libstdc++
functional
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1 // <functional> -*- C++ -*-
2 
3 // Copyright (C) 2001-2020 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 #if __cplusplus > 201703L
68 # include <bits/range_cmp.h>
69 # include <compare>
70 #endif
71 
72 namespace std _GLIBCXX_VISIBILITY(default)
73 {
74 _GLIBCXX_BEGIN_NAMESPACE_VERSION
75 
76 #if __cplusplus >= 201703L
77 # define __cpp_lib_invoke 201411L
78 # if __cplusplus > 201703L
79 # define __cpp_lib_constexpr_functional 201907L
80 # endif
81 
82  /// Invoke a callable object.
83  template<typename _Callable, typename... _Args>
84  inline _GLIBCXX20_CONSTEXPR invoke_result_t<_Callable, _Args...>
85  invoke(_Callable&& __fn, _Args&&... __args)
86  noexcept(is_nothrow_invocable_v<_Callable, _Args...>)
87  {
88  return std::__invoke(std::forward<_Callable>(__fn),
89  std::forward<_Args>(__args)...);
90  }
91 #endif // C++17
92 
93  template<typename _MemFunPtr,
94  bool __is_mem_fn = is_member_function_pointer<_MemFunPtr>::value>
95  class _Mem_fn_base
96  : public _Mem_fn_traits<_MemFunPtr>::__maybe_type
97  {
98  using _Traits = _Mem_fn_traits<_MemFunPtr>;
99 
100  using _Arity = typename _Traits::__arity;
101  using _Varargs = typename _Traits::__vararg;
102 
103  template<typename _Func, typename... _BoundArgs>
104  friend struct _Bind_check_arity;
105 
106  _MemFunPtr _M_pmf;
107 
108  public:
109 
110  using result_type = typename _Traits::__result_type;
111 
112  explicit constexpr
113  _Mem_fn_base(_MemFunPtr __pmf) noexcept : _M_pmf(__pmf) { }
114 
115  template<typename... _Args>
116  _GLIBCXX20_CONSTEXPR
117  auto
118  operator()(_Args&&... __args) const
119  noexcept(noexcept(
120  std::__invoke(_M_pmf, std::forward<_Args>(__args)...)))
121  -> decltype(std::__invoke(_M_pmf, std::forward<_Args>(__args)...))
122  { return std::__invoke(_M_pmf, std::forward<_Args>(__args)...); }
123  };
124 
125  // Partial specialization for member object pointers.
126  template<typename _MemObjPtr>
127  class _Mem_fn_base<_MemObjPtr, false>
128  {
129  using _Arity = integral_constant<size_t, 0>;
130  using _Varargs = false_type;
131 
132  template<typename _Func, typename... _BoundArgs>
133  friend struct _Bind_check_arity;
134 
135  _MemObjPtr _M_pm;
136 
137  public:
138  explicit constexpr
139  _Mem_fn_base(_MemObjPtr __pm) noexcept : _M_pm(__pm) { }
140 
141  template<typename _Tp>
142  _GLIBCXX20_CONSTEXPR
143  auto
144  operator()(_Tp&& __obj) const
145  noexcept(noexcept(std::__invoke(_M_pm, std::forward<_Tp>(__obj))))
146  -> decltype(std::__invoke(_M_pm, std::forward<_Tp>(__obj)))
147  { return std::__invoke(_M_pm, std::forward<_Tp>(__obj)); }
148  };
149 
150  template<typename _MemberPointer>
151  struct _Mem_fn; // undefined
152 
153  template<typename _Res, typename _Class>
154  struct _Mem_fn<_Res _Class::*>
155  : _Mem_fn_base<_Res _Class::*>
156  {
157  using _Mem_fn_base<_Res _Class::*>::_Mem_fn_base;
158  };
159 
160  // _GLIBCXX_RESOLVE_LIB_DEFECTS
161  // 2048. Unnecessary mem_fn overloads
162  /**
163  * @brief Returns a function object that forwards to the member
164  * pointer @a pm.
165  * @ingroup functors
166  */
167  template<typename _Tp, typename _Class>
168  _GLIBCXX20_CONSTEXPR
169  inline _Mem_fn<_Tp _Class::*>
170  mem_fn(_Tp _Class::* __pm) noexcept
171  {
172  return _Mem_fn<_Tp _Class::*>(__pm);
173  }
174 
175  /**
176  * @brief Determines if the given type _Tp is a function object that
177  * should be treated as a subexpression when evaluating calls to
178  * function objects returned by bind().
179  *
180  * C++11 [func.bind.isbind].
181  * @ingroup binders
182  */
183  template<typename _Tp>
184  struct is_bind_expression
185  : public false_type { };
186 
187  /**
188  * @brief Determines if the given type _Tp is a placeholder in a
189  * bind() expression and, if so, which placeholder it is.
190  *
191  * C++11 [func.bind.isplace].
192  * @ingroup binders
193  */
194  template<typename _Tp>
195  struct is_placeholder
196  : public integral_constant<int, 0>
197  { };
198 
199 #if __cplusplus > 201402L
200  template <typename _Tp> inline constexpr bool is_bind_expression_v
201  = is_bind_expression<_Tp>::value;
202  template <typename _Tp> inline constexpr int is_placeholder_v
203  = is_placeholder<_Tp>::value;
204 #endif // C++17
205 
206  /** @brief The type of placeholder objects defined by libstdc++.
207  * @ingroup binders
208  */
209  template<int _Num> struct _Placeholder { };
210 
211  /** @namespace std::placeholders
212  * @brief ISO C++ 2011 namespace for std::bind placeholders.
213  * @ingroup binders
214  */
215  namespace placeholders
216  {
217  /* Define a large number of placeholders. There is no way to
218  * simplify this with variadic templates, because we're introducing
219  * unique names for each.
220  */
221  extern const _Placeholder<1> _1;
222  extern const _Placeholder<2> _2;
223  extern const _Placeholder<3> _3;
224  extern const _Placeholder<4> _4;
225  extern const _Placeholder<5> _5;
226  extern const _Placeholder<6> _6;
227  extern const _Placeholder<7> _7;
228  extern const _Placeholder<8> _8;
229  extern const _Placeholder<9> _9;
230  extern const _Placeholder<10> _10;
231  extern const _Placeholder<11> _11;
232  extern const _Placeholder<12> _12;
233  extern const _Placeholder<13> _13;
234  extern const _Placeholder<14> _14;
235  extern const _Placeholder<15> _15;
236  extern const _Placeholder<16> _16;
237  extern const _Placeholder<17> _17;
238  extern const _Placeholder<18> _18;
239  extern const _Placeholder<19> _19;
240  extern const _Placeholder<20> _20;
241  extern const _Placeholder<21> _21;
242  extern const _Placeholder<22> _22;
243  extern const _Placeholder<23> _23;
244  extern const _Placeholder<24> _24;
245  extern const _Placeholder<25> _25;
246  extern const _Placeholder<26> _26;
247  extern const _Placeholder<27> _27;
248  extern const _Placeholder<28> _28;
249  extern const _Placeholder<29> _29;
250  }
251 
252  /**
253  * Partial specialization of is_placeholder that provides the placeholder
254  * number for the placeholder objects defined by libstdc++.
255  * @ingroup binders
256  */
257  template<int _Num>
258  struct is_placeholder<_Placeholder<_Num> >
259  : public integral_constant<int, _Num>
260  { };
261 
262  template<int _Num>
263  struct is_placeholder<const _Placeholder<_Num> >
264  : public integral_constant<int, _Num>
265  { };
266 
267 
268  // Like tuple_element_t but SFINAE-friendly.
269  template<std::size_t __i, typename _Tuple>
270  using _Safe_tuple_element_t
271  = typename enable_if<(__i < tuple_size<_Tuple>::value),
272  tuple_element<__i, _Tuple>>::type::type;
273 
274  /**
275  * Maps an argument to bind() into an actual argument to the bound
276  * function object [func.bind.bind]/10. Only the first parameter should
277  * be specified: the rest are used to determine among the various
278  * implementations. Note that, although this class is a function
279  * object, it isn't entirely normal because it takes only two
280  * parameters regardless of the number of parameters passed to the
281  * bind expression. The first parameter is the bound argument and
282  * the second parameter is a tuple containing references to the
283  * rest of the arguments.
284  */
285  template<typename _Arg,
286  bool _IsBindExp = is_bind_expression<_Arg>::value,
287  bool _IsPlaceholder = (is_placeholder<_Arg>::value > 0)>
288  class _Mu;
289 
290  /**
291  * If the argument is reference_wrapper<_Tp>, returns the
292  * underlying reference.
293  * C++11 [func.bind.bind] p10 bullet 1.
294  */
295  template<typename _Tp>
296  class _Mu<reference_wrapper<_Tp>, false, false>
297  {
298  public:
299  /* Note: This won't actually work for const volatile
300  * reference_wrappers, because reference_wrapper::get() is const
301  * but not volatile-qualified. This might be a defect in the TR.
302  */
303  template<typename _CVRef, typename _Tuple>
304  _GLIBCXX20_CONSTEXPR
305  _Tp&
306  operator()(_CVRef& __arg, _Tuple&) const volatile
307  { return __arg.get(); }
308  };
309 
310  /**
311  * If the argument is a bind expression, we invoke the underlying
312  * function object with the same cv-qualifiers as we are given and
313  * pass along all of our arguments (unwrapped).
314  * C++11 [func.bind.bind] p10 bullet 2.
315  */
316  template<typename _Arg>
317  class _Mu<_Arg, true, false>
318  {
319  public:
320  template<typename _CVArg, typename... _Args>
321  _GLIBCXX20_CONSTEXPR
322  auto
323  operator()(_CVArg& __arg,
324  tuple<_Args...>& __tuple) const volatile
325  -> decltype(__arg(declval<_Args>()...))
326  {
327  // Construct an index tuple and forward to __call
328  typedef typename _Build_index_tuple<sizeof...(_Args)>::__type
329  _Indexes;
330  return this->__call(__arg, __tuple, _Indexes());
331  }
332 
333  private:
334  // Invokes the underlying function object __arg by unpacking all
335  // of the arguments in the tuple.
336  template<typename _CVArg, typename... _Args, std::size_t... _Indexes>
337  _GLIBCXX20_CONSTEXPR
338  auto
339  __call(_CVArg& __arg, tuple<_Args...>& __tuple,
340  const _Index_tuple<_Indexes...>&) const volatile
341  -> decltype(__arg(declval<_Args>()...))
342  {
343  return __arg(std::get<_Indexes>(std::move(__tuple))...);
344  }
345  };
346 
347  /**
348  * If the argument is a placeholder for the Nth argument, returns
349  * a reference to the Nth argument to the bind function object.
350  * C++11 [func.bind.bind] p10 bullet 3.
351  */
352  template<typename _Arg>
353  class _Mu<_Arg, false, true>
354  {
355  public:
356  template<typename _Tuple>
357  _GLIBCXX20_CONSTEXPR
358  _Safe_tuple_element_t<(is_placeholder<_Arg>::value - 1), _Tuple>&&
359  operator()(const volatile _Arg&, _Tuple& __tuple) const volatile
360  {
361  return
362  ::std::get<(is_placeholder<_Arg>::value - 1)>(std::move(__tuple));
363  }
364  };
365 
366  /**
367  * If the argument is just a value, returns a reference to that
368  * value. The cv-qualifiers on the reference are determined by the caller.
369  * C++11 [func.bind.bind] p10 bullet 4.
370  */
371  template<typename _Arg>
372  class _Mu<_Arg, false, false>
373  {
374  public:
375  template<typename _CVArg, typename _Tuple>
376  _GLIBCXX20_CONSTEXPR
377  _CVArg&&
378  operator()(_CVArg&& __arg, _Tuple&) const volatile
379  { return std::forward<_CVArg>(__arg); }
380  };
381 
382  // std::get<I> for volatile-qualified tuples
383  template<std::size_t _Ind, typename... _Tp>
384  inline auto
385  __volget(volatile tuple<_Tp...>& __tuple)
386  -> __tuple_element_t<_Ind, tuple<_Tp...>> volatile&
387  { return std::get<_Ind>(const_cast<tuple<_Tp...>&>(__tuple)); }
388 
389  // std::get<I> for const-volatile-qualified tuples
390  template<std::size_t _Ind, typename... _Tp>
391  inline auto
392  __volget(const volatile tuple<_Tp...>& __tuple)
393  -> __tuple_element_t<_Ind, tuple<_Tp...>> const volatile&
394  { return std::get<_Ind>(const_cast<const tuple<_Tp...>&>(__tuple)); }
395 
396  /// Type of the function object returned from bind().
397  template<typename _Signature>
398  struct _Bind;
399 
400  template<typename _Functor, typename... _Bound_args>
401  class _Bind<_Functor(_Bound_args...)>
402  : public _Weak_result_type<_Functor>
403  {
404  typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
405  _Bound_indexes;
406 
407  _Functor _M_f;
408  tuple<_Bound_args...> _M_bound_args;
409 
410  // Call unqualified
411  template<typename _Result, typename... _Args, std::size_t... _Indexes>
412  _GLIBCXX20_CONSTEXPR
413  _Result
414  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
415  {
416  return std::__invoke(_M_f,
417  _Mu<_Bound_args>()(std::get<_Indexes>(_M_bound_args), __args)...
418  );
419  }
420 
421  // Call as const
422  template<typename _Result, typename... _Args, std::size_t... _Indexes>
423  _GLIBCXX20_CONSTEXPR
424  _Result
425  __call_c(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
426  {
427  return std::__invoke(_M_f,
428  _Mu<_Bound_args>()(std::get<_Indexes>(_M_bound_args), __args)...
429  );
430  }
431 
432  // Call as volatile
433  template<typename _Result, typename... _Args, std::size_t... _Indexes>
434  _Result
435  __call_v(tuple<_Args...>&& __args,
436  _Index_tuple<_Indexes...>) volatile
437  {
438  return std::__invoke(_M_f,
439  _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
440  );
441  }
442 
443  // Call as const volatile
444  template<typename _Result, typename... _Args, std::size_t... _Indexes>
445  _Result
446  __call_c_v(tuple<_Args...>&& __args,
447  _Index_tuple<_Indexes...>) const volatile
448  {
449  return std::__invoke(_M_f,
450  _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
451  );
452  }
453 
454  template<typename _BoundArg, typename _CallArgs>
455  using _Mu_type = decltype(
456  _Mu<typename remove_cv<_BoundArg>::type>()(
457  std::declval<_BoundArg&>(), std::declval<_CallArgs&>()) );
458 
459  template<typename _Fn, typename _CallArgs, typename... _BArgs>
460  using _Res_type_impl
461  = typename result_of< _Fn&(_Mu_type<_BArgs, _CallArgs>&&...) >::type;
462 
463  template<typename _CallArgs>
464  using _Res_type = _Res_type_impl<_Functor, _CallArgs, _Bound_args...>;
465 
466  template<typename _CallArgs>
467  using __dependent = typename
468  enable_if<bool(tuple_size<_CallArgs>::value+1), _Functor>::type;
469 
470  template<typename _CallArgs, template<class> class __cv_quals>
471  using _Res_type_cv = _Res_type_impl<
472  typename __cv_quals<__dependent<_CallArgs>>::type,
473  _CallArgs,
474  typename __cv_quals<_Bound_args>::type...>;
475 
476  public:
477  template<typename... _Args>
478  explicit _GLIBCXX20_CONSTEXPR
479  _Bind(const _Functor& __f, _Args&&... __args)
480  : _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
481  { }
482 
483  template<typename... _Args>
484  explicit _GLIBCXX20_CONSTEXPR
485  _Bind(_Functor&& __f, _Args&&... __args)
486  : _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
487  { }
488 
489  _Bind(const _Bind&) = default;
490  _Bind(_Bind&&) = default;
491 
492  // Call unqualified
493  template<typename... _Args,
494  typename _Result = _Res_type<tuple<_Args...>>>
495  _GLIBCXX20_CONSTEXPR
496  _Result
497  operator()(_Args&&... __args)
498  {
499  return this->__call<_Result>(
500  std::forward_as_tuple(std::forward<_Args>(__args)...),
501  _Bound_indexes());
502  }
503 
504  // Call as const
505  template<typename... _Args,
506  typename _Result = _Res_type_cv<tuple<_Args...>, add_const>>
507  _GLIBCXX20_CONSTEXPR
508  _Result
509  operator()(_Args&&... __args) const
510  {
511  return this->__call_c<_Result>(
512  std::forward_as_tuple(std::forward<_Args>(__args)...),
513  _Bound_indexes());
514  }
515 
516 #if __cplusplus > 201402L
517 # define _GLIBCXX_DEPR_BIND \
518  [[deprecated("std::bind does not support volatile in C++17")]]
519 #else
520 # define _GLIBCXX_DEPR_BIND
521 #endif
522  // Call as volatile
523  template<typename... _Args,
524  typename _Result = _Res_type_cv<tuple<_Args...>, add_volatile>>
525  _GLIBCXX_DEPR_BIND
526  _Result
527  operator()(_Args&&... __args) volatile
528  {
529  return this->__call_v<_Result>(
530  std::forward_as_tuple(std::forward<_Args>(__args)...),
531  _Bound_indexes());
532  }
533 
534  // Call as const volatile
535  template<typename... _Args,
536  typename _Result = _Res_type_cv<tuple<_Args...>, add_cv>>
537  _GLIBCXX_DEPR_BIND
538  _Result
539  operator()(_Args&&... __args) const volatile
540  {
541  return this->__call_c_v<_Result>(
542  std::forward_as_tuple(std::forward<_Args>(__args)...),
543  _Bound_indexes());
544  }
545  };
546 
547  /// Type of the function object returned from bind<R>().
548  template<typename _Result, typename _Signature>
549  struct _Bind_result;
550 
551  template<typename _Result, typename _Functor, typename... _Bound_args>
552  class _Bind_result<_Result, _Functor(_Bound_args...)>
553  {
554  typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
555  _Bound_indexes;
556 
557  _Functor _M_f;
558  tuple<_Bound_args...> _M_bound_args;
559 
560  // Call unqualified
561  template<typename _Res, typename... _Args, std::size_t... _Indexes>
562  _GLIBCXX20_CONSTEXPR
563  _Res
564  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
565  {
566  return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
567  (std::get<_Indexes>(_M_bound_args), __args)...);
568  }
569 
570  // Call as const
571  template<typename _Res, typename... _Args, std::size_t... _Indexes>
572  _GLIBCXX20_CONSTEXPR
573  _Res
574  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
575  {
576  return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
577  (std::get<_Indexes>(_M_bound_args), __args)...);
578  }
579 
580  // Call as volatile
581  template<typename _Res, typename... _Args, std::size_t... _Indexes>
582  _GLIBCXX20_CONSTEXPR
583  _Res
584  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
585  {
586  return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
587  (__volget<_Indexes>(_M_bound_args), __args)...);
588  }
589 
590  // Call as const volatile
591  template<typename _Res, typename... _Args, std::size_t... _Indexes>
592  _GLIBCXX20_CONSTEXPR
593  _Res
594  __call(tuple<_Args...>&& __args,
595  _Index_tuple<_Indexes...>) const volatile
596  {
597  return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
598  (__volget<_Indexes>(_M_bound_args), __args)...);
599  }
600 
601  public:
602  typedef _Result result_type;
603 
604  template<typename... _Args>
605  explicit _GLIBCXX20_CONSTEXPR
606  _Bind_result(const _Functor& __f, _Args&&... __args)
607  : _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
608  { }
609 
610  template<typename... _Args>
611  explicit _GLIBCXX20_CONSTEXPR
612  _Bind_result(_Functor&& __f, _Args&&... __args)
613  : _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
614  { }
615 
616  _Bind_result(const _Bind_result&) = default;
617  _Bind_result(_Bind_result&&) = default;
618 
619  // Call unqualified
620  template<typename... _Args>
621  _GLIBCXX20_CONSTEXPR
622  result_type
623  operator()(_Args&&... __args)
624  {
625  return this->__call<_Result>(
626  std::forward_as_tuple(std::forward<_Args>(__args)...),
627  _Bound_indexes());
628  }
629 
630  // Call as const
631  template<typename... _Args>
632  _GLIBCXX20_CONSTEXPR
633  result_type
634  operator()(_Args&&... __args) const
635  {
636  return this->__call<_Result>(
637  std::forward_as_tuple(std::forward<_Args>(__args)...),
638  _Bound_indexes());
639  }
640 
641  // Call as volatile
642  template<typename... _Args>
643  _GLIBCXX_DEPR_BIND
644  result_type
645  operator()(_Args&&... __args) volatile
646  {
647  return this->__call<_Result>(
648  std::forward_as_tuple(std::forward<_Args>(__args)...),
649  _Bound_indexes());
650  }
651 
652  // Call as const volatile
653  template<typename... _Args>
654  _GLIBCXX_DEPR_BIND
655  result_type
656  operator()(_Args&&... __args) const volatile
657  {
658  return this->__call<_Result>(
659  std::forward_as_tuple(std::forward<_Args>(__args)...),
660  _Bound_indexes());
661  }
662  };
663 #undef _GLIBCXX_DEPR_BIND
664 
665  /**
666  * @brief Class template _Bind is always a bind expression.
667  * @ingroup binders
668  */
669  template<typename _Signature>
670  struct is_bind_expression<_Bind<_Signature> >
671  : public true_type { };
672 
673  /**
674  * @brief Class template _Bind is always a bind expression.
675  * @ingroup binders
676  */
677  template<typename _Signature>
678  struct is_bind_expression<const _Bind<_Signature> >
679  : public true_type { };
680 
681  /**
682  * @brief Class template _Bind is always a bind expression.
683  * @ingroup binders
684  */
685  template<typename _Signature>
686  struct is_bind_expression<volatile _Bind<_Signature> >
687  : public true_type { };
688 
689  /**
690  * @brief Class template _Bind is always a bind expression.
691  * @ingroup binders
692  */
693  template<typename _Signature>
694  struct is_bind_expression<const volatile _Bind<_Signature>>
695  : public true_type { };
696 
697  /**
698  * @brief Class template _Bind_result is always a bind expression.
699  * @ingroup binders
700  */
701  template<typename _Result, typename _Signature>
702  struct is_bind_expression<_Bind_result<_Result, _Signature>>
703  : public true_type { };
704 
705  /**
706  * @brief Class template _Bind_result is always a bind expression.
707  * @ingroup binders
708  */
709  template<typename _Result, typename _Signature>
710  struct is_bind_expression<const _Bind_result<_Result, _Signature>>
711  : public true_type { };
712 
713  /**
714  * @brief Class template _Bind_result is always a bind expression.
715  * @ingroup binders
716  */
717  template<typename _Result, typename _Signature>
718  struct is_bind_expression<volatile _Bind_result<_Result, _Signature>>
719  : public true_type { };
720 
721  /**
722  * @brief Class template _Bind_result is always a bind expression.
723  * @ingroup binders
724  */
725  template<typename _Result, typename _Signature>
726  struct is_bind_expression<const volatile _Bind_result<_Result, _Signature>>
727  : public true_type { };
728 
729  template<typename _Func, typename... _BoundArgs>
730  struct _Bind_check_arity { };
731 
732  template<typename _Ret, typename... _Args, typename... _BoundArgs>
733  struct _Bind_check_arity<_Ret (*)(_Args...), _BoundArgs...>
734  {
735  static_assert(sizeof...(_BoundArgs) == sizeof...(_Args),
736  "Wrong number of arguments for function");
737  };
738 
739  template<typename _Ret, typename... _Args, typename... _BoundArgs>
740  struct _Bind_check_arity<_Ret (*)(_Args......), _BoundArgs...>
741  {
742  static_assert(sizeof...(_BoundArgs) >= sizeof...(_Args),
743  "Wrong number of arguments for function");
744  };
745 
746  template<typename _Tp, typename _Class, typename... _BoundArgs>
747  struct _Bind_check_arity<_Tp _Class::*, _BoundArgs...>
748  {
749  using _Arity = typename _Mem_fn<_Tp _Class::*>::_Arity;
750  using _Varargs = typename _Mem_fn<_Tp _Class::*>::_Varargs;
751  static_assert(_Varargs::value
752  ? sizeof...(_BoundArgs) >= _Arity::value + 1
753  : sizeof...(_BoundArgs) == _Arity::value + 1,
754  "Wrong number of arguments for pointer-to-member");
755  };
756 
757  // Trait type used to remove std::bind() from overload set via SFINAE
758  // when first argument has integer type, so that std::bind() will
759  // not be a better match than ::bind() from the BSD Sockets API.
760  template<typename _Tp, typename _Tp2 = typename decay<_Tp>::type>
761  using __is_socketlike = __or_<is_integral<_Tp2>, is_enum<_Tp2>>;
762 
763  template<bool _SocketLike, typename _Func, typename... _BoundArgs>
764  struct _Bind_helper
765  : _Bind_check_arity<typename decay<_Func>::type, _BoundArgs...>
766  {
767  typedef typename decay<_Func>::type __func_type;
768  typedef _Bind<__func_type(typename decay<_BoundArgs>::type...)> type;
769  };
770 
771  // Partial specialization for is_socketlike == true, does not define
772  // nested type so std::bind() will not participate in overload resolution
773  // when the first argument might be a socket file descriptor.
774  template<typename _Func, typename... _BoundArgs>
775  struct _Bind_helper<true, _Func, _BoundArgs...>
776  { };
777 
778  /**
779  * @brief Function template for std::bind.
780  * @ingroup binders
781  */
782  template<typename _Func, typename... _BoundArgs>
783  inline _GLIBCXX20_CONSTEXPR typename
784  _Bind_helper<__is_socketlike<_Func>::value, _Func, _BoundArgs...>::type
785  bind(_Func&& __f, _BoundArgs&&... __args)
786  {
787  typedef _Bind_helper<false, _Func, _BoundArgs...> __helper_type;
788  return typename __helper_type::type(std::forward<_Func>(__f),
789  std::forward<_BoundArgs>(__args)...);
790  }
791 
792  template<typename _Result, typename _Func, typename... _BoundArgs>
793  struct _Bindres_helper
794  : _Bind_check_arity<typename decay<_Func>::type, _BoundArgs...>
795  {
796  typedef typename decay<_Func>::type __functor_type;
797  typedef _Bind_result<_Result,
798  __functor_type(typename decay<_BoundArgs>::type...)>
799  type;
800  };
801 
802  /**
803  * @brief Function template for std::bind<R>.
804  * @ingroup binders
805  */
806  template<typename _Result, typename _Func, typename... _BoundArgs>
807  inline _GLIBCXX20_CONSTEXPR
808  typename _Bindres_helper<_Result, _Func, _BoundArgs...>::type
809  bind(_Func&& __f, _BoundArgs&&... __args)
810  {
811  typedef _Bindres_helper<_Result, _Func, _BoundArgs...> __helper_type;
812  return typename __helper_type::type(std::forward<_Func>(__f),
813  std::forward<_BoundArgs>(__args)...);
814  }
815 
816 #if __cplusplus > 201703L
817 #define __cpp_lib_bind_front 201907L
818 
819  template<typename _Fd, typename... _BoundArgs>
820  struct _Bind_front
821  {
822  static_assert(is_move_constructible_v<_Fd>);
823  static_assert((is_move_constructible_v<_BoundArgs> && ...));
824 
825  // First parameter is to ensure this constructor is never used
826  // instead of the copy/move constructor.
827  template<typename _Fn, typename... _Args>
828  explicit constexpr
829  _Bind_front(int, _Fn&& __fn, _Args&&... __args)
830  noexcept(__and_<is_nothrow_constructible<_Fd, _Fn>,
831  is_nothrow_constructible<_BoundArgs, _Args>...>::value)
832  : _M_fd(std::forward<_Fn>(__fn)),
833  _M_bound_args(std::forward<_Args>(__args)...)
834  { static_assert(sizeof...(_Args) == sizeof...(_BoundArgs)); }
835 
836  _Bind_front(const _Bind_front&) = default;
837  _Bind_front(_Bind_front&&) = default;
838  _Bind_front& operator=(const _Bind_front&) = default;
839  _Bind_front& operator=(_Bind_front&&) = default;
840  ~_Bind_front() = default;
841 
842  template<typename... _CallArgs>
843  constexpr
844  invoke_result_t<_Fd&, _BoundArgs&..., _CallArgs...>
845  operator()(_CallArgs&&... __call_args) &
846  noexcept(is_nothrow_invocable_v<_Fd&, _BoundArgs&..., _CallArgs...>)
847  {
848  return _S_call(*this, _BoundIndices(),
849  std::forward<_CallArgs>(__call_args)...);
850  }
851 
852  template<typename... _CallArgs>
853  constexpr
854  invoke_result_t<const _Fd&, const _BoundArgs&..., _CallArgs...>
855  operator()(_CallArgs&&... __call_args) const &
856  noexcept(is_nothrow_invocable_v<const _Fd&, const _BoundArgs&...,
857  _CallArgs...>)
858  {
859  return _S_call(*this, _BoundIndices(),
860  std::forward<_CallArgs>(__call_args)...);
861  }
862 
863  template<typename... _CallArgs>
864  constexpr
865  invoke_result_t<_Fd, _BoundArgs..., _CallArgs...>
866  operator()(_CallArgs&&... __call_args) &&
867  noexcept(is_nothrow_invocable_v<_Fd, _BoundArgs..., _CallArgs...>)
868  {
869  return _S_call(std::move(*this), _BoundIndices(),
870  std::forward<_CallArgs>(__call_args)...);
871  }
872 
873  template<typename... _CallArgs>
874  constexpr
875  invoke_result_t<const _Fd, const _BoundArgs..., _CallArgs...>
876  operator()(_CallArgs&&... __call_args) const &&
877  noexcept(is_nothrow_invocable_v<const _Fd, const _BoundArgs...,
878  _CallArgs...>)
879  {
880  return _S_call(std::move(*this), _BoundIndices(),
881  std::forward<_CallArgs>(__call_args)...);
882  }
883 
884  private:
885  using _BoundIndices = index_sequence_for<_BoundArgs...>;
886 
887  template<typename _Tp, size_t... _Ind, typename... _CallArgs>
888  static constexpr
889  decltype(auto)
890  _S_call(_Tp&& __g, index_sequence<_Ind...>, _CallArgs&&... __call_args)
891  {
892  return std::invoke(std::forward<_Tp>(__g)._M_fd,
893  std::get<_Ind>(std::forward<_Tp>(__g)._M_bound_args)...,
894  std::forward<_CallArgs>(__call_args)...);
895  }
896 
897  _Fd _M_fd;
898  std::tuple<_BoundArgs...> _M_bound_args;
899  };
900 
901  template<typename _Fn, typename... _Args>
902  using _Bind_front_t
903  = _Bind_front<decay_t<_Fn>, decay_t<_Args>...>;
904 
905  template<typename _Fn, typename... _Args>
906  constexpr _Bind_front_t<_Fn, _Args...>
907  bind_front(_Fn&& __fn, _Args&&... __args)
908  noexcept(is_nothrow_constructible_v<_Bind_front_t<_Fn, _Args...>,
909  int, _Fn, _Args...>)
910  {
911  return _Bind_front_t<_Fn, _Args...>(0, std::forward<_Fn>(__fn),
912  std::forward<_Args>(__args)...);
913  }
914 #endif
915 
916 #if __cplusplus >= 201402L
917  /// Generalized negator.
918  template<typename _Fn>
919  class _Not_fn
920  {
921  template<typename _Fn2, typename... _Args>
922  using __inv_res_t = typename __invoke_result<_Fn2, _Args...>::type;
923 
924  template<typename _Tp>
925  static decltype(!std::declval<_Tp>())
926  _S_not() noexcept(noexcept(!std::declval<_Tp>()));
927 
928  public:
929  template<typename _Fn2>
930  constexpr
931  _Not_fn(_Fn2&& __fn, int)
932  : _M_fn(std::forward<_Fn2>(__fn)) { }
933 
934  _Not_fn(const _Not_fn& __fn) = default;
935  _Not_fn(_Not_fn&& __fn) = default;
936  ~_Not_fn() = default;
937 
938  // Macro to define operator() with given cv-qualifiers ref-qualifiers,
939  // forwarding _M_fn and the function arguments with the same qualifiers,
940  // and deducing the return type and exception-specification.
941 #define _GLIBCXX_NOT_FN_CALL_OP( _QUALS ) \
942  template<typename... _Args> \
943  _GLIBCXX20_CONSTEXPR \
944  decltype(_S_not<__inv_res_t<_Fn _QUALS, _Args...>>()) \
945  operator()(_Args&&... __args) _QUALS \
946  noexcept(__is_nothrow_invocable<_Fn _QUALS, _Args...>::value \
947  && noexcept(_S_not<__inv_res_t<_Fn _QUALS, _Args...>>())) \
948  { \
949  return !std::__invoke(std::forward< _Fn _QUALS >(_M_fn), \
950  std::forward<_Args>(__args)...); \
951  }
952  _GLIBCXX_NOT_FN_CALL_OP( & )
953  _GLIBCXX_NOT_FN_CALL_OP( const & )
954  _GLIBCXX_NOT_FN_CALL_OP( && )
955  _GLIBCXX_NOT_FN_CALL_OP( const && )
956 #undef _GLIBCXX_NOT_FN_CALL_OP
957 
958  private:
959  _Fn _M_fn;
960  };
961 
962  template<typename _Tp, typename _Pred>
963  struct __is_byte_like : false_type { };
964 
965  template<typename _Tp>
966  struct __is_byte_like<_Tp, equal_to<_Tp>>
967  : __bool_constant<sizeof(_Tp) == 1 && is_integral<_Tp>::value> { };
968 
969  template<typename _Tp>
970  struct __is_byte_like<_Tp, equal_to<void>>
971  : __bool_constant<sizeof(_Tp) == 1 && is_integral<_Tp>::value> { };
972 
973 #if __cplusplus >= 201703L
974  // Declare std::byte (full definition is in <cstddef>).
975  enum class byte : unsigned char;
976 
977  template<>
978  struct __is_byte_like<byte, equal_to<byte>>
979  : true_type { };
980 
981  template<>
982  struct __is_byte_like<byte, equal_to<void>>
983  : true_type { };
984 
985 #define __cpp_lib_not_fn 201603
986  /// [func.not_fn] Function template not_fn
987  template<typename _Fn>
988  _GLIBCXX20_CONSTEXPR
989  inline auto
990  not_fn(_Fn&& __fn)
991  noexcept(std::is_nothrow_constructible<std::decay_t<_Fn>, _Fn&&>::value)
992  {
993  return _Not_fn<std::decay_t<_Fn>>{std::forward<_Fn>(__fn), 0};
994  }
995 
996  // Searchers
997 #define __cpp_lib_boyer_moore_searcher 201603
998 
999  template<typename _ForwardIterator1, typename _BinaryPredicate = equal_to<>>
1000  class default_searcher
1001  {
1002  public:
1003  _GLIBCXX20_CONSTEXPR
1004  default_searcher(_ForwardIterator1 __pat_first,
1005  _ForwardIterator1 __pat_last,
1006  _BinaryPredicate __pred = _BinaryPredicate())
1007  : _M_m(__pat_first, __pat_last, std::move(__pred))
1008  { }
1009 
1010  template<typename _ForwardIterator2>
1011  _GLIBCXX20_CONSTEXPR
1012  pair<_ForwardIterator2, _ForwardIterator2>
1013  operator()(_ForwardIterator2 __first, _ForwardIterator2 __last) const
1014  {
1015  _ForwardIterator2 __first_ret =
1016  std::search(__first, __last, std::get<0>(_M_m), std::get<1>(_M_m),
1017  std::get<2>(_M_m));
1018  auto __ret = std::make_pair(__first_ret, __first_ret);
1019  if (__ret.first != __last)
1020  std::advance(__ret.second, std::distance(std::get<0>(_M_m),
1021  std::get<1>(_M_m)));
1022  return __ret;
1023  }
1024 
1025  private:
1026  tuple<_ForwardIterator1, _ForwardIterator1, _BinaryPredicate> _M_m;
1027  };
1028 
1029  template<typename _Key, typename _Tp, typename _Hash, typename _Pred>
1030  struct __boyer_moore_map_base
1031  {
1032  template<typename _RAIter>
1033  __boyer_moore_map_base(_RAIter __pat, size_t __patlen,
1034  _Hash&& __hf, _Pred&& __pred)
1035  : _M_bad_char{ __patlen, std::move(__hf), std::move(__pred) }
1036  {
1037  if (__patlen > 0)
1038  for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
1039  _M_bad_char[__pat[__i]] = __patlen - 1 - __i;
1040  }
1041 
1042  using __diff_type = _Tp;
1043 
1044  __diff_type
1045  _M_lookup(_Key __key, __diff_type __not_found) const
1046  {
1047  auto __iter = _M_bad_char.find(__key);
1048  if (__iter == _M_bad_char.end())
1049  return __not_found;
1050  return __iter->second;
1051  }
1052 
1053  _Pred
1054  _M_pred() const { return _M_bad_char.key_eq(); }
1055 
1056  _GLIBCXX_STD_C::unordered_map<_Key, _Tp, _Hash, _Pred> _M_bad_char;
1057  };
1058 
1059  template<typename _Tp, size_t _Len, typename _Pred>
1060  struct __boyer_moore_array_base
1061  {
1062  template<typename _RAIter, typename _Unused>
1063  __boyer_moore_array_base(_RAIter __pat, size_t __patlen,
1064  _Unused&&, _Pred&& __pred)
1065  : _M_bad_char{ _GLIBCXX_STD_C::array<_Tp, _Len>{}, std::move(__pred) }
1066  {
1067  std::get<0>(_M_bad_char).fill(__patlen);
1068  if (__patlen > 0)
1069  for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
1070  {
1071  auto __ch = __pat[__i];
1072  using _UCh = make_unsigned_t<decltype(__ch)>;
1073  auto __uch = static_cast<_UCh>(__ch);
1074  std::get<0>(_M_bad_char)[__uch] = __patlen - 1 - __i;
1075  }
1076  }
1077 
1078  using __diff_type = _Tp;
1079 
1080  template<typename _Key>
1081  __diff_type
1082  _M_lookup(_Key __key, __diff_type __not_found) const
1083  {
1084  auto __ukey = static_cast<make_unsigned_t<_Key>>(__key);
1085  if (__ukey >= _Len)
1086  return __not_found;
1087  return std::get<0>(_M_bad_char)[__ukey];
1088  }
1089 
1090  const _Pred&
1091  _M_pred() const { return std::get<1>(_M_bad_char); }
1092 
1093  tuple<_GLIBCXX_STD_C::array<_Tp, _Len>, _Pred> _M_bad_char;
1094  };
1095 
1096  // Use __boyer_moore_array_base when pattern consists of narrow characters
1097  // (or std::byte) and uses std::equal_to as the predicate.
1098  template<typename _RAIter, typename _Hash, typename _Pred,
1099  typename _Val = typename iterator_traits<_RAIter>::value_type,
1100  typename _Diff = typename iterator_traits<_RAIter>::difference_type>
1101  using __boyer_moore_base_t
1102  = conditional_t<__is_byte_like<_Val, _Pred>::value,
1103  __boyer_moore_array_base<_Diff, 256, _Pred>,
1104  __boyer_moore_map_base<_Val, _Diff, _Hash, _Pred>>;
1105 
1106  template<typename _RAIter, typename _Hash
1107  = hash<typename iterator_traits<_RAIter>::value_type>,
1108  typename _BinaryPredicate = equal_to<>>
1109  class boyer_moore_searcher
1110  : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
1111  {
1112  using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
1113  using typename _Base::__diff_type;
1114 
1115  public:
1116  boyer_moore_searcher(_RAIter __pat_first, _RAIter __pat_last,
1117  _Hash __hf = _Hash(),
1118  _BinaryPredicate __pred = _BinaryPredicate());
1119 
1120  template<typename _RandomAccessIterator2>
1121  pair<_RandomAccessIterator2, _RandomAccessIterator2>
1122  operator()(_RandomAccessIterator2 __first,
1123  _RandomAccessIterator2 __last) const;
1124 
1125  private:
1126  bool
1127  _M_is_prefix(_RAIter __word, __diff_type __len,
1128  __diff_type __pos)
1129  {
1130  const auto& __pred = this->_M_pred();
1131  __diff_type __suffixlen = __len - __pos;
1132  for (__diff_type __i = 0; __i < __suffixlen; ++__i)
1133  if (!__pred(__word[__i], __word[__pos + __i]))
1134  return false;
1135  return true;
1136  }
1137 
1138  __diff_type
1139  _M_suffix_length(_RAIter __word, __diff_type __len,
1140  __diff_type __pos)
1141  {
1142  const auto& __pred = this->_M_pred();
1143  __diff_type __i = 0;
1144  while (__pred(__word[__pos - __i], __word[__len - 1 - __i])
1145  && __i < __pos)
1146  {
1147  ++__i;
1148  }
1149  return __i;
1150  }
1151 
1152  template<typename _Tp>
1153  __diff_type
1154  _M_bad_char_shift(_Tp __c) const
1155  { return this->_M_lookup(__c, _M_pat_end - _M_pat); }
1156 
1157  _RAIter _M_pat;
1158  _RAIter _M_pat_end;
1159  _GLIBCXX_STD_C::vector<__diff_type> _M_good_suffix;
1160  };
1161 
1162  template<typename _RAIter, typename _Hash
1163  = hash<typename iterator_traits<_RAIter>::value_type>,
1164  typename _BinaryPredicate = equal_to<>>
1165  class boyer_moore_horspool_searcher
1166  : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
1167  {
1168  using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
1169  using typename _Base::__diff_type;
1170 
1171  public:
1172  boyer_moore_horspool_searcher(_RAIter __pat,
1173  _RAIter __pat_end,
1174  _Hash __hf = _Hash(),
1175  _BinaryPredicate __pred
1176  = _BinaryPredicate())
1177  : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
1178  _M_pat(__pat), _M_pat_end(__pat_end)
1179  { }
1180 
1181  template<typename _RandomAccessIterator2>
1182  pair<_RandomAccessIterator2, _RandomAccessIterator2>
1183  operator()(_RandomAccessIterator2 __first,
1184  _RandomAccessIterator2 __last) const
1185  {
1186  const auto& __pred = this->_M_pred();
1187  auto __patlen = _M_pat_end - _M_pat;
1188  if (__patlen == 0)
1189  return std::make_pair(__first, __first);
1190  auto __len = __last - __first;
1191  while (__len >= __patlen)
1192  {
1193  for (auto __scan = __patlen - 1;
1194  __pred(__first[__scan], _M_pat[__scan]); --__scan)
1195  if (__scan == 0)
1196  return std::make_pair(__first, __first + __patlen);
1197  auto __shift = _M_bad_char_shift(__first[__patlen - 1]);
1198  __len -= __shift;
1199  __first += __shift;
1200  }
1201  return std::make_pair(__last, __last);
1202  }
1203 
1204  private:
1205  template<typename _Tp>
1206  __diff_type
1207  _M_bad_char_shift(_Tp __c) const
1208  { return this->_M_lookup(__c, _M_pat_end - _M_pat); }
1209 
1210  _RAIter _M_pat;
1211  _RAIter _M_pat_end;
1212  };
1213 
1214  template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
1215  boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
1216  boyer_moore_searcher(_RAIter __pat, _RAIter __pat_end,
1217  _Hash __hf, _BinaryPredicate __pred)
1218  : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
1219  _M_pat(__pat), _M_pat_end(__pat_end), _M_good_suffix(__pat_end - __pat)
1220  {
1221  auto __patlen = __pat_end - __pat;
1222  if (__patlen == 0)
1223  return;
1224  __diff_type __last_prefix = __patlen - 1;
1225  for (__diff_type __p = __patlen - 1; __p >= 0; --__p)
1226  {
1227  if (_M_is_prefix(__pat, __patlen, __p + 1))
1228  __last_prefix = __p + 1;
1229  _M_good_suffix[__p] = __last_prefix + (__patlen - 1 - __p);
1230  }
1231  for (__diff_type __p = 0; __p < __patlen - 1; ++__p)
1232  {
1233  auto __slen = _M_suffix_length(__pat, __patlen, __p);
1234  auto __pos = __patlen - 1 - __slen;
1235  if (!__pred(__pat[__p - __slen], __pat[__pos]))
1236  _M_good_suffix[__pos] = __patlen - 1 - __p + __slen;
1237  }
1238  }
1239 
1240  template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
1241  template<typename _RandomAccessIterator2>
1242  pair<_RandomAccessIterator2, _RandomAccessIterator2>
1243  boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
1244  operator()(_RandomAccessIterator2 __first,
1245  _RandomAccessIterator2 __last) const
1246  {
1247  auto __patlen = _M_pat_end - _M_pat;
1248  if (__patlen == 0)
1249  return std::make_pair(__first, __first);
1250  const auto& __pred = this->_M_pred();
1251  __diff_type __i = __patlen - 1;
1252  auto __stringlen = __last - __first;
1253  while (__i < __stringlen)
1254  {
1255  __diff_type __j = __patlen - 1;
1256  while (__j >= 0 && __pred(__first[__i], _M_pat[__j]))
1257  {
1258  --__i;
1259  --__j;
1260  }
1261  if (__j < 0)
1262  {
1263  const auto __match = __first + __i + 1;
1264  return std::make_pair(__match, __match + __patlen);
1265  }
1266  __i += std::max(_M_bad_char_shift(__first[__i]),
1267  _M_good_suffix[__j]);
1268  }
1269  return std::make_pair(__last, __last);
1270  }
1271 
1272 #endif // C++17
1273 #endif // C++14
1274 
1275 _GLIBCXX_END_NAMESPACE_VERSION
1276 } // namespace std
1277 
1278 #endif // C++11
1279 
1280 #endif // _GLIBCXX_FUNCTIONAL