xref: /freebsd/contrib/llvm-project/libcxx/include/any (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
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 <__type_traits/add_const.h>
91#include <__type_traits/add_pointer.h>
92#include <__type_traits/aligned_storage.h>
93#include <__type_traits/conditional.h>
94#include <__type_traits/decay.h>
95#include <__type_traits/is_constructible.h>
96#include <__type_traits/is_copy_constructible.h>
97#include <__type_traits/is_function.h>
98#include <__type_traits/is_nothrow_move_constructible.h>
99#include <__type_traits/is_reference.h>
100#include <__type_traits/is_same.h>
101#include <__type_traits/is_void.h>
102#include <__type_traits/remove_cv.h>
103#include <__type_traits/remove_cvref.h>
104#include <__type_traits/remove_reference.h>
105#include <__utility/forward.h>
106#include <__utility/in_place.h>
107#include <__utility/move.h>
108#include <__utility/unreachable.h>
109#include <__verbose_abort>
110#include <initializer_list>
111#include <typeinfo>
112#include <version>
113
114#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
115#  pragma GCC system_header
116#endif
117
118_LIBCPP_PUSH_MACROS
119#include <__undef_macros>
120
121namespace std {
122class _LIBCPP_EXPORTED_FROM_ABI _LIBCPP_AVAILABILITY_BAD_ANY_CAST bad_any_cast : public bad_cast {
123public:
124  const char* what() const _NOEXCEPT override;
125};
126} // namespace std
127
128_LIBCPP_BEGIN_NAMESPACE_STD
129
130#if _LIBCPP_STD_VER >= 17
131
132_LIBCPP_NORETURN inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST void __throw_bad_any_cast() {
133#  ifndef _LIBCPP_HAS_NO_EXCEPTIONS
134  throw bad_any_cast();
135#  else
136  _LIBCPP_VERBOSE_ABORT("bad_any_cast was thrown in -fno-exceptions mode");
137#  endif
138}
139
140// Forward declarations
141class _LIBCPP_TEMPLATE_VIS any;
142
143template <class _ValueType>
144_LIBCPP_HIDE_FROM_ABI add_pointer_t<add_const_t<_ValueType>> any_cast(any const*) _NOEXCEPT;
145
146template <class _ValueType>
147_LIBCPP_HIDE_FROM_ABI add_pointer_t<_ValueType> any_cast(any*) _NOEXCEPT;
148
149namespace __any_imp {
150_LIBCPP_SUPPRESS_DEPRECATED_PUSH
151using _Buffer = aligned_storage_t<3 * sizeof(void*), alignof(void*)>;
152_LIBCPP_SUPPRESS_DEPRECATED_POP
153
154template <class _Tp>
155using _IsSmallObject =
156    integral_constant<bool,
157                      sizeof(_Tp) <= sizeof(_Buffer) && alignof(_Buffer) % alignof(_Tp) == 0 &&
158                          is_nothrow_move_constructible<_Tp>::value >;
159
160enum class _Action { _Destroy, _Copy, _Move, _Get, _TypeInfo };
161
162template <class _Tp>
163struct _SmallHandler;
164template <class _Tp>
165struct _LargeHandler;
166
167template <class _Tp>
168struct _LIBCPP_TEMPLATE_VIS __unique_typeinfo {
169  static constexpr int __id = 0;
170};
171template <class _Tp>
172constexpr int __unique_typeinfo<_Tp>::__id;
173
174template <class _Tp>
175inline _LIBCPP_HIDE_FROM_ABI constexpr const void* __get_fallback_typeid() {
176  return &__unique_typeinfo<remove_cv_t<remove_reference_t<_Tp>>>::__id;
177}
178
179template <class _Tp>
180inline _LIBCPP_HIDE_FROM_ABI bool __compare_typeid(type_info const* __id, const void* __fallback_id) {
181#  if !defined(_LIBCPP_HAS_NO_RTTI)
182  if (__id && *__id == typeid(_Tp))
183    return true;
184#  endif
185  return !__id && __fallback_id == __any_imp::__get_fallback_typeid<_Tp>();
186}
187
188template <class _Tp>
189using _Handler = conditional_t< _IsSmallObject<_Tp>::value, _SmallHandler<_Tp>, _LargeHandler<_Tp>>;
190
191} // namespace __any_imp
192
193class _LIBCPP_TEMPLATE_VIS any {
194public:
195  // construct/destruct
196  _LIBCPP_HIDE_FROM_ABI constexpr any() _NOEXCEPT : __h_(nullptr) {}
197
198  _LIBCPP_HIDE_FROM_ABI any(any const& __other) : __h_(nullptr) {
199    if (__other.__h_)
200      __other.__call(_Action::_Copy, this);
201  }
202
203  _LIBCPP_HIDE_FROM_ABI any(any&& __other) _NOEXCEPT : __h_(nullptr) {
204    if (__other.__h_)
205      __other.__call(_Action::_Move, this);
206  }
207
208  template < class _ValueType,
209             class _Tp = decay_t<_ValueType>,
210             class     = enable_if_t< !is_same<_Tp, any>::value && !__is_inplace_type<_ValueType>::value &&
211                                  is_copy_constructible<_Tp>::value> >
212  _LIBCPP_HIDE_FROM_ABI any(_ValueType&& __value);
213
214  template <class _ValueType,
215            class... _Args,
216            class _Tp = decay_t<_ValueType>,
217            class     = enable_if_t< is_constructible<_Tp, _Args...>::value && is_copy_constructible<_Tp>::value > >
218  _LIBCPP_HIDE_FROM_ABI explicit any(in_place_type_t<_ValueType>, _Args&&... __args);
219
220  template <class _ValueType,
221            class _Up,
222            class... _Args,
223            class _Tp = decay_t<_ValueType>,
224            class     = enable_if_t< is_constructible<_Tp, initializer_list<_Up>&, _Args...>::value &&
225                                 is_copy_constructible<_Tp>::value> >
226  _LIBCPP_HIDE_FROM_ABI explicit any(in_place_type_t<_ValueType>, initializer_list<_Up>, _Args&&... __args);
227
228  _LIBCPP_HIDE_FROM_ABI ~any() { this->reset(); }
229
230  // assignments
231  _LIBCPP_HIDE_FROM_ABI any& operator=(any const& __rhs) {
232    any(__rhs).swap(*this);
233    return *this;
234  }
235
236  _LIBCPP_HIDE_FROM_ABI any& operator=(any&& __rhs) _NOEXCEPT {
237    any(std::move(__rhs)).swap(*this);
238    return *this;
239  }
240
241  template < class _ValueType,
242             class _Tp = decay_t<_ValueType>,
243             class     = enable_if_t< !is_same<_Tp, any>::value && is_copy_constructible<_Tp>::value> >
244  _LIBCPP_HIDE_FROM_ABI any& operator=(_ValueType&& __rhs);
245
246  template <class _ValueType,
247            class... _Args,
248            class _Tp = decay_t<_ValueType>,
249            class     = enable_if_t< is_constructible<_Tp, _Args...>::value && is_copy_constructible<_Tp>::value> >
250  _LIBCPP_HIDE_FROM_ABI _Tp& emplace(_Args&&...);
251
252  template <class _ValueType,
253            class _Up,
254            class... _Args,
255            class _Tp = decay_t<_ValueType>,
256            class     = enable_if_t< is_constructible<_Tp, initializer_list<_Up>&, _Args...>::value &&
257                                 is_copy_constructible<_Tp>::value> >
258  _LIBCPP_HIDE_FROM_ABI _Tp& emplace(initializer_list<_Up>, _Args&&...);
259
260  // 6.3.3 any modifiers
261  _LIBCPP_HIDE_FROM_ABI void reset() _NOEXCEPT {
262    if (__h_)
263      this->__call(_Action::_Destroy);
264  }
265
266  _LIBCPP_HIDE_FROM_ABI void swap(any& __rhs) _NOEXCEPT;
267
268  // 6.3.4 any observers
269  _LIBCPP_HIDE_FROM_ABI bool has_value() const _NOEXCEPT { return __h_ != nullptr; }
270
271#  if !defined(_LIBCPP_HAS_NO_RTTI)
272  _LIBCPP_HIDE_FROM_ABI const type_info& type() const _NOEXCEPT {
273    if (__h_) {
274      return *static_cast<type_info const*>(this->__call(_Action::_TypeInfo));
275    } else {
276      return typeid(void);
277    }
278  }
279#  endif
280
281private:
282  typedef __any_imp::_Action _Action;
283  using _HandleFuncPtr = void* (*)(_Action, any const*, any*, const type_info*, const void* __fallback_info);
284
285  union _Storage {
286    _LIBCPP_HIDE_FROM_ABI constexpr _Storage() : __ptr(nullptr) {}
287    void* __ptr;
288    __any_imp::_Buffer __buf;
289  };
290
291  _LIBCPP_HIDE_FROM_ABI void*
292  __call(_Action __a, any* __other = nullptr, type_info const* __info = nullptr, const void* __fallback_info = nullptr)
293      const {
294    return __h_(__a, this, __other, __info, __fallback_info);
295  }
296
297  _LIBCPP_HIDE_FROM_ABI void* __call(
298      _Action __a, any* __other = nullptr, type_info const* __info = nullptr, const void* __fallback_info = nullptr) {
299    return __h_(__a, this, __other, __info, __fallback_info);
300  }
301
302  template <class>
303  friend struct __any_imp::_SmallHandler;
304  template <class>
305  friend struct __any_imp::_LargeHandler;
306
307  template <class _ValueType>
308  friend add_pointer_t<add_const_t<_ValueType>> any_cast(any const*) _NOEXCEPT;
309
310  template <class _ValueType>
311  friend add_pointer_t<_ValueType> any_cast(any*) _NOEXCEPT;
312
313  _HandleFuncPtr __h_ = nullptr;
314  _Storage __s_;
315};
316
317namespace __any_imp {
318template <class _Tp>
319struct _LIBCPP_TEMPLATE_VIS _SmallHandler {
320  _LIBCPP_HIDE_FROM_ABI static void*
321  __handle(_Action __act, any const* __this, any* __other, type_info const* __info, const void* __fallback_info) {
322    switch (__act) {
323    case _Action::_Destroy:
324      __destroy(const_cast<any&>(*__this));
325      return nullptr;
326    case _Action::_Copy:
327      __copy(*__this, *__other);
328      return nullptr;
329    case _Action::_Move:
330      __move(const_cast<any&>(*__this), *__other);
331      return nullptr;
332    case _Action::_Get:
333      return __get(const_cast<any&>(*__this), __info, __fallback_info);
334    case _Action::_TypeInfo:
335      return __type_info();
336    }
337    __libcpp_unreachable();
338  }
339
340  template <class... _Args>
341  _LIBCPP_HIDE_FROM_ABI static _Tp& __create(any& __dest, _Args&&... __args) {
342    typedef allocator<_Tp> _Alloc;
343    typedef allocator_traits<_Alloc> _ATraits;
344    _Alloc __a;
345    _Tp* __ret = static_cast<_Tp*>(static_cast<void*>(&__dest.__s_.__buf));
346    _ATraits::construct(__a, __ret, std::forward<_Args>(__args)...);
347    __dest.__h_ = &_SmallHandler::__handle;
348    return *__ret;
349  }
350
351private:
352  _LIBCPP_HIDE_FROM_ABI static void __destroy(any& __this) {
353    typedef allocator<_Tp> _Alloc;
354    typedef allocator_traits<_Alloc> _ATraits;
355    _Alloc __a;
356    _Tp* __p = static_cast<_Tp*>(static_cast<void*>(&__this.__s_.__buf));
357    _ATraits::destroy(__a, __p);
358    __this.__h_ = nullptr;
359  }
360
361  _LIBCPP_HIDE_FROM_ABI static void __copy(any const& __this, any& __dest) {
362    _SmallHandler::__create(__dest, *static_cast<_Tp const*>(static_cast<void const*>(&__this.__s_.__buf)));
363  }
364
365  _LIBCPP_HIDE_FROM_ABI static void __move(any& __this, any& __dest) {
366    _SmallHandler::__create(__dest, std::move(*static_cast<_Tp*>(static_cast<void*>(&__this.__s_.__buf))));
367    __destroy(__this);
368  }
369
370  _LIBCPP_HIDE_FROM_ABI static void* __get(any& __this, type_info const* __info, const void* __fallback_id) {
371    if (__any_imp::__compare_typeid<_Tp>(__info, __fallback_id))
372      return static_cast<void*>(&__this.__s_.__buf);
373    return nullptr;
374  }
375
376  _LIBCPP_HIDE_FROM_ABI static void* __type_info() {
377#  if !defined(_LIBCPP_HAS_NO_RTTI)
378    return const_cast<void*>(static_cast<void const*>(&typeid(_Tp)));
379#  else
380    return nullptr;
381#  endif
382  }
383};
384
385template <class _Tp>
386struct _LIBCPP_TEMPLATE_VIS _LargeHandler {
387  _LIBCPP_HIDE_FROM_ABI static void*
388  __handle(_Action __act, any const* __this, any* __other, type_info const* __info, void const* __fallback_info) {
389    switch (__act) {
390    case _Action::_Destroy:
391      __destroy(const_cast<any&>(*__this));
392      return nullptr;
393    case _Action::_Copy:
394      __copy(*__this, *__other);
395      return nullptr;
396    case _Action::_Move:
397      __move(const_cast<any&>(*__this), *__other);
398      return nullptr;
399    case _Action::_Get:
400      return __get(const_cast<any&>(*__this), __info, __fallback_info);
401    case _Action::_TypeInfo:
402      return __type_info();
403    }
404    __libcpp_unreachable();
405  }
406
407  template <class... _Args>
408  _LIBCPP_HIDE_FROM_ABI static _Tp& __create(any& __dest, _Args&&... __args) {
409    typedef allocator<_Tp> _Alloc;
410    typedef allocator_traits<_Alloc> _ATraits;
411    typedef __allocator_destructor<_Alloc> _Dp;
412    _Alloc __a;
413    unique_ptr<_Tp, _Dp> __hold(_ATraits::allocate(__a, 1), _Dp(__a, 1));
414    _Tp* __ret = __hold.get();
415    _ATraits::construct(__a, __ret, std::forward<_Args>(__args)...);
416    __dest.__s_.__ptr = __hold.release();
417    __dest.__h_       = &_LargeHandler::__handle;
418    return *__ret;
419  }
420
421private:
422  _LIBCPP_HIDE_FROM_ABI static void __destroy(any& __this) {
423    typedef allocator<_Tp> _Alloc;
424    typedef allocator_traits<_Alloc> _ATraits;
425    _Alloc __a;
426    _Tp* __p = static_cast<_Tp*>(__this.__s_.__ptr);
427    _ATraits::destroy(__a, __p);
428    _ATraits::deallocate(__a, __p, 1);
429    __this.__h_ = nullptr;
430  }
431
432  _LIBCPP_HIDE_FROM_ABI static void __copy(any const& __this, any& __dest) {
433    _LargeHandler::__create(__dest, *static_cast<_Tp const*>(__this.__s_.__ptr));
434  }
435
436  _LIBCPP_HIDE_FROM_ABI static void __move(any& __this, any& __dest) {
437    __dest.__s_.__ptr = __this.__s_.__ptr;
438    __dest.__h_       = &_LargeHandler::__handle;
439    __this.__h_       = nullptr;
440  }
441
442  _LIBCPP_HIDE_FROM_ABI static void* __get(any& __this, type_info const* __info, void const* __fallback_info) {
443    if (__any_imp::__compare_typeid<_Tp>(__info, __fallback_info))
444      return static_cast<void*>(__this.__s_.__ptr);
445    return nullptr;
446  }
447
448  _LIBCPP_HIDE_FROM_ABI static void* __type_info() {
449#  if !defined(_LIBCPP_HAS_NO_RTTI)
450    return const_cast<void*>(static_cast<void const*>(&typeid(_Tp)));
451#  else
452    return nullptr;
453#  endif
454  }
455};
456
457} // namespace __any_imp
458
459template <class _ValueType, class _Tp, class>
460any::any(_ValueType&& __v) : __h_(nullptr) {
461  __any_imp::_Handler<_Tp>::__create(*this, std::forward<_ValueType>(__v));
462}
463
464template <class _ValueType, class... _Args, class _Tp, class>
465any::any(in_place_type_t<_ValueType>, _Args&&... __args) {
466  __any_imp::_Handler<_Tp>::__create(*this, std::forward<_Args>(__args)...);
467}
468
469template <class _ValueType, class _Up, class... _Args, class _Tp, class>
470any::any(in_place_type_t<_ValueType>, initializer_list<_Up> __il, _Args&&... __args) {
471  __any_imp::_Handler<_Tp>::__create(*this, __il, std::forward<_Args>(__args)...);
472}
473
474template <class _ValueType, class, class>
475inline _LIBCPP_HIDE_FROM_ABI any& any::operator=(_ValueType&& __v) {
476  any(std::forward<_ValueType>(__v)).swap(*this);
477  return *this;
478}
479
480template <class _ValueType, class... _Args, class _Tp, class>
481inline _LIBCPP_HIDE_FROM_ABI _Tp& any::emplace(_Args&&... __args) {
482  reset();
483  return __any_imp::_Handler<_Tp>::__create(*this, std::forward<_Args>(__args)...);
484}
485
486template <class _ValueType, class _Up, class... _Args, class _Tp, class>
487inline _LIBCPP_HIDE_FROM_ABI _Tp& any::emplace(initializer_list<_Up> __il, _Args&&... __args) {
488  reset();
489  return __any_imp::_Handler<_Tp>::__create(*this, __il, std::forward<_Args>(__args)...);
490}
491
492inline _LIBCPP_HIDE_FROM_ABI void any::swap(any& __rhs) _NOEXCEPT {
493  if (this == &__rhs)
494    return;
495  if (__h_ && __rhs.__h_) {
496    any __tmp;
497    __rhs.__call(_Action::_Move, &__tmp);
498    this->__call(_Action::_Move, &__rhs);
499    __tmp.__call(_Action::_Move, this);
500  } else if (__h_) {
501    this->__call(_Action::_Move, &__rhs);
502  } else if (__rhs.__h_) {
503    __rhs.__call(_Action::_Move, this);
504  }
505}
506
507// 6.4 Non-member functions
508
509inline _LIBCPP_HIDE_FROM_ABI void swap(any& __lhs, any& __rhs) _NOEXCEPT { __lhs.swap(__rhs); }
510
511template <class _Tp, class... _Args>
512inline _LIBCPP_HIDE_FROM_ABI any make_any(_Args&&... __args) {
513  return any(in_place_type<_Tp>, std::forward<_Args>(__args)...);
514}
515
516template <class _Tp, class _Up, class... _Args>
517inline _LIBCPP_HIDE_FROM_ABI any make_any(initializer_list<_Up> __il, _Args&&... __args) {
518  return any(in_place_type<_Tp>, __il, std::forward<_Args>(__args)...);
519}
520
521template <class _ValueType>
522inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST _ValueType any_cast(any const& __v) {
523  using _RawValueType = __remove_cvref_t<_ValueType>;
524  static_assert(is_constructible<_ValueType, _RawValueType const&>::value,
525                "ValueType is required to be a const lvalue reference "
526                "or a CopyConstructible type");
527  auto __tmp = std::any_cast<add_const_t<_RawValueType>>(&__v);
528  if (__tmp == nullptr)
529    __throw_bad_any_cast();
530  return static_cast<_ValueType>(*__tmp);
531}
532
533template <class _ValueType>
534inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST _ValueType any_cast(any& __v) {
535  using _RawValueType = __remove_cvref_t<_ValueType>;
536  static_assert(is_constructible<_ValueType, _RawValueType&>::value,
537                "ValueType is required to be an lvalue reference "
538                "or a CopyConstructible type");
539  auto __tmp = std::any_cast<_RawValueType>(&__v);
540  if (__tmp == nullptr)
541    __throw_bad_any_cast();
542  return static_cast<_ValueType>(*__tmp);
543}
544
545template <class _ValueType>
546inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST _ValueType any_cast(any&& __v) {
547  using _RawValueType = __remove_cvref_t<_ValueType>;
548  static_assert(is_constructible<_ValueType, _RawValueType>::value,
549                "ValueType is required to be an rvalue reference "
550                "or a CopyConstructible type");
551  auto __tmp = std::any_cast<_RawValueType>(&__v);
552  if (__tmp == nullptr)
553    __throw_bad_any_cast();
554  return static_cast<_ValueType>(std::move(*__tmp));
555}
556
557template <class _ValueType>
558inline _LIBCPP_HIDE_FROM_ABI add_pointer_t<add_const_t<_ValueType>> any_cast(any const* __any) _NOEXCEPT {
559  static_assert(!is_void_v<_ValueType>, "_ValueType may not be void.");
560  static_assert(!is_reference<_ValueType>::value, "_ValueType may not be a reference.");
561  return std::any_cast<_ValueType>(const_cast<any*>(__any));
562}
563
564template <class _RetType>
565inline _LIBCPP_HIDE_FROM_ABI _RetType __pointer_or_func_cast(void* __p, /*IsFunction*/ false_type) noexcept {
566  return static_cast<_RetType>(__p);
567}
568
569template <class _RetType>
570inline _LIBCPP_HIDE_FROM_ABI _RetType __pointer_or_func_cast(void*, /*IsFunction*/ true_type) noexcept {
571  return nullptr;
572}
573
574template <class _ValueType>
575_LIBCPP_HIDE_FROM_ABI add_pointer_t<_ValueType> any_cast(any* __any) _NOEXCEPT {
576  using __any_imp::_Action;
577  static_assert(!is_void_v<_ValueType>, "_ValueType may not be void.");
578  static_assert(!is_reference<_ValueType>::value, "_ValueType may not be a reference.");
579  typedef add_pointer_t<_ValueType> _ReturnType;
580  if (__any && __any->__h_) {
581    void* __p = __any->__call(
582        _Action::_Get,
583        nullptr,
584#  if !defined(_LIBCPP_HAS_NO_RTTI)
585        &typeid(_ValueType),
586#  else
587        nullptr,
588#  endif
589        __any_imp::__get_fallback_typeid<_ValueType>());
590    return std::__pointer_or_func_cast<_ReturnType>(__p, is_function<_ValueType>{});
591  }
592  return nullptr;
593}
594
595#endif // _LIBCPP_STD_VER >= 17
596
597_LIBCPP_END_NAMESPACE_STD
598
599_LIBCPP_POP_MACROS
600
601#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 17
602#  include <chrono>
603#endif
604
605#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
606#  include <atomic>
607#  include <concepts>
608#  include <cstdlib>
609#  include <iosfwd>
610#  include <iterator>
611#  include <memory>
612#  include <stdexcept>
613#  include <type_traits>
614#  include <variant>
615#endif
616
617#endif // _LIBCPP_ANY
618