a pointer to member function type (unary, volatile)
 391   template<typename _Res, typename _T1>
 392     struct _Reference_wrapper_base<_Res (_T1::*)() volatile>
 393     : unary_function<volatile _T1*, _Res>
 394     { };
 395
 396   // - a pointer to member function type (binary, volatile)
 397   template<typename _Res, typename _T1, typename _T2>
 398     struct _Reference_wrapper_base<_Res (_T1::*)(_T2) volatile>
 399     : binary_function<volatile _T1*, _T2, _Res>
 400     { };
 401
 402   // - a pointer to member function type (unary, const volatile)
 403   template<typename _Res, typename _T1>
 404     struct _Reference_wrapper_base<_Res (_T1::*)() const volatile>
 405     : unary_function<const volatile _T1*, _Res>
 406     { };
 407
 408   // - a pointer to member function type (binary, const volatile)
 409   template<typename _Res, typename _T1, typename _T2>
 410     struct _Reference_wrapper_base<_Res (_T1::*)(_T2) const volatile>
 411     : binary_function<const volatile _T1*, _T2, _Res>
 412     { };
 413
 414   /**
 415    *  @brief Primary class template for reference_wrapper.
 416    *  @ingroup functors
 417    *  @{
 418    */
 419   template<typename _Tp>
 420     class reference_wrapper
 421     : public _Reference_wrapper_base<typename remove_cv<_Tp>::type>
 422     {
 423       // If _Tp is a function type, we can't form result_of<_Tp(...)>,
 424       // so turn it into a function pointer type.
 425       typedef typename _Function_to_function_pointer<_Tp>::type
 426         _M_func_type;
 427
 428       _Tp* _M_data;
 429     public:
 430       typedef _Tp type;
 431
 432       reference_wrapper(_Tp& __indata)
 433       : _M_data(std::__addressof(__indata))
 434       { }
 435
 436       reference_wrapper(_Tp&&) = delete;
 437
 438       reference_wrapper(const reference_wrapper<_Tp>& __inref):
 439       _M_data(__inref._M_data)
 440       { }
 441
 442       reference_wrapper&
 443       operator=(const reference_wrapper<_Tp>& __inref)
 444       {
 445         _M_data = __inref._M_data;
 446         return *this;
 447       }
 448
 449       operator _Tp&() const
 450       { return this->get(); }
 451
 452       _Tp&
 453       get() const
 454       { return *_M_data; }
 455
 456       template<typename... _Args>
 457         typename result_of<_M_func_type(_Args...)>::type
 458         operator()(_Args&&... __args) const
 459         {
 460           return __invoke(get(), std::forward<_Args>(__args)...);
 461         }
 462     };
 463
 464
 465   /// Denotes a reference should be taken to a variable.
 466   template<typename _Tp>
 467     inline reference_wrapper<_Tp>
 468     ref(_Tp& __t)
 469     { return reference_wrapper<_Tp>(__t); }
 470
 471   /// Denotes a const reference should be taken to a variable.
 472   template<typename _Tp>
 473     inline reference_wrapper<const _Tp>
 474     cref(const _Tp& __t)
 475     { return reference_wrapper<const _Tp>(__t); }
 476
 477   /// Partial specialization.
 478   template<typename _Tp>
 479     inline reference_wrapper<_Tp>
 480     ref(reference_wrapper<_Tp> __t)
 481     { return ref(__t.get()); }
 482
 483   /// Partial specialization.
 484   template<typename _Tp>
 485     inline reference_wrapper<const _Tp>
 486     cref(reference_wrapper<_Tp> __t)
 487     { return cref(__t.get()); }
 488
 489   // @} group functors
 490
 491   template<typename _MemberPointer>
 492     class _Mem_fn;
 493
 494   /**
 495    * Derives from @c unary_function or @c binary_function, or perhaps
 496    * nothing, depending on the number of arguments provided. The
 497    * primary template is the basis case, which derives nothing.
 498    */
 499   template<typename _Res, typename... _ArgTypes>
 500     struct _Maybe_unary_or_binary_function { };
 501
 502   /// Derives from @c unary_function, as appropriate.
 503   template<typename _Res, typename _T1>
 504     struct _Maybe_unary_or_binary_function<_Res, _T1>
 505     : std::unary_function<_T1, _Res> { };
 506
 507   /// Derives from @c binary_function, as appropriate.
 508   template<typename _Res, typename _T1, typename _T2>
 509     struct _Maybe_unary_or_binary_function<_Res, _T1, _T2>
 510     : std::binary_function<_T1, _T2, _Res> { };
 511
 512   /// Implementation of @c mem_fn for member function pointers.
 513   template<typename _Res, typename _Class, typename... _ArgTypes>
 514     class _Mem_fn<_Res (_Class::*)(_ArgTypes...)>
 515     : public _Maybe_unary_or_binary_function<_Res, _Class*, _ArgTypes...>
 516     {
 517       typedef _Res (_Class::*_Functor)(_ArgTypes...);
 518
 519       template<typename _Tp>
 520         _Res
 521         _M_call(_Tp& __object, const volatile _Class *,
 522                 _ArgTypes... __args) const
 523         { return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
 524
 525       template<typename _Tp>
 526         _Res
 527         _M_call(_Tp& __ptr, const volatile void *, _ArgTypes... __args) const
 528         { return ((*__ptr).*__pmf)(std::forward<_ArgTypes>(__args)...); }
 529
 530     public:
 531       typedef _Res result_type;
 532
 533       explicit _Mem_fn(_Functor __pmf) : __pmf(__pmf) { }
 534
 535       // Handle objects
 536       _Res
 537       operator()(_Class& __object, _ArgTypes... __args) const
 538       { return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
 539
 540       // Handle pointers
 541       _Res
 542       operator()(_Class* __object, _ArgTypes... __args) const
 543       { return (__object->*__pmf)(std::forward<_ArgTypes>(__args)...); }
 544
 545       // Handle smart pointers, references and pointers to derived
 546       template<typename _Tp>
 547         _Res
 548         operator()(_Tp& __object, _ArgTypes... __args) const
 549         {
 550           return _M_call(__object, &__object,
 551               std::forward<_ArgTypes>(__args)...);
 552         }
 553
 554     private:
 555       _Functor __pmf;
 556     };
 557
 558   /// Implementation of @c mem_fn for const member function pointers.
 559   template<typename _Res, typename _Class, typename... _ArgTypes>
 560     class _Mem_fn<_Res (_Class::*)(_ArgTypes...) const>
 561     : public _Maybe_unary_or_binary_function<_Res, const _Class*,
 562                                              _ArgTypes...>
 563     {
 564       typedef _Res (_Class::*_Functor)(_ArgTypes...) const;
 565
 566       template<typename _Tp>
 567         _Res
 568         _M_call(_Tp& __object, const volatile _Class *,
 569                 _ArgTypes... __args) const
 570         { return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
 571
 572       template<typename _Tp>
 573         _Res
 574         _M_call(_Tp& __ptr, const volatile void *, _ArgTypes... __args) const
 575         { return ((*__ptr).*__pmf)(std::forward<_ArgTypes>(__args)...); }
 576
 577     public:
 578       typedef _Res result_type;
 579
 580       explicit _Mem_fn(_Functor __pmf) : __pmf(__pmf) { }
 581
 582       // Handle objects
 583       _Res
 584       operator()(const _Class& __object, _ArgTypes... __args) const
 585       { return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
 586
 587       // Handle pointers
 588       _Res
 589       operator()(const _Class* __object, _ArgTypes... __args) const
 590       { return (__object->*__pmf)(std::forward<_ArgTypes>(__args)...); }
 591
 592       // Handle smart pointers, references and pointers to derived
 593       template<typename _Tp>
 594         _Res operator()(_Tp& __object, _ArgTypes... __args) const
 595         {
 596           return _M_call(__object, &__object,
 597               std::forward<_ArgTypes>(__args)...);
 598         }
 599
 600     private:
 601       _Functor __pmf;
 602     };
 603
 604   /// Implementation of @c mem_fn for volatile member function pointers.
 605   template<typename _Res, typename _Class, typename... _ArgTypes>
 606     class _Mem_fn<_Res (_Class::*)(_ArgTypes...) volatile>
 607     : public _Maybe_unary_or_binary_function<_Res, volatile _Class*,
 608                                              _ArgTypes...>
 609     {
 610       typedef _Res (_Class::*_Functor)(_ArgTypes...) volatile;
 611
 612       template<typename _Tp>
 613         _Res
 614         _M_call(_Tp& __object, const volatile _Class *,
 615                 _ArgTypes... __args) const
 616         { return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
 617
 618       template<typename _Tp>
 619         _Res
 620         _M_call(_Tp& __ptr, const volatile void *, _ArgTypes... __args) const
 621         { return ((*__ptr).*__pmf)(std::forward<_ArgTypes>(__args)...); }
 622
 623     public:
 624       typedef _Res result_type;
 625
 626       explicit _Mem_fn(_Functor __pmf) : __pmf(__pmf) { }
 627
 628       // Handle objects
 629       _Res
 630       operator()(volatile _Class& __object, _ArgTypes... __args) const
 631       { return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
 632
 633       // Handle pointers
 634       _Res
 635       operator()(volatile _Class* __object, _ArgTypes... __args) const
 636       { return (__object->*__pmf)(std::forward<_ArgTypes>(__args)...); }
 637
 638       // Handle smart pointers, references and pointers to derived
 639       template<typename _Tp>
 640         _Res
 641         operator()(_Tp& __object, _ArgTypes... __args) const
 642         {
 643           return _M_call(__object, &__object,
 644               std::forward<_ArgTypes>(__args)...);
 645         }
 646
 647     private:
 648       _Functor __pmf;
 649     };
 650
 651   /// Implementation of @c mem_fn for const volatile member function pointers.
 652   template<typename _Res, typename _Class, typename... _ArgTypes>
 653     class _Mem_fn<_Res (_Class::*)(_ArgTypes...) const volatile>
 654     : public _Maybe_unary_or_binary_function<_Res, const volatile _Class*,
 655                                              _ArgTypes...>
 656     {
 657       typedef _Res (_Class::*_Functor)(_ArgTypes...) const volatile;
 658
 659       template<typename _Tp>
 660         _Res
 661         _M_call(_Tp& __object, const volatile _Class *,
 662                 _ArgTypes... __args) const
 663         { return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
 664
 665       template<typename _Tp>
 666         _Res
 667         _M_call(_Tp& __ptr, const volatile void *, _ArgTypes... __args) const
 668         { return ((*__ptr).*__pmf)(std::forward<_ArgTypes>(__args)...); }
 669
 670     public:
 671       typedef _Res result_type;
 672
 673       explicit _Mem_fn(_Functor __pmf) : __pmf(__pmf) { }
 674
 675       // Handle objects
 676       _Res
 677       operator()(const volatile _Class& __object, _ArgTypes... __args) const
 678       { return (__object.*__pmf)(std::forward<_ArgTypes>(__args)...); }
 679
 680       // Handle pointers
 681       _Res
 682       operator()(const volatile _Class* __object, _ArgTypes... __args) const
 683       { return (__object->*__pmf)(std::forward<_ArgTypes>(__args)...); }
 684
 685       // Handle smart pointers, references and pointers to derived
 686       template<typename _Tp>
 687         _Res operator()(_Tp& __object, _ArgTypes... __args) const
 688         {
 689           return _M_call(__object, &__object,
 690               std::forward<_ArgTypes>(__args)...);
 691         }
 692
 693     private:
 694       _Functor __pmf;
 695     };
 696
 697
 698   template<typename _Tp, bool>
 699     struct _Mem_fn_const_or_non
 700     {
 701       typedef const _Tp& type;
 702     };
 703
 704   template<typename _Tp>
 705     struct _Mem_fn_const_or_non<_Tp, false>
 706     {
 707       typedef _Tp& type;
 708     };
 709
 710   template<typename _Res, typename _Class>
 711     class _Mem_fn<_Res _Class::*>
 712     {
 713       // This bit of genius is due to Peter Dimov, improved slightly by
 714       // Douglas Gregor.
 715       template<typename _Tp>
 716         _Res&
 717         _M_call(_Tp& __object, _Class *) const
 718         { return __object.*__pm; }
 719
 720       template<typename _Tp, typename _Up>
 721         _Res&
 722         _M_call(_Tp& __object, _Up * const *) const
 723         { return (*__object).*__pm; }
 724
 725       template<typename _Tp, typename _Up>
 726         const _Res&
 727         _M_call(_Tp& __object, const _Up * const *) const
 728         { return (*__object).*__pm; }
 729
 730       template<typename _Tp>
 731         const _Res&
 732         _M_call(_Tp& __object, const _Class *) const
 733         { return __object.*__pm; }
 734
 735       template<typename _Tp>
 736         const _Res&
 737         _M_call(_Tp& __ptr, const volatile void*) const
 738         { return (*__ptr).*__pm; }
 739
 740       template<typename _Tp> static _Tp& __get_ref();
 741
 742       template<typename _Tp>
 743         static __sfinae_types::__one __check_const(_Tp&, _Class*);
 744       template<typename _Tp, typename _Up>
 745         static __sfinae_types::__one __check_const(_Tp&, _Up * const *);
 746       template<typename _Tp, typename _Up>
 747         static __sfinae_types::__two __check_const(_Tp&, const _Up * const *);
 748       template<typename _Tp>
 749         static __sfinae_types::__two __check_const(_Tp&, const _Class*);
 750       template<typename _Tp>
 751         static __sfinae_types::__two __check_const(_Tp&, const volatile void*);
 752
 753     public:
 754       template<typename _Tp>
 755         struct _Result_type
 756         : _Mem_fn_const_or_non<_Res,
 757           (sizeof(__sfinae_types::__two)
 758            == sizeof(__check_const<_Tp>(__get_ref<_Tp>(), (_Tp*)0)))>
 759         { };
 760
 761       template<typename _Signature>
 762         struct result;
 763
 764       template<typename _CVMem, typename _Tp>
 765         struct result<_CVMem(_Tp)>
 766         : public _Result_type<_Tp> { };
 767
 768       template<typename _CVMem, typename _Tp>
 769         struct result<_CVMem(_Tp&)>
 770         : public _Result_type<_Tp> { };
 771
 772       explicit
 773       _Mem_fn(_Res _Class::*__pm) : __pm(__pm) { }
 774
 775       // Handle objects
 776       _Res&
 777       operator()(_Class& __object) const
 778       { return __object.*__pm; }
 779
 780       const _Res&
 781       operator()(const _Class& __object) const
 782       { return __object.*__pm; }
 783
 784       // Handle pointers
 785       _Res&
 786       operator()(_Class* __object) const
 787       { return __object->*__pm; }
 788
 789       const _Res&
 790       operator()(const _Class* __object) const
 791       { return __object->*__pm; }
 792
 793       // Handle smart pointers and derived
 794       template<typename _Tp>
 795         typename _Result_type<_Tp>::type
 796         operator()(_Tp& __unknown) const
 797         { return _M_call(__unknown, &__unknown); }
 798
 799     private:
 800       _Res _Class::*__pm;
 801     };
 802
 803   /**
 804    *  @brief Returns a function object that forwards to the member
 805    *  pointer @a pm.
 806    *  @ingroup functors
 807    */
 808   template<typename _Tp, typename _Class>
 809     inline _Mem_fn<_Tp _Class::*>
 810     mem_fn(_Tp _Class::* __pm)
 811     {
 812       return _Mem_fn<_Tp _Class::*>(__pm);
 813     }
 814
 815   /**
 816    *  @brief Determines if the given type _Tp is a function object
 817    *  should be treated as a subexpression when evaluating calls to
 818    *  function objects returned by bind(). [TR1 3.6.1]
 819    *  @ingroup binders
 820    */
 821   template<typename _Tp>
 822     struct is_bind_expression
 823     : public false_type { };
 824
 825   /**
 826    *  @brief Determines if the given type _Tp is a placeholder in a
 827    *  bind() expression and, if so, which placeholder it is. [TR1 3.6.2]
 828    *  @ingroup binders
 829    */
 830   template<typename _Tp>
 831     struct is_placeholder
 832     : public integral_constant<int, 0>
 833     { };
 834
 835   /// The type of placeholder objects defined by libstdc++.
 836   template<int _Num> struct _Placeholder { };
 837
 838   /** @namespace std::placeholders
 839    *  @brief ISO C++ 0x entities sub namespace for functional.
 840    *  @ingroup binders
 841    *
 842    *  Define a large number of placeholders. There is no way to
 843    *  simplify this with variadic templates, because we're introducing
 844    *  unique names for each.
 845    */
 846   namespace placeholders
 847   {
 848     namespace
 849     {
 850       _Placeholder<1> _1;
 851       _Placeholder<2> _2;
 852       _Placeholder<3> _3;
 853       _Placeholder<4> _4;
 854       _Placeholder<5> _5;
 855       _Placeholder<6> _6;
 856       _Placeholder<7> _7;
 857       _Placeholder<8> _8;
 858       _Placeholder<9> _9;
 859       _Placeholder<10> _10;
 860       _Placeholder<11> _11;
 861       _Placeholder<12> _12;
 862       _Placeholder<13> _13;
 863       _Placeholder<14> _14;
 864       _Placeholder<15> _15;
 865       _Placeholder<16> _16;
 866       _Placeholder<17> _17;
 867       _Placeholder<18> _18;
 868       _Placeholder<19> _19;
 869       _Placeholder<20> _20;
 870       _Placeholder<21> _21;
 871       _Placeholder<22> _22;
 872       _Placeholder<23> _23;
 873       _Placeholder<24> _24;
 874       _Placeholder<25> _25;
 875       _Placeholder<26> _26;
 876       _Placeholder<27> _27;
 877       _Placeholder<28> _28;
 878       _Placeholder<29> _29;
 879     }
 880   }
 881
 882   /**
 883    *  Partial specialization of is_placeholder that provides the placeholder
 884    *  number for the placeholder objects defined by libstdc++.
 885    *  @ingroup binders
 886    */
 887   template<int _Num>
 888     struct is_placeholder<_Placeholder<_Num> >
 889     : public integral_constant<int, _Num>
 890     { };
 891
 892   /**
 893    * Used by _Safe_tuple_element to indicate that there is no tuple
 894    * element at this position.
 895    */
 896   struct _No_tuple_element;
 897
 898   /**
 899    * Implementation helper for _Safe_tuple_element. This primary
 900    * template handles the case where it is safe to use @c
 901    * tuple_element.
 902    */
 903   template<int __i, typename _Tuple, bool _IsSafe>
 904     struct _Safe_tuple_element_impl
 905     : tuple_element<__i, _Tuple> { };
 906
 907   /**
 908    * Implementation helper for _Safe_tuple_element. This partial
 909    * specialization handles the case where it is not safe to use @c
 910    * tuple_element. We just return @c _No_tuple_element.
 911    */
 912   template<int __i, typename _Tuple>
 913     struct _Safe_tuple_element_impl<__i, _Tuple, false>
 914     {
 915       typedef _No_tuple_element type;
 916     };
 917
 918   /**
 919    * Like tuple_element, but returns @c _No_tuple_element when
 920    * tuple_element would return an error.
 921    */
 922  template<int __i, typename _Tuple>
 923    struct _Safe_tuple_element
 924    : _Safe_tuple_element_impl<__i, _Tuple,
 925                               (__i >= 0 && __i < tuple_size<_Tuple>::value)>
 926    { };
 927
 928   /**
 929    *  Maps an argument to bind() into an actual argument to the bound
 930    *  function object [TR1 3.6.3/5]. Only the first parameter should
 931    *  be specified: the rest are used to determine among the various
 932    *  implementations. Note that, although this class is a function
 933    *  object, it isn't entirely normal because it takes only two
 934    *  parameters regardless of the number of parameters passed to the
 935    *  bind expression. The first parameter is the bound argument and
 936    *  the second parameter is a tuple containing references to the
 937    *  rest of the arguments.
 938    */
 939   template<typename _Arg,
 940            bool _IsBindExp = is_bind_expression<_Arg>::value,
 941            bool _IsPlaceholder = (is_placeholder<_Arg>::value > 0)>
 942     class _Mu;
 943
 944   /**
 945    *  If the argument is reference_wrapper<_Tp>, returns the
 946    *  underlying reference. [TR1 3.6.3/5 bullet 1]
 947    */
 948   template<typename _Tp>
 949     class _Mu<reference_wrapper<_Tp>, false, false>
 950     {
 951     public:
 952       typedef _Tp& result_type;
 953
 954       /* Note: This won't actually work for const volatile
 955        * reference_wrappers, because reference_wrapper::get() is const
 956        * but not volatile-qualified. This might be a defect in the TR.
 957        */
 958       template<typename _CVRef, typename _Tuple>
 959         result_type
 960         operator()(_CVRef& __arg, _Tuple&&) const volatile
 961         { return __arg.get(); }
 962     };
 963
 964   /**
 965    *  If the argument is a bind expression, we invoke the underlying
 966    *  function object with the same cv-qualifiers as we are given and
 967    *  pass along all of our arguments (unwrapped). [TR1 3.6.3/5 bullet 2]
 968    */
 969   template<typename _Arg>
 970     class _Mu<_Arg, true, false>
 971     {
 972     public:
 973       template<typename _Signature> class result;
 974
 975       // Determine the result type when we pass the arguments along. This
 976       // involves passing along the cv-qualifiers placed on _Mu and
 977       // unwrapping the argument bundle.
 978       template<typename _CVMu, typename _CVArg, typename... _Args>
 979         class result<_CVMu(_CVArg, tuple<_Args...>)>
 980         : public result_of<_CVArg(_Args...)> { };
 981
 982       template<typename _CVArg, typename... _Args>
 983         typename result_of<_CVArg(_Args...)>::type
 984         operator()(_CVArg& __arg,
 985                    tuple<_Args...>&& __tuple) const volatile
 986         {
 987           // Construct an index tuple and forward to __call
 988           typedef typename _Build_index_tuple<sizeof...(_Args)>::__type
 989             _Indexes;
 990           return this->__call(__arg, std::move(__tuple), _Indexes());
 991         }
 992
 993     private:
 994       // Invokes the underlying function object __arg by unpacking all
 995       // of the arguments in the tuple.
 996       template<typename _CVArg, typename... _Args, int... _Indexes>
 997         typename result_of<_CVArg(_Args...)>::type
 998         __call(_CVArg& __arg, tuple<_Args...>&& __tuple,
 999                const _Index_tuple<_Indexes...>&) const volatile
1000         {
1001           return __arg(std::forward<_Args>(get<_Indexes>(__tuple))...);
1002         }
1003     };
1004
1005   /**
1006    *  If the argument is a placeholder for the Nth argument, returns
1007    *  a reference to the Nth argument to the bind function object.
1008    *  [TR1 3.6.3/5 bullet 3]
1009    */
1010   template<typename _Arg>
1011     class _Mu<_Arg, false, true>
1012     {
1013     public:
1014       template<typename _Signature> class result;
1015
1016       template<typename _CVMu, typename _CVArg, typename _Tuple>
1017         class result<_CVMu(_CVArg, _Tuple)>
1018         {
1019           // Add a reference, if it hasn't already been done for us.
1020           // This allows us to be a little bit sloppy in constructing
1021           // the tuple that we pass to result_of<...>.
1022           typedef typename _Safe_tuple_element<(is_placeholder<_Arg>::value
1023                                                 - 1), _Tuple>::type
1024             __base_type;
1025
1026         public:
1027           typedef typename add_rvalue_reference<__base_type>::type type;
1028         };
1029
1030       template<typename _Tuple>
1031         typename result<_Mu(_Arg, _Tuple)>::type
1032         operator()(const volatile _Arg&, _Tuple&& __tuple) const volatile
1033         {
1034           return std::forward<typename result<_Mu(_Arg, _Tuple)>::type>(
1035               ::std::get<(is_placeholder<_Arg>::value - 1)>(__tuple));
1036         }
1037     };
1038
1039   /**
1040    *  If the argument is just a value, returns a reference to that
1041    *  value. The cv-qualifiers on the reference are the same as the
1042    *  cv-qualifiers on the _Mu object. [TR1 3.6.3/5 bullet 4]
1043    */
1044   template<typename _Arg>
1045     class _Mu<_Arg, false, false>
1046     {
1047     public:
1048       template<typename _Signature> struct result;
1049
1050       template<typename _CVMu, typename _CVArg, typename _Tuple>
1051         struct result<_CVMu(_CVArg, _Tuple)>
1052         {
1053           typedef typename add_lvalue_reference<_CVArg>::type type;
1054         };
1055
1056       // Pick up the cv-qualifiers of the argument
1057       template<typename _CVArg, typename _Tuple>
1058         _CVArg&&
1059         operator()(_CVArg&& __arg, _Tuple&&) const volatile
1060         { return std::forward<_CVArg>(__arg); }
1061     };
1062
1063   /**
1064    *  Maps member pointers into instances of _Mem_fn but leaves all
1065    *  other function objects untouched. Used by tr1::bind(). The
1066    *  primary template handles the non--member-pointer case.
1067    */
1068   template<typename _Tp>
1069     struct _Maybe_wrap_member_pointer
1070     {
1071       typedef _Tp type;
1072
1073       static const _Tp&
1074       __do_wrap(const _Tp& __x)
1075       { return __x; }
1076     };
1077
1078   /**
1079    *  Maps member pointers into instances of _Mem_fn but leaves all
1080    *  other function objects untouched. Used by tr1::bind(). This
1081    *  partial specialization handles the member pointer case.
1082    */
1083   template<typename _Tp, typename _Class>
1084     struct _Maybe_wrap_member_pointer<_Tp _Class::*>
1085     {
1086       typedef _Mem_fn<_Tp _Class::*> type;
1087
1088       static type
1089       __do_wrap(_Tp _Class::* __pm)
1090       { return type(__pm); }
1091     };
1092
1093   // Specialization needed to prevent "forming reference to void" errors when
1094   // bind<void>() is called, because argument deduction instantiates
1095   // _Maybe_wrap_member_pointer<void> outside the immediate context where
1096   // SFINAE applies.
1097   template<>
1098     struct _Maybe_wrap_member_pointer<void>
1099     {
1100       typedef void type;
1101     };
1102
1103   /// Type of the function object returned from bind().
1104   template<typename _Signature>
1105     struct _Bind;
1106
1107    template<typename _Functor, typename... _Bound_args>
1108     class _Bind<_Functor(_Bound_args...)>
1109     : public _Weak_result_type<_Functor>
1110     {
1111       typedef _Bind __self_type;
1112       typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
1113         _Bound_indexes;
1114
1115       _Functor _M_f;
1116       tuple<_Bound_args...> _M_bound_args;
1117
1118       // Call unqualified
1119       template<typename _Result, typename... _Args, int... _Indexes>
1120         _Result
1121         __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
1122         {
1123           return _M_f(_Mu<_Bound_args>()
1124                       (get<_Indexes>(_M_bound_args), std::move(__args))...);
1125         }
1126
1127       // Call as const
1128       template<typename _Result, typename... _Args, int... _Indexes>
1129         _Result
1130         __call_c(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
1131         {
1132           return _M_f(_Mu<_Bound_args>()
1133                       (get<_Indexes>(_M_bound_args), std::move(__args))...);
1134         }
1135
1136 #if 0
1137       // Call as volatile
1138       template<typename _Result, typename... _Args, int... _Indexes>
1139         _Result
1140         __call_v(tuple<_Args...>&& __args,
1141                  _Index_tuple<_Indexes...>) volatile
1142         {
1143           return _M_f(_Mu<_Bound_args>()
1144                       (get<_Indexes>(_M_bound_args), std::move(__args))...);
1145         }
1146
1147       // Call as const volatile
1148       template<typename _Result, typename... _Args, int... _Indexes>
1149         _Result
1150         __call_c_v(tuple<_Args...>&& __args,
1151                    _Index_tuple<_Indexes...>) const volatile
1152         {
1153           return _M_f(_Mu<_Bound_args>()
1154                       (get<_Indexes>(_M_bound_args), std::move(__args))...);
1155         }
1156 #endif
1157
1158      public:
1159       explicit _Bind(_Functor __f, _Bound_args... __bound_args)
1160       : _M_f(std::forward<_Functor>(__f)),
1161         _M_bound_args(std::forward<_Bound_args>(__bound_args)...)
1162       { }
1163
1164       // Call unqualified
1165       template<typename... _Args, typename _Result
1166         = decltype( std::declval<_Functor>()(
1167               _Mu<_Bound_args>()( std::declval<_Bound_args&>(),
1168                                   std::declval<tuple<_Args...>&&>() )... ) )>
1169         _Result
1170         operator()(_Args&&... __args)
1171         {
1172           return this->__call<_Result>(tuple<_Args...>
1173                                        (std::forward<_Args>(__args)...),
1174                                        _Bound_indexes());
1175         }
1176
1177       // Call as const
1178       template<typename... _Args, typename _Result
1179         = decltype( std::declval<const _Functor>()(
1180               _Mu<_Bound_args>()( std::declval<const _Bound_args&>(),
1181                                   std::declval<tuple<_Args...>&&>() )... ) )>
1182         _Result
1183         operator()(_Args&&... __args) const
1184         {
1185           return this->__call_c<_Result>(tuple<_Args...>
1186                                          (std::forward<_Args>(__args)...),
1187                                          _Bound_indexes());
1188         }
1189
1190 #if 0
1191       // Call as volatile
1192       template<typename... _Args, typename _Result
1193         = decltype( std::declval<volatile _Functor>()(
1194               _Mu<_Bound_args>()( std::declval<volatile _Bound_args&>(),
1195                                   std::declval<tuple<_Args...>&&>() )... ) )>
1196         _Result
1197         operator()(_Args&&... __args) volatile
1198         {
1199           return this->__call_v<_Result>(tuple<_Args...>
1200                                          (std::forward<_Args>(__args)...),
1201                                          _Bound_indexes());
1202         }
1203
1204       // Call as const volatile
1205       template<typename... _Args, typename _Result
1206         = decltype( std::declval<const volatile _Functor>()(
1207               _Mu<_Bound_args>()( std::declval<const volatile _Bound_args&>(),
1208                                   std::declval<tuple<_Args...>&&>() )... ) )>
1209         _Result
1210         operator()(_Args&&... __args) const volatile
1211         {
1212           return this->__call_c_v<_Result>(tuple<_Args...>
1213                                            (std::forward<_Args>(__args)...),
1214                                            _Bound_indexes());
1215         }
1216 #endif
1217     };
1218
1219   /// Type of the function object returned from bind<R>().
1220   template<typename _Result, typename _Signature>
1221     struct _Bind_result;
1222
1223   template<typename _Result, typename _Functor, typename... _Bound_args>
1224     class _Bind_result<_Result, _Functor(_Bound_args...)>
1225     {
1226       typedef _Bind_result __self_type;
1227       typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
1228         _Bound_indexes;
1229
1230       _Functor _M_f;
1231       tuple<_Bound_args...> _M_bound_args;
1232
1233       // sfinae types
1234       template<typename _Res>
1235         struct __enable_if_void : enable_if<is_void<_Res>::value, int> { };
1236       template<typename _Res>
1237         struct __disable_if_void : enable_if<!is_void<_Res>::value, int> { };
1238
1239       // Call unqualified
1240       template<typename _Res, typename... _Args, int... _Indexes>
1241         _Result
1242         __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1243             typename __disable_if_void<_Res>::type = 0)
1244         {
1245           return _M_f(_Mu<_Bound_args>()
1246                       (get<_Indexes>(_M_bound_args), std::move(__args))...);
1247         }
1248
1249       // Call unqualified, return void
1250       template<typename _Res, typename... _Args, int... _Indexes>
1251         void
1252         __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1253             typename __enable_if_void<_Res>::type = 0)
1254         {
1255           _M_f(_Mu<_Bound_args>()
1256                (get<_Indexes>(_M_bound_args), std::move(__args))...);
1257         }
1258
1259       // Call as const
1260       template<typename _Res, typename... _Args, int... _Indexes>
1261         _Result
1262         __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1263             typename __disable_if_void<_Res>::type = 0) const
1264         {
1265           return _M_f(_Mu<_Bound_args>()
1266                       (get<_Indexes>(_M_bound_args), std::move(__args))...);
1267         }
1268
1269       // Call as const, return void
1270       template<typename _Res, typename... _Args, int... _Indexes>
1271         void
1272         __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1273             typename __enable_if_void<_Res>::type = 0) const
1274         {
1275           _M_f(_Mu<_Bound_args>()
1276                (get<_Indexes>(_M_bound_args),  std::move(__args))...);
1277         }
1278
1279       // Call as volatile
1280       template<typename _Res, typename... _Args, int... _Indexes>
1281         _Result
1282         __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1283             typename __disable_if_void<_Res>::type = 0) volatile
1284         {
1285           return _M_f(_Mu<_Bound_args>()
1286                       (get<_Indexes>(_M_bound_args), std::move(__args))...);
1287         }
1288
1289       // Call as volatile, return void
1290       template<typename _Res, typename... _Args, int... _Indexes>
1291         void
1292         __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1293             typename __enable_if_void<_Res>::type = 0) volatile
1294         {
1295           _M_f(_Mu<_Bound_args>()
1296                (get<_Indexes>(_M_bound_args), std::move(__args))...);
1297         }
1298
1299       // Call as const volatile
1300       template<typename _Res, typename... _Args, int... _Indexes>
1301         _Result
1302         __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
1303             typename __disable_if_void<_Res>::type = 0) const volatile
1304         {
1305           return _M_f(_Mu<_Bound_args>()
1306                       (get<_Indexes>(_M_bound_args), std::move(__args))...);
1307         }
1308
1309       // Call as const volatile, return void
1310       template<typename _Res, typename... _Args, int... _Indexes>
1311         void
1312         __call(tuple<_Args...>&& __args,
1313                _Index_tuple<_Indexes...>,
1314             typename __enable_if_void<_Res>::type = 0) const volatile
1315         {
1316           _M_f(_Mu<_Bound_args>()
1317                (get<_Indexes>(_M_bound_args), std::move(__args))...);
1318         }
1319
1320     public:
1321       typedef _Result result_type;
1322
1323       explicit
1324       _Bind_result(_Functor __f, _Bound_args... __bound_args)
1325       : _M_f(std::forward<_Functor>(__f)),
1326         _M_bound_args(std::forward<_Bound_args>(__bound_args)...)
1327       { }
1328
1329       // Call unqualified
1330       template<typename... _Args>
1331         result_type
1332         operator()(_Args&&... __args)
1333         {
1334           return this->__call<_Result>(
1335               tuple<_Args...>(std::forward<_Args>(__args)...),
1336               _Bound_indexes());
1337         }
1338
1339       // Call as const
1340       template<typename... _Args>
1341         result_type
1342         operator()(_Args&&... __args) const
1343         {
1344           return this->__call<_Result>(
1345               tuple<_Args...>(std::forward<_Args>(__args)...),
1346               _Bound_indexes());
1347         }
1348
1349       // Call as volatile
1350       template<typename... _Args>
1351         result_type
1352         operator()(_Args&&... __args) volatile
1353         {
1354           return this->__call<_Result>(
1355               tuple<_Args...>(std::forward<_Args>(__args)...),
1356               _Bound_indexes());
1357         }
1358
1359       // Call as const volatile
1360       template<typename... _Args>
1361         result_type
1362         operator()(_Args&&... __args) const volatile
1363         {
1364           return this->__call<_Result>(
1365               tuple<_Args...>(std::forward<_Args>(__args)...),
1366               _Bound_indexes());
1367         }
1368     };
1369
1370   /**
1371    *  @brief Class template _Bind is always a bind expression.
1372    *  @ingroup binders
1373    */
1374   template<typename _Signature>
1375     struct is_bind_expression<_Bind<_Signature> >
1376     : public true_type { };
1377
1378   /**
1379    *  @brief Class template _Bind is always a bind expression.
1380    *  @ingroup binders
1381    */
1382   template<typename _Result, typename _Signature>
1383     struct is_bind_expression<_Bind_result<_Result, _Signature> >
1384     : public true_type { };
1385
1386   /**
1387    *  @brief Function template for std::bind.
1388    *  @ingroup binders
1389    */
1390   template<typename _Functor, typename... _ArgTypes>
1391     inline
1392     _Bind<typename _Maybe_wrap_member_pointer<_Functor>::type(_ArgTypes...)>
1393     bind(_Functor __f, _ArgTypes... __args)
1394     {
1395       typedef _Maybe_wrap_member_pointer<_Functor> __maybe_type;
1396       typedef typename __maybe_type::type __functor_type;
1397       typedef _Bind<__functor_type(_ArgTypes...)> __result_type;
1398       return __result_type(__maybe_type::__do_wrap(__f),
1399                            std::forward<_ArgTypes>(__args)...);
1400     }
1401
1402   /**
1403    *  @brief Function template for std::bind.
1404    *  @ingroup binders
1405    */
1406   template<typename _Result, typename _Functor, typename... _ArgTypes>
1407     inline
1408     _Bind_result<_Result,
1409                  typename _Maybe_wrap_member_pointer<_Functor>::type
1410                             (_ArgTypes...)>
1411     bind(_Functor __f, _ArgTypes... __args)
1412     {
1413       typedef _Maybe_wrap_member_pointer<_Functor> __maybe_type;
1414       typedef typename __maybe_type::type __functor_type;
1415       typedef _Bind_result<_Result, __functor_type(_ArgTypes...)>
1416         __result_type;
1417       return __result_type(__maybe_type::__do_wrap(__f),
1418                            std::forward<_ArgTypes>(__args)...);
1419     }
1420
1421   /**
1422    *  @brief Exception class thrown when class template function's
1423    *  operator() is called with an empty target.
1424    *  @ingroup exceptions
1425    */
1426   class bad_function_call : public std::exception { };
1427
1428   /**
1429    *  Trait identifying "location-invariant" types, meaning that the
1430    *  address of the object (or any of its members) will not escape.
1431    *  Also implies a trivial copy constructor and assignment operator.
1432    */
1433   template<typename _Tp>
1434     struct __is_location_invariant
1435     : integral_constant<bool, (is_pointer<_Tp>::value
1436                                || is_member_pointer<_Tp>::value)>
1437     { };
1438
1439   class _Undefined_class;
1440
1441   union _Nocopy_types
1442   {
1443     void*       _M_object;
1444     const void* _M_const_object;
1445     void (*_M_function_pointer)();
1446     void (_Undefined_class::*_M_member_pointer)();
1447   };
1448
1449   union _Any_data
1450   {
1451     void*       _M_access()       { return &_M_pod_data[0]; }
1452     const void* _M_access() const { return &_M_pod_data[0]; }
1453
1454     template<typename _Tp>
1455       _Tp&
1456       _M_access()
1457       { return *static_cast<_Tp*>(_M_access()); }
1458
1459     template<typename _Tp>
1460       const _Tp&
1461       _M_access() const
1462       { return *static_cast<const _Tp*>(_M_access()); }
1463
1464     _Nocopy_types _M_unused;
1465     char _M_pod_data[sizeof(_Nocopy_types)];
1466   };
1467
1468   enum _Manager_operation
1469   {
1470     __get_type_info,
1471     __get_functor_ptr,
1472     __clone_functor,
1473     __destroy_functor
1474   };
1475
1476   // Simple type wrapper that helps avoid annoying const problems
1477   // when casting between void pointers and pointers-to-pointers.
1478   template<typename _Tp>
1479     struct _Simple_type_wrapper
1480     {
1481       _Simple_type_wrapper(_Tp __value) : __value(__value) { }
1482
1483       _Tp __value;
1484     };
1485
1486   template<typename _Tp>
1487     struct __is_location_invariant<_Simple_type_wrapper<_Tp> >
1488     : __is_location_invariant<_Tp>
1489     { };
1490
1491   // Converts a reference to a function object into a callable
1492   // function object.
1493   template<typename _Functor>
1494     inline _Functor&
1495     __callable_functor(_Functor& __f)
1496     { return __f; }
1497
1498   template<typename _Member, typename _Class>
1499     inline _Mem_fn<_Member _Class::*>
1500     __callable_functor(_Member _Class::* &__p)
1501     { return mem_fn(__p); }
1502
1503   template<typename _Member, typename _Class>
1504     inline _Mem_fn<_Member _Class::*>
1505     __callable_functor(_Member _Class::* const &__p)
1506     { return mem_fn(__p); }
1507
1508   template<typename _Signature>
1509     class function;
1510
1511   /// Base class of all polymorphic function object wrappers.
1512   class _Function_base
1513   {
1514   public:
1515     static const std::size_t _M_max_size = sizeof(_Nocopy_types);
1516     static const std::size_t _M_max_align = __alignof__(_Nocopy_types);
1517
1518     template<typename _Functor>
1519       class _Base_manager
1520       {
1521       protected:
1522         static const bool __stored_locally =
1523         (__is_location_invariant<_Functor>::value
1524          && sizeof(_Functor) <= _M_max_size
1525          && __alignof__(_Functor) <= _M_max_align
1526          && (_M_max_align % __alignof__(_Functor) == 0));
1527
1528         typedef integral_constant<bool, __stored_locally> _Local_storage;
1529
1530         // Retrieve a pointer to the function object
1531         static _Functor*
1532         _M_get_pointer(const _Any_data& __source)
1533         {
1534           const _Functor* __ptr =
1535             __stored_locally? &__source._M_access<_Functor>()
1536             /* have stored a pointer */ : __source._M_access<_Functor*>();
1537           return const_cast<_Functor*>(__ptr);
1538         }
1539
1540         // Clone a location-invariant function object that fits within
1541         // an _Any_data structure.
1542         static void
1543         _M_clone(_Any_data& __dest, const _Any_data& __source, true_type)
1544         {
1545           new (__dest._M_access()) _Functor(__source._M_access<_Functor>());
1546         }
1547
1548         // Clone a function object that is not location-invariant or
1549         // that cannot fit into an _Any_data structure.
1550         static void
1551         _M_clone(_Any_data& __dest, const _Any_data& __source, false_type)
1552         {
1553           __dest._M_access<_Functor*>() =
1554             new _Functor(*__source._M_access<_Functor*>());
1555         }
1556
1557         // Destroying a location-invariant object may still require
1558         // destruction.
1559         static void
1560         _M_destroy(_Any_data& __victim, true_type)
1561         {
1562           __victim._M_access<_Functor>().~_Functor();
1563         }
1564
1565         // Destroying an object located on the heap.
1566         static void
1567         _M_destroy(_Any_data& __victim, false_type)
1568         {
1569           delete __victim._M_access<_Functor*>();
1570         }
1571
1572       public:
1573         static bool
1574         _M_manager(_Any_data& __dest, const _Any_data& __source,
1575                    _Manager_operation __op)
1576         {
1577           switch (__op)
1578             {
1579 #ifdef __GXX_RTTI
1580             case __get_type_info:
1581               __dest._M_access<const type_info*>() = &typeid(_Functor);
1582               break;
1583 #endif
1584             case __get_functor_ptr:
1585               __dest._M_access<_Functor*>() = _M_get_pointer(__source);
1586               break;
1587
1588             case __clone_functor:
1589               _M_clone(__dest, __source, _Local_storage());
1590               break;
1591
1592             case __destroy_functor:
1593               _M_destroy(__dest, _Local_storage());
1594               break;
1595             }
1596           return false;
1597         }
1598
1599         static void
1600         _M_init_functor(_Any_data& __functor, _Functor&& __f)
1601         { _M_init_functor(__functor, std::move(__f), _Local_storage()); }
1602
1603         template<typename _Signature>
1604           static bool
1605           _M_not_empty_function(const function<_Signature>& __f)
1606           { return static_cast<bool>(__f); }
1607
1608         template<typename _Tp>
1609           static bool
1610           _M_not_empty_function(const _Tp*& __fp)
1611           { return __fp; }
1612
1613         template<typename _Class, typename _Tp>
1614           static bool
1615           _M_not_empty_function(_Tp _Class::* const& __mp)
1616           { return __mp; }
1617
1618         template<typename _Tp>
1619           static bool
1620           _M_not_empty_function(const _Tp&)
1621           { return true; }
1622
1623       private:
1624         static void
1625         _M_init_functor(_Any_data& __functor, _Functor&& __f, true_type)
1626         { new (__functor._M_access()) _Functor(std::move(__f)); }
1627
1628         static void
1629         _M_init_functor(_Any_data& __functor, _Functor&& __f, false_type)
1630         { __functor._M_access<_Functor*>() = new _Functor(std::move(__f)); }
1631       };
1632
1633     template<typename _Functor>
1634       class _Ref_manager : public _Base_manager<_Functor*>
1635       {
1636         typedef _Function_base::_Base_manager<_Functor*> _Base;
1637
1638     public:
1639         static bool
1640         _M_manager(_Any_data& __dest, const _Any_data& __source,
1641                    _Manager_operation __op)
1642         {
1643           switch (__op)
1644             {
1645 #ifdef __GXX_RTTI
1646             case __get_type_info:
1647               __dest._M_access<const type_info*>() = &typeid(_Functor);
1648               break;
1649 #endif
1650             case __get_functor_ptr:
1651               __dest._M_access<_Functor*>() = *_Base::_M_get_pointer(__source);
1652               return is_const<_Functor>::value;
1653               break;
1654
1655             default:
1656               _Base::_M_manager(__dest, __source, __op);
1657             }
1658           return false;
1659         }
1660
1661         static void
1662         _M_init_functor(_Any_data& __functor, reference_wrapper<_Functor> __f)
1663         {
1664           // TBD: Use address_of function instead.
1665           _Base::_M_init_functor(__functor, &__f.get());
1666         }
1667       };
1668
1669     _Function_base() : _M_manager(0) { }
1670
1671     ~_Function_base()
1672     {
1673       if (_M_manager)
1674         _M_manager(_M_functor, _M_functor, __destroy_functor);
1675     }
1676
1677
1678     bool _M_empty() const { return !_M_manager; }
1679
1680     typedef bool (*_Manager_type)(_Any_data&, const _Any_data&,
1681                                   _Manager_operation);
1682
1683     _Any_data     _M_functor;
1684     _Manager_type _M_manager;
1685   };
1686
1687   template<typename _Signature, typename _Functor>
1688     class _Function_handler;
1689
1690   template<typename _Res, typename _Functor, typename... _ArgTypes>
1691     class _Function_handler<_Res(_ArgTypes...), _Functor>
1692     : public _Function_base::_Base_manager<_Functor>
1693     {
1694       typedef _Function_base::_Base_manager<_Functor> _Base;
1695
1696     public:
1697       static _Res
1698       _M_invoke(const _Any_data& __functor, _ArgTypes... __args)
1699       {
1700         return (*_Base::_M_get_pointer(__functor))(
1701             std::forward<_ArgTypes>(__args)...);
1702       }
1703     };
1704
1705   template<typename _Functor, typename... _ArgTypes>
1706     class _Function_handler<void(_ArgTypes...), _Functor>
1707     : public _Function_base::_Base_manager<_Functor>
1708     {
1709       typedef _Function_base::_Base_manager<_Functor> _Base;
1710
1711      public:
1712       static void
1713       _M_invoke(const _Any_data& __functor, _ArgTypes... __args)
1714       {
1715         (*_Base::_M_get_pointer(__functor))(
1716             std::forward<_ArgTypes>(__args)...);
1717       }
1718     };
1719
1720   template<typename _Res, typename _Functor, typename... _ArgTypes>
1721     class _Function_handler<_Res(_ArgTypes...), reference_wrapper<_Functor> >
1722     : public _Function_base::_Ref_manager<_Functor>
1723     {
1724       typedef _Function_base::_Ref_manager<_Functor> _Base;
1725
1726      public:
1727       static _Res
1728       _M_invoke(const _Any_data& __functor, _ArgTypes... __args)
1729       {
1730         return __callable_functor(**_Base::_M_get_pointer(__functor))(
1731               std::forward<_ArgTypes>(__args)...);
1732       }
1733     };
1734
1735   template<typename _Functor, typename... _ArgTypes>
1736     class _Function_handler<void(_ArgTypes...), reference_wrapper<_Functor> >
1737     : public _Function_base::_Ref_manager<_Functor>
1738     {
1739       typedef _Function_base::_Ref_manager<_Functor> _Base;
1740
1741      public:
1742       static void
1743       _M_invoke(const _Any_data& __functor, _ArgTypes... __args)
1744       {
1745         __callable_functor(**_Base::_M_get_pointer(__functor))(
1746             std::forward<_ArgTypes>(__args)...);
1747       }
1748     };
1749
1750   template<typename _Class, typename _Member, typename _Res,
1751            typename... _ArgTypes>
1752     class _Function_handler<_Res(_ArgTypes...), _Member _Class::*>
1753     : public _Function_handler<void(_ArgTypes...), _Member _Class::*>
1754     {
1755       typedef _Function_handler<void(_ArgTypes...), _Member _Class::*>
1756         _Base;
1757
1758      public:
1759       static _Res
1760       _M_invoke(const _Any_data& __functor, _ArgTypes... __args)
1761       {
1762         return mem_fn(_Base::_M_get_pointer(__functor)->__value)(
1763             std::forward<_ArgTypes>(__args)...);
1764       }
1765     };
1766
1767   template<typename _Class, typename _Member, typename... _ArgTypes>
1768     class _Function_handler<void(_ArgTypes...), _Member _Class::*>
1769     : public _Function_base::_Base_manager<
1770                  _Simple_type_wrapper< _Member _Class::* > >
1771     {
1772       typedef _Member _Class::* _Functor;
1773       typedef _Simple_type_wrapper<_Functor> _Wrapper;
1774       typedef _Function_base::_Base_manager<_Wrapper> _Base;
1775
1776      public:
1777       static bool
1778       _M_manager(_Any_data& __dest, const _Any_data& __source,
1779                  _Manager_operation __op)
1780       {
1781         switch (__op)
1782           {
1783 #ifdef __GXX_RTTI
1784           case __get_type_info:
1785             __dest._M_access<const type_info*>() = &typeid(_Functor);
1786             break;
1787 #endif
1788           case __get_functor_ptr:
1789             __dest._M_access<_Functor*>() =
1790               &_Base::_M_get_pointer(__source)->__value;
1791             break;
1792
1793           default:
1794             _Base::_M_manager(__dest, __source, __op);
1795           }
1796         return false;
1797       }
1798
1799       static void
1800       _M_invoke(const _Any_data& __functor, _ArgTypes... __args)
1801       {
1802         mem_fn(_Base::_M_get_pointer(__functor)->__value)(
1803             std::forward<_ArgTypes>(__args)...);
1804       }
1805     };
1806
1807   /**
1808    *  @brief Primary class template for std::function.
1809    *  @ingroup functors
1810    *
1811    *  Polymorphic function wrapper.
1812    */
1813   template<typename _Res, typename... _ArgTypes>
1814     class function<_Res(_ArgTypes...)>
1815     : public _Maybe_unary_or_binary_function<_Res, _ArgTypes...>,
1816       private _Function_base
1817     {
1818       typedef _Res _Signature_type(_ArgTypes...);
1819
1820       struct _Useless { };
1821
1822     public:
1823       typedef _Res result_type;
1824
1825       // [3.7.2.1] construct/copy/destroy
1826
1827       /**
1828        *  @brief Default construct creates an empty function call wrapper.
1829        *  @post @c !(bool)*this
1830        */
1831       function() : _Function_base() { }
1832
1833       /**
1834        *  @brief Creates an empty function call wrapper.
1835        *  @post @c !(bool)*this
1836        */
1837       function(nullptr_t) : _Function_base() { }
1838
1839       /**
1840        *  @brief %Function copy constructor.
1841        *  @param x A %function object with identical call signature.
1842        *  @post @c (bool)*this == (bool)x
1843        *
1844        *  The newly-created %function contains a copy of the target of @a
1845        *  x (if it has one).
1846        */
1847       function(const function& __x);
1848
1849       /**
1850        *  @brief %Function move constructor.
1851        *  @param x A %function object rvalue with identical call signature.
1852        *
1853        *  The newly-created %function contains the target of @a x
1854        *  (if it has one).
1855        */
1856       function(function&& __x) : _Function_base()
1857       {
1858         __x.swap(*this);
1859       }
1860
1861       // TODO: needs allocator_arg_t
1862
1863       /**
1864        *  @brief Builds a %function that targets a copy of the incoming
1865        *  function object.
1866        *  @param f A %function object that is callable with parameters of
1867        *  type @c T1, @c T2, ..., @c TN and returns a value convertible
1868        *  to @c Res.
1869        *
1870        *  The newly-created %function object will target a copy of @a
1871        *  f. If @a f is @c reference_wrapper<F>, then this function
1872        *  object will contain a reference to the function object @c
1873        *  f.get(). If @a f is a NULL function pointer or NULL
1874        *  pointer-to-member, the newly-created object will be empty.
1875        *
1876        *  If @a f is a non-NULL function pointer or an object of type @c
1877        *  reference_wrapper<F>, this function will not throw.
1878        */
1879       template<typename _Functor>
1880         function(_Functor __f,
1881                  typename enable_if<
1882                            !is_integral<_Functor>::value, _Useless>::type
1883                    = _Useless());
1884
1885       /**
1886        *  @brief %Function assignment operator.
1887        *  @param x A %function with identical call signature.
1888        *  @post @c (bool)*this == (bool)x
1889        *  @returns @c *this
1890        *
1891        *  The target of @a x is copied to @c *this. If @a x has no
1892        *  target, then @c *this will be empty.
1893        *
1894        *  If @a x targets a function pointer or a reference to a function
1895        *  object, then this operation will not throw an %exception.
1896        */
1897       function&
1898       operator=(const function& __x)
1899       {
1900         function(__x).swap(*this);
1901         return *this;
1902       }
1903
1904       /**
1905        *  @brief %Function move-assignment operator.
1906        *  @param x A %function rvalue with identical call signature.
1907        *  @returns @c *this
1908        *
1909        *  The target of @a x is moved to @c *this. If @a x has no
1910        *  target, then @c *this will be empty.
1911        *
1912        *  If @a x targets a function pointer or a reference to a function
1913        *  object, then this operation will not throw an %exception.
1914        */
1915       function&
1916       operator=(function&& __x)
1917       {
1918         function(std::move(__x)).swap(*this);
1919         return *this;
1920       }
1921
1922       /**
1923        *  @brief %Function assignment to zero.
1924        *  @post @c !(bool)*this
1925        *  @returns @c *this
1926        *
1927        *  The target of @c *this is deallocated, leaving it empty.
1928        */
1929       function&
1930       operator=(nullptr_t)
1931       {
1932         if (_M_manager)
1933           {
1934             _M_manager(_M_functor, _M_functor, __destroy_functor);
1935             _M_manager = 0;
1936             _M_invoker = 0;
1937           }
1938         return *this;
1939       }
1940
1941       /**
1942        *  @brief %Function assignment to a new target.
1943        *  @param f A %function object that is callable with parameters of
1944        *  type @c T1, @c T2, ..., @c TN and returns a value convertible
1945        *  to @c Res.
1946        *  @return @c *this
1947        *
1948        *  This  %function object wrapper will target a copy of @a
1949        *  f. If @a f is @c reference_wrapper<F>, then this function
1950        *  object will contain a reference to the function object @c
1951        *  f.get(). If @a f is a NULL function pointer or NULL
1952        *  pointer-to-member, @c this object will be empty.
1953        *
1954        *  If @a f is a non-NULL function pointer or an object of type @c
1955        *  reference_wrapper<F>, this function will not throw.
1956        */
1957       template<typename _Functor>
1958         typename enable_if<!is_integral<_Functor>::value, function&>::type
1959         operator=(_Functor&& __f)
1960         {
1961           function(std::forward<_Functor>(__f)).swap(*this);
1962           return *this;
1963         }
1964
1965       /// @overload
1966       template<typename _Functor>
1967         typename enable_if<!is_integral<_Functor>::value, function&>::type
1968         operator=(reference_wrapper<_Functor> __f)
1969         {
1970           function(__f).swap(*this);
1971           return *this;
1972         }
1973
1974       // [3.7.2.2] function modifiers
1975
1976       /**
1977        *  @brief Swap the targets of two %function objects.
1978        *  @param f A %function with identical call signature.
1979        *
1980        *  Swap the targets of @c this function object and @a f. This
1981        *  function will not throw an %exception.
1982        */
1983       void swap(function& __x)
1984       {
1985         std::swap(_M_functor, __x._M_functor);
1986         std::swap(_M_manager, __x._M_manager);
1987         std::swap(_M_invoker, __x._M_invoker);
1988       }
1989
1990       // TODO: needs allocator_arg_t
1991       /*
1992       template<typename _Functor, typename _Alloc>
1993         void
1994         assign(_Functor&& __f, const _Alloc& __a)
1995         {
1996           function(allocator_arg, __a,
1997                    std::forward<_Functor>(__f)).swap(*this);
1998         }
1999       */
2000
2001       // [3.7.2.3] function capacity
2002
2003       /**
2004        *  @brief Determine if the %function wrapper has a target.
2005        *
2006        *  @return @c true when this %function object contains a target,
2007        *  or @c false when it is empty.
2008        *
2009        *  This function will not throw an %exception.
2010        */
2011       explicit operator bool() const
2012       { return !_M_empty(); }
2013
2014       // [3.7.2.4] function invocation
2015
2016       /**
2017        *  @brief Invokes the function targeted by @c *this.
2018        *  @returns the result of the target.
2019        *  @throws bad_function_call when @c !(bool)*this
2020        *
2021        *  The function call operator invokes the target function object
2022        *  stored by @c this.
2023        */
2024       _Res operator()(_ArgTypes... __args) const;
2025
2026 #ifdef __GXX_RTTI
2027       // [3.7.2.5] function target access
2028       /**
2029        *  @brief Determine the type of the target of this function object
2030        *  wrapper.
2031        *
2032        *  @returns the type identifier of the target function object, or
2033        *  @c typeid(void) if @c !(bool)*this.
2034        *
2035        *  This function will not throw an %exception.
2036        */
2037       const type_info& target_type() const;
2038
2039       /**
2040        *  @brief Access the stored target function object.
2041        *
2042        *  @return Returns a pointer to the stored target function object,
2043        *  if @c typeid(Functor).equals(target_type()); otherwise, a NULL
2044        *  pointer.
2045        *
2046        * This function will not throw an %exception.
2047        */
2048       template<typename _Functor>       _Functor* target();
2049
2050       /// @overload
2051       template<typename _Functor> const _Functor* target() const;
2052 #endif
2053
2054       // deleted overloads
2055       template<typename _Res2, typename... _ArgTypes2>
2056         void operator==(const function<_Res2(_ArgTypes2...)>&) const = delete;
2057       template<typename _Res2, typename... _ArgTypes2>
2058         void operator!=(const function<_Res2(_ArgTypes2...)>&) const = delete;
2059
2060     private:
2061       typedef _Res (*_Invoker_type)(const _Any_data&, _ArgTypes...);
2062       _Invoker_type _M_invoker;
2063   };
2064
2065   // Out-of-line member definitions.
2066   template<typename _Res, typename... _ArgTypes>
2067     function<_Res(_ArgTypes...)>::
2068     function(const function& __x)
2069     : _Function_base()
2070     {
2071       if (static_cast<bool>(__x))
2072         {
2073           _M_invoker = __x._M_invoker;
2074           _M_manager = __x._M_manager;
2075           __x._M_manager(_M_functor, __x._M_functor, __clone_functor);
2076         }
2077     }
2078
2079   template<typename _Res, typename... _ArgTypes>
2080     template<typename _Functor>
2081       function<_Res(_ArgTypes...)>::
2082       function(_Functor __f,
2083                typename enable_if<
2084                         !is_integral<_Functor>::value, _Useless>::type)
2085       : _Function_base()
2086       {
2087         typedef _Function_handler<_Signature_type, _Functor> _My_handler;
2088
2089         if (_My_handler::_M_not_empty_function(__f))
2090           {
2091             _M_invoker = &_My_handler::_M_invoke;
2092             _M_manager = &_My_handler::_M_manager;
2093             _My_handler::_M_init_functor(_M_functor, std::move(__f));
2094           }
2095       }
2096
2097   template<typename _Res, typename... _ArgTypes>
2098     _Res
2099     function<_Res(_ArgTypes...)>::
2100     operator()(_ArgTypes... __args) const
2101     {
2102       if (_M_empty())
2103         __throw_bad_function_call();
2104       return _M_invoker(_M_functor, std::forward<_ArgTypes>(__args)...);
2105     }
2106
2107 #ifdef __GXX_RTTI
2108   template<typename _Res, typename... _ArgTypes>
2109     const type_info&
2110     function<_Res(_ArgTypes...)>::
2111     target_type() const
2112     {
2113       if (_M_manager)
2114         {
2115           _Any_data __typeinfo_result;
2116           _M_manager(__typeinfo_result, _M_functor, __get_type_info);
2117           return *__typeinfo_result._M_access<const type_info*>();
2118         }
2119       else
2120         return typeid(void);
2121     }
2122
2123   template<typename _Res, typename... _ArgTypes>
2124     template<typename _Functor>
2125       _Functor*
2126       function<_Res(_ArgTypes...)>::
2127       target()
2128       {
2129         if (typeid(_Functor) == target_type() && _M_manager)
2130           {
2131             _Any_data __ptr;
2132             if (_M_manager(__ptr, _M_functor, __get_functor_ptr)
2133                 && !is_const<_Functor>::value)
2134               return 0;
2135             else
2136               return __ptr._M_access<_Functor*>();
2137           }
2138         else
2139           return 0;
2140       }
2141
2142   template<typename _Res, typename... _ArgTypes>
2143     template<typename _Functor>
2144       const _Functor*
2145       function<_Res(_ArgTypes...)>::
2146       target() const
2147       {
2148         if (typeid(_Functor) == target_type() && _M_manager)
2149           {
2150             _Any_data __ptr;
2151             _M_manager(__ptr, _M_functor, __get_functor_ptr);
2152             return __ptr._M_access<const _Functor*>();
2153           }
2154         else
2155           return 0;
2156       }
2157 #endif
2158
2159   // [20.7.15.2.6] null pointer comparisons
2160
2161   /**
2162    *  @brief Compares a polymorphic function object wrapper against 0
2163    *  (the NULL pointer).
2164    *  @returns @c true if the wrapper has no target, @c false otherwise
2165    *
2166    *  This function will not throw an %exception.
2167    */
2168   template<typename _Res, typename... _Args>
2169     inline bool
2170     operator==(const function<_Res(_Args...)>& __f, nullptr_t)
2171     { return !static_cast<bool>(__f); }
2172
2173   /// @overload
2174   template<typename _Res, typename... _Args>
2175     inline bool
2176     operator==(nullptr_t, const function<_Res(_Args...)>& __f)
2177     { return !static_cast<bool>(__f); }
2178
2179   /**
2180    *  @brief Compares a polymorphic function object wrapper against 0
2181    *  (the NULL pointer).
2182    *  @returns @c false if the wrapper has no target, @c true otherwise
2183    *
2184    *  This function will not throw an %exception.
2185    */
2186   template<typename _Res, typename... _Args>
2187     inline bool
2188     operator!=(const function<_Res(_Args...)>& __f, nullptr_t)
2189     { return static_cast<bool>(__f); }
2190
2191   /// @overload
2192   template<typename _Res, typename... _Args>
2193     inline bool
2194     operator!=(nullptr_t, const function<_Res(_Args...)>& __f)
2195     { return static_cast<bool>(__f); }
2196
2197   // [20.7.15.2.7] specialized algorithms
2198
2199   /**
2200    *  @brief Swap the targets of two polymorphic function object wrappers.
2201    *
2202    *  This function will not throw an %exception.
2203    */
2204   template<typename _Res, typename... _Args>
2205     inline void
2206     swap(function<_Res(_Args...)>& __x, function<_Res(_Args...)>& __y)
2207     { __x.swap(__y); }
2208 }
2209
2210 #endif // __GXX_EXPERIMENTAL_CXX0X__
2211
2212 #endif // _GLIBCXX_FUNCTIONAL