xref: /freebsd/contrib/llvm-project/libcxx/include/any (revision 9f23cbd6cae82fd77edfad7173432fa8dccd0a95) 
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_ANY
11#define _LIBCPP_ANY
12
13/*
14   any synopsis
15
16namespace std {
17
18  class bad_any_cast : public bad_cast
19  {
20  public:
21    virtual const char* what() const noexcept;
22  };
23
24  class any
25  {
26  public:
27
28    // 6.3.1 any construct/destruct
29    any() noexcept;
30
31    any(const any& other);
32    any(any&& other) noexcept;
33
34    template <class ValueType>
35      any(ValueType&& value);
36
37    ~any();
38
39    // 6.3.2 any assignments
40    any& operator=(const any& rhs);
41    any& operator=(any&& rhs) noexcept;
42
43    template <class ValueType>
44      any& operator=(ValueType&& rhs);
45
46    // 6.3.3 any modifiers
47    template <class ValueType, class... Args>
48      decay_t<ValueType>& emplace(Args&&... args);
49    template <class ValueType, class U, class... Args>
50      decay_t<ValueType>& emplace(initializer_list<U>, Args&&...);
51    void reset() noexcept;
52    void swap(any& rhs) noexcept;
53
54    // 6.3.4 any observers
55    bool has_value() const noexcept;
56    const type_info& type() const noexcept;
57  };
58
59   // 6.4 Non-member functions
60  void swap(any& x, any& y) noexcept;
61
62  template <class T, class ...Args>
63    any make_any(Args&& ...args);
64  template <class T, class U, class ...Args>
65    any make_any(initializer_list<U>, Args&& ...args);
66
67  template<class ValueType>
68    ValueType any_cast(const any& operand);
69  template<class ValueType>
70    ValueType any_cast(any& operand);
71  template<class ValueType>
72    ValueType any_cast(any&& operand);
73
74  template<class ValueType>
75    const ValueType* any_cast(const any* operand) noexcept;
76  template<class ValueType>
77    ValueType* any_cast(any* operand) noexcept;
78
79} // namespace std
80
81*/
82
83#include <__assert> // all public C++ headers provide the assertion handler
84#include <__availability>
85#include <__config>
86#include <__memory/allocator.h>
87#include <__memory/allocator_destructor.h>
88#include <__memory/allocator_traits.h>
89#include <__memory/unique_ptr.h>
90#include <__utility/forward.h>
91#include <__utility/in_place.h>
92#include <__utility/move.h>
93#include <__utility/unreachable.h>
94#include <cstdlib>
95#include <initializer_list>
96#include <type_traits>
97#include <typeinfo>
98#include <version>
99
100#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
101#  pragma GCC system_header
102#endif
103
104namespace std {
105class _LIBCPP_EXCEPTION_ABI _LIBCPP_AVAILABILITY_BAD_ANY_CAST bad_any_cast : public bad_cast
106{
107public:
108    const char* what() const _NOEXCEPT override;
109};
110} // namespace std
111
112_LIBCPP_BEGIN_NAMESPACE_STD
113
114#if _LIBCPP_STD_VER > 14
115
116_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
117_LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
118void __throw_bad_any_cast()
119{
120#ifndef _LIBCPP_NO_EXCEPTIONS
121    throw bad_any_cast();
122#else
123    _VSTD::abort();
124#endif
125}
126
127// Forward declarations
128class _LIBCPP_TEMPLATE_VIS any;
129
130template <class _ValueType>
131_LIBCPP_INLINE_VISIBILITY
132add_pointer_t<add_const_t<_ValueType>>
133any_cast(any const *) _NOEXCEPT;
134
135template <class _ValueType>
136_LIBCPP_INLINE_VISIBILITY
137add_pointer_t<_ValueType> any_cast(any *) _NOEXCEPT;
138
139namespace __any_imp
140{
141  _LIBCPP_SUPPRESS_DEPRECATED_PUSH
142  using _Buffer = aligned_storage_t<3*sizeof(void*), alignment_of<void*>::value>;
143  _LIBCPP_SUPPRESS_DEPRECATED_POP
144
145  template <class _Tp>
146  using _IsSmallObject = integral_constant<bool
147        , sizeof(_Tp) <= sizeof(_Buffer)
148          && alignment_of<_Buffer>::value
149             % alignment_of<_Tp>::value == 0
150          && is_nothrow_move_constructible<_Tp>::value
151        >;
152
153  enum class _Action {
154    _Destroy,
155    _Copy,
156    _Move,
157    _Get,
158    _TypeInfo
159  };
160
161  template <class _Tp> struct _SmallHandler;
162  template <class _Tp> struct _LargeHandler;
163
164  template <class _Tp>
165  struct  _LIBCPP_TEMPLATE_VIS __unique_typeinfo { static constexpr int __id = 0; };
166  template <class _Tp> constexpr int __unique_typeinfo<_Tp>::__id;
167
168  template <class _Tp>
169  inline _LIBCPP_INLINE_VISIBILITY
170  constexpr const void* __get_fallback_typeid() {
171      return &__unique_typeinfo<remove_cv_t<remove_reference_t<_Tp>>>::__id;
172  }
173
174  template <class _Tp>
175  inline _LIBCPP_INLINE_VISIBILITY
176  bool __compare_typeid(type_info const* __id, const void* __fallback_id)
177  {
178#if !defined(_LIBCPP_HAS_NO_RTTI)
179      if (__id && *__id == typeid(_Tp))
180          return true;
181#endif
182      if (!__id && __fallback_id == __any_imp::__get_fallback_typeid<_Tp>())
183          return true;
184      return false;
185  }
186
187  template <class _Tp>
188  using _Handler = conditional_t<
189    _IsSmallObject<_Tp>::value, _SmallHandler<_Tp>, _LargeHandler<_Tp>>;
190
191} // namespace __any_imp
192
193class _LIBCPP_TEMPLATE_VIS any
194{
195public:
196  // construct/destruct
197  _LIBCPP_INLINE_VISIBILITY
198  constexpr any() _NOEXCEPT : __h_(nullptr) {}
199
200  _LIBCPP_INLINE_VISIBILITY
201  any(any const & __other) : __h_(nullptr)
202  {
203    if (__other.__h_) __other.__call(_Action::_Copy, this);
204  }
205
206  _LIBCPP_INLINE_VISIBILITY
207  any(any && __other) _NOEXCEPT : __h_(nullptr)
208  {
209    if (__other.__h_) __other.__call(_Action::_Move, this);
210  }
211
212  template <
213      class _ValueType
214    , class _Tp = decay_t<_ValueType>
215    , class = enable_if_t<
216        !is_same<_Tp, any>::value &&
217        !__is_inplace_type<_ValueType>::value &&
218        is_copy_constructible<_Tp>::value>
219    >
220  _LIBCPP_INLINE_VISIBILITY
221  any(_ValueType && __value);
222
223  template <class _ValueType, class ..._Args,
224    class _Tp = decay_t<_ValueType>,
225    class = enable_if_t<
226        is_constructible<_Tp, _Args...>::value &&
227        is_copy_constructible<_Tp>::value
228    >
229  >
230  _LIBCPP_INLINE_VISIBILITY
231  explicit any(in_place_type_t<_ValueType>, _Args&&... __args);
232
233  template <class _ValueType, class _Up, class ..._Args,
234    class _Tp = decay_t<_ValueType>,
235    class = enable_if_t<
236        is_constructible<_Tp, initializer_list<_Up>&, _Args...>::value &&
237        is_copy_constructible<_Tp>::value>
238  >
239  _LIBCPP_INLINE_VISIBILITY
240  explicit any(in_place_type_t<_ValueType>, initializer_list<_Up>, _Args&&... __args);
241
242  _LIBCPP_INLINE_VISIBILITY
243  ~any() { this->reset(); }
244
245  // assignments
246  _LIBCPP_INLINE_VISIBILITY
247  any & operator=(any const & __rhs) {
248    any(__rhs).swap(*this);
249    return *this;
250  }
251
252  _LIBCPP_INLINE_VISIBILITY
253  any & operator=(any && __rhs) _NOEXCEPT {
254    any(_VSTD::move(__rhs)).swap(*this);
255    return *this;
256  }
257
258  template <
259      class _ValueType
260    , class _Tp = decay_t<_ValueType>
261    , class = enable_if_t<
262          !is_same<_Tp, any>::value
263          && is_copy_constructible<_Tp>::value>
264    >
265  _LIBCPP_INLINE_VISIBILITY
266  any & operator=(_ValueType && __rhs);
267
268  template <class _ValueType, class ..._Args,
269    class _Tp = decay_t<_ValueType>,
270    class = enable_if_t<
271        is_constructible<_Tp, _Args...>::value &&
272        is_copy_constructible<_Tp>::value>
273    >
274  _LIBCPP_INLINE_VISIBILITY
275  _Tp& emplace(_Args&&...);
276
277  template <class _ValueType, class _Up, class ..._Args,
278    class _Tp = decay_t<_ValueType>,
279    class = enable_if_t<
280        is_constructible<_Tp, initializer_list<_Up>&, _Args...>::value &&
281        is_copy_constructible<_Tp>::value>
282  >
283  _LIBCPP_INLINE_VISIBILITY
284  _Tp& emplace(initializer_list<_Up>, _Args&&...);
285
286  // 6.3.3 any modifiers
287  _LIBCPP_INLINE_VISIBILITY
288  void reset() _NOEXCEPT { if (__h_) this->__call(_Action::_Destroy); }
289
290  _LIBCPP_INLINE_VISIBILITY
291  void swap(any & __rhs) _NOEXCEPT;
292
293  // 6.3.4 any observers
294  _LIBCPP_INLINE_VISIBILITY
295  bool has_value() const _NOEXCEPT { return __h_ != nullptr; }
296
297#if !defined(_LIBCPP_HAS_NO_RTTI)
298  _LIBCPP_INLINE_VISIBILITY
299  const type_info & type() const _NOEXCEPT {
300    if (__h_) {
301        return *static_cast<type_info const *>(this->__call(_Action::_TypeInfo));
302    } else {
303        return typeid(void);
304    }
305  }
306#endif
307
308private:
309    typedef __any_imp::_Action _Action;
310    using _HandleFuncPtr =  void* (*)(_Action, any const *, any *, const type_info *,
311      const void* __fallback_info);
312
313    union _Storage {
314        constexpr _Storage() : __ptr(nullptr) {}
315        void *  __ptr;
316        __any_imp::_Buffer __buf;
317    };
318
319    _LIBCPP_INLINE_VISIBILITY
320    void * __call(_Action __a, any * __other = nullptr,
321                  type_info const * __info = nullptr,
322                   const void* __fallback_info = nullptr) const
323    {
324        return __h_(__a, this, __other, __info, __fallback_info);
325    }
326
327    _LIBCPP_INLINE_VISIBILITY
328    void * __call(_Action __a, any * __other = nullptr,
329                  type_info const * __info = nullptr,
330                  const void* __fallback_info = nullptr)
331    {
332        return __h_(__a, this, __other, __info, __fallback_info);
333    }
334
335    template <class>
336    friend struct __any_imp::_SmallHandler;
337    template <class>
338    friend struct __any_imp::_LargeHandler;
339
340    template <class _ValueType>
341    friend add_pointer_t<add_const_t<_ValueType>>
342    any_cast(any const *) _NOEXCEPT;
343
344    template <class _ValueType>
345    friend add_pointer_t<_ValueType>
346    any_cast(any *) _NOEXCEPT;
347
348    _HandleFuncPtr __h_ = nullptr;
349    _Storage __s_;
350};
351
352namespace __any_imp
353{
354  template <class _Tp>
355  struct _LIBCPP_TEMPLATE_VIS _SmallHandler
356  {
357     _LIBCPP_INLINE_VISIBILITY
358     static void* __handle(_Action __act, any const * __this, any * __other,
359                           type_info const * __info, const void* __fallback_info)
360     {
361        switch (__act)
362        {
363        case _Action::_Destroy:
364          __destroy(const_cast<any &>(*__this));
365          return nullptr;
366        case _Action::_Copy:
367            __copy(*__this, *__other);
368            return nullptr;
369        case _Action::_Move:
370          __move(const_cast<any &>(*__this), *__other);
371          return nullptr;
372        case _Action::_Get:
373            return __get(const_cast<any &>(*__this), __info, __fallback_info);
374        case _Action::_TypeInfo:
375          return __type_info();
376        }
377        __libcpp_unreachable();
378    }
379
380    template <class ..._Args>
381    _LIBCPP_INLINE_VISIBILITY
382    static _Tp& __create(any & __dest, _Args&&... __args) {
383        typedef allocator<_Tp> _Alloc;
384        typedef allocator_traits<_Alloc> _ATraits;
385        _Alloc __a;
386        _Tp * __ret = static_cast<_Tp*>(static_cast<void*>(&__dest.__s_.__buf));
387        _ATraits::construct(__a, __ret, _VSTD::forward<_Args>(__args)...);
388        __dest.__h_ = &_SmallHandler::__handle;
389        return *__ret;
390    }
391
392  private:
393    _LIBCPP_INLINE_VISIBILITY
394    static void __destroy(any & __this) {
395        typedef allocator<_Tp> _Alloc;
396        typedef allocator_traits<_Alloc> _ATraits;
397        _Alloc __a;
398        _Tp * __p = static_cast<_Tp *>(static_cast<void*>(&__this.__s_.__buf));
399        _ATraits::destroy(__a, __p);
400        __this.__h_ = nullptr;
401    }
402
403    _LIBCPP_INLINE_VISIBILITY
404    static void __copy(any const & __this, any & __dest) {
405        _SmallHandler::__create(__dest, *static_cast<_Tp const *>(
406            static_cast<void const *>(&__this.__s_.__buf)));
407    }
408
409    _LIBCPP_INLINE_VISIBILITY
410    static void __move(any & __this, any & __dest) {
411        _SmallHandler::__create(__dest, _VSTD::move(
412            *static_cast<_Tp*>(static_cast<void*>(&__this.__s_.__buf))));
413        __destroy(__this);
414    }
415
416    _LIBCPP_INLINE_VISIBILITY
417    static void* __get(any & __this,
418                       type_info const * __info,
419                       const void* __fallback_id)
420    {
421        if (__any_imp::__compare_typeid<_Tp>(__info, __fallback_id))
422            return static_cast<void*>(&__this.__s_.__buf);
423        return nullptr;
424    }
425
426    _LIBCPP_INLINE_VISIBILITY
427    static void* __type_info()
428    {
429#if !defined(_LIBCPP_HAS_NO_RTTI)
430        return const_cast<void*>(static_cast<void const *>(&typeid(_Tp)));
431#else
432        return nullptr;
433#endif
434    }
435  };
436
437  template <class _Tp>
438  struct _LIBCPP_TEMPLATE_VIS _LargeHandler
439  {
440    _LIBCPP_INLINE_VISIBILITY
441    static void* __handle(_Action __act, any const * __this,
442                          any * __other, type_info const * __info,
443                          void const* __fallback_info)
444    {
445        switch (__act)
446        {
447        case _Action::_Destroy:
448          __destroy(const_cast<any &>(*__this));
449          return nullptr;
450        case _Action::_Copy:
451          __copy(*__this, *__other);
452          return nullptr;
453        case _Action::_Move:
454          __move(const_cast<any &>(*__this), *__other);
455          return nullptr;
456        case _Action::_Get:
457            return __get(const_cast<any &>(*__this), __info, __fallback_info);
458        case _Action::_TypeInfo:
459          return __type_info();
460        }
461        __libcpp_unreachable();
462    }
463
464    template <class ..._Args>
465    _LIBCPP_INLINE_VISIBILITY
466    static _Tp& __create(any & __dest, _Args&&... __args) {
467        typedef allocator<_Tp> _Alloc;
468        typedef allocator_traits<_Alloc> _ATraits;
469        typedef __allocator_destructor<_Alloc> _Dp;
470        _Alloc __a;
471        unique_ptr<_Tp, _Dp> __hold(_ATraits::allocate(__a, 1), _Dp(__a, 1));
472        _Tp * __ret = __hold.get();
473        _ATraits::construct(__a, __ret, _VSTD::forward<_Args>(__args)...);
474        __dest.__s_.__ptr = __hold.release();
475        __dest.__h_ = &_LargeHandler::__handle;
476        return *__ret;
477    }
478
479  private:
480
481    _LIBCPP_INLINE_VISIBILITY
482    static void __destroy(any & __this){
483        typedef allocator<_Tp> _Alloc;
484        typedef allocator_traits<_Alloc> _ATraits;
485        _Alloc __a;
486        _Tp * __p = static_cast<_Tp *>(__this.__s_.__ptr);
487        _ATraits::destroy(__a, __p);
488        _ATraits::deallocate(__a, __p, 1);
489        __this.__h_ = nullptr;
490    }
491
492    _LIBCPP_INLINE_VISIBILITY
493    static void __copy(any const & __this, any & __dest) {
494        _LargeHandler::__create(__dest, *static_cast<_Tp const *>(__this.__s_.__ptr));
495    }
496
497    _LIBCPP_INLINE_VISIBILITY
498    static void __move(any & __this, any & __dest) {
499      __dest.__s_.__ptr = __this.__s_.__ptr;
500      __dest.__h_ = &_LargeHandler::__handle;
501      __this.__h_ = nullptr;
502    }
503
504    _LIBCPP_INLINE_VISIBILITY
505    static void* __get(any & __this, type_info const * __info,
506                       void const* __fallback_info)
507    {
508        if (__any_imp::__compare_typeid<_Tp>(__info, __fallback_info))
509            return static_cast<void*>(__this.__s_.__ptr);
510        return nullptr;
511
512    }
513
514    _LIBCPP_INLINE_VISIBILITY
515    static void* __type_info()
516    {
517#if !defined(_LIBCPP_HAS_NO_RTTI)
518        return const_cast<void*>(static_cast<void const *>(&typeid(_Tp)));
519#else
520        return nullptr;
521#endif
522    }
523  };
524
525} // namespace __any_imp
526
527
528template <class _ValueType, class _Tp, class>
529any::any(_ValueType && __v) : __h_(nullptr)
530{
531  __any_imp::_Handler<_Tp>::__create(*this, _VSTD::forward<_ValueType>(__v));
532}
533
534template <class _ValueType, class ..._Args, class _Tp, class>
535any::any(in_place_type_t<_ValueType>, _Args&&... __args) {
536  __any_imp::_Handler<_Tp>::__create(*this, _VSTD::forward<_Args>(__args)...);
537}
538
539template <class _ValueType, class _Up, class ..._Args, class _Tp, class>
540any::any(in_place_type_t<_ValueType>, initializer_list<_Up> __il, _Args&&... __args) {
541  __any_imp::_Handler<_Tp>::__create(*this, __il, _VSTD::forward<_Args>(__args)...);
542}
543
544template <class _ValueType, class, class>
545inline _LIBCPP_INLINE_VISIBILITY
546any & any::operator=(_ValueType && __v)
547{
548  any(_VSTD::forward<_ValueType>(__v)).swap(*this);
549  return *this;
550}
551
552template <class _ValueType, class ..._Args, class _Tp, class>
553inline _LIBCPP_INLINE_VISIBILITY
554_Tp& any::emplace(_Args&&... __args) {
555  reset();
556  return __any_imp::_Handler<_Tp>::__create(*this, _VSTD::forward<_Args>(__args)...);
557}
558
559template <class _ValueType, class _Up, class ..._Args, class _Tp, class>
560inline _LIBCPP_INLINE_VISIBILITY
561_Tp& any::emplace(initializer_list<_Up> __il, _Args&&... __args) {
562  reset();
563  return __any_imp::_Handler<_Tp>::__create(*this, __il, _VSTD::forward<_Args>(__args)...);
564}
565
566inline _LIBCPP_INLINE_VISIBILITY
567void any::swap(any & __rhs) _NOEXCEPT
568{
569    if (this == &__rhs)
570      return;
571    if (__h_ && __rhs.__h_) {
572        any __tmp;
573        __rhs.__call(_Action::_Move, &__tmp);
574        this->__call(_Action::_Move, &__rhs);
575        __tmp.__call(_Action::_Move, this);
576    }
577    else if (__h_) {
578        this->__call(_Action::_Move, &__rhs);
579    }
580    else if (__rhs.__h_) {
581        __rhs.__call(_Action::_Move, this);
582    }
583}
584
585// 6.4 Non-member functions
586
587inline _LIBCPP_INLINE_VISIBILITY
588void swap(any & __lhs, any & __rhs) _NOEXCEPT
589{
590    __lhs.swap(__rhs);
591}
592
593template <class _Tp, class ..._Args>
594inline _LIBCPP_INLINE_VISIBILITY
595any make_any(_Args&&... __args) {
596    return any(in_place_type<_Tp>, _VSTD::forward<_Args>(__args)...);
597}
598
599template <class _Tp, class _Up, class ..._Args>
600inline _LIBCPP_INLINE_VISIBILITY
601any make_any(initializer_list<_Up> __il, _Args&&... __args) {
602    return any(in_place_type<_Tp>, __il, _VSTD::forward<_Args>(__args)...);
603}
604
605template <class _ValueType>
606inline _LIBCPP_INLINE_VISIBILITY
607_LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
608_ValueType any_cast(any const & __v)
609{
610    using _RawValueType = __remove_cvref_t<_ValueType>;
611    static_assert(is_constructible<_ValueType, _RawValueType const &>::value,
612                  "ValueType is required to be a const lvalue reference "
613                  "or a CopyConstructible type");
614    auto __tmp = _VSTD::any_cast<add_const_t<_RawValueType>>(&__v);
615    if (__tmp == nullptr)
616        __throw_bad_any_cast();
617    return static_cast<_ValueType>(*__tmp);
618}
619
620template <class _ValueType>
621inline _LIBCPP_INLINE_VISIBILITY
622_LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
623_ValueType any_cast(any & __v)
624{
625    using _RawValueType = __remove_cvref_t<_ValueType>;
626    static_assert(is_constructible<_ValueType, _RawValueType &>::value,
627                  "ValueType is required to be an lvalue reference "
628                  "or a CopyConstructible type");
629    auto __tmp = _VSTD::any_cast<_RawValueType>(&__v);
630    if (__tmp == nullptr)
631        __throw_bad_any_cast();
632    return static_cast<_ValueType>(*__tmp);
633}
634
635template <class _ValueType>
636inline _LIBCPP_INLINE_VISIBILITY
637_LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
638_ValueType any_cast(any && __v)
639{
640    using _RawValueType = __remove_cvref_t<_ValueType>;
641    static_assert(is_constructible<_ValueType, _RawValueType>::value,
642                  "ValueType is required to be an rvalue reference "
643                  "or a CopyConstructible type");
644    auto __tmp = _VSTD::any_cast<_RawValueType>(&__v);
645    if (__tmp == nullptr)
646        __throw_bad_any_cast();
647    return static_cast<_ValueType>(_VSTD::move(*__tmp));
648}
649
650template <class _ValueType>
651inline _LIBCPP_INLINE_VISIBILITY
652add_pointer_t<add_const_t<_ValueType>>
653any_cast(any const * __any) _NOEXCEPT
654{
655    static_assert(!is_reference<_ValueType>::value,
656                  "_ValueType may not be a reference.");
657    return _VSTD::any_cast<_ValueType>(const_cast<any *>(__any));
658}
659
660template <class _RetType>
661inline _LIBCPP_INLINE_VISIBILITY
662_RetType __pointer_or_func_cast(void* __p, /*IsFunction*/false_type) noexcept {
663  return static_cast<_RetType>(__p);
664}
665
666template <class _RetType>
667inline _LIBCPP_INLINE_VISIBILITY
668_RetType __pointer_or_func_cast(void*, /*IsFunction*/true_type) noexcept {
669  return nullptr;
670}
671
672template <class _ValueType>
673_LIBCPP_HIDE_FROM_ABI
674add_pointer_t<_ValueType>
675any_cast(any * __any) _NOEXCEPT
676{
677    using __any_imp::_Action;
678    static_assert(!is_reference<_ValueType>::value,
679                  "_ValueType may not be a reference.");
680    typedef add_pointer_t<_ValueType> _ReturnType;
681    if (__any && __any->__h_) {
682      void *__p = __any->__call(_Action::_Get, nullptr,
683#if !defined(_LIBCPP_HAS_NO_RTTI)
684                          &typeid(_ValueType),
685#else
686                          nullptr,
687#endif
688                          __any_imp::__get_fallback_typeid<_ValueType>());
689        return _VSTD::__pointer_or_func_cast<_ReturnType>(
690            __p, is_function<_ValueType>{});
691    }
692    return nullptr;
693}
694
695#endif // _LIBCPP_STD_VER > 14
696
697_LIBCPP_END_NAMESPACE_STD
698
699#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 17
700#  include <chrono>
701#endif
702
703#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
704#  include <atomic>
705#  include <concepts>
706#  include <iosfwd>
707#  include <iterator>
708#  include <memory>
709#  include <variant>
710#endif
711
712#endif // _LIBCPP_ANY
713