libstdc++
functional
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1 // <functional> -*- C++ -*-
2 
3 // Copyright (C) 2001-2019 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10 
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24 
25 /*
26  * Copyright (c) 1997
27  * Silicon Graphics Computer Systems, Inc.
28  *
29  * Permission to use, copy, modify, distribute and sell this software
30  * and its documentation for any purpose is hereby granted without fee,
31  * provided that the above copyright notice appear in all copies and
32  * that both that copyright notice and this permission notice appear
33  * in supporting documentation. Silicon Graphics makes no
34  * representations about the suitability of this software for any
35  * purpose. It is provided "as is" without express or implied warranty.
36  *
37  */
38 
39 /** @file include/functional
40  * This is a Standard C++ Library header.
41  */
42 
43 #ifndef _GLIBCXX_FUNCTIONAL
44 #define _GLIBCXX_FUNCTIONAL 1
45 
46 #pragma GCC system_header
47 
48 #include <bits/c++config.h>
49 #include <bits/stl_function.h>
50 
51 #if __cplusplus >= 201103L
52 
53 #include <new>
54 #include <tuple>
55 #include <type_traits>
56 #include <bits/functional_hash.h>
57 #include <bits/invoke.h>
58 #include <bits/refwrap.h> // std::reference_wrapper and _Mem_fn_traits
59 #include <bits/std_function.h> // std::function
60 #if __cplusplus > 201402L
61 # include <unordered_map>
62 # include <vector>
63 # include <array>
64 # include <utility>
65 # include <bits/stl_algo.h>
66 #endif
67 
68 namespace std _GLIBCXX_VISIBILITY(default)
69 {
70 _GLIBCXX_BEGIN_NAMESPACE_VERSION
71 
72 #if __cplusplus > 201402L
73 # define __cpp_lib_invoke 201411
74 
75  /// Invoke a callable object.
76  template<typename _Callable, typename... _Args>
77  inline invoke_result_t<_Callable, _Args...>
78  invoke(_Callable&& __fn, _Args&&... __args)
79  noexcept(is_nothrow_invocable_v<_Callable, _Args...>)
80  {
81  return std::__invoke(std::forward<_Callable>(__fn),
82  std::forward<_Args>(__args)...);
83  }
84 #endif
85 
86  template<typename _MemFunPtr,
87  bool __is_mem_fn = is_member_function_pointer<_MemFunPtr>::value>
88  class _Mem_fn_base
89  : public _Mem_fn_traits<_MemFunPtr>::__maybe_type
90  {
91  using _Traits = _Mem_fn_traits<_MemFunPtr>;
92 
93  using _Arity = typename _Traits::__arity;
94  using _Varargs = typename _Traits::__vararg;
95 
96  template<typename _Func, typename... _BoundArgs>
97  friend struct _Bind_check_arity;
98 
99  _MemFunPtr _M_pmf;
100 
101  public:
102 
103  using result_type = typename _Traits::__result_type;
104 
105  explicit constexpr
106  _Mem_fn_base(_MemFunPtr __pmf) noexcept : _M_pmf(__pmf) { }
107 
108  template<typename... _Args>
109  auto
110  operator()(_Args&&... __args) const
111  noexcept(noexcept(
112  std::__invoke(_M_pmf, std::forward<_Args>(__args)...)))
113  -> decltype(std::__invoke(_M_pmf, std::forward<_Args>(__args)...))
114  { return std::__invoke(_M_pmf, std::forward<_Args>(__args)...); }
115  };
116 
117  // Partial specialization for member object pointers.
118  template<typename _MemObjPtr>
119  class _Mem_fn_base<_MemObjPtr, false>
120  {
121  using _Arity = integral_constant<size_t, 0>;
122  using _Varargs = false_type;
123 
124  template<typename _Func, typename... _BoundArgs>
125  friend struct _Bind_check_arity;
126 
127  _MemObjPtr _M_pm;
128 
129  public:
130  explicit constexpr
131  _Mem_fn_base(_MemObjPtr __pm) noexcept : _M_pm(__pm) { }
132 
133  template<typename _Tp>
134  auto
135  operator()(_Tp&& __obj) const
136  noexcept(noexcept(std::__invoke(_M_pm, std::forward<_Tp>(__obj))))
137  -> decltype(std::__invoke(_M_pm, std::forward<_Tp>(__obj)))
138  { return std::__invoke(_M_pm, std::forward<_Tp>(__obj)); }
139  };
140 
141  template<typename _MemberPointer>
142  struct _Mem_fn; // undefined
143 
144  template<typename _Res, typename _Class>
145  struct _Mem_fn<_Res _Class::*>
146  : _Mem_fn_base<_Res _Class::*>
147  {
148  using _Mem_fn_base<_Res _Class::*>::_Mem_fn_base;
149  };
150 
151  // _GLIBCXX_RESOLVE_LIB_DEFECTS
152  // 2048. Unnecessary mem_fn overloads
153  /**
154  * @brief Returns a function object that forwards to the member
155  * pointer @a pm.
156  * @ingroup functors
157  */
158  template<typename _Tp, typename _Class>
159  inline _Mem_fn<_Tp _Class::*>
160  mem_fn(_Tp _Class::* __pm) noexcept
161  {
162  return _Mem_fn<_Tp _Class::*>(__pm);
163  }
164 
165  /**
166  * @brief Determines if the given type _Tp is a function object that
167  * should be treated as a subexpression when evaluating calls to
168  * function objects returned by bind().
169  *
170  * C++11 [func.bind.isbind].
171  * @ingroup binders
172  */
173  template<typename _Tp>
174  struct is_bind_expression
175  : public false_type { };
176 
177  /**
178  * @brief Determines if the given type _Tp is a placeholder in a
179  * bind() expression and, if so, which placeholder it is.
180  *
181  * C++11 [func.bind.isplace].
182  * @ingroup binders
183  */
184  template<typename _Tp>
185  struct is_placeholder
186  : public integral_constant<int, 0>
187  { };
188 
189 #if __cplusplus > 201402L
190  template <typename _Tp> inline constexpr bool is_bind_expression_v
191  = is_bind_expression<_Tp>::value;
192  template <typename _Tp> inline constexpr int is_placeholder_v
193  = is_placeholder<_Tp>::value;
194 #endif // C++17
195 
196  /** @brief The type of placeholder objects defined by libstdc++.
197  * @ingroup binders
198  */
199  template<int _Num> struct _Placeholder { };
200 
201  /** @namespace std::placeholders
202  * @brief ISO C++11 entities sub-namespace for functional.
203  * @ingroup binders
204  */
205  namespace placeholders
206  {
207  /* Define a large number of placeholders. There is no way to
208  * simplify this with variadic templates, because we're introducing
209  * unique names for each.
210  */
211  extern const _Placeholder<1> _1;
212  extern const _Placeholder<2> _2;
213  extern const _Placeholder<3> _3;
214  extern const _Placeholder<4> _4;
215  extern const _Placeholder<5> _5;
216  extern const _Placeholder<6> _6;
217  extern const _Placeholder<7> _7;
218  extern const _Placeholder<8> _8;
219  extern const _Placeholder<9> _9;
220  extern const _Placeholder<10> _10;
221  extern const _Placeholder<11> _11;
222  extern const _Placeholder<12> _12;
223  extern const _Placeholder<13> _13;
224  extern const _Placeholder<14> _14;
225  extern const _Placeholder<15> _15;
226  extern const _Placeholder<16> _16;
227  extern const _Placeholder<17> _17;
228  extern const _Placeholder<18> _18;
229  extern const _Placeholder<19> _19;
230  extern const _Placeholder<20> _20;
231  extern const _Placeholder<21> _21;
232  extern const _Placeholder<22> _22;
233  extern const _Placeholder<23> _23;
234  extern const _Placeholder<24> _24;
235  extern const _Placeholder<25> _25;
236  extern const _Placeholder<26> _26;
237  extern const _Placeholder<27> _27;
238  extern const _Placeholder<28> _28;
239  extern const _Placeholder<29> _29;
240  }
241 
242  /**
243  * Partial specialization of is_placeholder that provides the placeholder
244  * number for the placeholder objects defined by libstdc++.
245  * @ingroup binders
246  */
247  template<int _Num>
248  struct is_placeholder<_Placeholder<_Num> >
249  : public integral_constant<int, _Num>
250  { };
251 
252  template<int _Num>
253  struct is_placeholder<const _Placeholder<_Num> >
254  : public integral_constant<int, _Num>
255  { };
256 
257 
258  // Like tuple_element_t but SFINAE-friendly.
259  template<std::size_t __i, typename _Tuple>
260  using _Safe_tuple_element_t
261  = typename enable_if<(__i < tuple_size<_Tuple>::value),
262  tuple_element<__i, _Tuple>>::type::type;
263 
264  /**
265  * Maps an argument to bind() into an actual argument to the bound
266  * function object [func.bind.bind]/10. Only the first parameter should
267  * be specified: the rest are used to determine among the various
268  * implementations. Note that, although this class is a function
269  * object, it isn't entirely normal because it takes only two
270  * parameters regardless of the number of parameters passed to the
271  * bind expression. The first parameter is the bound argument and
272  * the second parameter is a tuple containing references to the
273  * rest of the arguments.
274  */
275  template<typename _Arg,
276  bool _IsBindExp = is_bind_expression<_Arg>::value,
277  bool _IsPlaceholder = (is_placeholder<_Arg>::value > 0)>
278  class _Mu;
279 
280  /**
281  * If the argument is reference_wrapper<_Tp>, returns the
282  * underlying reference.
283  * C++11 [func.bind.bind] p10 bullet 1.
284  */
285  template<typename _Tp>
286  class _Mu<reference_wrapper<_Tp>, false, false>
287  {
288  public:
289  /* Note: This won't actually work for const volatile
290  * reference_wrappers, because reference_wrapper::get() is const
291  * but not volatile-qualified. This might be a defect in the TR.
292  */
293  template<typename _CVRef, typename _Tuple>
294  _Tp&
295  operator()(_CVRef& __arg, _Tuple&) const volatile
296  { return __arg.get(); }
297  };
298 
299  /**
300  * If the argument is a bind expression, we invoke the underlying
301  * function object with the same cv-qualifiers as we are given and
302  * pass along all of our arguments (unwrapped).
303  * C++11 [func.bind.bind] p10 bullet 2.
304  */
305  template<typename _Arg>
306  class _Mu<_Arg, true, false>
307  {
308  public:
309  template<typename _CVArg, typename... _Args>
310  auto
311  operator()(_CVArg& __arg,
312  tuple<_Args...>& __tuple) const volatile
313  -> decltype(__arg(declval<_Args>()...))
314  {
315  // Construct an index tuple and forward to __call
316  typedef typename _Build_index_tuple<sizeof...(_Args)>::__type
317  _Indexes;
318  return this->__call(__arg, __tuple, _Indexes());
319  }
320 
321  private:
322  // Invokes the underlying function object __arg by unpacking all
323  // of the arguments in the tuple.
324  template<typename _CVArg, typename... _Args, std::size_t... _Indexes>
325  auto
326  __call(_CVArg& __arg, tuple<_Args...>& __tuple,
327  const _Index_tuple<_Indexes...>&) const volatile
328  -> decltype(__arg(declval<_Args>()...))
329  {
330  return __arg(std::get<_Indexes>(std::move(__tuple))...);
331  }
332  };
333 
334  /**
335  * If the argument is a placeholder for the Nth argument, returns
336  * a reference to the Nth argument to the bind function object.
337  * C++11 [func.bind.bind] p10 bullet 3.
338  */
339  template<typename _Arg>
340  class _Mu<_Arg, false, true>
341  {
342  public:
343  template<typename _Tuple>
344  _Safe_tuple_element_t<(is_placeholder<_Arg>::value - 1), _Tuple>&&
345  operator()(const volatile _Arg&, _Tuple& __tuple) const volatile
346  {
347  return
348  ::std::get<(is_placeholder<_Arg>::value - 1)>(std::move(__tuple));
349  }
350  };
351 
352  /**
353  * If the argument is just a value, returns a reference to that
354  * value. The cv-qualifiers on the reference are determined by the caller.
355  * C++11 [func.bind.bind] p10 bullet 4.
356  */
357  template<typename _Arg>
358  class _Mu<_Arg, false, false>
359  {
360  public:
361  template<typename _CVArg, typename _Tuple>
362  _CVArg&&
363  operator()(_CVArg&& __arg, _Tuple&) const volatile
364  { return std::forward<_CVArg>(__arg); }
365  };
366 
367  // std::get<I> for volatile-qualified tuples
368  template<std::size_t _Ind, typename... _Tp>
369  inline auto
370  __volget(volatile tuple<_Tp...>& __tuple)
371  -> __tuple_element_t<_Ind, tuple<_Tp...>> volatile&
372  { return std::get<_Ind>(const_cast<tuple<_Tp...>&>(__tuple)); }
373 
374  // std::get<I> for const-volatile-qualified tuples
375  template<std::size_t _Ind, typename... _Tp>
376  inline auto
377  __volget(const volatile tuple<_Tp...>& __tuple)
378  -> __tuple_element_t<_Ind, tuple<_Tp...>> const volatile&
379  { return std::get<_Ind>(const_cast<const tuple<_Tp...>&>(__tuple)); }
380 
381  /// Type of the function object returned from bind().
382  template<typename _Signature>
383  struct _Bind;
384 
385  template<typename _Functor, typename... _Bound_args>
386  class _Bind<_Functor(_Bound_args...)>
387  : public _Weak_result_type<_Functor>
388  {
389  typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
390  _Bound_indexes;
391 
392  _Functor _M_f;
393  tuple<_Bound_args...> _M_bound_args;
394 
395  // Call unqualified
396  template<typename _Result, typename... _Args, std::size_t... _Indexes>
397  _Result
398  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
399  {
400  return std::__invoke(_M_f,
401  _Mu<_Bound_args>()(std::get<_Indexes>(_M_bound_args), __args)...
402  );
403  }
404 
405  // Call as const
406  template<typename _Result, typename... _Args, std::size_t... _Indexes>
407  _Result
408  __call_c(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
409  {
410  return std::__invoke(_M_f,
411  _Mu<_Bound_args>()(std::get<_Indexes>(_M_bound_args), __args)...
412  );
413  }
414 
415  // Call as volatile
416  template<typename _Result, typename... _Args, std::size_t... _Indexes>
417  _Result
418  __call_v(tuple<_Args...>&& __args,
419  _Index_tuple<_Indexes...>) volatile
420  {
421  return std::__invoke(_M_f,
422  _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
423  );
424  }
425 
426  // Call as const volatile
427  template<typename _Result, typename... _Args, std::size_t... _Indexes>
428  _Result
429  __call_c_v(tuple<_Args...>&& __args,
430  _Index_tuple<_Indexes...>) const volatile
431  {
432  return std::__invoke(_M_f,
433  _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
434  );
435  }
436 
437  template<typename _BoundArg, typename _CallArgs>
438  using _Mu_type = decltype(
439  _Mu<typename remove_cv<_BoundArg>::type>()(
440  std::declval<_BoundArg&>(), std::declval<_CallArgs&>()) );
441 
442  template<typename _Fn, typename _CallArgs, typename... _BArgs>
443  using _Res_type_impl
444  = typename result_of< _Fn&(_Mu_type<_BArgs, _CallArgs>&&...) >::type;
445 
446  template<typename _CallArgs>
447  using _Res_type = _Res_type_impl<_Functor, _CallArgs, _Bound_args...>;
448 
449  template<typename _CallArgs>
450  using __dependent = typename
451  enable_if<bool(tuple_size<_CallArgs>::value+1), _Functor>::type;
452 
453  template<typename _CallArgs, template<class> class __cv_quals>
454  using _Res_type_cv = _Res_type_impl<
455  typename __cv_quals<__dependent<_CallArgs>>::type,
456  _CallArgs,
457  typename __cv_quals<_Bound_args>::type...>;
458 
459  public:
460  template<typename... _Args>
461  explicit _Bind(const _Functor& __f, _Args&&... __args)
462  : _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
463  { }
464 
465  template<typename... _Args>
466  explicit _Bind(_Functor&& __f, _Args&&... __args)
467  : _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
468  { }
469 
470  _Bind(const _Bind&) = default;
471 
472  _Bind(_Bind&& __b)
473  : _M_f(std::move(__b._M_f)), _M_bound_args(std::move(__b._M_bound_args))
474  { }
475 
476  // Call unqualified
477  template<typename... _Args,
478  typename _Result = _Res_type<tuple<_Args...>>>
479  _Result
480  operator()(_Args&&... __args)
481  {
482  return this->__call<_Result>(
483  std::forward_as_tuple(std::forward<_Args>(__args)...),
484  _Bound_indexes());
485  }
486 
487  // Call as const
488  template<typename... _Args,
489  typename _Result = _Res_type_cv<tuple<_Args...>, add_const>>
490  _Result
491  operator()(_Args&&... __args) const
492  {
493  return this->__call_c<_Result>(
494  std::forward_as_tuple(std::forward<_Args>(__args)...),
495  _Bound_indexes());
496  }
497 
498 #if __cplusplus > 201402L
499 # define _GLIBCXX_DEPR_BIND \
500  [[deprecated("std::bind does not support volatile in C++17")]]
501 #else
502 # define _GLIBCXX_DEPR_BIND
503 #endif
504  // Call as volatile
505  template<typename... _Args,
506  typename _Result = _Res_type_cv<tuple<_Args...>, add_volatile>>
507  _GLIBCXX_DEPR_BIND
508  _Result
509  operator()(_Args&&... __args) volatile
510  {
511  return this->__call_v<_Result>(
512  std::forward_as_tuple(std::forward<_Args>(__args)...),
513  _Bound_indexes());
514  }
515 
516  // Call as const volatile
517  template<typename... _Args,
518  typename _Result = _Res_type_cv<tuple<_Args...>, add_cv>>
519  _GLIBCXX_DEPR_BIND
520  _Result
521  operator()(_Args&&... __args) const volatile
522  {
523  return this->__call_c_v<_Result>(
524  std::forward_as_tuple(std::forward<_Args>(__args)...),
525  _Bound_indexes());
526  }
527  };
528 
529  /// Type of the function object returned from bind<R>().
530  template<typename _Result, typename _Signature>
531  struct _Bind_result;
532 
533  template<typename _Result, typename _Functor, typename... _Bound_args>
534  class _Bind_result<_Result, _Functor(_Bound_args...)>
535  {
536  typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
537  _Bound_indexes;
538 
539  _Functor _M_f;
540  tuple<_Bound_args...> _M_bound_args;
541 
542  // sfinae types
543  template<typename _Res>
544  using __enable_if_void
545  = typename enable_if<is_void<_Res>{}>::type;
546 
547  template<typename _Res>
548  using __disable_if_void
549  = typename enable_if<!is_void<_Res>{}, _Result>::type;
550 
551  // Call unqualified
552  template<typename _Res, typename... _Args, std::size_t... _Indexes>
553  __disable_if_void<_Res>
554  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
555  {
556  return std::__invoke(_M_f, _Mu<_Bound_args>()
557  (std::get<_Indexes>(_M_bound_args), __args)...);
558  }
559 
560  // Call unqualified, return void
561  template<typename _Res, typename... _Args, std::size_t... _Indexes>
562  __enable_if_void<_Res>
563  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
564  {
565  std::__invoke(_M_f, _Mu<_Bound_args>()
566  (std::get<_Indexes>(_M_bound_args), __args)...);
567  }
568 
569  // Call as const
570  template<typename _Res, typename... _Args, std::size_t... _Indexes>
571  __disable_if_void<_Res>
572  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
573  {
574  return std::__invoke(_M_f, _Mu<_Bound_args>()
575  (std::get<_Indexes>(_M_bound_args), __args)...);
576  }
577 
578  // Call as const, return void
579  template<typename _Res, typename... _Args, std::size_t... _Indexes>
580  __enable_if_void<_Res>
581  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
582  {
583  std::__invoke(_M_f, _Mu<_Bound_args>()
584  (std::get<_Indexes>(_M_bound_args), __args)...);
585  }
586 
587  // Call as volatile
588  template<typename _Res, typename... _Args, std::size_t... _Indexes>
589  __disable_if_void<_Res>
590  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
591  {
592  return std::__invoke(_M_f, _Mu<_Bound_args>()
593  (__volget<_Indexes>(_M_bound_args), __args)...);
594  }
595 
596  // Call as volatile, return void
597  template<typename _Res, typename... _Args, std::size_t... _Indexes>
598  __enable_if_void<_Res>
599  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
600  {
601  std::__invoke(_M_f, _Mu<_Bound_args>()
602  (__volget<_Indexes>(_M_bound_args), __args)...);
603  }
604 
605  // Call as const volatile
606  template<typename _Res, typename... _Args, std::size_t... _Indexes>
607  __disable_if_void<_Res>
608  __call(tuple<_Args...>&& __args,
609  _Index_tuple<_Indexes...>) const volatile
610  {
611  return std::__invoke(_M_f, _Mu<_Bound_args>()
612  (__volget<_Indexes>(_M_bound_args), __args)...);
613  }
614 
615  // Call as const volatile, return void
616  template<typename _Res, typename... _Args, std::size_t... _Indexes>
617  __enable_if_void<_Res>
618  __call(tuple<_Args...>&& __args,
619  _Index_tuple<_Indexes...>) const volatile
620  {
621  std::__invoke(_M_f, _Mu<_Bound_args>()
622  (__volget<_Indexes>(_M_bound_args), __args)...);
623  }
624 
625  public:
626  typedef _Result result_type;
627 
628  template<typename... _Args>
629  explicit _Bind_result(const _Functor& __f, _Args&&... __args)
630  : _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
631  { }
632 
633  template<typename... _Args>
634  explicit _Bind_result(_Functor&& __f, _Args&&... __args)
635  : _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
636  { }
637 
638  _Bind_result(const _Bind_result&) = default;
639 
640  _Bind_result(_Bind_result&& __b)
641  : _M_f(std::move(__b._M_f)), _M_bound_args(std::move(__b._M_bound_args))
642  { }
643 
644  // Call unqualified
645  template<typename... _Args>
646  result_type
647  operator()(_Args&&... __args)
648  {
649  return this->__call<_Result>(
650  std::forward_as_tuple(std::forward<_Args>(__args)...),
651  _Bound_indexes());
652  }
653 
654  // Call as const
655  template<typename... _Args>
656  result_type
657  operator()(_Args&&... __args) const
658  {
659  return this->__call<_Result>(
660  std::forward_as_tuple(std::forward<_Args>(__args)...),
661  _Bound_indexes());
662  }
663 
664  // Call as volatile
665  template<typename... _Args>
666  _GLIBCXX_DEPR_BIND
667  result_type
668  operator()(_Args&&... __args) volatile
669  {
670  return this->__call<_Result>(
671  std::forward_as_tuple(std::forward<_Args>(__args)...),
672  _Bound_indexes());
673  }
674 
675  // Call as const volatile
676  template<typename... _Args>
677  _GLIBCXX_DEPR_BIND
678  result_type
679  operator()(_Args&&... __args) const volatile
680  {
681  return this->__call<_Result>(
682  std::forward_as_tuple(std::forward<_Args>(__args)...),
683  _Bound_indexes());
684  }
685  };
686 #undef _GLIBCXX_DEPR_BIND
687 
688  /**
689  * @brief Class template _Bind is always a bind expression.
690  * @ingroup binders
691  */
692  template<typename _Signature>
693  struct is_bind_expression<_Bind<_Signature> >
694  : public true_type { };
695 
696  /**
697  * @brief Class template _Bind is always a bind expression.
698  * @ingroup binders
699  */
700  template<typename _Signature>
701  struct is_bind_expression<const _Bind<_Signature> >
702  : public true_type { };
703 
704  /**
705  * @brief Class template _Bind is always a bind expression.
706  * @ingroup binders
707  */
708  template<typename _Signature>
709  struct is_bind_expression<volatile _Bind<_Signature> >
710  : public true_type { };
711 
712  /**
713  * @brief Class template _Bind is always a bind expression.
714  * @ingroup binders
715  */
716  template<typename _Signature>
717  struct is_bind_expression<const volatile _Bind<_Signature>>
718  : public true_type { };
719 
720  /**
721  * @brief Class template _Bind_result is always a bind expression.
722  * @ingroup binders
723  */
724  template<typename _Result, typename _Signature>
725  struct is_bind_expression<_Bind_result<_Result, _Signature>>
726  : public true_type { };
727 
728  /**
729  * @brief Class template _Bind_result is always a bind expression.
730  * @ingroup binders
731  */
732  template<typename _Result, typename _Signature>
733  struct is_bind_expression<const _Bind_result<_Result, _Signature>>
734  : public true_type { };
735 
736  /**
737  * @brief Class template _Bind_result is always a bind expression.
738  * @ingroup binders
739  */
740  template<typename _Result, typename _Signature>
741  struct is_bind_expression<volatile _Bind_result<_Result, _Signature>>
742  : public true_type { };
743 
744  /**
745  * @brief Class template _Bind_result is always a bind expression.
746  * @ingroup binders
747  */
748  template<typename _Result, typename _Signature>
749  struct is_bind_expression<const volatile _Bind_result<_Result, _Signature>>
750  : public true_type { };
751 
752  template<typename _Func, typename... _BoundArgs>
753  struct _Bind_check_arity { };
754 
755  template<typename _Ret, typename... _Args, typename... _BoundArgs>
756  struct _Bind_check_arity<_Ret (*)(_Args...), _BoundArgs...>
757  {
758  static_assert(sizeof...(_BoundArgs) == sizeof...(_Args),
759  "Wrong number of arguments for function");
760  };
761 
762  template<typename _Ret, typename... _Args, typename... _BoundArgs>
763  struct _Bind_check_arity<_Ret (*)(_Args......), _BoundArgs...>
764  {
765  static_assert(sizeof...(_BoundArgs) >= sizeof...(_Args),
766  "Wrong number of arguments for function");
767  };
768 
769  template<typename _Tp, typename _Class, typename... _BoundArgs>
770  struct _Bind_check_arity<_Tp _Class::*, _BoundArgs...>
771  {
772  using _Arity = typename _Mem_fn<_Tp _Class::*>::_Arity;
773  using _Varargs = typename _Mem_fn<_Tp _Class::*>::_Varargs;
774  static_assert(_Varargs::value
775  ? sizeof...(_BoundArgs) >= _Arity::value + 1
776  : sizeof...(_BoundArgs) == _Arity::value + 1,
777  "Wrong number of arguments for pointer-to-member");
778  };
779 
780  // Trait type used to remove std::bind() from overload set via SFINAE
781  // when first argument has integer type, so that std::bind() will
782  // not be a better match than ::bind() from the BSD Sockets API.
783  template<typename _Tp, typename _Tp2 = typename decay<_Tp>::type>
784  using __is_socketlike = __or_<is_integral<_Tp2>, is_enum<_Tp2>>;
785 
786  template<bool _SocketLike, typename _Func, typename... _BoundArgs>
787  struct _Bind_helper
788  : _Bind_check_arity<typename decay<_Func>::type, _BoundArgs...>
789  {
790  typedef typename decay<_Func>::type __func_type;
791  typedef _Bind<__func_type(typename decay<_BoundArgs>::type...)> type;
792  };
793 
794  // Partial specialization for is_socketlike == true, does not define
795  // nested type so std::bind() will not participate in overload resolution
796  // when the first argument might be a socket file descriptor.
797  template<typename _Func, typename... _BoundArgs>
798  struct _Bind_helper<true, _Func, _BoundArgs...>
799  { };
800 
801  /**
802  * @brief Function template for std::bind.
803  * @ingroup binders
804  */
805  template<typename _Func, typename... _BoundArgs>
806  inline typename
807  _Bind_helper<__is_socketlike<_Func>::value, _Func, _BoundArgs...>::type
808  bind(_Func&& __f, _BoundArgs&&... __args)
809  {
810  typedef _Bind_helper<false, _Func, _BoundArgs...> __helper_type;
811  return typename __helper_type::type(std::forward<_Func>(__f),
812  std::forward<_BoundArgs>(__args)...);
813  }
814 
815  template<typename _Result, typename _Func, typename... _BoundArgs>
816  struct _Bindres_helper
817  : _Bind_check_arity<typename decay<_Func>::type, _BoundArgs...>
818  {
819  typedef typename decay<_Func>::type __functor_type;
820  typedef _Bind_result<_Result,
821  __functor_type(typename decay<_BoundArgs>::type...)>
822  type;
823  };
824 
825  /**
826  * @brief Function template for std::bind<R>.
827  * @ingroup binders
828  */
829  template<typename _Result, typename _Func, typename... _BoundArgs>
830  inline
831  typename _Bindres_helper<_Result, _Func, _BoundArgs...>::type
832  bind(_Func&& __f, _BoundArgs&&... __args)
833  {
834  typedef _Bindres_helper<_Result, _Func, _BoundArgs...> __helper_type;
835  return typename __helper_type::type(std::forward<_Func>(__f),
836  std::forward<_BoundArgs>(__args)...);
837  }
838 
839 #if __cplusplus > 201703L
840 #define __cpp_lib_bind_front 201907L
841 
842  template<typename _Fd, typename... _BoundArgs>
843  struct _Bind_front
844  {
845  static_assert(is_move_constructible_v<_Fd>);
846  static_assert((is_move_constructible_v<_BoundArgs> && ...));
847 
848  // First parameter is to ensure this constructor is never used
849  // instead of the copy/move constructor.
850  template<typename _Fn, typename... _Args>
851  explicit constexpr
852  _Bind_front(int, _Fn&& __fn, _Args&&... __args)
853  noexcept(__and_<is_nothrow_constructible<_Fd, _Fn>,
854  is_nothrow_constructible<_BoundArgs, _Args>...>::value)
855  : _M_fd(std::forward<_Fn>(__fn)),
856  _M_bound_args(std::forward<_Args>(__args)...)
857  { static_assert(sizeof...(_Args) == sizeof...(_BoundArgs)); }
858 
859  _Bind_front(const _Bind_front&) = default;
860  _Bind_front(_Bind_front&&) = default;
861  _Bind_front& operator=(const _Bind_front&) = default;
862  _Bind_front& operator=(_Bind_front&&) = default;
863  ~_Bind_front() = default;
864 
865  template<typename... _CallArgs>
866  constexpr
867  invoke_result_t<_Fd&, _BoundArgs&..., _CallArgs...>
868  operator()(_CallArgs&&... __call_args) &
869  noexcept(is_nothrow_invocable_v<_Fd&, _BoundArgs&..., _CallArgs...>)
870  {
871  return _S_call(*this, _BoundIndices(),
872  std::forward<_CallArgs>(__call_args)...);
873  }
874 
875  template<typename... _CallArgs>
876  constexpr
877  invoke_result_t<const _Fd&, const _BoundArgs&..., _CallArgs...>
878  operator()(_CallArgs&&... __call_args) const &
879  noexcept(is_nothrow_invocable_v<const _Fd&, const _BoundArgs&...,
880  _CallArgs...>)
881  {
882  return _S_call(*this, _BoundIndices(),
883  std::forward<_CallArgs>(__call_args)...);
884  }
885 
886  template<typename... _CallArgs>
887  constexpr
888  invoke_result_t<_Fd, _BoundArgs..., _CallArgs...>
889  operator()(_CallArgs&&... __call_args) &&
890  noexcept(is_nothrow_invocable_v<_Fd, _BoundArgs..., _CallArgs...>)
891  {
892  return _S_call(std::move(*this), _BoundIndices(),
893  std::forward<_CallArgs>(__call_args)...);
894  }
895 
896  template<typename... _CallArgs>
897  constexpr
898  invoke_result_t<const _Fd, const _BoundArgs..., _CallArgs...>
899  operator()(_CallArgs&&... __call_args) const &&
900  noexcept(is_nothrow_invocable_v<const _Fd, const _BoundArgs...,
901  _CallArgs...>)
902  {
903  return _S_call(std::move(*this), _BoundIndices(),
904  std::forward<_CallArgs>(__call_args)...);
905  }
906 
907  private:
908  using _BoundIndices = index_sequence_for<_BoundArgs...>;
909 
910  template<typename _Tp, size_t... _Ind, typename... _CallArgs>
911  static constexpr
912  decltype(auto)
913  _S_call(_Tp&& __g, index_sequence<_Ind...>, _CallArgs&&... __call_args)
914  {
915  return std::invoke(std::forward<_Tp>(__g)._M_fd,
916  std::get<_Ind>(std::forward<_Tp>(__g)._M_bound_args)...,
917  std::forward<_CallArgs>(__call_args)...);
918  }
919 
920  _Fd _M_fd;
921  std::tuple<_BoundArgs...> _M_bound_args;
922  };
923 
924  template<typename _Fn, typename... _Args>
925  using _Bind_front_t
926  = _Bind_front<decay_t<_Fn>, decay_t<_Args>...>;
927 
928  template<typename _Fn, typename... _Args>
929  _Bind_front_t<_Fn, _Args...>
930  bind_front(_Fn&& __fn, _Args&&... __args)
931  noexcept(is_nothrow_constructible_v<int, _Bind_front_t<_Fn, _Args...>,
932  _Fn, _Args...>)
933  {
934  return _Bind_front_t<_Fn, _Args...>(0, std::forward<_Fn>(__fn),
935  std::forward<_Args>(__args)...);
936  }
937 #endif
938 
939 #if __cplusplus >= 201402L
940  /// Generalized negator.
941  template<typename _Fn>
942  class _Not_fn
943  {
944  template<typename _Fn2, typename... _Args>
945  using __inv_res_t = typename __invoke_result<_Fn2, _Args...>::type;
946 
947  template<typename _Tp>
948  static decltype(!std::declval<_Tp>())
949  _S_not() noexcept(noexcept(!std::declval<_Tp>()));
950 
951  public:
952  template<typename _Fn2>
953  _Not_fn(_Fn2&& __fn, int)
954  : _M_fn(std::forward<_Fn2>(__fn)) { }
955 
956  _Not_fn(const _Not_fn& __fn) = default;
957  _Not_fn(_Not_fn&& __fn) = default;
958  ~_Not_fn() = default;
959 
960  // Macro to define operator() with given cv-qualifiers ref-qualifiers,
961  // forwarding _M_fn and the function arguments with the same qualifiers,
962  // and deducing the return type and exception-specification.
963 #define _GLIBCXX_NOT_FN_CALL_OP( _QUALS ) \
964  template<typename... _Args> \
965  decltype(_S_not<__inv_res_t<_Fn _QUALS, _Args...>>()) \
966  operator()(_Args&&... __args) _QUALS \
967  noexcept(__is_nothrow_invocable<_Fn _QUALS, _Args...>::value \
968  && noexcept(_S_not<__inv_res_t<_Fn _QUALS, _Args...>>())) \
969  { \
970  return !std::__invoke(std::forward< _Fn _QUALS >(_M_fn), \
971  std::forward<_Args>(__args)...); \
972  }
973  _GLIBCXX_NOT_FN_CALL_OP( & )
974  _GLIBCXX_NOT_FN_CALL_OP( const & )
975  _GLIBCXX_NOT_FN_CALL_OP( && )
976  _GLIBCXX_NOT_FN_CALL_OP( const && )
977 #undef _GLIBCXX_NOT_FN_CALL
978 
979  private:
980  _Fn _M_fn;
981  };
982 
983  template<typename _Tp, typename _Pred>
984  struct __is_byte_like : false_type { };
985 
986  template<typename _Tp>
987  struct __is_byte_like<_Tp, equal_to<_Tp>>
988  : __bool_constant<sizeof(_Tp) == 1 && is_integral<_Tp>::value> { };
989 
990  template<typename _Tp>
991  struct __is_byte_like<_Tp, equal_to<void>>
992  : __bool_constant<sizeof(_Tp) == 1 && is_integral<_Tp>::value> { };
993 
994 #if __cplusplus >= 201703L
995  // Declare std::byte (full definition is in <cstddef>).
996  enum class byte : unsigned char;
997 
998  template<>
999  struct __is_byte_like<byte, equal_to<byte>>
1000  : true_type { };
1001 
1002  template<>
1003  struct __is_byte_like<byte, equal_to<void>>
1004  : true_type { };
1005 
1006 #define __cpp_lib_not_fn 201603
1007  /// [func.not_fn] Function template not_fn
1008  template<typename _Fn>
1009  inline auto
1010  not_fn(_Fn&& __fn)
1011  noexcept(std::is_nothrow_constructible<std::decay_t<_Fn>, _Fn&&>::value)
1012  {
1013  return _Not_fn<std::decay_t<_Fn>>{std::forward<_Fn>(__fn), 0};
1014  }
1015 
1016  // Searchers
1017 #define __cpp_lib_boyer_moore_searcher 201603
1018 
1019  template<typename _ForwardIterator1, typename _BinaryPredicate = equal_to<>>
1020  class default_searcher
1021  {
1022  public:
1023  default_searcher(_ForwardIterator1 __pat_first,
1024  _ForwardIterator1 __pat_last,
1025  _BinaryPredicate __pred = _BinaryPredicate())
1026  : _M_m(__pat_first, __pat_last, std::move(__pred))
1027  { }
1028 
1029  template<typename _ForwardIterator2>
1030  pair<_ForwardIterator2, _ForwardIterator2>
1031  operator()(_ForwardIterator2 __first, _ForwardIterator2 __last) const
1032  {
1033  _ForwardIterator2 __first_ret =
1034  std::search(__first, __last, std::get<0>(_M_m), std::get<1>(_M_m),
1035  std::get<2>(_M_m));
1036  auto __ret = std::make_pair(__first_ret, __first_ret);
1037  if (__ret.first != __last)
1038  std::advance(__ret.second, std::distance(std::get<0>(_M_m),
1039  std::get<1>(_M_m)));
1040  return __ret;
1041  }
1042 
1043  private:
1044  tuple<_ForwardIterator1, _ForwardIterator1, _BinaryPredicate> _M_m;
1045  };
1046 
1047  template<typename _Key, typename _Tp, typename _Hash, typename _Pred>
1048  struct __boyer_moore_map_base
1049  {
1050  template<typename _RAIter>
1051  __boyer_moore_map_base(_RAIter __pat, size_t __patlen,
1052  _Hash&& __hf, _Pred&& __pred)
1053  : _M_bad_char{ __patlen, std::move(__hf), std::move(__pred) }
1054  {
1055  if (__patlen > 0)
1056  for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
1057  _M_bad_char[__pat[__i]] = __patlen - 1 - __i;
1058  }
1059 
1060  using __diff_type = _Tp;
1061 
1062  __diff_type
1063  _M_lookup(_Key __key, __diff_type __not_found) const
1064  {
1065  auto __iter = _M_bad_char.find(__key);
1066  if (__iter == _M_bad_char.end())
1067  return __not_found;
1068  return __iter->second;
1069  }
1070 
1071  _Pred
1072  _M_pred() const { return _M_bad_char.key_eq(); }
1073 
1074  _GLIBCXX_STD_C::unordered_map<_Key, _Tp, _Hash, _Pred> _M_bad_char;
1075  };
1076 
1077  template<typename _Tp, size_t _Len, typename _Pred>
1078  struct __boyer_moore_array_base
1079  {
1080  template<typename _RAIter, typename _Unused>
1081  __boyer_moore_array_base(_RAIter __pat, size_t __patlen,
1082  _Unused&&, _Pred&& __pred)
1083  : _M_bad_char{ _GLIBCXX_STD_C::array<_Tp, _Len>{}, std::move(__pred) }
1084  {
1085  std::get<0>(_M_bad_char).fill(__patlen);
1086  if (__patlen > 0)
1087  for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
1088  {
1089  auto __ch = __pat[__i];
1090  using _UCh = make_unsigned_t<decltype(__ch)>;
1091  auto __uch = static_cast<_UCh>(__ch);
1092  std::get<0>(_M_bad_char)[__uch] = __patlen - 1 - __i;
1093  }
1094  }
1095 
1096  using __diff_type = _Tp;
1097 
1098  template<typename _Key>
1099  __diff_type
1100  _M_lookup(_Key __key, __diff_type __not_found) const
1101  {
1102  auto __ukey = static_cast<make_unsigned_t<_Key>>(__key);
1103  if (__ukey >= _Len)
1104  return __not_found;
1105  return std::get<0>(_M_bad_char)[__ukey];
1106  }
1107 
1108  const _Pred&
1109  _M_pred() const { return std::get<1>(_M_bad_char); }
1110 
1111  tuple<_GLIBCXX_STD_C::array<_Tp, _Len>, _Pred> _M_bad_char;
1112  };
1113 
1114  // Use __boyer_moore_array_base when pattern consists of narrow characters
1115  // (or std::byte) and uses std::equal_to as the predicate.
1116  template<typename _RAIter, typename _Hash, typename _Pred,
1117  typename _Val = typename iterator_traits<_RAIter>::value_type,
1118  typename _Diff = typename iterator_traits<_RAIter>::difference_type>
1119  using __boyer_moore_base_t
1120  = conditional_t<__is_byte_like<_Val, _Pred>::value,
1121  __boyer_moore_array_base<_Diff, 256, _Pred>,
1122  __boyer_moore_map_base<_Val, _Diff, _Hash, _Pred>>;
1123 
1124  template<typename _RAIter, typename _Hash
1125  = hash<typename iterator_traits<_RAIter>::value_type>,
1126  typename _BinaryPredicate = equal_to<>>
1127  class boyer_moore_searcher
1128  : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
1129  {
1130  using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
1131  using typename _Base::__diff_type;
1132 
1133  public:
1134  boyer_moore_searcher(_RAIter __pat_first, _RAIter __pat_last,
1135  _Hash __hf = _Hash(),
1136  _BinaryPredicate __pred = _BinaryPredicate());
1137 
1138  template<typename _RandomAccessIterator2>
1139  pair<_RandomAccessIterator2, _RandomAccessIterator2>
1140  operator()(_RandomAccessIterator2 __first,
1141  _RandomAccessIterator2 __last) const;
1142 
1143  private:
1144  bool
1145  _M_is_prefix(_RAIter __word, __diff_type __len,
1146  __diff_type __pos)
1147  {
1148  const auto& __pred = this->_M_pred();
1149  __diff_type __suffixlen = __len - __pos;
1150  for (__diff_type __i = 0; __i < __suffixlen; ++__i)
1151  if (!__pred(__word[__i], __word[__pos + __i]))
1152  return false;
1153  return true;
1154  }
1155 
1156  __diff_type
1157  _M_suffix_length(_RAIter __word, __diff_type __len,
1158  __diff_type __pos)
1159  {
1160  const auto& __pred = this->_M_pred();
1161  __diff_type __i = 0;
1162  while (__pred(__word[__pos - __i], __word[__len - 1 - __i])
1163  && __i < __pos)
1164  {
1165  ++__i;
1166  }
1167  return __i;
1168  }
1169 
1170  template<typename _Tp>
1171  __diff_type
1172  _M_bad_char_shift(_Tp __c) const
1173  { return this->_M_lookup(__c, _M_pat_end - _M_pat); }
1174 
1175  _RAIter _M_pat;
1176  _RAIter _M_pat_end;
1177  _GLIBCXX_STD_C::vector<__diff_type> _M_good_suffix;
1178  };
1179 
1180  template<typename _RAIter, typename _Hash
1181  = hash<typename iterator_traits<_RAIter>::value_type>,
1182  typename _BinaryPredicate = equal_to<>>
1183  class boyer_moore_horspool_searcher
1184  : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
1185  {
1186  using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
1187  using typename _Base::__diff_type;
1188 
1189  public:
1190  boyer_moore_horspool_searcher(_RAIter __pat,
1191  _RAIter __pat_end,
1192  _Hash __hf = _Hash(),
1193  _BinaryPredicate __pred
1194  = _BinaryPredicate())
1195  : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
1196  _M_pat(__pat), _M_pat_end(__pat_end)
1197  { }
1198 
1199  template<typename _RandomAccessIterator2>
1200  pair<_RandomAccessIterator2, _RandomAccessIterator2>
1201  operator()(_RandomAccessIterator2 __first,
1202  _RandomAccessIterator2 __last) const
1203  {
1204  const auto& __pred = this->_M_pred();
1205  auto __patlen = _M_pat_end - _M_pat;
1206  if (__patlen == 0)
1207  return std::make_pair(__first, __first);
1208  auto __len = __last - __first;
1209  while (__len >= __patlen)
1210  {
1211  for (auto __scan = __patlen - 1;
1212  __pred(__first[__scan], _M_pat[__scan]); --__scan)
1213  if (__scan == 0)
1214  return std::make_pair(__first, __first + __patlen);
1215  auto __shift = _M_bad_char_shift(__first[__patlen - 1]);
1216  __len -= __shift;
1217  __first += __shift;
1218  }
1219  return std::make_pair(__last, __last);
1220  }
1221 
1222  private:
1223  template<typename _Tp>
1224  __diff_type
1225  _M_bad_char_shift(_Tp __c) const
1226  { return this->_M_lookup(__c, _M_pat_end - _M_pat); }
1227 
1228  _RAIter _M_pat;
1229  _RAIter _M_pat_end;
1230  };
1231 
1232  template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
1233  boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
1234  boyer_moore_searcher(_RAIter __pat, _RAIter __pat_end,
1235  _Hash __hf, _BinaryPredicate __pred)
1236  : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
1237  _M_pat(__pat), _M_pat_end(__pat_end), _M_good_suffix(__pat_end - __pat)
1238  {
1239  auto __patlen = __pat_end - __pat;
1240  if (__patlen == 0)
1241  return;
1242  __diff_type __last_prefix = __patlen - 1;
1243  for (__diff_type __p = __patlen - 1; __p >= 0; --__p)
1244  {
1245  if (_M_is_prefix(__pat, __patlen, __p + 1))
1246  __last_prefix = __p + 1;
1247  _M_good_suffix[__p] = __last_prefix + (__patlen - 1 - __p);
1248  }
1249  for (__diff_type __p = 0; __p < __patlen - 1; ++__p)
1250  {
1251  auto __slen = _M_suffix_length(__pat, __patlen, __p);
1252  auto __pos = __patlen - 1 - __slen;
1253  if (!__pred(__pat[__p - __slen], __pat[__pos]))
1254  _M_good_suffix[__pos] = __patlen - 1 - __p + __slen;
1255  }
1256  }
1257 
1258  template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
1259  template<typename _RandomAccessIterator2>
1260  pair<_RandomAccessIterator2, _RandomAccessIterator2>
1261  boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
1262  operator()(_RandomAccessIterator2 __first,
1263  _RandomAccessIterator2 __last) const
1264  {
1265  auto __patlen = _M_pat_end - _M_pat;
1266  if (__patlen == 0)
1267  return std::make_pair(__first, __first);
1268  const auto& __pred = this->_M_pred();
1269  __diff_type __i = __patlen - 1;
1270  auto __stringlen = __last - __first;
1271  while (__i < __stringlen)
1272  {
1273  __diff_type __j = __patlen - 1;
1274  while (__j >= 0 && __pred(__first[__i], _M_pat[__j]))
1275  {
1276  --__i;
1277  --__j;
1278  }
1279  if (__j < 0)
1280  {
1281  const auto __match = __first + __i + 1;
1282  return std::make_pair(__match, __match + __patlen);
1283  }
1284  __i += std::max(_M_bad_char_shift(__first[__i]),
1285  _M_good_suffix[__j]);
1286  }
1287  return std::make_pair(__last, __last);
1288  }
1289 
1290 #endif // C++17
1291 #endif // C++14
1292 
1293 _GLIBCXX_END_NAMESPACE_VERSION
1294 } // namespace std
1295 
1296 #endif // C++11
1297 
1298 #endif // _GLIBCXX_FUNCTIONAL