1// <functional> -*- C++ -*-
2
3// Copyright (C) 2001-2021 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
19
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
24
25/*
26 * Copyright (c) 1997
27 * Silicon Graphics Computer Systems, Inc.
28 *
29 * Permission to use, copy, modify, distribute and sell this software
30 * and its documentation for any purpose is hereby granted without fee,
31 * provided that the above copyright notice appear in all copies and
32 * that both that copyright notice and this permission notice appear
33 * in supporting documentation. Silicon Graphics makes no
34 * representations about the suitability of this software for any
35 * purpose. It is provided "as is" without express or implied warranty.
36 *
37 */
38
39/** @file include/functional
40 * This is a Standard C++ Library header.
41 */
42
43#ifndef _GLIBCXX_FUNCTIONAL
44#define _GLIBCXX_FUNCTIONAL 1
45
46#pragma GCC system_header
47
48#include <bits/c++config.h>
49#include <bits/stl_function.h>
50
51#if __cplusplus >= 201103L
52
53#include <new>
54#include <tuple>
55#include <type_traits>
56#include <bits/functional_hash.h>
57#include <bits/invoke.h>
58#include <bits/refwrap.h> // std::reference_wrapper and _Mem_fn_traits
59#include <bits/std_function.h> // std::function
60#if __cplusplus > 201402L
61# include <unordered_map>
62# include <vector>
63# include <array>
64# include <utility>
65# include <bits/stl_algo.h>
66#endif
67#if __cplusplus > 201703L
68# include <bits/ranges_cmp.h>
69# include <compare>
70#endif
71
72#endif // C++11
73
74namespace std _GLIBCXX_VISIBILITY(default)
75{
76_GLIBCXX_BEGIN_NAMESPACE_VERSION
77
78 /** @brief The type of placeholder objects defined by libstdc++.
79 * @ingroup binders
80 */
81 template<int _Num> struct _Placeholder { };
82
83#if __cplusplus >= 201103L
84
85#if __cplusplus >= 201703L
86# define __cpp_lib_invoke 201411L
87# if __cplusplus > 201703L
88# define __cpp_lib_constexpr_functional 201907L
89# endif
90
91 /// Invoke a callable object.
92 template<typename _Callable, typename... _Args>
93 inline _GLIBCXX20_CONSTEXPR invoke_result_t<_Callable, _Args...>
94 invoke(_Callable&& __fn, _Args&&... __args)
95 noexcept(is_nothrow_invocable_v<_Callable, _Args...>)
96 {
97 return std::__invoke(std::forward<_Callable>(__fn),
98 std::forward<_Args>(__args)...);
99 }
100#endif // C++17
101
102 template<typename _MemFunPtr,
103 bool __is_mem_fn = is_member_function_pointer<_MemFunPtr>::value>
104 class _Mem_fn_base
105 : public _Mem_fn_traits<_MemFunPtr>::__maybe_type
106 {
107 using _Traits = _Mem_fn_traits<_MemFunPtr>;
108
109 using _Arity = typename _Traits::__arity;
110 using _Varargs = typename _Traits::__vararg;
111
112 template<typename _Func, typename... _BoundArgs>
113 friend struct _Bind_check_arity;
114
115 _MemFunPtr _M_pmf;
116
117 public:
118
119 using result_type = typename _Traits::__result_type;
120
121 explicit constexpr
122 _Mem_fn_base(_MemFunPtr __pmf) noexcept : _M_pmf(__pmf) { }
123
124 template<typename... _Args>
125 _GLIBCXX20_CONSTEXPR
126 auto
127 operator()(_Args&&... __args) const
128 noexcept(noexcept(
129 std::__invoke(_M_pmf, std::forward<_Args>(__args)...)))
130 -> decltype(std::__invoke(_M_pmf, std::forward<_Args>(__args)...))
131 { return std::__invoke(_M_pmf, std::forward<_Args>(__args)...); }
132 };
133
134 // Partial specialization for member object pointers.
135 template<typename _MemObjPtr>
136 class _Mem_fn_base<_MemObjPtr, false>
137 {
138 using _Arity = integral_constant<size_t, 0>;
139 using _Varargs = false_type;
140
141 template<typename _Func, typename... _BoundArgs>
142 friend struct _Bind_check_arity;
143
144 _MemObjPtr _M_pm;
145
146 public:
147 explicit constexpr
148 _Mem_fn_base(_MemObjPtr __pm) noexcept : _M_pm(__pm) { }
149
150 template<typename _Tp>
151 _GLIBCXX20_CONSTEXPR
152 auto
153 operator()(_Tp&& __obj) const
154 noexcept(noexcept(std::__invoke(_M_pm, std::forward<_Tp>(__obj))))
155 -> decltype(std::__invoke(_M_pm, std::forward<_Tp>(__obj)))
156 { return std::__invoke(_M_pm, std::forward<_Tp>(__obj)); }
157 };
158
159 template<typename _MemberPointer>
160 struct _Mem_fn; // undefined
161
162 template<typename _Res, typename _Class>
163 struct _Mem_fn<_Res _Class::*>
164 : _Mem_fn_base<_Res _Class::*>
165 {
166 using _Mem_fn_base<_Res _Class::*>::_Mem_fn_base;
167 };
168
169 // _GLIBCXX_RESOLVE_LIB_DEFECTS
170 // 2048. Unnecessary mem_fn overloads
171 /**
172 * @brief Returns a function object that forwards to the member
173 * pointer @a pm.
174 * @ingroup functors
175 */
176 template<typename _Tp, typename _Class>
177 _GLIBCXX20_CONSTEXPR
178 inline _Mem_fn<_Tp _Class::*>
179 mem_fn(_Tp _Class::* __pm) noexcept
180 {
181 return _Mem_fn<_Tp _Class::*>(__pm);
182 }
183
184 /**
185 * @brief Determines if the given type _Tp is a function object that
186 * should be treated as a subexpression when evaluating calls to
187 * function objects returned by bind().
188 *
189 * C++11 [func.bind.isbind].
190 * @ingroup binders
191 */
192 template<typename _Tp>
193 struct is_bind_expression
194 : public false_type { };
195
196 /**
197 * @brief Determines if the given type _Tp is a placeholder in a
198 * bind() expression and, if so, which placeholder it is.
199 *
200 * C++11 [func.bind.isplace].
201 * @ingroup binders
202 */
203 template<typename _Tp>
204 struct is_placeholder
205 : public integral_constant<int, 0>
206 { };
207
208#if __cplusplus > 201402L
209 template <typename _Tp> inline constexpr bool is_bind_expression_v
210 = is_bind_expression<_Tp>::value;
211 template <typename _Tp> inline constexpr int is_placeholder_v
212 = is_placeholder<_Tp>::value;
213#endif // C++17
214
215 /** @namespace std::placeholders
216 * @brief ISO C++ 2011 namespace for std::bind placeholders.
217 * @ingroup binders
218 */
219 namespace placeholders
220 {
221 /* Define a large number of placeholders. There is no way to
222 * simplify this with variadic templates, because we're introducing
223 * unique names for each.
224 */
225 extern const _Placeholder<1> _1;
226 extern const _Placeholder<2> _2;
227 extern const _Placeholder<3> _3;
228 extern const _Placeholder<4> _4;
229 extern const _Placeholder<5> _5;
230 extern const _Placeholder<6> _6;
231 extern const _Placeholder<7> _7;
232 extern const _Placeholder<8> _8;
233 extern const _Placeholder<9> _9;
234 extern const _Placeholder<10> _10;
235 extern const _Placeholder<11> _11;
236 extern const _Placeholder<12> _12;
237 extern const _Placeholder<13> _13;
238 extern const _Placeholder<14> _14;
239 extern const _Placeholder<15> _15;
240 extern const _Placeholder<16> _16;
241 extern const _Placeholder<17> _17;
242 extern const _Placeholder<18> _18;
243 extern const _Placeholder<19> _19;
244 extern const _Placeholder<20> _20;
245 extern const _Placeholder<21> _21;
246 extern const _Placeholder<22> _22;
247 extern const _Placeholder<23> _23;
248 extern const _Placeholder<24> _24;
249 extern const _Placeholder<25> _25;
250 extern const _Placeholder<26> _26;
251 extern const _Placeholder<27> _27;
252 extern const _Placeholder<28> _28;
253 extern const _Placeholder<29> _29;
254 }
255
256 /**
257 * Partial specialization of is_placeholder that provides the placeholder
258 * number for the placeholder objects defined by libstdc++.
259 * @ingroup binders
260 */
261 template<int _Num>
262 struct is_placeholder<_Placeholder<_Num> >
263 : public integral_constant<int, _Num>
264 { };
265
266 template<int _Num>
267 struct is_placeholder<const _Placeholder<_Num> >
268 : public integral_constant<int, _Num>
269 { };
270
271
272 // Like tuple_element_t but SFINAE-friendly.
273 template<std::size_t __i, typename _Tuple>
274 using _Safe_tuple_element_t
275 = typename enable_if<(__i < tuple_size<_Tuple>::value),
276 tuple_element<__i, _Tuple>>::type::type;
277
278 /**
279 * Maps an argument to bind() into an actual argument to the bound
280 * function object [func.bind.bind]/10. Only the first parameter should
281 * be specified: the rest are used to determine among the various
282 * implementations. Note that, although this class is a function
283 * object, it isn't entirely normal because it takes only two
284 * parameters regardless of the number of parameters passed to the
285 * bind expression. The first parameter is the bound argument and
286 * the second parameter is a tuple containing references to the
287 * rest of the arguments.
288 */
289 template<typename _Arg,
290 bool _IsBindExp = is_bind_expression<_Arg>::value,
291 bool _IsPlaceholder = (is_placeholder<_Arg>::value > 0)>
292 class _Mu;
293
294 /**
295 * If the argument is reference_wrapper<_Tp>, returns the
296 * underlying reference.
297 * C++11 [func.bind.bind] p10 bullet 1.
298 */
299 template<typename _Tp>
300 class _Mu<reference_wrapper<_Tp>, false, false>
301 {
302 public:
303 /* Note: This won't actually work for const volatile
304 * reference_wrappers, because reference_wrapper::get() is const
305 * but not volatile-qualified. This might be a defect in the TR.
306 */
307 template<typename _CVRef, typename _Tuple>
308 _GLIBCXX20_CONSTEXPR
309 _Tp&
310 operator()(_CVRef& __arg, _Tuple&) const volatile
311 { return __arg.get(); }
312 };
313
314 /**
315 * If the argument is a bind expression, we invoke the underlying
316 * function object with the same cv-qualifiers as we are given and
317 * pass along all of our arguments (unwrapped).
318 * C++11 [func.bind.bind] p10 bullet 2.
319 */
320 template<typename _Arg>
321 class _Mu<_Arg, true, false>
322 {
323 public:
324 template<typename _CVArg, typename... _Args>
325 _GLIBCXX20_CONSTEXPR
326 auto
327 operator()(_CVArg& __arg,
328 tuple<_Args...>& __tuple) const volatile
329 -> decltype(__arg(declval<_Args>()...))
330 {
331 // Construct an index tuple and forward to __call
332 typedef typename _Build_index_tuple<sizeof...(_Args)>::__type
333 _Indexes;
334 return this->__call(__arg, __tuple, _Indexes());
335 }
336
337 private:
338 // Invokes the underlying function object __arg by unpacking all
339 // of the arguments in the tuple.
340 template<typename _CVArg, typename... _Args, std::size_t... _Indexes>
341 _GLIBCXX20_CONSTEXPR
342 auto
343 __call(_CVArg& __arg, tuple<_Args...>& __tuple,
344 const _Index_tuple<_Indexes...>&) const volatile
345 -> decltype(__arg(declval<_Args>()...))
346 {
347 return __arg(std::get<_Indexes>(std::move(__tuple))...);
348 }
349 };
350
351 /**
352 * If the argument is a placeholder for the Nth argument, returns
353 * a reference to the Nth argument to the bind function object.
354 * C++11 [func.bind.bind] p10 bullet 3.
355 */
356 template<typename _Arg>
357 class _Mu<_Arg, false, true>
358 {
359 public:
360 template<typename _Tuple>
361 _GLIBCXX20_CONSTEXPR
362 _Safe_tuple_element_t<(is_placeholder<_Arg>::value - 1), _Tuple>&&
363 operator()(const volatile _Arg&, _Tuple& __tuple) const volatile
364 {
365 return
366 ::std::get<(is_placeholder<_Arg>::value - 1)>(std::move(__tuple));
367 }
368 };
369
370 /**
371 * If the argument is just a value, returns a reference to that
372 * value. The cv-qualifiers on the reference are determined by the caller.
373 * C++11 [func.bind.bind] p10 bullet 4.
374 */
375 template<typename _Arg>
376 class _Mu<_Arg, false, false>
377 {
378 public:
379 template<typename _CVArg, typename _Tuple>
380 _GLIBCXX20_CONSTEXPR
381 _CVArg&&
382 operator()(_CVArg&& __arg, _Tuple&) const volatile
383 { return std::forward<_CVArg>(__arg); }
384 };
385
386 // std::get<I> for volatile-qualified tuples
387 template<std::size_t _Ind, typename... _Tp>
388 inline auto
389 __volget(volatile tuple<_Tp...>& __tuple)
390 -> __tuple_element_t<_Ind, tuple<_Tp...>> volatile&
391 { return std::get<_Ind>(const_cast<tuple<_Tp...>&>(__tuple)); }
392
393 // std::get<I> for const-volatile-qualified tuples
394 template<std::size_t _Ind, typename... _Tp>
395 inline auto
396 __volget(const volatile tuple<_Tp...>& __tuple)
397 -> __tuple_element_t<_Ind, tuple<_Tp...>> const volatile&
398 { return std::get<_Ind>(const_cast<const tuple<_Tp...>&>(__tuple)); }
399
400 /// Type of the function object returned from bind().
401 template<typename _Signature>
402 class _Bind;
403
404 template<typename _Functor, typename... _Bound_args>
405 class _Bind<_Functor(_Bound_args...)>
406 : public _Weak_result_type<_Functor>
407 {
408 typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
409 _Bound_indexes;
410
411 _Functor _M_f;
412 tuple<_Bound_args...> _M_bound_args;
413
414 // Call unqualified
415 template<typename _Result, typename... _Args, std::size_t... _Indexes>
416 _GLIBCXX20_CONSTEXPR
417 _Result
418 __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
419 {
420 return std::__invoke(_M_f,
421 _Mu<_Bound_args>()(std::get<_Indexes>(_M_bound_args), __args)...
422 );
423 }
424
425 // Call as const
426 template<typename _Result, typename... _Args, std::size_t... _Indexes>
427 _GLIBCXX20_CONSTEXPR
428 _Result
429 __call_c(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
430 {
431 return std::__invoke(_M_f,
432 _Mu<_Bound_args>()(std::get<_Indexes>(_M_bound_args), __args)...
433 );
434 }
435
436 // Call as volatile
437 template<typename _Result, typename... _Args, std::size_t... _Indexes>
438 _Result
439 __call_v(tuple<_Args...>&& __args,
440 _Index_tuple<_Indexes...>) volatile
441 {
442 return std::__invoke(_M_f,
443 _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
444 );
445 }
446
447 // Call as const volatile
448 template<typename _Result, typename... _Args, std::size_t... _Indexes>
449 _Result
450 __call_c_v(tuple<_Args...>&& __args,
451 _Index_tuple<_Indexes...>) const volatile
452 {
453 return std::__invoke(_M_f,
454 _Mu<_Bound_args>()(__volget<_Indexes>(_M_bound_args), __args)...
455 );
456 }
457
458 template<typename _BoundArg, typename _CallArgs>
459 using _Mu_type = decltype(
460 _Mu<typename remove_cv<_BoundArg>::type>()(
461 std::declval<_BoundArg&>(), std::declval<_CallArgs&>()) );
462
463 template<typename _Fn, typename _CallArgs, typename... _BArgs>
464 using _Res_type_impl
465 = typename result_of< _Fn&(_Mu_type<_BArgs, _CallArgs>&&...) >::type;
466
467 template<typename _CallArgs>
468 using _Res_type = _Res_type_impl<_Functor, _CallArgs, _Bound_args...>;
469
470 template<typename _CallArgs>
471 using __dependent = typename
472 enable_if<bool(tuple_size<_CallArgs>::value+1), _Functor>::type;
473
474 template<typename _CallArgs, template<class> class __cv_quals>
475 using _Res_type_cv = _Res_type_impl<
476 typename __cv_quals<__dependent<_CallArgs>>::type,
477 _CallArgs,
478 typename __cv_quals<_Bound_args>::type...>;
479
480 public:
481 template<typename... _Args>
482 explicit _GLIBCXX20_CONSTEXPR
483 _Bind(const _Functor& __f, _Args&&... __args)
484 : _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
485 { }
486
487 template<typename... _Args>
488 explicit _GLIBCXX20_CONSTEXPR
489 _Bind(_Functor&& __f, _Args&&... __args)
490 : _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
491 { }
492
493 _Bind(const _Bind&) = default;
494 _Bind(_Bind&&) = default;
495
496 // Call unqualified
497 template<typename... _Args,
498 typename _Result = _Res_type<tuple<_Args...>>>
499 _GLIBCXX20_CONSTEXPR
500 _Result
501 operator()(_Args&&... __args)
502 {
503 return this->__call<_Result>(
504 std::forward_as_tuple(std::forward<_Args>(__args)...),
505 _Bound_indexes());
506 }
507
508 // Call as const
509 template<typename... _Args,
510 typename _Result = _Res_type_cv<tuple<_Args...>, add_const>>
511 _GLIBCXX20_CONSTEXPR
512 _Result
513 operator()(_Args&&... __args) const
514 {
515 return this->__call_c<_Result>(
516 std::forward_as_tuple(std::forward<_Args>(__args)...),
517 _Bound_indexes());
518 }
519
520#if __cplusplus > 201402L
521# define _GLIBCXX_DEPR_BIND \
522 [[deprecated("std::bind does not support volatile in C++17")]]
523#else
524# define _GLIBCXX_DEPR_BIND
525#endif
526 // Call as volatile
527 template<typename... _Args,
528 typename _Result = _Res_type_cv<tuple<_Args...>, add_volatile>>
529 _GLIBCXX_DEPR_BIND
530 _Result
531 operator()(_Args&&... __args) volatile
532 {
533 return this->__call_v<_Result>(
534 std::forward_as_tuple(std::forward<_Args>(__args)...),
535 _Bound_indexes());
536 }
537
538 // Call as const volatile
539 template<typename... _Args,
540 typename _Result = _Res_type_cv<tuple<_Args...>, add_cv>>
541 _GLIBCXX_DEPR_BIND
542 _Result
543 operator()(_Args&&... __args) const volatile
544 {
545 return this->__call_c_v<_Result>(
546 std::forward_as_tuple(std::forward<_Args>(__args)...),
547 _Bound_indexes());
548 }
549 };
550
551 /// Type of the function object returned from bind<R>().
552 template<typename _Result, typename _Signature>
553 class _Bind_result;
554
555 template<typename _Result, typename _Functor, typename... _Bound_args>
556 class _Bind_result<_Result, _Functor(_Bound_args...)>
557 {
558 typedef typename _Build_index_tuple<sizeof...(_Bound_args)>::__type
559 _Bound_indexes;
560
561 _Functor _M_f;
562 tuple<_Bound_args...> _M_bound_args;
563
564 // Call unqualified
565 template<typename _Res, typename... _Args, std::size_t... _Indexes>
566 _GLIBCXX20_CONSTEXPR
567 _Res
568 __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
569 {
570 return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
571 (std::get<_Indexes>(_M_bound_args), __args)...);
572 }
573
574 // Call as const
575 template<typename _Res, typename... _Args, std::size_t... _Indexes>
576 _GLIBCXX20_CONSTEXPR
577 _Res
578 __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
579 {
580 return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
581 (std::get<_Indexes>(_M_bound_args), __args)...);
582 }
583
584 // Call as volatile
585 template<typename _Res, typename... _Args, std::size_t... _Indexes>
586 _GLIBCXX20_CONSTEXPR
587 _Res
588 __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
589 {
590 return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
591 (__volget<_Indexes>(_M_bound_args), __args)...);
592 }
593
594 // Call as const volatile
595 template<typename _Res, typename... _Args, std::size_t... _Indexes>
596 _GLIBCXX20_CONSTEXPR
597 _Res
598 __call(tuple<_Args...>&& __args,
599 _Index_tuple<_Indexes...>) const volatile
600 {
601 return std::__invoke_r<_Res>(_M_f, _Mu<_Bound_args>()
602 (__volget<_Indexes>(_M_bound_args), __args)...);
603 }
604
605 public:
606 typedef _Result result_type;
607
608 template<typename... _Args>
609 explicit _GLIBCXX20_CONSTEXPR
610 _Bind_result(const _Functor& __f, _Args&&... __args)
611 : _M_f(__f), _M_bound_args(std::forward<_Args>(__args)...)
612 { }
613
614 template<typename... _Args>
615 explicit _GLIBCXX20_CONSTEXPR
616 _Bind_result(_Functor&& __f, _Args&&... __args)
617 : _M_f(std::move(__f)), _M_bound_args(std::forward<_Args>(__args)...)
618 { }
619
620 _Bind_result(const _Bind_result&) = default;
621 _Bind_result(_Bind_result&&) = default;
622
623 // Call unqualified
624 template<typename... _Args>
625 _GLIBCXX20_CONSTEXPR
626 result_type
627 operator()(_Args&&... __args)
628 {
629 return this->__call<_Result>(
630 std::forward_as_tuple(std::forward<_Args>(__args)...),
631 _Bound_indexes());
632 }
633
634 // Call as const
635 template<typename... _Args>
636 _GLIBCXX20_CONSTEXPR
637 result_type
638 operator()(_Args&&... __args) const
639 {
640 return this->__call<_Result>(
641 std::forward_as_tuple(std::forward<_Args>(__args)...),
642 _Bound_indexes());
643 }
644
645 // Call as volatile
646 template<typename... _Args>
647 _GLIBCXX_DEPR_BIND
648 result_type
649 operator()(_Args&&... __args) volatile
650 {
651 return this->__call<_Result>(
652 std::forward_as_tuple(std::forward<_Args>(__args)...),
653 _Bound_indexes());
654 }
655
656 // Call as const volatile
657 template<typename... _Args>
658 _GLIBCXX_DEPR_BIND
659 result_type
660 operator()(_Args&&... __args) const volatile
661 {
662 return this->__call<_Result>(
663 std::forward_as_tuple(std::forward<_Args>(__args)...),
664 _Bound_indexes());
665 }
666 };
667#undef _GLIBCXX_DEPR_BIND
668
669 /**
670 * @brief Class template _Bind is always a bind expression.
671 * @ingroup binders
672 */
673 template<typename _Signature>
674 struct is_bind_expression<_Bind<_Signature> >
675 : public true_type { };
676
677 /**
678 * @brief Class template _Bind is always a bind expression.
679 * @ingroup binders
680 */
681 template<typename _Signature>
682 struct is_bind_expression<const _Bind<_Signature> >
683 : public true_type { };
684
685 /**
686 * @brief Class template _Bind is always a bind expression.
687 * @ingroup binders
688 */
689 template<typename _Signature>
690 struct is_bind_expression<volatile _Bind<_Signature> >
691 : public true_type { };
692
693 /**
694 * @brief Class template _Bind is always a bind expression.
695 * @ingroup binders
696 */
697 template<typename _Signature>
698 struct is_bind_expression<const volatile _Bind<_Signature>>
699 : public true_type { };
700
701 /**
702 * @brief Class template _Bind_result is always a bind expression.
703 * @ingroup binders
704 */
705 template<typename _Result, typename _Signature>
706 struct is_bind_expression<_Bind_result<_Result, _Signature>>
707 : public true_type { };
708
709 /**
710 * @brief Class template _Bind_result is always a bind expression.
711 * @ingroup binders
712 */
713 template<typename _Result, typename _Signature>
714 struct is_bind_expression<const _Bind_result<_Result, _Signature>>
715 : public true_type { };
716
717 /**
718 * @brief Class template _Bind_result is always a bind expression.
719 * @ingroup binders
720 */
721 template<typename _Result, typename _Signature>
722 struct is_bind_expression<volatile _Bind_result<_Result, _Signature>>
723 : public true_type { };
724
725 /**
726 * @brief Class template _Bind_result is always a bind expression.
727 * @ingroup binders
728 */
729 template<typename _Result, typename _Signature>
730 struct is_bind_expression<const volatile _Bind_result<_Result, _Signature>>
731 : public true_type { };
732
733 template<typename _Func, typename... _BoundArgs>
734 struct _Bind_check_arity { };
735
736 template<typename _Ret, typename... _Args, typename... _BoundArgs>
737 struct _Bind_check_arity<_Ret (*)(_Args...), _BoundArgs...>
738 {
739 static_assert(sizeof...(_BoundArgs) == sizeof...(_Args),
740 "Wrong number of arguments for function");
741 };
742
743 template<typename _Ret, typename... _Args, typename... _BoundArgs>
744 struct _Bind_check_arity<_Ret (*)(_Args......), _BoundArgs...>
745 {
746 static_assert(sizeof...(_BoundArgs) >= sizeof...(_Args),
747 "Wrong number of arguments for function");
748 };
749
750 template<typename _Tp, typename _Class, typename... _BoundArgs>
751 struct _Bind_check_arity<_Tp _Class::*, _BoundArgs...>
752 {
753 using _Arity = typename _Mem_fn<_Tp _Class::*>::_Arity;
754 using _Varargs = typename _Mem_fn<_Tp _Class::*>::_Varargs;
755 static_assert(_Varargs::value
756 ? sizeof...(_BoundArgs) >= _Arity::value + 1
757 : sizeof...(_BoundArgs) == _Arity::value + 1,
758 "Wrong number of arguments for pointer-to-member");
759 };
760
761 // Trait type used to remove std::bind() from overload set via SFINAE
762 // when first argument has integer type, so that std::bind() will
763 // not be a better match than ::bind() from the BSD Sockets API.
764 template<typename _Tp, typename _Tp2 = typename decay<_Tp>::type>
765 using __is_socketlike = __or_<is_integral<_Tp2>, is_enum<_Tp2>>;
766
767 template<bool _SocketLike, typename _Func, typename... _BoundArgs>
768 struct _Bind_helper
769 : _Bind_check_arity<typename decay<_Func>::type, _BoundArgs...>
770 {
771 typedef typename decay<_Func>::type __func_type;
772 typedef _Bind<__func_type(typename decay<_BoundArgs>::type...)> type;
773 };
774
775 // Partial specialization for is_socketlike == true, does not define
776 // nested type so std::bind() will not participate in overload resolution
777 // when the first argument might be a socket file descriptor.
778 template<typename _Func, typename... _BoundArgs>
779 struct _Bind_helper<true, _Func, _BoundArgs...>
780 { };
781
782 /**
783 * @brief Function template for std::bind.
784 * @ingroup binders
785 */
786 template<typename _Func, typename... _BoundArgs>
787 inline _GLIBCXX20_CONSTEXPR typename
788 _Bind_helper<__is_socketlike<_Func>::value, _Func, _BoundArgs...>::type
789 bind(_Func&& __f, _BoundArgs&&... __args)
790 {
791 typedef _Bind_helper<false, _Func, _BoundArgs...> __helper_type;
792 return typename __helper_type::type(std::forward<_Func>(__f),
793 std::forward<_BoundArgs>(__args)...);
794 }
795
796 template<typename _Result, typename _Func, typename... _BoundArgs>
797 struct _Bindres_helper
798 : _Bind_check_arity<typename decay<_Func>::type, _BoundArgs...>
799 {
800 typedef typename decay<_Func>::type __functor_type;
801 typedef _Bind_result<_Result,
802 __functor_type(typename decay<_BoundArgs>::type...)>
803 type;
804 };
805
806 /**
807 * @brief Function template for std::bind<R>.
808 * @ingroup binders
809 */
810 template<typename _Result, typename _Func, typename... _BoundArgs>
811 inline _GLIBCXX20_CONSTEXPR
812 typename _Bindres_helper<_Result, _Func, _BoundArgs...>::type
813 bind(_Func&& __f, _BoundArgs&&... __args)
814 {
815 typedef _Bindres_helper<_Result, _Func, _BoundArgs...> __helper_type;
816 return typename __helper_type::type(std::forward<_Func>(__f),
817 std::forward<_BoundArgs>(__args)...);
818 }
819
820#if __cplusplus > 201703L
821#define __cpp_lib_bind_front 201907L
822
823 template<typename _Fd, typename... _BoundArgs>
824 struct _Bind_front
825 {
826 static_assert(is_move_constructible_v<_Fd>);
827 static_assert((is_move_constructible_v<_BoundArgs> && ...));
828
829 // First parameter is to ensure this constructor is never used
830 // instead of the copy/move constructor.
831 template<typename _Fn, typename... _Args>
832 explicit constexpr
833 _Bind_front(int, _Fn&& __fn, _Args&&... __args)
834 noexcept(__and_<is_nothrow_constructible<_Fd, _Fn>,
835 is_nothrow_constructible<_BoundArgs, _Args>...>::value)
836 : _M_fd(std::forward<_Fn>(__fn)),
837 _M_bound_args(std::forward<_Args>(__args)...)
838 { static_assert(sizeof...(_Args) == sizeof...(_BoundArgs)); }
839
840 _Bind_front(const _Bind_front&) = default;
841 _Bind_front(_Bind_front&&) = default;
842 _Bind_front& operator=(const _Bind_front&) = default;
843 _Bind_front& operator=(_Bind_front&&) = default;
844 ~_Bind_front() = default;
845
846 template<typename... _CallArgs>
847 constexpr
848 invoke_result_t<_Fd&, _BoundArgs&..., _CallArgs...>
849 operator()(_CallArgs&&... __call_args) &
850 noexcept(is_nothrow_invocable_v<_Fd&, _BoundArgs&..., _CallArgs...>)
851 {
852 return _S_call(*this, _BoundIndices(),
853 std::forward<_CallArgs>(__call_args)...);
854 }
855
856 template<typename... _CallArgs>
857 constexpr
858 invoke_result_t<const _Fd&, const _BoundArgs&..., _CallArgs...>
859 operator()(_CallArgs&&... __call_args) const &
860 noexcept(is_nothrow_invocable_v<const _Fd&, const _BoundArgs&...,
861 _CallArgs...>)
862 {
863 return _S_call(*this, _BoundIndices(),
864 std::forward<_CallArgs>(__call_args)...);
865 }
866
867 template<typename... _CallArgs>
868 constexpr
869 invoke_result_t<_Fd, _BoundArgs..., _CallArgs...>
870 operator()(_CallArgs&&... __call_args) &&
871 noexcept(is_nothrow_invocable_v<_Fd, _BoundArgs..., _CallArgs...>)
872 {
873 return _S_call(std::move(*this), _BoundIndices(),
874 std::forward<_CallArgs>(__call_args)...);
875 }
876
877 template<typename... _CallArgs>
878 constexpr
879 invoke_result_t<const _Fd, const _BoundArgs..., _CallArgs...>
880 operator()(_CallArgs&&... __call_args) const &&
881 noexcept(is_nothrow_invocable_v<const _Fd, const _BoundArgs...,
882 _CallArgs...>)
883 {
884 return _S_call(std::move(*this), _BoundIndices(),
885 std::forward<_CallArgs>(__call_args)...);
886 }
887
888 private:
889 using _BoundIndices = index_sequence_for<_BoundArgs...>;
890
891 template<typename _Tp, size_t... _Ind, typename... _CallArgs>
892 static constexpr
893 decltype(auto)
894 _S_call(_Tp&& __g, index_sequence<_Ind...>, _CallArgs&&... __call_args)
895 {
896 return std::invoke(std::forward<_Tp>(__g)._M_fd,
897 std::get<_Ind>(std::forward<_Tp>(__g)._M_bound_args)...,
898 std::forward<_CallArgs>(__call_args)...);
899 }
900
901 _Fd _M_fd;
902 std::tuple<_BoundArgs...> _M_bound_args;
903 };
904
905 template<typename _Fn, typename... _Args>
906 using _Bind_front_t
907 = _Bind_front<decay_t<_Fn>, decay_t<_Args>...>;
908
909 template<typename _Fn, typename... _Args>
910 constexpr _Bind_front_t<_Fn, _Args...>
911 bind_front(_Fn&& __fn, _Args&&... __args)
912 noexcept(is_nothrow_constructible_v<_Bind_front_t<_Fn, _Args...>,
913 int, _Fn, _Args...>)
914 {
915 return _Bind_front_t<_Fn, _Args...>(0, std::forward<_Fn>(__fn),
916 std::forward<_Args>(__args)...);
917 }
918#endif
919
920#if __cplusplus >= 201402L
921 /// Generalized negator.
922 template<typename _Fn>
923 class _Not_fn
924 {
925 template<typename _Fn2, typename... _Args>
926 using __inv_res_t = typename __invoke_result<_Fn2, _Args...>::type;
927
928 template<typename _Tp>
929 static decltype(!std::declval<_Tp>())
930 _S_not() noexcept(noexcept(!std::declval<_Tp>()));
931
932 public:
933 template<typename _Fn2>
934 constexpr
935 _Not_fn(_Fn2&& __fn, int)
936 : _M_fn(std::forward<_Fn2>(__fn)) { }
937
938 _Not_fn(const _Not_fn& __fn) = default;
939 _Not_fn(_Not_fn&& __fn) = default;
940 ~_Not_fn() = default;
941
942 // Macro to define operator() with given cv-qualifiers ref-qualifiers,
943 // forwarding _M_fn and the function arguments with the same qualifiers,
944 // and deducing the return type and exception-specification.
945#define _GLIBCXX_NOT_FN_CALL_OP( _QUALS ) \
946 template<typename... _Args> \
947 _GLIBCXX20_CONSTEXPR \
948 decltype(_S_not<__inv_res_t<_Fn _QUALS, _Args...>>()) \
949 operator()(_Args&&... __args) _QUALS \
950 noexcept(__is_nothrow_invocable<_Fn _QUALS, _Args...>::value \
951 && noexcept(_S_not<__inv_res_t<_Fn _QUALS, _Args...>>())) \
952 { \
953 return !std::__invoke(std::forward< _Fn _QUALS >(_M_fn), \
954 std::forward<_Args>(__args)...); \
955 }
956 _GLIBCXX_NOT_FN_CALL_OP( & )
957 _GLIBCXX_NOT_FN_CALL_OP( const & )
958 _GLIBCXX_NOT_FN_CALL_OP( && )
959 _GLIBCXX_NOT_FN_CALL_OP( const && )
960#undef _GLIBCXX_NOT_FN_CALL_OP
961
962 private:
963 _Fn _M_fn;
964 };
965
966 template<typename _Tp, typename _Pred>
967 struct __is_byte_like : false_type { };
968
969 template<typename _Tp>
970 struct __is_byte_like<_Tp, equal_to<_Tp>>
971 : __bool_constant<sizeof(_Tp) == 1 && is_integral<_Tp>::value> { };
972
973 template<typename _Tp>
974 struct __is_byte_like<_Tp, equal_to<void>>
975 : __bool_constant<sizeof(_Tp) == 1 && is_integral<_Tp>::value> { };
976
977#if __cplusplus >= 201703L
978 // Declare std::byte (full definition is in <cstddef>).
979 enum class byte : unsigned char;
980
981 template<>
982 struct __is_byte_like<byte, equal_to<byte>>
983 : true_type { };
984
985 template<>
986 struct __is_byte_like<byte, equal_to<void>>
987 : true_type { };
988
989#define __cpp_lib_not_fn 201603
990 /// [func.not_fn] Function template not_fn
991 template<typename _Fn>
992 _GLIBCXX20_CONSTEXPR
993 inline auto
994 not_fn(_Fn&& __fn)
995 noexcept(std::is_nothrow_constructible<std::decay_t<_Fn>, _Fn&&>::value)
996 {
997 return _Not_fn<std::decay_t<_Fn>>{std::forward<_Fn>(__fn), 0};
998 }
999
1000 // Searchers
1001#define __cpp_lib_boyer_moore_searcher 201603
1002
1003 template<typename _ForwardIterator1, typename _BinaryPredicate = equal_to<>>
1004 class default_searcher
1005 {
1006 public:
1007 _GLIBCXX20_CONSTEXPR
1008 default_searcher(_ForwardIterator1 __pat_first,
1009 _ForwardIterator1 __pat_last,
1010 _BinaryPredicate __pred = _BinaryPredicate())
1011 : _M_m(__pat_first, __pat_last, std::move(__pred))
1012 { }
1013
1014 template<typename _ForwardIterator2>
1015 _GLIBCXX20_CONSTEXPR
1016 pair<_ForwardIterator2, _ForwardIterator2>
1017 operator()(_ForwardIterator2 __first, _ForwardIterator2 __last) const
1018 {
1019 _ForwardIterator2 __first_ret =
1020 std::search(__first, __last, std::get<0>(_M_m), std::get<1>(_M_m),
1021 std::get<2>(_M_m));
1022 auto __ret = std::make_pair(__first_ret, __first_ret);
1023 if (__ret.first != __last)
1024 std::advance(__ret.second, std::distance(std::get<0>(_M_m),
1025 std::get<1>(_M_m)));
1026 return __ret;
1027 }
1028
1029 private:
1030 tuple<_ForwardIterator1, _ForwardIterator1, _BinaryPredicate> _M_m;
1031 };
1032
1033 template<typename _Key, typename _Tp, typename _Hash, typename _Pred>
1034 struct __boyer_moore_map_base
1035 {
1036 template<typename _RAIter>
1037 __boyer_moore_map_base(_RAIter __pat, size_t __patlen,
1038 _Hash&& __hf, _Pred&& __pred)
1039 : _M_bad_char{ __patlen, std::move(__hf), std::move(__pred) }
1040 {
1041 if (__patlen > 0)
1042 for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
1043 _M_bad_char[__pat[__i]] = __patlen - 1 - __i;
1044 }
1045
1046 using __diff_type = _Tp;
1047
1048 __diff_type
1049 _M_lookup(_Key __key, __diff_type __not_found) const
1050 {
1051 auto __iter = _M_bad_char.find(__key);
1052 if (__iter == _M_bad_char.end())
1053 return __not_found;
1054 return __iter->second;
1055 }
1056
1057 _Pred
1058 _M_pred() const { return _M_bad_char.key_eq(); }
1059
1060 _GLIBCXX_STD_C::unordered_map<_Key, _Tp, _Hash, _Pred> _M_bad_char;
1061 };
1062
1063 template<typename _Tp, size_t _Len, typename _Pred>
1064 struct __boyer_moore_array_base
1065 {
1066 template<typename _RAIter, typename _Unused>
1067 __boyer_moore_array_base(_RAIter __pat, size_t __patlen,
1068 _Unused&&, _Pred&& __pred)
1069 : _M_bad_char{ array<_Tp, _Len>{}, std::move(__pred) }
1070 {
1071 std::get<0>(_M_bad_char).fill(__patlen);
1072 if (__patlen > 0)
1073 for (__diff_type __i = 0; __i < __patlen - 1; ++__i)
1074 {
1075 auto __ch = __pat[__i];
1076 using _UCh = make_unsigned_t<decltype(__ch)>;
1077 auto __uch = static_cast<_UCh>(__ch);
1078 std::get<0>(_M_bad_char)[__uch] = __patlen - 1 - __i;
1079 }
1080 }
1081
1082 using __diff_type = _Tp;
1083
1084 template<typename _Key>
1085 __diff_type
1086 _M_lookup(_Key __key, __diff_type __not_found) const
1087 {
1088 auto __ukey = static_cast<make_unsigned_t<_Key>>(__key);
1089 if (__ukey >= _Len)
1090 return __not_found;
1091 return std::get<0>(_M_bad_char)[__ukey];
1092 }
1093
1094 const _Pred&
1095 _M_pred() const { return std::get<1>(_M_bad_char); }
1096
1097 tuple<array<_Tp, _Len>, _Pred> _M_bad_char;
1098 };
1099
1100 // Use __boyer_moore_array_base when pattern consists of narrow characters
1101 // (or std::byte) and uses std::equal_to as the predicate.
1102 template<typename _RAIter, typename _Hash, typename _Pred,
1103 typename _Val = typename iterator_traits<_RAIter>::value_type,
1104 typename _Diff = typename iterator_traits<_RAIter>::difference_type>
1105 using __boyer_moore_base_t
1106 = conditional_t<__is_byte_like<_Val, _Pred>::value,
1107 __boyer_moore_array_base<_Diff, 256, _Pred>,
1108 __boyer_moore_map_base<_Val, _Diff, _Hash, _Pred>>;
1109
1110 template<typename _RAIter, typename _Hash
1111 = hash<typename iterator_traits<_RAIter>::value_type>,
1112 typename _BinaryPredicate = equal_to<>>
1113 class boyer_moore_searcher
1114 : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
1115 {
1116 using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
1117 using typename _Base::__diff_type;
1118
1119 public:
1120 boyer_moore_searcher(_RAIter __pat_first, _RAIter __pat_last,
1121 _Hash __hf = _Hash(),
1122 _BinaryPredicate __pred = _BinaryPredicate());
1123
1124 template<typename _RandomAccessIterator2>
1125 pair<_RandomAccessIterator2, _RandomAccessIterator2>
1126 operator()(_RandomAccessIterator2 __first,
1127 _RandomAccessIterator2 __last) const;
1128
1129 private:
1130 bool
1131 _M_is_prefix(_RAIter __word, __diff_type __len,
1132 __diff_type __pos)
1133 {
1134 const auto& __pred = this->_M_pred();
1135 __diff_type __suffixlen = __len - __pos;
1136 for (__diff_type __i = 0; __i < __suffixlen; ++__i)
1137 if (!__pred(__word[__i], __word[__pos + __i]))
1138 return false;
1139 return true;
1140 }
1141
1142 __diff_type
1143 _M_suffix_length(_RAIter __word, __diff_type __len,
1144 __diff_type __pos)
1145 {
1146 const auto& __pred = this->_M_pred();
1147 __diff_type __i = 0;
1148 while (__pred(__word[__pos - __i], __word[__len - 1 - __i])
1149 && __i < __pos)
1150 {
1151 ++__i;
1152 }
1153 return __i;
1154 }
1155
1156 template<typename _Tp>
1157 __diff_type
1158 _M_bad_char_shift(_Tp __c) const
1159 { return this->_M_lookup(__c, _M_pat_end - _M_pat); }
1160
1161 _RAIter _M_pat;
1162 _RAIter _M_pat_end;
1163 _GLIBCXX_STD_C::vector<__diff_type> _M_good_suffix;
1164 };
1165
1166 template<typename _RAIter, typename _Hash
1167 = hash<typename iterator_traits<_RAIter>::value_type>,
1168 typename _BinaryPredicate = equal_to<>>
1169 class boyer_moore_horspool_searcher
1170 : __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>
1171 {
1172 using _Base = __boyer_moore_base_t<_RAIter, _Hash, _BinaryPredicate>;
1173 using typename _Base::__diff_type;
1174
1175 public:
1176 boyer_moore_horspool_searcher(_RAIter __pat,
1177 _RAIter __pat_end,
1178 _Hash __hf = _Hash(),
1179 _BinaryPredicate __pred
1180 = _BinaryPredicate())
1181 : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
1182 _M_pat(__pat), _M_pat_end(__pat_end)
1183 { }
1184
1185 template<typename _RandomAccessIterator2>
1186 pair<_RandomAccessIterator2, _RandomAccessIterator2>
1187 operator()(_RandomAccessIterator2 __first,
1188 _RandomAccessIterator2 __last) const
1189 {
1190 const auto& __pred = this->_M_pred();
1191 auto __patlen = _M_pat_end - _M_pat;
1192 if (__patlen == 0)
1193 return std::make_pair(__first, __first);
1194 auto __len = __last - __first;
1195 while (__len >= __patlen)
1196 {
1197 for (auto __scan = __patlen - 1;
1198 __pred(__first[__scan], _M_pat[__scan]); --__scan)
1199 if (__scan == 0)
1200 return std::make_pair(__first, __first + __patlen);
1201 auto __shift = _M_bad_char_shift(__first[__patlen - 1]);
1202 __len -= __shift;
1203 __first += __shift;
1204 }
1205 return std::make_pair(__last, __last);
1206 }
1207
1208 private:
1209 template<typename _Tp>
1210 __diff_type
1211 _M_bad_char_shift(_Tp __c) const
1212 { return this->_M_lookup(__c, _M_pat_end - _M_pat); }
1213
1214 _RAIter _M_pat;
1215 _RAIter _M_pat_end;
1216 };
1217
1218 template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
1219 boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
1220 boyer_moore_searcher(_RAIter __pat, _RAIter __pat_end,
1221 _Hash __hf, _BinaryPredicate __pred)
1222 : _Base(__pat, __pat_end - __pat, std::move(__hf), std::move(__pred)),
1223 _M_pat(__pat), _M_pat_end(__pat_end), _M_good_suffix(__pat_end - __pat)
1224 {
1225 auto __patlen = __pat_end - __pat;
1226 if (__patlen == 0)
1227 return;
1228 __diff_type __last_prefix = __patlen - 1;
1229 for (__diff_type __p = __patlen - 1; __p >= 0; --__p)
1230 {
1231 if (_M_is_prefix(word: __pat, len: __patlen, pos: __p + 1))
1232 __last_prefix = __p + 1;
1233 _M_good_suffix[__p] = __last_prefix + (__patlen - 1 - __p);
1234 }
1235 for (__diff_type __p = 0; __p < __patlen - 1; ++__p)
1236 {
1237 auto __slen = _M_suffix_length(word: __pat, len: __patlen, pos: __p);
1238 auto __pos = __patlen - 1 - __slen;
1239 if (!__pred(__pat[__p - __slen], __pat[__pos]))
1240 _M_good_suffix[__pos] = __patlen - 1 - __p + __slen;
1241 }
1242 }
1243
1244 template<typename _RAIter, typename _Hash, typename _BinaryPredicate>
1245 template<typename _RandomAccessIterator2>
1246 pair<_RandomAccessIterator2, _RandomAccessIterator2>
1247 boyer_moore_searcher<_RAIter, _Hash, _BinaryPredicate>::
1248 operator()(_RandomAccessIterator2 __first,
1249 _RandomAccessIterator2 __last) const
1250 {
1251 auto __patlen = _M_pat_end - _M_pat;
1252 if (__patlen == 0)
1253 return std::make_pair(__first, __first);
1254 const auto& __pred = this->_M_pred();
1255 __diff_type __i = __patlen - 1;
1256 auto __stringlen = __last - __first;
1257 while (__i < __stringlen)
1258 {
1259 __diff_type __j = __patlen - 1;
1260 while (__j >= 0 && __pred(__first[__i], _M_pat[__j]))
1261 {
1262 --__i;
1263 --__j;
1264 }
1265 if (__j < 0)
1266 {
1267 const auto __match = __first + __i + 1;
1268 return std::make_pair(__match, __match + __patlen);
1269 }
1270 __i += std::max(_M_bad_char_shift(__first[__i]),
1271 _M_good_suffix[__j]);
1272 }
1273 return std::make_pair(__last, __last);
1274 }
1275
1276#endif // C++17
1277#endif // C++14
1278#endif // C++11
1279
1280_GLIBCXX_END_NAMESPACE_VERSION
1281} // namespace std
1282
1283#endif // _GLIBCXX_FUNCTIONAL
1284

source code of include/c++/11/functional