libstdc++
functional
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1 // <functional> -*- C++ -*-
2 
3 // Copyright (C) 2001-2025 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 #ifdef _GLIBCXX_SYSHDR
47 #pragma GCC system_header
48 #endif
49 
50 #include <bits/c++config.h>
51 #include <bits/stl_function.h> // std::equal_to, std::unary_function etc.
52 
53 #if __cplusplus >= 201103L
54 
55 #include <tuple>
56 #include <type_traits>
57 #include <bits/functional_hash.h>
58 #include <bits/invoke.h>
59 #include <bits/refwrap.h> // std::reference_wrapper and _Mem_fn_traits
60 #if _GLIBCXX_HOSTED
61 # include <bits/std_function.h> // std::function
62 #endif
63 #if __cplusplus >= 201703L
64 # if _GLIBCXX_HOSTED
65 # include <unordered_map>
66 # include <vector>
67 # include <array>
68 # endif
69 # include <bits/stl_algobase.h> // std::search
70 #endif
71 #if __cplusplus >= 202002L
72 # include <bits/ranges_cmp.h> // std::identity, ranges::equal_to etc.
73 # include <compare>
74 #endif
75 #if __cplusplus > 202002L && _GLIBCXX_HOSTED
76 # include <bits/move_only_function.h>
77 #endif
78 
79 #define __glibcxx_want_boyer_moore_searcher
80 #define __glibcxx_want_bind_front
81 #define __glibcxx_want_bind_back
82 #define __glibcxx_want_constexpr_functional
83 #define __glibcxx_want_invoke
84 #define __glibcxx_want_invoke_r
85 #define __glibcxx_want_move_only_function
86 #define __glibcxx_want_not_fn
87 #define __glibcxx_want_ranges
88 #define __glibcxx_want_reference_wrapper
89 #define __glibcxx_want_transparent_operators
90 #include <bits/version.h>
91 
92 #endif // C++11
93 
94 namespace std _GLIBCXX_VISIBILITY(default)
95 {
96 _GLIBCXX_BEGIN_NAMESPACE_VERSION
97 
98  /** @brief The type of placeholder objects defined by libstdc++.
99  * @ingroup binders
100  * @since C++11
101  */
102  template<int _Num> struct _Placeholder { };
103 
104 #ifdef __cpp_lib_invoke // C++ >= 17
105 
106  /** Invoke a callable object.
107  *
108  * `std::invoke` takes a callable object as its first argument and calls it
109  * with the remaining arguments. The callable object can be a pointer or
110  * reference to a function, a lambda closure, a class with `operator()`,
111  * or even a pointer-to-member. For a pointer-to-member the first argument
112  * must be a reference or pointer to the object that the pointer-to-member
113  * will be applied to.
114  *
115  * @since C++17
116  */
117  template<typename _Callable, typename... _Args>
118  inline _GLIBCXX20_CONSTEXPR invoke_result_t<_Callable, _Args...>
119  invoke(_Callable&& __fn, _Args&&... __args)
120  noexcept(is_nothrow_invocable_v<_Callable, _Args...>)
121  {
122  return std::__invoke(std::forward<_Callable>(__fn),
123  std::forward<_Args>(__args)...);
124  }
125 #endif
126 
127 #ifdef __cpp_lib_invoke_r // C++ >= 23
128 
129  /** Invoke a callable object and convert the result to `_Res`.
130  *
131  * `std::invoke_r<R>(f, args...)` is equivalent to `std::invoke(f, args...)`
132  * with the result implicitly converted to `R`.
133  *
134  * @since C++23
135  */
136  template<typename _Res, typename _Callable, typename... _Args>
137  requires is_invocable_r_v<_Res, _Callable, _Args...>
138  constexpr _Res
139  invoke_r(_Callable&& __fn, _Args&&... __args)
140  noexcept(is_nothrow_invocable_r_v<_Res, _Callable, _Args...>)
141  {
142  return std::__invoke_r<_Res>(std::forward<_Callable>(__fn),
143  std::forward<_Args>(__args)...);
144  }
145 #endif // __cpp_lib_invoke_r
146 
147  /// @cond undocumented
148 
149 #if __cplusplus >= 201103L
150  template<typename _MemFunPtr,
151  bool __is_mem_fn = is_member_function_pointer<_MemFunPtr>::value>
152  class _Mem_fn_base
153  : public _Mem_fn_traits<_MemFunPtr>::__maybe_type
154  {
155  using _Traits = _Mem_fn_traits<_MemFunPtr>;
156 
157  using _Arity = typename _Traits::__arity;
158  using _Varargs = typename _Traits::__vararg;
159 
160  template<typename _Func, typename... _BoundArgs>
161  friend struct _Bind_check_arity;
162 
163  _MemFunPtr _M_pmf;
164 
165  public:
166 
167  using result_type = typename _Traits::__result_type;
168 
169  explicit constexpr
170  _Mem_fn_base(_MemFunPtr __pmf) noexcept : _M_pmf(__pmf) { }
171 
172  template<typename... _Args>
173  _GLIBCXX20_CONSTEXPR
174  auto
175  operator()(_Args&&... __args) const
176  noexcept(noexcept(
177  std::__invoke(_M_pmf, std::forward<_Args>(__args)...)))
178  -> decltype(std::__invoke(_M_pmf, std::forward<_Args>(__args)...))
179  { return std::__invoke(_M_pmf, std::forward<_Args>(__args)...); }
180  };
181 
182  // Partial specialization for member object pointers.
183  template<typename _MemObjPtr>
184  class _Mem_fn_base<_MemObjPtr, false>
185  {
186  using _Arity = integral_constant<size_t, 0>;
187  using _Varargs = false_type;
188 
189  template<typename _Func, typename... _BoundArgs>
190  friend struct _Bind_check_arity;
191 
192  _MemObjPtr _M_pm;
193 
194  public:
195  explicit constexpr
196  _Mem_fn_base(_MemObjPtr __pm) noexcept : _M_pm(__pm) { }
197 
198  template<typename _Tp>
199  _GLIBCXX20_CONSTEXPR
200  auto
201  operator()(_Tp&& __obj) const
202  noexcept(noexcept(std::__invoke(_M_pm, std::forward<_Tp>(__obj))))
203  -> decltype(std::__invoke(_M_pm, std::forward<_Tp>(__obj)))
204  { return std::__invoke(_M_pm, std::forward<_Tp>(__obj)); }
205  };
206 
207  template<typename _MemberPointer>
208  struct _Mem_fn; // undefined
209 
210  template<typename _Res, typename _Class>
211  struct _Mem_fn<_Res _Class::*>
212  : _Mem_fn_base<_Res _Class::*>
213  {
214  using _Mem_fn_base<_Res _Class::*>::_Mem_fn_base;
215  };
216  /// @endcond
217 
218  // _GLIBCXX_RESOLVE_LIB_DEFECTS
219  // 2048. Unnecessary mem_fn overloads
220  /**
221  * @brief Returns a function object that forwards to the member pointer
222  * pointer `pm`.
223  *
224  * This allows a pointer-to-member to be transformed into a function object
225  * that can be called with an object expression as its first argument.
226  *
227  * For a pointer-to-data-member the result must be called with exactly one
228  * argument, the object expression that would be used as the first operand
229  * in a `obj.*memptr` or `objp->*memptr` expression.
230  *
231  * For a pointer-to-member-function the result must be called with an object
232  * expression and any additional arguments to pass to the member function,
233  * as in an expression like `(obj.*memfun)(args...)` or
234  * `(objp->*memfun)(args...)`.
235  *
236  * The object expression can be a pointer, reference, `reference_wrapper`,
237  * or smart pointer, and the call wrapper will dereference it as needed
238  * to apply the pointer-to-member.
239  *
240  * @ingroup functors
241  * @since C++11
242  */
243  template<typename _Tp, typename _Class>
244  _GLIBCXX20_CONSTEXPR
245  inline _Mem_fn<_Tp _Class::*>
246  mem_fn(_Tp _Class::* __pm) noexcept
247  {
248  return _Mem_fn<_Tp _Class::*>(__pm);
249  }
250 
251  /**
252  * @brief Trait that identifies a bind expression.
253  *
254  * Determines if the given type `_Tp` is a function object that
255  * should be treated as a subexpression when evaluating calls to
256  * function objects returned by `std::bind`.
257  *
258  * C++11 [func.bind.isbind].
259  * @ingroup binders
260  * @since C++11
261  */
262  template<typename _Tp>
263  struct is_bind_expression
264  : public false_type { };
265 
266  /**
267  * @brief Determines if the given type _Tp is a placeholder in a
268  * bind() expression and, if so, which placeholder it is.
269  *
270  * C++11 [func.bind.isplace].
271  * @ingroup binders
272  * @since C++11
273  */
274  template<typename _Tp>
275  struct is_placeholder
276  : public integral_constant<int, 0>
277  { };
278 
279 #if __cplusplus > 201402L
280  template <typename _Tp> inline constexpr bool is_bind_expression_v
281  = is_bind_expression<_Tp>::value;
282  template <typename _Tp> inline constexpr int is_placeholder_v
283  = is_placeholder<_Tp>::value;
284 #endif // C++17
285 
286  /** @namespace std::placeholders
287  * @brief ISO C++ 2011 namespace for std::bind placeholders.
288  * @ingroup binders
289  * @since C++11
290  */
291  namespace placeholders
292  {
293  /* Define a large number of placeholders. There is no way to
294  * simplify this with variadic templates, because we're introducing
295  * unique names for each.
296  */
297 #if __cpp_inline_variables
298 # define _GLIBCXX_PLACEHOLDER inline
299 #else
300 # define _GLIBCXX_PLACEHOLDER extern
301 #endif
302 
303  _GLIBCXX_PLACEHOLDER const _Placeholder<1> _1;
304  _GLIBCXX_PLACEHOLDER const _Placeholder<2> _2;
305  _GLIBCXX_PLACEHOLDER const _Placeholder<3> _3;
306  _GLIBCXX_PLACEHOLDER const _Placeholder<4> _4;
307  _GLIBCXX_PLACEHOLDER const _Placeholder<5> _5;
308  _GLIBCXX_PLACEHOLDER const _Placeholder<6> _6;
309  _GLIBCXX_PLACEHOLDER const _Placeholder<7> _7;
310  _GLIBCXX_PLACEHOLDER const _Placeholder<8> _8;
311  _GLIBCXX_PLACEHOLDER const _Placeholder<9> _9;
312  _GLIBCXX_PLACEHOLDER const _Placeholder<10> _10;
313  _GLIBCXX_PLACEHOLDER const _Placeholder<11> _11;
314  _GLIBCXX_PLACEHOLDER const _Placeholder<12> _12;
315  _GLIBCXX_PLACEHOLDER const _Placeholder<13> _13;
316  _GLIBCXX_PLACEHOLDER const _Placeholder<14> _14;
317  _GLIBCXX_PLACEHOLDER const _Placeholder<15> _15;
318  _GLIBCXX_PLACEHOLDER const _Placeholder<16> _16;
319  _GLIBCXX_PLACEHOLDER const _Placeholder<17> _17;
320  _GLIBCXX_PLACEHOLDER const _Placeholder<18> _18;
321  _GLIBCXX_PLACEHOLDER const _Placeholder<19> _19;
322  _GLIBCXX_PLACEHOLDER const _Placeholder<20> _20;
323  _GLIBCXX_PLACEHOLDER const _Placeholder<21> _21;
324  _GLIBCXX_PLACEHOLDER const _Placeholder<22> _22;
325  _GLIBCXX_PLACEHOLDER const _Placeholder<23> _23;
326  _GLIBCXX_PLACEHOLDER const _Placeholder<24> _24;
327  _GLIBCXX_PLACEHOLDER const _Placeholder<25> _25;
328  _GLIBCXX_PLACEHOLDER const _Placeholder<26> _26;
329  _GLIBCXX_PLACEHOLDER const _Placeholder<27> _27;
330  _GLIBCXX_PLACEHOLDER const _Placeholder<28> _28;
331  _GLIBCXX_PLACEHOLDER const _Placeholder<29> _29;
332 
333 #undef _GLIBCXX_PLACEHOLDER
334  }
335 
336  /**
337  * Partial specialization of is_placeholder that provides the placeholder
338  * number for the placeholder objects defined by libstdc++.
339  * @ingroup binders
340  * @since C++11
341  */
342  template<int _Num>
343  struct is_placeholder<_Placeholder<_Num> >
344  : public integral_constant<int, _Num>
345  { };
346 
347  template<int _Num>
348  struct is_placeholder<const _Placeholder<_Num> >
349  : public integral_constant<int, _Num>
350  { };
351 
352  /// @cond undocumented
353 
354  // Like tuple_element_t but SFINAE-friendly.
355  template<std::size_t __i, typename _Tuple>
356  using _Safe_tuple_element_t
357  = typename enable_if<(__i < tuple_size<_Tuple>::value),
358  tuple_element<__i, _Tuple>>::type::type;
359 
360  /**
361  * Maps an argument to bind() into an actual argument to the bound
362  * function object [func.bind.bind]/10. Only the first parameter should
363  * be specified: the rest are used to determine among the various
364  * implementations. Note that, although this class is a function
365  * object, it isn't entirely normal because it takes only two
366  * parameters regardless of the number of parameters passed to the
367  * bind expression. The first parameter is the bound argument and
368  * the second parameter is a tuple containing references to the
369  * rest of the arguments.
370  */
371  template<typename _Arg,
372  bool _IsBindExp = is_bind_expression<_Arg>::value,
373  bool _IsPlaceholder = (is_placeholder<_Arg>::value > 0)>
374  class _Mu;
375 
376  /**
377  * If the argument is reference_wrapper<_Tp>, returns the
378  * underlying reference.
379  * C++11 [func.bind.bind] p10 bullet 1.
380  */
381  template<typename _Tp>
382  class _Mu<reference_wrapper<_Tp>, false, false>
383  {
384  public:
385  /* Note: This won't actually work for const volatile
386  * reference_wrappers, because reference_wrapper::get() is const
387  * but not volatile-qualified. This might be a defect in the TR.
388  */
389  template<typename _CVRef, typename _Tuple>
390  _GLIBCXX20_CONSTEXPR
391  _Tp&
392  operator()(_CVRef& __arg, _Tuple&) const volatile
393  { return __arg.get(); }
394  };
395 
396  /**
397  * If the argument is a bind expression, we invoke the underlying
398  * function object with the same cv-qualifiers as we are given and
399  * pass along all of our arguments (unwrapped).
400  * C++11 [func.bind.bind] p10 bullet 2.
401  */
402  template<typename _Arg>
403  class _Mu<_Arg, true, false>
404  {
405  public:
406  template<typename _CVArg, typename... _Args>
407  _GLIBCXX20_CONSTEXPR
408  auto
409  operator()(_CVArg& __arg,
410  tuple<_Args...>& __tuple) const volatile
411  -> decltype(__arg(declval<_Args>()...))
412  {
413  // Construct an index tuple and forward to __call
414  typedef typename _Build_index_tuple<sizeof...(_Args)>::__type
415  _Indexes;
416  return this->__call(__arg, __tuple, _Indexes());
417  }
418 
419  private:
420  // Invokes the underlying function object __arg by unpacking all
421  // of the arguments in the tuple.
422  template<typename _CVArg, typename... _Args, std::size_t... _Indexes>
423  _GLIBCXX20_CONSTEXPR
424  auto
425  __call(_CVArg& __arg, tuple<_Args...>& __tuple,
426  const _Index_tuple<_Indexes...>&) const volatile
427  -> decltype(__arg(declval<_Args>()...))
428  {
429  return __arg(std::get<_Indexes>(std::move(__tuple))...);
430  }
431  };
432 
433  /**
434  * If the argument is a placeholder for the Nth argument, returns
435  * a reference to the Nth argument to the bind function object.
436  * C++11 [func.bind.bind] p10 bullet 3.
437  */
438  template<typename _Arg>
439  class _Mu<_Arg, false, true>
440  {
441  public:
442  template<typename _Tuple>
443  _GLIBCXX20_CONSTEXPR
444  _Safe_tuple_element_t<(is_placeholder<_Arg>::value - 1), _Tuple>&&
445  operator()(const volatile _Arg&, _Tuple& __tuple) const volatile
446  {
447  return
448  ::std::get<(is_placeholder<_Arg>::value - 1)>(std::move(__tuple));
449  }
450  };
451 
452  /**
453  * If the argument is just a value, returns a reference to that
454  * value. The cv-qualifiers on the reference are determined by the caller.
455  * C++11 [func.bind.bind] p10 bullet 4.
456  */
457  template<typename _Arg>
458  class _Mu<_Arg, false, false>
459  {
460  public:
461  template<typename _CVArg, typename _Tuple>
462  _GLIBCXX20_CONSTEXPR
463  _CVArg&&
464  operator()(_CVArg&& __arg, _Tuple&) const volatile
465  { return std::forward<_CVArg>(__arg); }
466  };
467 
468  // std::get<I> for volatile-qualified tuples
469  template<std::size_t _Ind, typename... _Tp>
470  inline auto
471  __volget(volatile tuple<_Tp...>& __tuple)
472  -> __tuple_element_t<_Ind, tuple<_Tp...>> volatile&
473  { return std::get<_Ind>(const_cast<tuple<_Tp...>&>(__tuple)); }
474 
475  // std::get<I> for const-volatile-qualified tuples
476  template<std::size_t _Ind, typename... _Tp>
477  inline auto
478  __volget(const volatile tuple<_Tp...>& __tuple)
479  -> __tuple_element_t<_Ind, tuple<_Tp...>> const volatile&
480  { return std::get<_Ind>(const_cast<const tuple<_Tp...>&>(__tuple)); }
481 
482  /// @endcond
483 
484 #if __cplusplus == 201703L && _GLIBCXX_USE_DEPRECATED
485 # define _GLIBCXX_VOLATILE_BIND
486 // _GLIBCXX_RESOLVE_LIB_DEFECTS
487 // 2487. bind() should be const-overloaded, not cv-overloaded
488 # define _GLIBCXX_DEPR_BIND \
489  [[deprecated("std::bind does not support volatile in C++17")]]
490 #elif __cplusplus < 201703L
491 # define _GLIBCXX_VOLATILE_BIND
492 # define _GLIBCXX_DEPR_BIND
493 #endif
494 
495  /// Type of the function object returned from bind().
496  template<typename _Signature>
497  class _Bind;
498 
499  template<typename _Functor, typename... _Bound_args>
500  class _Bind<_Functor(_Bound_args...)>
501  : public _Weak_result_type<_Functor>
502  {
503  typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
504  _Bound_indexes;
505 
506  _Functor _M_f;
507  tuple<_Bound_args...> _M_bound_args;
508 
509  // Call unqualified
510  template<typename _Result, typename... _Args, std::size_t... _Indexes>
511  _GLIBCXX20_CONSTEXPR
512  _Result
513  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
514  {
515  return std::__invoke(_M_f,
516  _Mu<_Bound_args>()(std::get<_Indexes>(_M_bound_args), __args)...
517  );
518  }
519 
520  // Call as const
521  template<typename _Result, typename... _Args, std::size_t... _Indexes>
522  _GLIBCXX20_CONSTEXPR
523  _Result
524  __call_c(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
525  {
526  return std::__invoke(_M_f,
527  _Mu<_Bound_args>()(std::get<_Indexes>(_M_bound_args), __args)...
528  );
529  }
530 
531 #ifdef _GLIBCXX_VOLATILE_BIND
532  // Call as volatile
533  template<typename _Result, typename... _Args, std::size_t... _Indexes>
534  _Result
535  __call_v(tuple<_Args...>&& __args,
536  _Index_tuple<_Indexes...>) volatile
537  {
538  return std::__invoke(_M_f,
539  _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
540  );
541  }
542 
543  // Call as const volatile
544  template<typename _Result, typename... _Args, std::size_t... _Indexes>
545  _Result
546  __call_c_v(tuple<_Args...>&& __args,
547  _Index_tuple<_Indexes...>) const volatile
548  {
549  return std::__invoke(_M_f,
550  _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
551  );
552  }
553 #endif // volatile
554 
555  template<typename _BoundArg, typename _CallArgs>
556  using _Mu_type = decltype(
557  _Mu<typename remove_cv<_BoundArg>::type>()(
558  std::declval<_BoundArg&>(), std::declval<_CallArgs&>()) );
559 
560  template<typename _Fn, typename _CallArgs, typename... _BArgs>
561  using _Res_type_impl
562  = __invoke_result_t<_Fn&, _Mu_type<_BArgs, _CallArgs>&&...>;
563 
564  template<typename _CallArgs>
565  using _Res_type = _Res_type_impl<_Functor, _CallArgs, _Bound_args...>;
566 
567  template<typename _CallArgs>
568  using __dependent = typename
569  enable_if<bool(tuple_size<_CallArgs>::value+1), _Functor>::type;
570 
571  template<typename _CallArgs, template<class> class __cv_quals>
572  using _Res_type_cv = _Res_type_impl<
573  typename __cv_quals<__dependent<_CallArgs>>::type,
574  _CallArgs,
575  typename __cv_quals<_Bound_args>::type...>;
576 
577  public:
578  template<typename... _Args>
579  explicit _GLIBCXX20_CONSTEXPR
580  _Bind(const _Functor& __f, _Args&&... __args)
581  : _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
582  { }
583 
584  template<typename... _Args>
585  explicit _GLIBCXX20_CONSTEXPR
586  _Bind(_Functor&& __f, _Args&&... __args)
587  : _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
588  { }
589 
590  _Bind(const _Bind&) = default;
591  _Bind(_Bind&&) = default;
592 
593  // Call unqualified
594  template<typename... _Args,
595  typename _Result = _Res_type<tuple<_Args...>>>
596  _GLIBCXX20_CONSTEXPR
597  _Result
598  operator()(_Args&&... __args)
599  {
600  return this->__call<_Result>(
601  std::forward_as_tuple(std::forward<_Args>(__args)...),
602  _Bound_indexes());
603  }
604 
605  // Call as const
606  template<typename... _Args,
607  typename _Result = _Res_type_cv<tuple<_Args...>, add_const>>
608  _GLIBCXX20_CONSTEXPR
609  _Result
610  operator()(_Args&&... __args) const
611  {
612  return this->__call_c<_Result>(
613  std::forward_as_tuple(std::forward<_Args>(__args)...),
614  _Bound_indexes());
615  }
616 
617 #ifdef _GLIBCXX_VOLATILE_BIND
618  // Call as volatile
619  template<typename... _Args,
620  typename _Result = _Res_type_cv<tuple<_Args...>, add_volatile>>
621  _GLIBCXX_DEPR_BIND
622  _Result
623  operator()(_Args&&... __args) volatile
624  {
625  return this->__call_v<_Result>(
626  std::forward_as_tuple(std::forward<_Args>(__args)...),
627  _Bound_indexes());
628  }
629 
630  // Call as const volatile
631  template<typename... _Args,
632  typename _Result = _Res_type_cv<tuple<_Args...>, add_cv>>
633  _GLIBCXX_DEPR_BIND
634  _Result
635  operator()(_Args&&... __args) const volatile
636  {
637  return this->__call_c_v<_Result>(
638  std::forward_as_tuple(std::forward<_Args>(__args)...),
639  _Bound_indexes());
640  }
641 #endif // volatile
642  };
643 
644  /// Type of the function object returned from bind<R>().
645  template<typename _Result, typename _Signature>
646  class _Bind_result;
647 
648  template<typename _Result, typename _Functor, typename... _Bound_args>
649  class _Bind_result<_Result, _Functor(_Bound_args...)>
650  {
651  typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
652  _Bound_indexes;
653 
654  _Functor _M_f;
655  tuple<_Bound_args...> _M_bound_args;
656 
657  // Call unqualified
658  template<typename _Res, typename... _Args, std::size_t... _Indexes>
659  _GLIBCXX20_CONSTEXPR
660  _Res
661  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
662  {
663  return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
664  (std::get<_Indexes>(_M_bound_args), __args)...);
665  }
666 
667  // Call as const
668  template<typename _Res, typename... _Args, std::size_t... _Indexes>
669  _GLIBCXX20_CONSTEXPR
670  _Res
671  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
672  {
673  return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
674  (std::get<_Indexes>(_M_bound_args), __args)...);
675  }
676 
677 #ifdef _GLIBCXX_VOLATILE_BIND
678  // Call as volatile
679  template<typename _Res, typename... _Args, std::size_t... _Indexes>
680  _Res
681  __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
682  {
683  return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
684  (__volget<_Indexes>(_M_bound_args), __args)...);
685  }
686 
687  // Call as const volatile
688  template<typename _Res, typename... _Args, std::size_t... _Indexes>
689  _Res
690  __call(tuple<_Args...>&& __args,
691  _Index_tuple<_Indexes...>) const volatile
692  {
693  return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
694  (__volget<_Indexes>(_M_bound_args), __args)...);
695  }
696 #endif // volatile
697 
698  public:
699  typedef _Result result_type;
700 
701  template<typename... _Args>
702  explicit _GLIBCXX20_CONSTEXPR
703  _Bind_result(const _Functor& __f, _Args&&... __args)
704  : _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
705  { }
706 
707  template<typename... _Args>
708  explicit _GLIBCXX20_CONSTEXPR
709  _Bind_result(_Functor&& __f, _Args&&... __args)
710  : _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
711  { }
712 
713  _Bind_result(const _Bind_result&) = default;
714  _Bind_result(_Bind_result&&) = default;
715 
716  // Call unqualified
717  template<typename... _Args>
718  _GLIBCXX20_CONSTEXPR
719  result_type
720  operator()(_Args&&... __args)
721  {
722  return this->__call<_Result>(
723  std::forward_as_tuple(std::forward<_Args>(__args)...),
724  _Bound_indexes());
725  }
726 
727  // Call as const
728  template<typename... _Args>
729  _GLIBCXX20_CONSTEXPR
730  result_type
731  operator()(_Args&&... __args) const
732  {
733  return this->__call<_Result>(
734  std::forward_as_tuple(std::forward<_Args>(__args)...),
735  _Bound_indexes());
736  }
737 
738 #ifdef _GLIBCXX_VOLATILE_BIND
739  // Call as volatile
740  template<typename... _Args>
741  _GLIBCXX_DEPR_BIND
742  result_type
743  operator()(_Args&&... __args) volatile
744  {
745  return this->__call<_Result>(
746  std::forward_as_tuple(std::forward<_Args>(__args)...),
747  _Bound_indexes());
748  }
749 
750  // Call as const volatile
751  template<typename... _Args>
752  _GLIBCXX_DEPR_BIND
753  result_type
754  operator()(_Args&&... __args) const volatile
755  {
756  return this->__call<_Result>(
757  std::forward_as_tuple(std::forward<_Args>(__args)...),
758  _Bound_indexes());
759  }
760 #else
761  template<typename... _Args>
762  void operator()(_Args&&...) const volatile = delete;
763 #endif // volatile
764  };
765 
766 #undef _GLIBCXX_VOLATILE_BIND
767 #undef _GLIBCXX_DEPR_BIND
768 
769  /**
770  * @brief Class template _Bind is always a bind expression.
771  * @ingroup binders
772  */
773  template<typename _Signature>
774  struct is_bind_expression<_Bind<_Signature> >
775  : public true_type { };
776 
777  /**
778  * @brief Class template _Bind is always a bind expression.
779  * @ingroup binders
780  */
781  template<typename _Signature>
782  struct is_bind_expression<const _Bind<_Signature> >
783  : public true_type { };
784 
785  /**
786  * @brief Class template _Bind is always a bind expression.
787  * @ingroup binders
788  */
789  template<typename _Signature>
790  struct is_bind_expression<volatile _Bind<_Signature> >
791  : public true_type { };
792 
793  /**
794  * @brief Class template _Bind is always a bind expression.
795  * @ingroup binders
796  */
797  template<typename _Signature>
798  struct is_bind_expression<const volatile _Bind<_Signature>>
799  : public true_type { };
800 
801  /**
802  * @brief Class template _Bind_result is always a bind expression.
803  * @ingroup binders
804  */
805  template<typename _Result, typename _Signature>
806  struct is_bind_expression<_Bind_result<_Result, _Signature>>
807  : public true_type { };
808 
809  /**
810  * @brief Class template _Bind_result is always a bind expression.
811  * @ingroup binders
812  */
813  template<typename _Result, typename _Signature>
814  struct is_bind_expression<const _Bind_result<_Result, _Signature>>
815  : public true_type { };
816 
817  /**
818  * @brief Class template _Bind_result is always a bind expression.
819  * @ingroup binders
820  */
821  template<typename _Result, typename _Signature>
822  struct is_bind_expression<volatile _Bind_result<_Result, _Signature>>
823  : public true_type { };
824 
825  /**
826  * @brief Class template _Bind_result is always a bind expression.
827  * @ingroup binders
828  */
829  template<typename _Result, typename _Signature>
830  struct is_bind_expression<const volatile _Bind_result<_Result, _Signature>>
831  : public true_type { };
832 
833  template<typename _Func, typename... _BoundArgs>
834  struct _Bind_check_arity { };
835 
836  template<typename _Ret, typename... _Args, typename... _BoundArgs>
837  struct _Bind_check_arity<_Ret (*)(_Args...), _BoundArgs...>
838  {
839  static_assert(sizeof...(_BoundArgs) == sizeof...(_Args),
840  "Wrong number of arguments for function");
841  };
842 
843  template<typename _Ret, typename... _Args, typename... _BoundArgs>
844  struct _Bind_check_arity<_Ret (*)(_Args..., ...), _BoundArgs...>
845  {
846  static_assert(sizeof...(_BoundArgs) >= sizeof...(_Args),
847  "Wrong number of arguments for function");
848  };
849 
850  template<typename _Tp, typename _Class, typename... _BoundArgs>
851  struct _Bind_check_arity<_Tp _Class::*, _BoundArgs...>
852  {
853  using _Arity = typename _Mem_fn<_Tp _Class::*>::_Arity;
854  using _Varargs = typename _Mem_fn<_Tp _Class::*>::_Varargs;
855  static_assert(_Varargs::value
856  ? sizeof...(_BoundArgs) >= _Arity::value + 1
857  : sizeof...(_BoundArgs) == _Arity::value + 1,
858  "Wrong number of arguments for pointer-to-member");
859  };
860 
861  // Trait type used to remove std::bind() from overload set via SFINAE
862  // when first argument has integer type, so that std::bind() will
863  // not be a better match than ::bind() from the BSD Sockets API.
864  template<typename _Tp, typename _Tp2 = typename decay<_Tp>::type>
865  using __is_socketlike = __or_<is_integral<_Tp2>, is_enum<_Tp2>>;
866 
867  template<bool _SocketLike, typename _Func, typename... _BoundArgs>
868  struct _Bind_helper
869  : _Bind_check_arity<typename decay<_Func>::type, _BoundArgs...>
870  {
871  typedef typename decay<_Func>::type __func_type;
872  typedef _Bind<__func_type(typename decay<_BoundArgs>::type...)> type;
873  };
874 
875  // Partial specialization for is_socketlike == true, does not define
876  // nested type so std::bind() will not participate in overload resolution
877  // when the first argument might be a socket file descriptor.
878  template<typename _Func, typename... _BoundArgs>
879  struct _Bind_helper<true, _Func, _BoundArgs...>
880  { };
881 
882  /**
883  * @brief Function template for std::bind.
884  * @ingroup binders
885  * @since C++11
886  */
887  template<typename _Func, typename... _BoundArgs>
888  inline _GLIBCXX20_CONSTEXPR typename
889  _Bind_helper<__is_socketlike<_Func>::value, _Func, _BoundArgs...>::type
890  bind(_Func&& __f, _BoundArgs&&... __args)
891  {
892  typedef _Bind_helper<false, _Func, _BoundArgs...> __helper_type;
893  return typename __helper_type::type(std::forward<_Func>(__f),
894  std::forward<_BoundArgs>(__args)...);
895  }
896 
897  template<typename _Result, typename _Func, typename... _BoundArgs>
898  struct _Bindres_helper
899  : _Bind_check_arity<typename decay<_Func>::type, _BoundArgs...>
900  {
901  typedef typename decay<_Func>::type __functor_type;
902  typedef _Bind_result<_Result,
903  __functor_type(typename decay<_BoundArgs>::type...)>
904  type;
905  };
906 
907  /**
908  * @brief Function template for std::bind<R>.
909  * @ingroup binders
910  * @since C++11
911  */
912  template<typename _Result, typename _Func, typename... _BoundArgs>
913  inline _GLIBCXX20_CONSTEXPR
914  typename _Bindres_helper<_Result, _Func, _BoundArgs...>::type
915  bind(_Func&& __f, _BoundArgs&&... __args)
916  {
917  typedef _Bindres_helper<_Result, _Func, _BoundArgs...> __helper_type;
918  return typename __helper_type::type(std::forward<_Func>(__f),
919  std::forward<_BoundArgs>(__args)...);
920  }
921 
922 #ifdef __cpp_lib_bind_front // C++ >= 20
923 
924  template<typename _Fd, typename... _BoundArgs>
925  struct _Bind_front
926  {
927  static_assert(is_move_constructible_v<_Fd>);
928  static_assert((is_move_constructible_v<_BoundArgs> && ...));
929 
930  // First parameter is to ensure this constructor is never used
931  // instead of the copy/move constructor.
932  template<typename _Fn, typename... _Args>
933  explicit constexpr
934  _Bind_front(int, _Fn&& __fn, _Args&&... __args)
935  noexcept(__and_<is_nothrow_constructible<_Fd, _Fn>,
936  is_nothrow_constructible<_BoundArgs, _Args>...>::value)
937  : _M_fd(std::forward<_Fn>(__fn)),
938  _M_bound_args(std::forward<_Args>(__args)...)
939  { static_assert(sizeof...(_Args) == sizeof...(_BoundArgs)); }
940 
941 #if __cpp_explicit_this_parameter
942  template<typename _Self, typename... _CallArgs>
943  constexpr
944  invoke_result_t<__like_t<_Self, _Fd>, __like_t<_Self, _BoundArgs>..., _CallArgs...>
945  operator()(this _Self&& __self, _CallArgs&&... __call_args)
946  noexcept(is_nothrow_invocable_v<__like_t<_Self, _Fd>,
947  __like_t<_Self, _BoundArgs>..., _CallArgs...>)
948  {
949  return _S_call(__like_t<_Self, _Bind_front>(__self), _BoundIndices(),
950  std::forward<_CallArgs>(__call_args)...);
951  }
952 #else
953  template<typename... _CallArgs>
954  requires true
955  constexpr
956  invoke_result_t<_Fd&, _BoundArgs&..., _CallArgs...>
957  operator()(_CallArgs&&... __call_args) &
958  noexcept(is_nothrow_invocable_v<_Fd&, _BoundArgs&..., _CallArgs...>)
959  {
960  return _S_call(*this, _BoundIndices(),
961  std::forward<_CallArgs>(__call_args)...);
962  }
963 
964  template<typename... _CallArgs>
965  requires true
966  constexpr
967  invoke_result_t<const _Fd&, const _BoundArgs&..., _CallArgs...>
968  operator()(_CallArgs&&... __call_args) const &
969  noexcept(is_nothrow_invocable_v<const _Fd&, const _BoundArgs&...,
970  _CallArgs...>)
971  {
972  return _S_call(*this, _BoundIndices(),
973  std::forward<_CallArgs>(__call_args)...);
974  }
975 
976  template<typename... _CallArgs>
977  requires true
978  constexpr
979  invoke_result_t<_Fd, _BoundArgs..., _CallArgs...>
980  operator()(_CallArgs&&... __call_args) &&
981  noexcept(is_nothrow_invocable_v<_Fd, _BoundArgs..., _CallArgs...>)
982  {
983  return _S_call(std::move(*this), _BoundIndices(),
984  std::forward<_CallArgs>(__call_args)...);
985  }
986 
987  template<typename... _CallArgs>
988  requires true
989  constexpr
990  invoke_result_t<const _Fd, const _BoundArgs..., _CallArgs...>
991  operator()(_CallArgs&&... __call_args) const &&
992  noexcept(is_nothrow_invocable_v<const _Fd, const _BoundArgs...,
993  _CallArgs...>)
994  {
995  return _S_call(std::move(*this), _BoundIndices(),
996  std::forward<_CallArgs>(__call_args)...);
997  }
998 
999  template<typename... _CallArgs>
1000  void operator()(_CallArgs&&...) & = delete;
1001 
1002  template<typename... _CallArgs>
1003  void operator()(_CallArgs&&...) const & = delete;
1004 
1005  template<typename... _CallArgs>
1006  void operator()(_CallArgs&&...) && = delete;
1007 
1008  template<typename... _CallArgs>
1009  void operator()(_CallArgs&&...) const && = delete;
1010 #endif
1011 
1012  private:
1013  using _BoundIndices = index_sequence_for<_BoundArgs...>;
1014 
1015  template<typename _Tp, size_t... _Ind, typename... _CallArgs>
1016  static constexpr
1017  decltype(auto)
1018  _S_call(_Tp&& __g, index_sequence<_Ind...>, _CallArgs&&... __call_args)
1019  {
1020  return std::invoke(std::forward<_Tp>(__g)._M_fd,
1021  std::get<_Ind>(std::forward<_Tp>(__g)._M_bound_args)...,
1022  std::forward<_CallArgs>(__call_args)...);
1023  }
1024 
1025  [[no_unique_address]] _Fd _M_fd;
1026  [[no_unique_address]] std::tuple<_BoundArgs...> _M_bound_args;
1027  };
1028 
1029  template<typename _Fn, typename... _Args>
1030  using _Bind_front_t = _Bind_front<decay_t<_Fn>, decay_t<_Args>...>;
1031 
1032  /** Create call wrapper by partial application of arguments to function.
1033  *
1034  * The result of `std::bind_front(f, args...)` is a function object that
1035  * stores `f` and the bound arguments, `args...`. When that function
1036  * object is invoked with `call_args...` it returns the result of calling
1037  * `f(args..., call_args...)`.
1038  *
1039  * @since C++20
1040  */
1041  template<typename _Fn, typename... _Args>
1042  constexpr _Bind_front_t<_Fn, _Args...>
1043  bind_front(_Fn&& __fn, _Args&&... __args)
1044  noexcept(is_nothrow_constructible_v<_Bind_front_t<_Fn, _Args...>,
1045  int, _Fn, _Args...>)
1046  {
1047  return _Bind_front_t<_Fn, _Args...>(0, std::forward<_Fn>(__fn),
1048  std::forward<_Args>(__args)...);
1049  }
1050 #endif // __cpp_lib_bind_front
1051 
1052 #ifdef __cpp_lib_bind_back // C++ >= 23
1053  template<typename _Fd, typename... _BoundArgs>
1054  struct _Bind_back
1055  {
1056  static_assert(is_move_constructible_v<_Fd>);
1057  static_assert((is_move_constructible_v<_BoundArgs> && ...));
1058 
1059  // First parameter is to ensure this constructor is never used
1060  // instead of the copy/move constructor.
1061  template<typename _Fn, typename... _Args>
1062  explicit constexpr
1063  _Bind_back(int, _Fn&& __fn, _Args&&... __args)
1064  noexcept(__and_<is_nothrow_constructible<_Fd, _Fn>,
1065  is_nothrow_constructible<_BoundArgs, _Args>...>::value)
1066  : _M_fd(std::forward<_Fn>(__fn)),
1067  _M_bound_args(std::forward<_Args>(__args)...)
1068  { static_assert(sizeof...(_Args) == sizeof...(_BoundArgs)); }
1069 
1070  template<typename _Self, typename... _CallArgs>
1071  constexpr
1072  invoke_result_t<__like_t<_Self, _Fd>, _CallArgs..., __like_t<_Self, _BoundArgs>...>
1073  operator()(this _Self&& __self, _CallArgs&&... __call_args)
1074  noexcept(is_nothrow_invocable_v<__like_t<_Self, _Fd>,
1075  _CallArgs..., __like_t<_Self, _BoundArgs>...>)
1076  {
1077  return _S_call(__like_t<_Self, _Bind_back>(__self), _BoundIndices(),
1078  std::forward<_CallArgs>(__call_args)...);
1079  }
1080 
1081  private:
1082  using _BoundIndices = index_sequence_for<_BoundArgs...>;
1083 
1084  template<typename _Tp, size_t... _Ind, typename... _CallArgs>
1085  static constexpr
1086  decltype(auto)
1087  _S_call(_Tp&& __g, index_sequence<_Ind...>, _CallArgs&&... __call_args)
1088  {
1089  return std::invoke(std::forward<_Tp>(__g)._M_fd,
1090  std::forward<_CallArgs>(__call_args)...,
1091  std::get<_Ind>(std::forward<_Tp>(__g)._M_bound_args)...);
1092  }
1093 
1094  [[no_unique_address]] _Fd _M_fd;
1095  [[no_unique_address]] std::tuple<_BoundArgs...> _M_bound_args;
1096  };
1097 
1098  template<typename _Fn, typename... _Args>
1099  using _Bind_back_t = _Bind_back<decay_t<_Fn>, decay_t<_Args>...>;
1100 
1101  /** Create call wrapper by partial application of arguments to function.
1102  *
1103  * The result of `std::bind_back(f, args...)` is a function object that
1104  * stores `f` and the bound arguments, `args...`. When that function
1105  * object is invoked with `call_args...` it returns the result of calling
1106  * `f(call_args..., args...)`.
1107  *
1108  * @since C++23
1109  */
1110  template<typename _Fn, typename... _Args>
1111  constexpr _Bind_back_t<_Fn, _Args...>
1112  bind_back(_Fn&& __fn, _Args&&... __args)
1113  noexcept(is_nothrow_constructible_v<_Bind_back_t<_Fn, _Args...>,
1114  int, _Fn, _Args...>)
1115  {
1116  return _Bind_back_t<_Fn, _Args...>(0, std::forward<_Fn>(__fn),
1117  std::forward<_Args>(__args)...);
1118  }
1119 #endif // __cpp_lib_bind_back
1120 
1121 #if __cplusplus >= 201402L
1122  /// Generalized negator.
1123  template<typename _Fn>
1124  class _Not_fn
1125  {
1126  template<typename _Fn2, typename... _Args>
1127  using __inv_res_t = typename __invoke_result<_Fn2, _Args...>::type;
1128 
1129  template<typename _Tp>
1130  static decltype(!std::declval<_Tp>())
1131  _S_not() noexcept(noexcept(!std::declval<_Tp>()));
1132 
1133  public:
1134  template<typename _Fn2>
1135  constexpr
1136  _Not_fn(_Fn2&& __fn, int)
1137  : _M_fn(std::forward<_Fn2>(__fn)) { }
1138 
1139  _Not_fn(const _Not_fn& __fn) = default;
1140  _Not_fn(_Not_fn&& __fn) = default;
1141  ~_Not_fn() = default;
1142 
1143  // Macro to define operator() with given cv-qualifiers ref-qualifiers,
1144  // forwarding _M_fn and the function arguments with the same qualifiers,
1145  // and deducing the return type and exception-specification.
1146 #define _GLIBCXX_NOT_FN_CALL_OP( _QUALS ) \
1147  template<typename... _Args, \
1148  typename = enable_if_t<__is_invocable<_Fn _QUALS, _Args...>::value>> \
1149  _GLIBCXX20_CONSTEXPR \
1150  decltype(_S_not<__inv_res_t<_Fn _QUALS, _Args...>>()) \
1151  operator()(_Args&&... __args) _QUALS \
1152  noexcept(__is_nothrow_invocable<_Fn _QUALS, _Args...>::value \
1153  && noexcept(_S_not<__inv_res_t<_Fn _QUALS, _Args...>>())) \
1154  { \
1155  return !std::__invoke(std::forward< _Fn _QUALS >(_M_fn), \
1156  std::forward<_Args>(__args)...); \
1157  } \
1158  \
1159  template<typename... _Args, \
1160  typename = enable_if_t<!__is_invocable<_Fn _QUALS, _Args...>::value>> \
1161  void operator()(_Args&&... __args) _QUALS = delete;
1162 
1163  _GLIBCXX_NOT_FN_CALL_OP( & )
1164  _GLIBCXX_NOT_FN_CALL_OP( const & )
1165  _GLIBCXX_NOT_FN_CALL_OP( && )
1166  _GLIBCXX_NOT_FN_CALL_OP( const && )
1167 #undef _GLIBCXX_NOT_FN_CALL_OP
1168 
1169  private:
1170  _Fn _M_fn;
1171  };
1172 
1173  template<typename _Tp, typename _Pred>
1174  struct __is_byte_like : false_type { };
1175 
1176  template<typename _Tp>
1177  struct __is_byte_like<_Tp, equal_to<_Tp>>
1178  : __bool_constant<sizeof(_Tp) == 1 && is_integral<_Tp>::value> { };
1179 
1180  template<typename _Tp>
1181  struct __is_byte_like<_Tp, equal_to<void>>
1182  : __bool_constant<sizeof(_Tp) == 1 && is_integral<_Tp>::value> { };
1183 
1184 #if __cplusplus >= 201703L
1185  // Declare std::byte (full definition is in <cstddef>).
1186  enum class byte : unsigned char;
1187 
1188  template<>
1189  struct __is_byte_like<byte, equal_to<byte>>
1190  : true_type { };
1191 
1192  template<>
1193  struct __is_byte_like<byte, equal_to<void>>
1194  : true_type { };
1195 #endif
1196 
1197  // [func.not_fn] Function template not_fn
1198 #ifdef __cpp_lib_not_fn // C++ >= 17
1199  /** Wrap a function object to create one that negates its result.
1200  *
1201  * The function template `std::not_fn` creates a "forwarding call wrapper",
1202  * which is a function object that wraps another function object and
1203  * when called, forwards its arguments to the wrapped function object.
1204  *
1205  * The result of invoking the wrapper is the negation (using `!`) of
1206  * the wrapped function object.
1207  *
1208  * @ingroup functors
1209  * @since C++17
1210  */
1211  template<typename _Fn>
1212  _GLIBCXX20_CONSTEXPR
1213  inline auto
1214  not_fn(_Fn&& __fn)
1215  noexcept(std::is_nothrow_constructible<std::decay_t<_Fn>, _Fn&&>::value)
1216  {
1217  return _Not_fn<std::decay_t<_Fn>>{std::forward<_Fn>(__fn), 0};
1218  }
1219 #endif
1220 
1221 #if __cplusplus >= 201703L
1222  // Searchers
1223 
1224  template<typename _ForwardIterator1, typename _BinaryPredicate = equal_to<>>
1225  class default_searcher
1226  {
1227  public:
1228  _GLIBCXX20_CONSTEXPR
1229  default_searcher(_ForwardIterator1 __pat_first,
1230  _ForwardIterator1 __pat_last,
1231  _BinaryPredicate __pred = _BinaryPredicate())
1232  : _M_m(__pat_first, __pat_last, std::move(__pred))
1233  { }
1234 
1235  template<typename _ForwardIterator2>
1236  _GLIBCXX20_CONSTEXPR
1237  pair<_ForwardIterator2, _ForwardIterator2>
1238  operator()(_ForwardIterator2 __first, _ForwardIterator2 __last) const
1239  {
1240  _ForwardIterator2 __first_ret =
1241  std::search(__first, __last, std::get<0>(_M_m), std::get<1>(_M_m),
1242  std::get<2>(_M_m));
1243  auto __ret = std::make_pair(__first_ret, __first_ret);
1244  if (__ret.first != __last)
1245  std::advance(__ret.second, std::distance(std::get<0>(_M_m),
1246  std::get<1>(_M_m)));
1247  return __ret;
1248  }
1249 
1250  private:
1251  tuple<_ForwardIterator1, _ForwardIterator1, _BinaryPredicate> _M_m;
1252  };
1253 
1254 #ifdef __cpp_lib_boyer_moore_searcher // C++ >= 17 && HOSTED
1255 
1256  template<typename _Key, typename _Tp, typename _Hash, typename _Pred>
1257  struct __boyer_moore_map_base
1258  {
1259  template<typename _RAIter>
1260  __boyer_moore_map_base(_RAIter __pat, size_t __patlen,
1261  _Hash&& __hf, _Pred&& __pred)
1262  : _M_bad_char{ __patlen, std::move(__hf), std::move(__pred) }
1263  {
1264  if (__patlen > 0)
1265  for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
1266  _M_bad_char[__pat[__i]] = __patlen - 1 - __i;
1267  }
1268 
1269  using __diff_type = _Tp;
1270 
1271  __diff_type
1272  _M_lookup(_Key __key, __diff_type __not_found) const
1273  {
1274  auto __iter = _M_bad_char.find(__key);
1275  if (__iter == _M_bad_char.end())
1276  return __not_found;
1277  return __iter->second;
1278  }
1279 
1280  _Pred
1281  _M_pred() const { return _M_bad_char.key_eq(); }
1282 
1283  _GLIBCXX_STD_C::unordered_map<_Key, _Tp, _Hash, _Pred> _M_bad_char;
1284  };
1285 
1286  template<typename _Tp, size_t _Len, typename _Pred>
1287  struct __boyer_moore_array_base
1288  {
1289  template<typename _RAIter, typename _Unused>
1290  __boyer_moore_array_base(_RAIter __pat, size_t __patlen,
1291  _Unused&&, _Pred&& __pred)
1292  : _M_bad_char{ array<_Tp, _Len>{}, std::move(__pred) }
1293  {
1294  std::get<0>(_M_bad_char).fill(__patlen);
1295  if (__patlen > 0)
1296  for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
1297  {
1298  auto __ch = __pat[__i];
1299  using _UCh = make_unsigned_t<decltype(__ch)>;
1300  auto __uch = static_cast<_UCh>(__ch);
1301  std::get<0>(_M_bad_char)[__uch] = __patlen - 1 - __i;
1302  }
1303  }
1304 
1305  using __diff_type = _Tp;
1306 
1307  template<typename _Key>
1308  __diff_type
1309  _M_lookup(_Key __key, __diff_type __not_found) const
1310  {
1311  auto __ukey = static_cast<make_unsigned_t<_Key>>(__key);
1312  if (__ukey >= _Len)
1313  return __not_found;
1314  return std::get<0>(_M_bad_char)[__ukey];
1315  }
1316 
1317  const _Pred&
1318  _M_pred() const { return std::get<1>(_M_bad_char); }
1319 
1320  tuple<array<_Tp, _Len>, _Pred> _M_bad_char;
1321  };
1322 
1323  // Use __boyer_moore_array_base when pattern consists of narrow characters
1324  // (or std::byte) and uses std::equal_to as the predicate.
1325  template<typename _RAIter, typename _Hash, typename _Pred,
1326  typename _Val = typename iterator_traits<_RAIter>::value_type,
1327  typename _Diff = typename iterator_traits<_RAIter>::difference_type>
1328  using __boyer_moore_base_t
1329  = __conditional_t<__is_byte_like<_Val, _Pred>::value,
1330  __boyer_moore_array_base<_Diff, 256, _Pred>,
1331  __boyer_moore_map_base<_Val, _Diff, _Hash, _Pred>>;
1332 
1333  template<typename _RAIter, typename _Hash
1334  = hash<typename iterator_traits<_RAIter>::value_type>,
1335  typename _BinaryPredicate = equal_to<>>
1336  class boyer_moore_searcher
1337  : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
1338  {
1339  using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
1340  using typename _Base::__diff_type;
1341 
1342  public:
1343  boyer_moore_searcher(_RAIter __pat_first, _RAIter __pat_last,
1344  _Hash __hf = _Hash(),
1345  _BinaryPredicate __pred = _BinaryPredicate());
1346 
1347  template<typename _RandomAccessIterator2>
1348  pair<_RandomAccessIterator2, _RandomAccessIterator2>
1349  operator()(_RandomAccessIterator2 __first,
1350  _RandomAccessIterator2 __last) const;
1351 
1352  private:
1353  bool
1354  _M_is_prefix(_RAIter __word, __diff_type __len,
1355  __diff_type __pos)
1356  {
1357  const auto& __pred = this->_M_pred();
1358  __diff_type __suffixlen = __len - __pos;
1359  for (__diff_type __i = 0; __i < __suffixlen; ++__i)
1360  if (!__pred(__word[__i], __word[__pos + __i]))
1361  return false;
1362  return true;
1363  }
1364 
1365  __diff_type
1366  _M_suffix_length(_RAIter __word, __diff_type __len,
1367  __diff_type __pos)
1368  {
1369  const auto& __pred = this->_M_pred();
1370  __diff_type __i = 0;
1371  while (__pred(__word[__pos - __i], __word[__len - 1 - __i])
1372  && __i < __pos)
1373  {
1374  ++__i;
1375  }
1376  return __i;
1377  }
1378 
1379  template<typename _Tp>
1380  __diff_type
1381  _M_bad_char_shift(_Tp __c) const
1382  { return this->_M_lookup(__c, _M_pat_end - _M_pat); }
1383 
1384  _RAIter _M_pat;
1385  _RAIter _M_pat_end;
1386  _GLIBCXX_STD_C::vector<__diff_type> _M_good_suffix;
1387  };
1388 
1389  template<typename _RAIter, typename _Hash
1390  = hash<typename iterator_traits<_RAIter>::value_type>,
1391  typename _BinaryPredicate = equal_to<>>
1392  class boyer_moore_horspool_searcher
1393  : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
1394  {
1395  using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
1396  using typename _Base::__diff_type;
1397 
1398  public:
1399  boyer_moore_horspool_searcher(_RAIter __pat,
1400  _RAIter __pat_end,
1401  _Hash __hf = _Hash(),
1402  _BinaryPredicate __pred
1403  = _BinaryPredicate())
1404  : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
1405  _M_pat(__pat), _M_pat_end(__pat_end)
1406  { }
1407 
1408  template<typename _RandomAccessIterator2>
1409  pair<_RandomAccessIterator2, _RandomAccessIterator2>
1410  operator()(_RandomAccessIterator2 __first,
1411  _RandomAccessIterator2 __last) const
1412  {
1413  const auto& __pred = this->_M_pred();
1414  auto __patlen = _M_pat_end - _M_pat;
1415  if (__patlen == 0)
1416  return std::make_pair(__first, __first);
1417  auto __len = __last - __first;
1418  while (__len >= __patlen)
1419  {
1420  for (auto __scan = __patlen - 1;
1421  __pred(__first[__scan], _M_pat[__scan]); --__scan)
1422  if (__scan == 0)
1423  return std::make_pair(__first, __first + __patlen);
1424  auto __shift = _M_bad_char_shift(__first[__patlen - 1]);
1425  __len -= __shift;
1426  __first += __shift;
1427  }
1428  return std::make_pair(__last, __last);
1429  }
1430 
1431  private:
1432  template<typename _Tp>
1433  __diff_type
1434  _M_bad_char_shift(_Tp __c) const
1435  { return this->_M_lookup(__c, _M_pat_end - _M_pat); }
1436 
1437  _RAIter _M_pat;
1438  _RAIter _M_pat_end;
1439  };
1440 
1441  template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
1442  boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
1443  boyer_moore_searcher(_RAIter __pat, _RAIter __pat_end,
1444  _Hash __hf, _BinaryPredicate __pred)
1445  : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
1446  _M_pat(__pat), _M_pat_end(__pat_end), _M_good_suffix(__pat_end - __pat)
1447  {
1448  auto __patlen = __pat_end - __pat;
1449  if (__patlen == 0)
1450  return;
1451  __diff_type __last_prefix = __patlen - 1;
1452  for (__diff_type __p = __patlen - 1; __p >= 0; --__p)
1453  {
1454  if (_M_is_prefix(__pat, __patlen, __p + 1))
1455  __last_prefix = __p + 1;
1456  _M_good_suffix[__p] = __last_prefix + (__patlen - 1 - __p);
1457  }
1458  for (__diff_type __p = 0; __p < __patlen - 1; ++__p)
1459  {
1460  auto __slen = _M_suffix_length(__pat, __patlen, __p);
1461  auto __pos = __patlen - 1 - __slen;
1462  if (!__pred(__pat[__p - __slen], __pat[__pos]))
1463  _M_good_suffix[__pos] = __patlen - 1 - __p + __slen;
1464  }
1465  }
1466 
1467  template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
1468  template<typename _RandomAccessIterator2>
1469  pair<_RandomAccessIterator2, _RandomAccessIterator2>
1470  boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
1471  operator()(_RandomAccessIterator2 __first,
1472  _RandomAccessIterator2 __last) const
1473  {
1474  auto __patlen = _M_pat_end - _M_pat;
1475  if (__patlen == 0)
1476  return std::make_pair(__first, __first);
1477  const auto& __pred = this->_M_pred();
1478  __diff_type __i = __patlen - 1;
1479  auto __stringlen = __last - __first;
1480  while (__i < __stringlen)
1481  {
1482  __diff_type __j = __patlen - 1;
1483  while (__j >= 0 && __pred(__first[__i], _M_pat[__j]))
1484  {
1485  --__i;
1486  --__j;
1487  }
1488  if (__j < 0)
1489  {
1490  const auto __match = __first + __i + 1;
1491  return std::make_pair(__match, __match + __patlen);
1492  }
1493  __i += std::max(_M_bad_char_shift(__first[__i]),
1494  _M_good_suffix[__j]);
1495  }
1496  return std::make_pair(__last, __last);
1497  }
1498 #endif // __cpp_lib_boyer_moore_searcher
1499 
1500 #endif // C++17
1501 #endif // C++14
1502 #endif // C++11
1503 
1504 _GLIBCXX_END_NAMESPACE_VERSION
1505 } // namespace std
1506 
1507 #endif // _GLIBCXX_FUNCTIONAL