libstdc++
functional
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1 // <functional> -*- C++ -*-
2 
3 // Copyright (C) 2001-2022 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 <bits/stl_algo.h>
65 #endif
66 #if __cplusplus > 201703L
67 # include <bits/ranges_cmp.h>
68 # include <compare>
69 #endif
70 #if __cplusplus > 202002L
71 # include <bits/move_only_function.h>
72 #endif
73 
74 #endif // C++11
75 
76 namespace std _GLIBCXX_VISIBILITY(default)
77 {
78 _GLIBCXX_BEGIN_NAMESPACE_VERSION
79 
80  /** @brief The type of placeholder objects defined by libstdc++.
81  * @ingroup binders
82  * @since C++11
83  */
84  template<int _Num> struct _Placeholder { };
85 
86 #if __cplusplus >= 201103L
87 
88 #if __cplusplus >= 201703L
89 # define __cpp_lib_invoke 201411L
90 # if __cplusplus > 201703L
91 # define __cpp_lib_constexpr_functional 201907L
92 # endif
93 
94  /** Invoke a callable object.
95  *
96  * `std::invoke` takes a callable object as its first argument and calls it
97  * with the remaining arguments. The callable object can be a pointer or
98  * reference to a function, a lambda closure, a class with `operator()`,
99  * or even a pointer-to-member. For a pointer-to-member the first argument
100  * must be a reference or pointer to the object that the pointer-to-member
101  * will be applied to.
102  *
103  * @since C++17
104  */
105  template<typename _Callable, typename... _Args>
106  inline _GLIBCXX20_CONSTEXPR invoke_result_t<_Callable, _Args...>
107  invoke(_Callable&& __fn, _Args&&... __args)
108  noexcept(is_nothrow_invocable_v<_Callable, _Args...>)
109  {
110  return std::__invoke(std::forward<_Callable>(__fn),
111  std::forward<_Args>(__args)...);
112  }
113 
114 #if __cplusplus > 202002L
115 # define __cpp_lib_invoke_r 202106L
116 
117  /** Invoke a callable object and convert the result to `_Res`.
118  *
119  * `std::invoke_r<R>(f, args...)` is equivalent to `std::invoke(f, args...)`
120  * with the result implicitly converted to `R`.
121  *
122  * @since C++23
123  */
124  template<typename _Res, typename _Callable, typename... _Args>
125  requires is_invocable_r_v<_Res, _Callable, _Args...>
126  constexpr _Res
127  invoke_r(_Callable&& __fn, _Args&&... __args)
128  noexcept(is_nothrow_invocable_r_v<_Res, _Callable, _Args...>)
129  {
130  return std::__invoke_r<_Res>(std::forward<_Callable>(__fn),
131  std::forward<_Args>(__args)...);
132  }
133 #endif // C++23
134 #endif // C++17
135 
136  /// @cond undocumented
137 
138  template<typename _MemFunPtr,
139  bool __is_mem_fn = is_member_function_pointer<_MemFunPtr>::value>
140  class _Mem_fn_base
141  : public _Mem_fn_traits<_MemFunPtr>::__maybe_type
142  {
143  using _Traits = _Mem_fn_traits<_MemFunPtr>;
144 
145  using _Arity = typename _Traits::__arity;
146  using _Varargs = typename _Traits::__vararg;
147 
148  template<typename _Func, typename... _BoundArgs>
149  friend struct _Bind_check_arity;
150 
151  _MemFunPtr _M_pmf;
152 
153  public:
154 
155  using result_type = typename _Traits::__result_type;
156 
157  explicit constexpr
158  _Mem_fn_base(_MemFunPtr __pmf) noexcept : _M_pmf(__pmf) { }
159 
160  template<typename... _Args>
161  _GLIBCXX20_CONSTEXPR
162  auto
163  operator()(_Args&&... __args) const
164  noexcept(noexcept(
165  std::__invoke(_M_pmf, std::forward<_Args>(__args)...)))
166  -> decltype(std::__invoke(_M_pmf, std::forward<_Args>(__args)...))
167  { return std::__invoke(_M_pmf, std::forward<_Args>(__args)...); }
168  };
169 
170  // Partial specialization for member object pointers.
171  template<typename _MemObjPtr>
172  class _Mem_fn_base<_MemObjPtr, false>
173  {
174  using _Arity = integral_constant<size_t, 0>;
175  using _Varargs = false_type;
176 
177  template<typename _Func, typename... _BoundArgs>
178  friend struct _Bind_check_arity;
179 
180  _MemObjPtr _M_pm;
181 
182  public:
183  explicit constexpr
184  _Mem_fn_base(_MemObjPtr __pm) noexcept : _M_pm(__pm) { }
185 
186  template<typename _Tp>
187  _GLIBCXX20_CONSTEXPR
188  auto
189  operator()(_Tp&& __obj) const
190  noexcept(noexcept(std::__invoke(_M_pm, std::forward<_Tp>(__obj))))
191  -> decltype(std::__invoke(_M_pm, std::forward<_Tp>(__obj)))
192  { return std::__invoke(_M_pm, std::forward<_Tp>(__obj)); }
193  };
194 
195  template<typename _MemberPointer>
196  struct _Mem_fn; // undefined
197 
198  template<typename _Res, typename _Class>
199  struct _Mem_fn<_Res _Class::*>
200  : _Mem_fn_base<_Res _Class::*>
201  {
202  using _Mem_fn_base<_Res _Class::*>::_Mem_fn_base;
203  };
204  /// @endcond
205 
206  // _GLIBCXX_RESOLVE_LIB_DEFECTS
207  // 2048. Unnecessary mem_fn overloads
208  /**
209  * @brief Returns a function object that forwards to the member pointer
210  * pointer `pm`.
211  *
212  * This allows a pointer-to-member to be transformed into a function object
213  * that can be called with an object expression as its first argument.
214  *
215  * For a pointer-to-data-member the result must be called with exactly one
216  * argument, the object expression that would be used as the first operand
217  * in a `obj.*memptr` or `objp->*memptr` expression.
218  *
219  * For a pointer-to-member-function the result must be called with an object
220  * expression and any additional arguments to pass to the member function,
221  * as in an expression like `(obj.*memfun)(args...)` or
222  * `(objp->*memfun)(args...)`.
223  *
224  * The object expression can be a pointer, reference, `reference_wrapper`,
225  * or smart pointer, and the call wrapper will dereference it as needed
226  * to apply the pointer-to-member.
227  *
228  * @ingroup functors
229  * @since C++11
230  */
231  template<typename _Tp, typename _Class>
232  _GLIBCXX20_CONSTEXPR
233  inline _Mem_fn<_Tp _Class::*>
234  mem_fn(_Tp _Class::* __pm) noexcept
235  {
236  return _Mem_fn<_Tp _Class::*>(__pm);
237  }
238 
239  /**
240  * @brief Trait that identifies a bind expression.
241  *
242  * Determines if the given type `_Tp` is a function object that
243  * should be treated as a subexpression when evaluating calls to
244  * function objects returned by `std::bind`.
245  *
246  * C++11 [func.bind.isbind].
247  * @ingroup binders
248  * @since C++11
249  */
250  template<typename _Tp>
251  struct is_bind_expression
252  : public false_type { };
253 
254  /**
255  * @brief Determines if the given type _Tp is a placeholder in a
256  * bind() expression and, if so, which placeholder it is.
257  *
258  * C++11 [func.bind.isplace].
259  * @ingroup binders
260  * @since C++11
261  */
262  template<typename _Tp>
263  struct is_placeholder
264  : public integral_constant<int, 0>
265  { };
266 
267 #if __cplusplus > 201402L
268  template <typename _Tp> inline constexpr bool is_bind_expression_v
269  = is_bind_expression<_Tp>::value;
270  template <typename _Tp> inline constexpr int is_placeholder_v
271  = is_placeholder<_Tp>::value;
272 #endif // C++17
273 
274  /** @namespace std::placeholders
275  * @brief ISO C++ 2011 namespace for std::bind placeholders.
276  * @ingroup binders
277  * @since C++11
278  */
279  namespace placeholders
280  {
281  /* Define a large number of placeholders. There is no way to
282  * simplify this with variadic templates, because we're introducing
283  * unique names for each.
284  */
285  extern const _Placeholder<1> _1;
286  extern const _Placeholder<2> _2;
287  extern const _Placeholder<3> _3;
288  extern const _Placeholder<4> _4;
289  extern const _Placeholder<5> _5;
290  extern const _Placeholder<6> _6;
291  extern const _Placeholder<7> _7;
292  extern const _Placeholder<8> _8;
293  extern const _Placeholder<9> _9;
294  extern const _Placeholder<10> _10;
295  extern const _Placeholder<11> _11;
296  extern const _Placeholder<12> _12;
297  extern const _Placeholder<13> _13;
298  extern const _Placeholder<14> _14;
299  extern const _Placeholder<15> _15;
300  extern const _Placeholder<16> _16;
301  extern const _Placeholder<17> _17;
302  extern const _Placeholder<18> _18;
303  extern const _Placeholder<19> _19;
304  extern const _Placeholder<20> _20;
305  extern const _Placeholder<21> _21;
306  extern const _Placeholder<22> _22;
307  extern const _Placeholder<23> _23;
308  extern const _Placeholder<24> _24;
309  extern const _Placeholder<25> _25;
310  extern const _Placeholder<26> _26;
311  extern const _Placeholder<27> _27;
312  extern const _Placeholder<28> _28;
313  extern const _Placeholder<29> _29;
314  }
315 
316  /**
317  * Partial specialization of is_placeholder that provides the placeholder
318  * number for the placeholder objects defined by libstdc++.
319  * @ingroup binders
320  * @since C++11
321  */
322  template<int _Num>
323  struct is_placeholder<_Placeholder<_Num> >
324  : public integral_constant<int, _Num>
325  { };
326 
327  template<int _Num>
328  struct is_placeholder<const _Placeholder<_Num> >
329  : public integral_constant<int, _Num>
330  { };
331 
332  /// @cond undocumented
333 
334  // Like tuple_element_t but SFINAE-friendly.
335  template<std::size_t __i, typename _Tuple>
336  using _Safe_tuple_element_t
337  = typename enable_if<(__i < tuple_size<_Tuple>::value),
338  tuple_element<__i, _Tuple>>::type::type;
339 
340  /**
341  * Maps an argument to bind() into an actual argument to the bound
342  * function object [func.bind.bind]/10. Only the first parameter should
343  * be specified: the rest are used to determine among the various
344  * implementations. Note that, although this class is a function
345  * object, it isn't entirely normal because it takes only two
346  * parameters regardless of the number of parameters passed to the
347  * bind expression. The first parameter is the bound argument and
348  * the second parameter is a tuple containing references to the
349  * rest of the arguments.
350  */
351  template<typename _Arg,
352  bool _IsBindExp = is_bind_expression<_Arg>::value,
353  bool _IsPlaceholder = (is_placeholder<_Arg>::value > 0)>
354  class _Mu;
355 
356  /**
357  * If the argument is reference_wrapper<_Tp>, returns the
358  * underlying reference.
359  * C++11 [func.bind.bind] p10 bullet 1.
360  */
361  template<typename _Tp>
362  class _Mu<reference_wrapper<_Tp>, false, false>
363  {
364  public:
365  /* Note: This won't actually work for const volatile
366  * reference_wrappers, because reference_wrapper::get() is const
367  * but not volatile-qualified. This might be a defect in the TR.
368  */
369  template<typename _CVRef, typename _Tuple>
370  _GLIBCXX20_CONSTEXPR
371  _Tp&
372  operator()(_CVRef& __arg, _Tuple&) const volatile
373  { return __arg.get(); }
374  };
375 
376  /**
377  * If the argument is a bind expression, we invoke the underlying
378  * function object with the same cv-qualifiers as we are given and
379  * pass along all of our arguments (unwrapped).
380  * C++11 [func.bind.bind] p10 bullet 2.
381  */
382  template<typename _Arg>
383  class _Mu<_Arg, true, false>
384  {
385  public:
386  template<typename _CVArg, typename... _Args>
387  _GLIBCXX20_CONSTEXPR
388  auto
389  operator()(_CVArg& __arg,
390  tuple<_Args...>& __tuple) const volatile
391  -> decltype(__arg(declval<_Args>()...))
392  {
393  // Construct an index tuple and forward to __call
394  typedef typename _Build_index_tuple<sizeof...(_Args)>::__type
395  _Indexes;
396  return this->__call(__arg, __tuple, _Indexes());
397  }
398 
399  private:
400  // Invokes the underlying function object __arg by unpacking all
401  // of the arguments in the tuple.
402  template<typename _CVArg, typename... _Args, std::size_t... _Indexes>
403  _GLIBCXX20_CONSTEXPR
404  auto
405  __call(_CVArg& __arg, tuple<_Args...>& __tuple,
406  const _Index_tuple<_Indexes...>&) const volatile
407  -> decltype(__arg(declval<_Args>()...))
408  {
409  return __arg(std::get<_Indexes>(std::move(__tuple))...);
410  }
411  };
412 
413  /**
414  * If the argument is a placeholder for the Nth argument, returns
415  * a reference to the Nth argument to the bind function object.
416  * C++11 [func.bind.bind] p10 bullet 3.
417  */
418  template<typename _Arg>
419  class _Mu<_Arg, false, true>
420  {
421  public:
422  template<typename _Tuple>
423  _GLIBCXX20_CONSTEXPR
424  _Safe_tuple_element_t<(is_placeholder<_Arg>::value - 1), _Tuple>&&
425  operator()(const volatile _Arg&, _Tuple& __tuple) const volatile
426  {
427  return
428  ::std::get<(is_placeholder<_Arg>::value - 1)>(std::move(__tuple));
429  }
430  };
431 
432  /**
433  * If the argument is just a value, returns a reference to that
434  * value. The cv-qualifiers on the reference are determined by the caller.
435  * C++11 [func.bind.bind] p10 bullet 4.
436  */
437  template<typename _Arg>
438  class _Mu<_Arg, false, false>
439  {
440  public:
441  template<typename _CVArg, typename _Tuple>
442  _GLIBCXX20_CONSTEXPR
443  _CVArg&&
444  operator()(_CVArg&& __arg, _Tuple&) const volatile
445  { return std::forward<_CVArg>(__arg); }
446  };
447 
448  // std::get<I> for volatile-qualified tuples
449  template<std::size_t _Ind, typename... _Tp>
450  inline auto
451  __volget(volatile tuple<_Tp...>& __tuple)
452  -> __tuple_element_t<_Ind, tuple<_Tp...>> volatile&
453  { return std::get<_Ind>(const_cast<tuple<_Tp...>&>(__tuple)); }
454 
455  // std::get<I> for const-volatile-qualified tuples
456  template<std::size_t _Ind, typename... _Tp>
457  inline auto
458  __volget(const volatile tuple<_Tp...>& __tuple)
459  -> __tuple_element_t<_Ind, tuple<_Tp...>> const volatile&
460  { return std::get<_Ind>(const_cast<const tuple<_Tp...>&>(__tuple)); }
461 
462  /// @endcond
463 
464 #if __cplusplus == 201703L && _GLIBCXX_USE_DEPRECATED
465 # define _GLIBCXX_VOLATILE_BIND
466 // _GLIBCXX_RESOLVE_LIB_DEFECTS
467 // 2487. bind() should be const-overloaded, not cv-overloaded
468 # define _GLIBCXX_DEPR_BIND \
469  [[deprecated("std::bind does not support volatile in C++17")]]
470 #elif __cplusplus < 201703L
471 # define _GLIBCXX_VOLATILE_BIND
472 # define _GLIBCXX_DEPR_BIND
473 #endif
474 
475  /// Type of the function object returned from bind().
476  template<typename _Signature>
477  class _Bind;
478 
479  template<typename _Functor, typename... _Bound_args>
480  class _Bind<_Functor(_Bound_args...)>
481  : public _Weak_result_type<_Functor>
482  {
483  typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
484  _Bound_indexes;
485 
486  _Functor _M_f;
487  tuple<_Bound_args...> _M_bound_args;
488 
489  // Call unqualified
490  template<typename _Result, typename... _Args, std::size_t... _Indexes>
491  _GLIBCXX20_CONSTEXPR
492  _Result
493  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
494  {
495  return std::__invoke(_M_f,
496  _Mu<_Bound_args>()(std::get<_Indexes>(_M_bound_args), __args)...
497  );
498  }
499 
500  // Call as const
501  template<typename _Result, typename... _Args, std::size_t... _Indexes>
502  _GLIBCXX20_CONSTEXPR
503  _Result
504  __call_c(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
505  {
506  return std::__invoke(_M_f,
507  _Mu<_Bound_args>()(std::get<_Indexes>(_M_bound_args), __args)...
508  );
509  }
510 
511 #ifdef _GLIBCXX_VOLATILE_BIND
512  // Call as volatile
513  template<typename _Result, typename... _Args, std::size_t... _Indexes>
514  _Result
515  __call_v(tuple<_Args...>&& __args,
516  _Index_tuple<_Indexes...>) volatile
517  {
518  return std::__invoke(_M_f,
519  _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
520  );
521  }
522 
523  // Call as const volatile
524  template<typename _Result, typename... _Args, std::size_t... _Indexes>
525  _Result
526  __call_c_v(tuple<_Args...>&& __args,
527  _Index_tuple<_Indexes...>) const volatile
528  {
529  return std::__invoke(_M_f,
530  _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
531  );
532  }
533 #endif // volatile
534 
535  template<typename _BoundArg, typename _CallArgs>
536  using _Mu_type = decltype(
537  _Mu<typename remove_cv<_BoundArg>::type>()(
538  std::declval<_BoundArg&>(), std::declval<_CallArgs&>()) );
539 
540  template<typename _Fn, typename _CallArgs, typename... _BArgs>
541  using _Res_type_impl
542  = typename result_of< _Fn&(_Mu_type<_BArgs, _CallArgs>&&...) >::type;
543 
544  template<typename _CallArgs>
545  using _Res_type = _Res_type_impl<_Functor, _CallArgs, _Bound_args...>;
546 
547  template<typename _CallArgs>
548  using __dependent = typename
549  enable_if<bool(tuple_size<_CallArgs>::value+1), _Functor>::type;
550 
551  template<typename _CallArgs, template<class> class __cv_quals>
552  using _Res_type_cv = _Res_type_impl<
553  typename __cv_quals<__dependent<_CallArgs>>::type,
554  _CallArgs,
555  typename __cv_quals<_Bound_args>::type...>;
556 
557  public:
558  template<typename... _Args>
559  explicit _GLIBCXX20_CONSTEXPR
560  _Bind(const _Functor& __f, _Args&&... __args)
561  : _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
562  { }
563 
564  template<typename... _Args>
565  explicit _GLIBCXX20_CONSTEXPR
566  _Bind(_Functor&& __f, _Args&&... __args)
567  : _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
568  { }
569 
570  _Bind(const _Bind&) = default;
571  _Bind(_Bind&&) = default;
572 
573  // Call unqualified
574  template<typename... _Args,
575  typename _Result = _Res_type<tuple<_Args...>>>
576  _GLIBCXX20_CONSTEXPR
577  _Result
578  operator()(_Args&&... __args)
579  {
580  return this->__call<_Result>(
581  std::forward_as_tuple(std::forward<_Args>(__args)...),
582  _Bound_indexes());
583  }
584 
585  // Call as const
586  template<typename... _Args,
587  typename _Result = _Res_type_cv<tuple<_Args...>, add_const>>
588  _GLIBCXX20_CONSTEXPR
589  _Result
590  operator()(_Args&&... __args) const
591  {
592  return this->__call_c<_Result>(
593  std::forward_as_tuple(std::forward<_Args>(__args)...),
594  _Bound_indexes());
595  }
596 
597 #ifdef _GLIBCXX_VOLATILE_BIND
598  // Call as volatile
599  template<typename... _Args,
600  typename _Result = _Res_type_cv<tuple<_Args...>, add_volatile>>
601  _GLIBCXX_DEPR_BIND
602  _Result
603  operator()(_Args&&... __args) volatile
604  {
605  return this->__call_v<_Result>(
606  std::forward_as_tuple(std::forward<_Args>(__args)...),
607  _Bound_indexes());
608  }
609 
610  // Call as const volatile
611  template<typename... _Args,
612  typename _Result = _Res_type_cv<tuple<_Args...>, add_cv>>
613  _GLIBCXX_DEPR_BIND
614  _Result
615  operator()(_Args&&... __args) const volatile
616  {
617  return this->__call_c_v<_Result>(
618  std::forward_as_tuple(std::forward<_Args>(__args)...),
619  _Bound_indexes());
620  }
621 #endif // volatile
622  };
623 
624  /// Type of the function object returned from bind<R>().
625  template<typename _Result, typename _Signature>
626  class _Bind_result;
627 
628  template<typename _Result, typename _Functor, typename... _Bound_args>
629  class _Bind_result<_Result, _Functor(_Bound_args...)>
630  {
631  typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
632  _Bound_indexes;
633 
634  _Functor _M_f;
635  tuple<_Bound_args...> _M_bound_args;
636 
637  // Call unqualified
638  template<typename _Res, typename... _Args, std::size_t... _Indexes>
639  _GLIBCXX20_CONSTEXPR
640  _Res
641  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
642  {
643  return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
644  (std::get<_Indexes>(_M_bound_args), __args)...);
645  }
646 
647  // Call as const
648  template<typename _Res, typename... _Args, std::size_t... _Indexes>
649  _GLIBCXX20_CONSTEXPR
650  _Res
651  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
652  {
653  return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
654  (std::get<_Indexes>(_M_bound_args), __args)...);
655  }
656 
657 #ifdef _GLIBCXX_VOLATILE_BIND
658  // Call as volatile
659  template<typename _Res, typename... _Args, std::size_t... _Indexes>
660  _Res
661  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
662  {
663  return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
664  (__volget<_Indexes>(_M_bound_args), __args)...);
665  }
666 
667  // Call as const volatile
668  template<typename _Res, typename... _Args, std::size_t... _Indexes>
669  _Res
670  __call(tuple<_Args...>&& __args,
671  _Index_tuple<_Indexes...>) const volatile
672  {
673  return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
674  (__volget<_Indexes>(_M_bound_args), __args)...);
675  }
676 #endif // volatile
677 
678  public:
679  typedef _Result result_type;
680 
681  template<typename... _Args>
682  explicit _GLIBCXX20_CONSTEXPR
683  _Bind_result(const _Functor& __f, _Args&&... __args)
684  : _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
685  { }
686 
687  template<typename... _Args>
688  explicit _GLIBCXX20_CONSTEXPR
689  _Bind_result(_Functor&& __f, _Args&&... __args)
690  : _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
691  { }
692 
693  _Bind_result(const _Bind_result&) = default;
694  _Bind_result(_Bind_result&&) = default;
695 
696  // Call unqualified
697  template<typename... _Args>
698  _GLIBCXX20_CONSTEXPR
699  result_type
700  operator()(_Args&&... __args)
701  {
702  return this->__call<_Result>(
703  std::forward_as_tuple(std::forward<_Args>(__args)...),
704  _Bound_indexes());
705  }
706 
707  // Call as const
708  template<typename... _Args>
709  _GLIBCXX20_CONSTEXPR
710  result_type
711  operator()(_Args&&... __args) const
712  {
713  return this->__call<_Result>(
714  std::forward_as_tuple(std::forward<_Args>(__args)...),
715  _Bound_indexes());
716  }
717 
718 #ifdef _GLIBCXX_VOLATILE_BIND
719  // Call as volatile
720  template<typename... _Args>
721  _GLIBCXX_DEPR_BIND
722  result_type
723  operator()(_Args&&... __args) volatile
724  {
725  return this->__call<_Result>(
726  std::forward_as_tuple(std::forward<_Args>(__args)...),
727  _Bound_indexes());
728  }
729 
730  // Call as const volatile
731  template<typename... _Args>
732  _GLIBCXX_DEPR_BIND
733  result_type
734  operator()(_Args&&... __args) const volatile
735  {
736  return this->__call<_Result>(
737  std::forward_as_tuple(std::forward<_Args>(__args)...),
738  _Bound_indexes());
739  }
740 #else
741  template<typename... _Args>
742  void operator()(_Args&&...) const volatile = delete;
743 #endif // volatile
744  };
745 
746 #undef _GLIBCXX_VOLATILE_BIND
747 #undef _GLIBCXX_DEPR_BIND
748 
749  /**
750  * @brief Class template _Bind is always a bind expression.
751  * @ingroup binders
752  */
753  template<typename _Signature>
754  struct is_bind_expression<_Bind<_Signature> >
755  : public true_type { };
756 
757  /**
758  * @brief Class template _Bind is always a bind expression.
759  * @ingroup binders
760  */
761  template<typename _Signature>
762  struct is_bind_expression<const _Bind<_Signature> >
763  : public true_type { };
764 
765  /**
766  * @brief Class template _Bind is always a bind expression.
767  * @ingroup binders
768  */
769  template<typename _Signature>
770  struct is_bind_expression<volatile _Bind<_Signature> >
771  : public true_type { };
772 
773  /**
774  * @brief Class template _Bind is always a bind expression.
775  * @ingroup binders
776  */
777  template<typename _Signature>
778  struct is_bind_expression<const volatile _Bind<_Signature>>
779  : public true_type { };
780 
781  /**
782  * @brief Class template _Bind_result is always a bind expression.
783  * @ingroup binders
784  */
785  template<typename _Result, typename _Signature>
786  struct is_bind_expression<_Bind_result<_Result, _Signature>>
787  : public true_type { };
788 
789  /**
790  * @brief Class template _Bind_result is always a bind expression.
791  * @ingroup binders
792  */
793  template<typename _Result, typename _Signature>
794  struct is_bind_expression<const _Bind_result<_Result, _Signature>>
795  : public true_type { };
796 
797  /**
798  * @brief Class template _Bind_result is always a bind expression.
799  * @ingroup binders
800  */
801  template<typename _Result, typename _Signature>
802  struct is_bind_expression<volatile _Bind_result<_Result, _Signature>>
803  : public true_type { };
804 
805  /**
806  * @brief Class template _Bind_result is always a bind expression.
807  * @ingroup binders
808  */
809  template<typename _Result, typename _Signature>
810  struct is_bind_expression<const volatile _Bind_result<_Result, _Signature>>
811  : public true_type { };
812 
813  template<typename _Func, typename... _BoundArgs>
814  struct _Bind_check_arity { };
815 
816  template<typename _Ret, typename... _Args, typename... _BoundArgs>
817  struct _Bind_check_arity<_Ret (*)(_Args...), _BoundArgs...>
818  {
819  static_assert(sizeof...(_BoundArgs) == sizeof...(_Args),
820  "Wrong number of arguments for function");
821  };
822 
823  template<typename _Ret, typename... _Args, typename... _BoundArgs>
824  struct _Bind_check_arity<_Ret (*)(_Args......), _BoundArgs...>
825  {
826  static_assert(sizeof...(_BoundArgs) >= sizeof...(_Args),
827  "Wrong number of arguments for function");
828  };
829 
830  template<typename _Tp, typename _Class, typename... _BoundArgs>
831  struct _Bind_check_arity<_Tp _Class::*, _BoundArgs...>
832  {
833  using _Arity = typename _Mem_fn<_Tp _Class::*>::_Arity;
834  using _Varargs = typename _Mem_fn<_Tp _Class::*>::_Varargs;
835  static_assert(_Varargs::value
836  ? sizeof...(_BoundArgs) >= _Arity::value + 1
837  : sizeof...(_BoundArgs) == _Arity::value + 1,
838  "Wrong number of arguments for pointer-to-member");
839  };
840 
841  // Trait type used to remove std::bind() from overload set via SFINAE
842  // when first argument has integer type, so that std::bind() will
843  // not be a better match than ::bind() from the BSD Sockets API.
844  template<typename _Tp, typename _Tp2 = typename decay<_Tp>::type>
845  using __is_socketlike = __or_<is_integral<_Tp2>, is_enum<_Tp2>>;
846 
847  template<bool _SocketLike, typename _Func, typename... _BoundArgs>
848  struct _Bind_helper
849  : _Bind_check_arity<typename decay<_Func>::type, _BoundArgs...>
850  {
851  typedef typename decay<_Func>::type __func_type;
852  typedef _Bind<__func_type(typename decay<_BoundArgs>::type...)> type;
853  };
854 
855  // Partial specialization for is_socketlike == true, does not define
856  // nested type so std::bind() will not participate in overload resolution
857  // when the first argument might be a socket file descriptor.
858  template<typename _Func, typename... _BoundArgs>
859  struct _Bind_helper<true, _Func, _BoundArgs...>
860  { };
861 
862  /**
863  * @brief Function template for std::bind.
864  * @ingroup binders
865  * @since C++11
866  */
867  template<typename _Func, typename... _BoundArgs>
868  inline _GLIBCXX20_CONSTEXPR typename
869  _Bind_helper<__is_socketlike<_Func>::value, _Func, _BoundArgs...>::type
870  bind(_Func&& __f, _BoundArgs&&... __args)
871  {
872  typedef _Bind_helper<false, _Func, _BoundArgs...> __helper_type;
873  return typename __helper_type::type(std::forward<_Func>(__f),
874  std::forward<_BoundArgs>(__args)...);
875  }
876 
877  template<typename _Result, typename _Func, typename... _BoundArgs>
878  struct _Bindres_helper
879  : _Bind_check_arity<typename decay<_Func>::type, _BoundArgs...>
880  {
881  typedef typename decay<_Func>::type __functor_type;
882  typedef _Bind_result<_Result,
883  __functor_type(typename decay<_BoundArgs>::type...)>
884  type;
885  };
886 
887  /**
888  * @brief Function template for std::bind<R>.
889  * @ingroup binders
890  * @since C++11
891  */
892  template<typename _Result, typename _Func, typename... _BoundArgs>
893  inline _GLIBCXX20_CONSTEXPR
894  typename _Bindres_helper<_Result, _Func, _BoundArgs...>::type
895  bind(_Func&& __f, _BoundArgs&&... __args)
896  {
897  typedef _Bindres_helper<_Result, _Func, _BoundArgs...> __helper_type;
898  return typename __helper_type::type(std::forward<_Func>(__f),
899  std::forward<_BoundArgs>(__args)...);
900  }
901 
902 #if __cplusplus > 201703L
903 #define __cpp_lib_bind_front 201907L
904 
905  template<typename _Fd, typename... _BoundArgs>
906  struct _Bind_front
907  {
908  static_assert(is_move_constructible_v<_Fd>);
909  static_assert((is_move_constructible_v<_BoundArgs> && ...));
910 
911  // First parameter is to ensure this constructor is never used
912  // instead of the copy/move constructor.
913  template<typename _Fn, typename... _Args>
914  explicit constexpr
915  _Bind_front(int, _Fn&& __fn, _Args&&... __args)
916  noexcept(__and_<is_nothrow_constructible<_Fd, _Fn>,
917  is_nothrow_constructible<_BoundArgs, _Args>...>::value)
918  : _M_fd(std::forward<_Fn>(__fn)),
919  _M_bound_args(std::forward<_Args>(__args)...)
920  { static_assert(sizeof...(_Args) == sizeof...(_BoundArgs)); }
921 
922  _Bind_front(const _Bind_front&) = default;
923  _Bind_front(_Bind_front&&) = default;
924  _Bind_front& operator=(const _Bind_front&) = default;
925  _Bind_front& operator=(_Bind_front&&) = default;
926  ~_Bind_front() = default;
927 
928  template<typename... _CallArgs>
929  constexpr
930  invoke_result_t<_Fd&, _BoundArgs&..., _CallArgs...>
931  operator()(_CallArgs&&... __call_args) &
932  noexcept(is_nothrow_invocable_v<_Fd&, _BoundArgs&..., _CallArgs...>)
933  {
934  return _S_call(*this, _BoundIndices(),
935  std::forward<_CallArgs>(__call_args)...);
936  }
937 
938  template<typename... _CallArgs>
939  constexpr
940  invoke_result_t<const _Fd&, const _BoundArgs&..., _CallArgs...>
941  operator()(_CallArgs&&... __call_args) const &
942  noexcept(is_nothrow_invocable_v<const _Fd&, const _BoundArgs&...,
943  _CallArgs...>)
944  {
945  return _S_call(*this, _BoundIndices(),
946  std::forward<_CallArgs>(__call_args)...);
947  }
948 
949  template<typename... _CallArgs>
950  constexpr
951  invoke_result_t<_Fd, _BoundArgs..., _CallArgs...>
952  operator()(_CallArgs&&... __call_args) &&
953  noexcept(is_nothrow_invocable_v<_Fd, _BoundArgs..., _CallArgs...>)
954  {
955  return _S_call(std::move(*this), _BoundIndices(),
956  std::forward<_CallArgs>(__call_args)...);
957  }
958 
959  template<typename... _CallArgs>
960  constexpr
961  invoke_result_t<const _Fd, const _BoundArgs..., _CallArgs...>
962  operator()(_CallArgs&&... __call_args) const &&
963  noexcept(is_nothrow_invocable_v<const _Fd, const _BoundArgs...,
964  _CallArgs...>)
965  {
966  return _S_call(std::move(*this), _BoundIndices(),
967  std::forward<_CallArgs>(__call_args)...);
968  }
969 
970  private:
971  using _BoundIndices = index_sequence_for<_BoundArgs...>;
972 
973  template<typename _Tp, size_t... _Ind, typename... _CallArgs>
974  static constexpr
975  decltype(auto)
976  _S_call(_Tp&& __g, index_sequence<_Ind...>, _CallArgs&&... __call_args)
977  {
978  return std::invoke(std::forward<_Tp>(__g)._M_fd,
979  std::get<_Ind>(std::forward<_Tp>(__g)._M_bound_args)...,
980  std::forward<_CallArgs>(__call_args)...);
981  }
982 
983  _Fd _M_fd;
984  std::tuple<_BoundArgs...> _M_bound_args;
985  };
986 
987  template<typename _Fn, typename... _Args>
988  using _Bind_front_t
989  = _Bind_front<decay_t<_Fn>, decay_t<_Args>...>;
990 
991  /** Create call wrapper by partial application of arguments to function.
992  *
993  * The result of `std::bind_front(f, args...)` is a function object that
994  * stores `f` and the bound arguments, `args...`. When that function
995  * object is invoked with `call_args...` it returns the result of calling
996  * `f(args..., call_args...)`.
997  *
998  * @since C++20
999  */
1000  template<typename _Fn, typename... _Args>
1001  constexpr _Bind_front_t<_Fn, _Args...>
1002  bind_front(_Fn&& __fn, _Args&&... __args)
1003  noexcept(is_nothrow_constructible_v<_Bind_front_t<_Fn, _Args...>,
1004  int, _Fn, _Args...>)
1005  {
1006  return _Bind_front_t<_Fn, _Args...>(0, std::forward<_Fn>(__fn),
1007  std::forward<_Args>(__args)...);
1008  }
1009 #endif // C++20
1010 
1011 #if __cplusplus >= 201402L
1012  /// Generalized negator.
1013  template<typename _Fn>
1014  class _Not_fn
1015  {
1016  template<typename _Fn2, typename... _Args>
1017  using __inv_res_t = typename __invoke_result<_Fn2, _Args...>::type;
1018 
1019  template<typename _Tp>
1020  static decltype(!std::declval<_Tp>())
1021  _S_not() noexcept(noexcept(!std::declval<_Tp>()));
1022 
1023  public:
1024  template<typename _Fn2>
1025  constexpr
1026  _Not_fn(_Fn2&& __fn, int)
1027  : _M_fn(std::forward<_Fn2>(__fn)) { }
1028 
1029  _Not_fn(const _Not_fn& __fn) = default;
1030  _Not_fn(_Not_fn&& __fn) = default;
1031  ~_Not_fn() = default;
1032 
1033  // Macro to define operator() with given cv-qualifiers ref-qualifiers,
1034  // forwarding _M_fn and the function arguments with the same qualifiers,
1035  // and deducing the return type and exception-specification.
1036 #define _GLIBCXX_NOT_FN_CALL_OP( _QUALS ) \
1037  template<typename... _Args> \
1038  _GLIBCXX20_CONSTEXPR \
1039  decltype(_S_not<__inv_res_t<_Fn _QUALS, _Args...>>()) \
1040  operator()(_Args&&... __args) _QUALS \
1041  noexcept(__is_nothrow_invocable<_Fn _QUALS, _Args...>::value \
1042  && noexcept(_S_not<__inv_res_t<_Fn _QUALS, _Args...>>())) \
1043  { \
1044  return !std::__invoke(std::forward< _Fn _QUALS >(_M_fn), \
1045  std::forward<_Args>(__args)...); \
1046  }
1047  _GLIBCXX_NOT_FN_CALL_OP( & )
1048  _GLIBCXX_NOT_FN_CALL_OP( const & )
1049  _GLIBCXX_NOT_FN_CALL_OP( && )
1050  _GLIBCXX_NOT_FN_CALL_OP( const && )
1051 #undef _GLIBCXX_NOT_FN_CALL_OP
1052 
1053  private:
1054  _Fn _M_fn;
1055  };
1056 
1057  template<typename _Tp, typename _Pred>
1058  struct __is_byte_like : false_type { };
1059 
1060  template<typename _Tp>
1061  struct __is_byte_like<_Tp, equal_to<_Tp>>
1062  : __bool_constant<sizeof(_Tp) == 1 && is_integral<_Tp>::value> { };
1063 
1064  template<typename _Tp>
1065  struct __is_byte_like<_Tp, equal_to<void>>
1066  : __bool_constant<sizeof(_Tp) == 1 && is_integral<_Tp>::value> { };
1067 
1068 #if __cplusplus >= 201703L
1069  // Declare std::byte (full definition is in <cstddef>).
1070  enum class byte : unsigned char;
1071 
1072  template<>
1073  struct __is_byte_like<byte, equal_to<byte>>
1074  : true_type { };
1075 
1076  template<>
1077  struct __is_byte_like<byte, equal_to<void>>
1078  : true_type { };
1079 
1080  // [func.not_fn] Function template not_fn
1081 #define __cpp_lib_not_fn 201603L
1082  /** Wrap a function object to create one that negates its result.
1083  *
1084  * The function template `std::not_fn` creates a "forwarding call wrapper",
1085  * which is a function object that wraps another function object and
1086  * when called, forwards its arguments to the wrapped function object.
1087  *
1088  * The result of invoking the wrapper is the negation (using `!`) of
1089  * the wrapped function object.
1090  *
1091  * @ingroup functors
1092  * @since C++17
1093  */
1094  template<typename _Fn>
1095  _GLIBCXX20_CONSTEXPR
1096  inline auto
1097  not_fn(_Fn&& __fn)
1098  noexcept(std::is_nothrow_constructible<std::decay_t<_Fn>, _Fn&&>::value)
1099  {
1100  return _Not_fn<std::decay_t<_Fn>>{std::forward<_Fn>(__fn), 0};
1101  }
1102 
1103  // Searchers
1104 #define __cpp_lib_boyer_moore_searcher 201603L
1105 
1106  template<typename _ForwardIterator1, typename _BinaryPredicate = equal_to<>>
1107  class default_searcher
1108  {
1109  public:
1110  _GLIBCXX20_CONSTEXPR
1111  default_searcher(_ForwardIterator1 __pat_first,
1112  _ForwardIterator1 __pat_last,
1113  _BinaryPredicate __pred = _BinaryPredicate())
1114  : _M_m(__pat_first, __pat_last, std::move(__pred))
1115  { }
1116 
1117  template<typename _ForwardIterator2>
1118  _GLIBCXX20_CONSTEXPR
1119  pair<_ForwardIterator2, _ForwardIterator2>
1120  operator()(_ForwardIterator2 __first, _ForwardIterator2 __last) const
1121  {
1122  _ForwardIterator2 __first_ret =
1123  std::search(__first, __last, std::get<0>(_M_m), std::get<1>(_M_m),
1124  std::get<2>(_M_m));
1125  auto __ret = std::make_pair(__first_ret, __first_ret);
1126  if (__ret.first != __last)
1127  std::advance(__ret.second, std::distance(std::get<0>(_M_m),
1128  std::get<1>(_M_m)));
1129  return __ret;
1130  }
1131 
1132  private:
1133  tuple<_ForwardIterator1, _ForwardIterator1, _BinaryPredicate> _M_m;
1134  };
1135 
1136  template<typename _Key, typename _Tp, typename _Hash, typename _Pred>
1137  struct __boyer_moore_map_base
1138  {
1139  template<typename _RAIter>
1140  __boyer_moore_map_base(_RAIter __pat, size_t __patlen,
1141  _Hash&& __hf, _Pred&& __pred)
1142  : _M_bad_char{ __patlen, std::move(__hf), std::move(__pred) }
1143  {
1144  if (__patlen > 0)
1145  for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
1146  _M_bad_char[__pat[__i]] = __patlen - 1 - __i;
1147  }
1148 
1149  using __diff_type = _Tp;
1150 
1151  __diff_type
1152  _M_lookup(_Key __key, __diff_type __not_found) const
1153  {
1154  auto __iter = _M_bad_char.find(__key);
1155  if (__iter == _M_bad_char.end())
1156  return __not_found;
1157  return __iter->second;
1158  }
1159 
1160  _Pred
1161  _M_pred() const { return _M_bad_char.key_eq(); }
1162 
1163  _GLIBCXX_STD_C::unordered_map<_Key, _Tp, _Hash, _Pred> _M_bad_char;
1164  };
1165 
1166  template<typename _Tp, size_t _Len, typename _Pred>
1167  struct __boyer_moore_array_base
1168  {
1169  template<typename _RAIter, typename _Unused>
1170  __boyer_moore_array_base(_RAIter __pat, size_t __patlen,
1171  _Unused&&, _Pred&& __pred)
1172  : _M_bad_char{ array<_Tp, _Len>{}, std::move(__pred) }
1173  {
1174  std::get<0>(_M_bad_char).fill(__patlen);
1175  if (__patlen > 0)
1176  for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
1177  {
1178  auto __ch = __pat[__i];
1179  using _UCh = make_unsigned_t<decltype(__ch)>;
1180  auto __uch = static_cast<_UCh>(__ch);
1181  std::get<0>(_M_bad_char)[__uch] = __patlen - 1 - __i;
1182  }
1183  }
1184 
1185  using __diff_type = _Tp;
1186 
1187  template<typename _Key>
1188  __diff_type
1189  _M_lookup(_Key __key, __diff_type __not_found) const
1190  {
1191  auto __ukey = static_cast<make_unsigned_t<_Key>>(__key);
1192  if (__ukey >= _Len)
1193  return __not_found;
1194  return std::get<0>(_M_bad_char)[__ukey];
1195  }
1196 
1197  const _Pred&
1198  _M_pred() const { return std::get<1>(_M_bad_char); }
1199 
1200  tuple<array<_Tp, _Len>, _Pred> _M_bad_char;
1201  };
1202 
1203  // Use __boyer_moore_array_base when pattern consists of narrow characters
1204  // (or std::byte) and uses std::equal_to as the predicate.
1205  template<typename _RAIter, typename _Hash, typename _Pred,
1206  typename _Val = typename iterator_traits<_RAIter>::value_type,
1207  typename _Diff = typename iterator_traits<_RAIter>::difference_type>
1208  using __boyer_moore_base_t
1209  = __conditional_t<__is_byte_like<_Val, _Pred>::value,
1210  __boyer_moore_array_base<_Diff, 256, _Pred>,
1211  __boyer_moore_map_base<_Val, _Diff, _Hash, _Pred>>;
1212 
1213  template<typename _RAIter, typename _Hash
1214  = hash<typename iterator_traits<_RAIter>::value_type>,
1215  typename _BinaryPredicate = equal_to<>>
1216  class boyer_moore_searcher
1217  : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
1218  {
1219  using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
1220  using typename _Base::__diff_type;
1221 
1222  public:
1223  boyer_moore_searcher(_RAIter __pat_first, _RAIter __pat_last,
1224  _Hash __hf = _Hash(),
1225  _BinaryPredicate __pred = _BinaryPredicate());
1226 
1227  template<typename _RandomAccessIterator2>
1228  pair<_RandomAccessIterator2, _RandomAccessIterator2>
1229  operator()(_RandomAccessIterator2 __first,
1230  _RandomAccessIterator2 __last) const;
1231 
1232  private:
1233  bool
1234  _M_is_prefix(_RAIter __word, __diff_type __len,
1235  __diff_type __pos)
1236  {
1237  const auto& __pred = this->_M_pred();
1238  __diff_type __suffixlen = __len - __pos;
1239  for (__diff_type __i = 0; __i < __suffixlen; ++__i)
1240  if (!__pred(__word[__i], __word[__pos + __i]))
1241  return false;
1242  return true;
1243  }
1244 
1245  __diff_type
1246  _M_suffix_length(_RAIter __word, __diff_type __len,
1247  __diff_type __pos)
1248  {
1249  const auto& __pred = this->_M_pred();
1250  __diff_type __i = 0;
1251  while (__pred(__word[__pos - __i], __word[__len - 1 - __i])
1252  && __i < __pos)
1253  {
1254  ++__i;
1255  }
1256  return __i;
1257  }
1258 
1259  template<typename _Tp>
1260  __diff_type
1261  _M_bad_char_shift(_Tp __c) const
1262  { return this->_M_lookup(__c, _M_pat_end - _M_pat); }
1263 
1264  _RAIter _M_pat;
1265  _RAIter _M_pat_end;
1266  _GLIBCXX_STD_C::vector<__diff_type> _M_good_suffix;
1267  };
1268 
1269  template<typename _RAIter, typename _Hash
1270  = hash<typename iterator_traits<_RAIter>::value_type>,
1271  typename _BinaryPredicate = equal_to<>>
1272  class boyer_moore_horspool_searcher
1273  : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
1274  {
1275  using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
1276  using typename _Base::__diff_type;
1277 
1278  public:
1279  boyer_moore_horspool_searcher(_RAIter __pat,
1280  _RAIter __pat_end,
1281  _Hash __hf = _Hash(),
1282  _BinaryPredicate __pred
1283  = _BinaryPredicate())
1284  : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
1285  _M_pat(__pat), _M_pat_end(__pat_end)
1286  { }
1287 
1288  template<typename _RandomAccessIterator2>
1289  pair<_RandomAccessIterator2, _RandomAccessIterator2>
1290  operator()(_RandomAccessIterator2 __first,
1291  _RandomAccessIterator2 __last) const
1292  {
1293  const auto& __pred = this->_M_pred();
1294  auto __patlen = _M_pat_end - _M_pat;
1295  if (__patlen == 0)
1296  return std::make_pair(__first, __first);
1297  auto __len = __last - __first;
1298  while (__len >= __patlen)
1299  {
1300  for (auto __scan = __patlen - 1;
1301  __pred(__first[__scan], _M_pat[__scan]); --__scan)
1302  if (__scan == 0)
1303  return std::make_pair(__first, __first + __patlen);
1304  auto __shift = _M_bad_char_shift(__first[__patlen - 1]);
1305  __len -= __shift;
1306  __first += __shift;
1307  }
1308  return std::make_pair(__last, __last);
1309  }
1310 
1311  private:
1312  template<typename _Tp>
1313  __diff_type
1314  _M_bad_char_shift(_Tp __c) const
1315  { return this->_M_lookup(__c, _M_pat_end - _M_pat); }
1316 
1317  _RAIter _M_pat;
1318  _RAIter _M_pat_end;
1319  };
1320 
1321  template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
1322  boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
1323  boyer_moore_searcher(_RAIter __pat, _RAIter __pat_end,
1324  _Hash __hf, _BinaryPredicate __pred)
1325  : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
1326  _M_pat(__pat), _M_pat_end(__pat_end), _M_good_suffix(__pat_end - __pat)
1327  {
1328  auto __patlen = __pat_end - __pat;
1329  if (__patlen == 0)
1330  return;
1331  __diff_type __last_prefix = __patlen - 1;
1332  for (__diff_type __p = __patlen - 1; __p >= 0; --__p)
1333  {
1334  if (_M_is_prefix(__pat, __patlen, __p + 1))
1335  __last_prefix = __p + 1;
1336  _M_good_suffix[__p] = __last_prefix + (__patlen - 1 - __p);
1337  }
1338  for (__diff_type __p = 0; __p < __patlen - 1; ++__p)
1339  {
1340  auto __slen = _M_suffix_length(__pat, __patlen, __p);
1341  auto __pos = __patlen - 1 - __slen;
1342  if (!__pred(__pat[__p - __slen], __pat[__pos]))
1343  _M_good_suffix[__pos] = __patlen - 1 - __p + __slen;
1344  }
1345  }
1346 
1347  template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
1348  template<typename _RandomAccessIterator2>
1349  pair<_RandomAccessIterator2, _RandomAccessIterator2>
1350  boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
1351  operator()(_RandomAccessIterator2 __first,
1352  _RandomAccessIterator2 __last) const
1353  {
1354  auto __patlen = _M_pat_end - _M_pat;
1355  if (__patlen == 0)
1356  return std::make_pair(__first, __first);
1357  const auto& __pred = this->_M_pred();
1358  __diff_type __i = __patlen - 1;
1359  auto __stringlen = __last - __first;
1360  while (__i < __stringlen)
1361  {
1362  __diff_type __j = __patlen - 1;
1363  while (__j >= 0 && __pred(__first[__i], _M_pat[__j]))
1364  {
1365  --__i;
1366  --__j;
1367  }
1368  if (__j < 0)
1369  {
1370  const auto __match = __first + __i + 1;
1371  return std::make_pair(__match, __match + __patlen);
1372  }
1373  __i += std::max(_M_bad_char_shift(__first[__i]),
1374  _M_good_suffix[__j]);
1375  }
1376  return std::make_pair(__last, __last);
1377  }
1378 
1379 #endif // C++17
1380 #endif // C++14
1381 #endif // C++11
1382 
1383 _GLIBCXX_END_NAMESPACE_VERSION
1384 } // namespace std
1385 
1386 #endif // _GLIBCXX_FUNCTIONAL