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1// -*- C++ -*-
2//===------------------------------ any -----------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is distributed under the University of Illinois Open Source
7// License. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_EXPERIMENTAL_ANY
12#define _LIBCPP_EXPERIMENTAL_ANY
13
14/*
15   experimental/any synopsis
16
17namespace std {
18namespace experimental {
19inline namespace fundamentals_v1 {
20
21  class bad_any_cast : public bad_cast
22  {
23  public:
24    virtual const char* what() const noexcept;
25  };
26
27  class any
28  {
29  public:
30
31    // 6.3.1 any construct/destruct
32    any() noexcept;
33
34    any(const any& other);
35    any(any&& other) noexcept;
36
37    template <class ValueType>
38      any(ValueType&& value);
39
40    ~any();
41
42    // 6.3.2 any assignments
43    any& operator=(const any& rhs);
44    any& operator=(any&& rhs) noexcept;
45
46    template <class ValueType>
47      any& operator=(ValueType&& rhs);
48
49    // 6.3.3 any modifiers
50    void clear() noexcept;
51    void swap(any& rhs) noexcept;
52
53    // 6.3.4 any observers
54    bool empty() const noexcept;
55    const type_info& type() const noexcept;
56  };
57
58   // 6.4 Non-member functions
59  void swap(any& x, any& y) noexcept;
60
61  template<class ValueType>
62    ValueType any_cast(const any& operand);
63  template<class ValueType>
64    ValueType any_cast(any& operand);
65  template<class ValueType>
66    ValueType any_cast(any&& operand);
67
68  template<class ValueType>
69    const ValueType* any_cast(const any* operand) noexcept;
70  template<class ValueType>
71    ValueType* any_cast(any* operand) noexcept;
72
73} // namespace fundamentals_v1
74} // namespace experimental
75} // namespace std
76
77*/
78
79#include <experimental/__config>
80#include <memory>
81#include <new>
82#include <typeinfo>
83#include <type_traits>
84#include <cstdlib>
85
86#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
87#pragma GCC system_header
88#endif
89
90_LIBCPP_BEGIN_NAMESPACE_LFTS
91
92class _LIBCPP_EXCEPTION_ABI bad_any_cast : public bad_cast
93{
94public:
95    virtual const char* what() const _NOEXCEPT;
96};
97
98#if _LIBCPP_STD_VER > 11                                            // C++ > 11
99
100_LIBCPP_NORETURN inline _LIBCPP_ALWAYS_INLINE
101void __throw_bad_any_cast()
102{
103#ifndef _LIBCPP_NO_EXCEPTIONS
104    throw bad_any_cast();
105#else
106    _VSTD::abort();
107#endif
108}
109
110// Forward declarations
111class any;
112
113template <class _ValueType>
114typename add_pointer<typename add_const<_ValueType>::type>::type
115_LIBCPP_INLINE_VISIBILITY
116any_cast(any const *) _NOEXCEPT;
117
118template <class _ValueType>
119typename add_pointer<_ValueType>::type
120_LIBCPP_INLINE_VISIBILITY
121any_cast(any *) _NOEXCEPT;
122
123namespace __any_imp
124{
125  typedef typename aligned_storage<3*sizeof(void*), alignment_of<void*>::value>::type
126    _Buffer;
127
128  template <class _Tp>
129  struct _IsSmallObject
130    : public integral_constant<bool
131        , sizeof(_Tp) <= sizeof(_Buffer)
132          && alignment_of<_Buffer>::value
133             % alignment_of<_Tp>::value == 0
134          && is_nothrow_move_constructible<_Tp>::value
135        >
136  {};
137
138  enum class _Action
139  {
140    _Destroy,
141    _Copy,
142    _Move,
143    _Get,
144    _TypeInfo
145  };
146
147  template <class _Tp>
148  struct _SmallHandler;
149
150  template <class _Tp>
151  struct _LargeHandler;
152
153  template <class _Tp>
154  using _Handler = typename conditional<_IsSmallObject<_Tp>::value
155                                      , _SmallHandler<_Tp>
156                                      , _LargeHandler<_Tp>
157                                    >::type;
158  template <class _ValueType>
159  using _EnableIfNotAny = typename
160    enable_if<
161      !is_same<typename decay<_ValueType>::type, any>::value
162    >::type;
163
164} // namespace __any_imp
165
166class any
167{
168public:
169  // 6.3.1 any construct/destruct
170  _LIBCPP_INLINE_VISIBILITY
171  any() _NOEXCEPT : __h(nullptr) {}
172
173  _LIBCPP_INLINE_VISIBILITY
174  any(any const & __other) : __h(nullptr)
175  {
176    if (__other.__h) __other.__call(_Action::_Copy, this);
177  }
178
179  _LIBCPP_INLINE_VISIBILITY
180  any(any && __other) _NOEXCEPT : __h(nullptr)
181  {
182    if (__other.__h) __other.__call(_Action::_Move, this);
183  }
184
185  template <
186      class _ValueType
187    , class = __any_imp::_EnableIfNotAny<_ValueType>
188    >
189  _LIBCPP_INLINE_VISIBILITY
190  any(_ValueType && __value);
191
192  _LIBCPP_INLINE_VISIBILITY
193  ~any()
194  {
195    this->clear();
196  }
197
198  // 6.3.2 any assignments
199  _LIBCPP_INLINE_VISIBILITY
200  any & operator=(any const & __rhs)
201  {
202    any(__rhs).swap(*this);
203    return *this;
204  }
205
206  _LIBCPP_INLINE_VISIBILITY
207  any & operator=(any && __rhs) _NOEXCEPT
208  {
209    any(_VSTD::move(__rhs)).swap(*this);
210    return *this;
211  }
212
213  template <
214      class _ValueType
215    , class = __any_imp::_EnableIfNotAny<_ValueType>
216    >
217  _LIBCPP_INLINE_VISIBILITY
218  any & operator=(_ValueType && __rhs);
219
220  // 6.3.3 any modifiers
221  _LIBCPP_INLINE_VISIBILITY
222  void clear() _NOEXCEPT
223  {
224    if (__h) this->__call(_Action::_Destroy);
225  }
226
227  _LIBCPP_INLINE_VISIBILITY
228  void swap(any & __rhs) _NOEXCEPT;
229
230  // 6.3.4 any observers
231  _LIBCPP_INLINE_VISIBILITY
232  bool empty() const _NOEXCEPT
233  {
234    return __h == nullptr;
235  }
236
237#if !defined(_LIBCPP_NO_RTTI)
238  _LIBCPP_INLINE_VISIBILITY
239  const type_info & type() const _NOEXCEPT
240  {
241    if (__h) {
242        return *static_cast<type_info const *>(this->__call(_Action::_TypeInfo));
243    } else {
244        return typeid(void);
245    }
246  }
247#endif
248
249private:
250    typedef __any_imp::_Action _Action;
251
252    typedef void* (*_HandleFuncPtr)(_Action, any const *, any *, const type_info *);
253
254    union _Storage
255    {
256        void *  __ptr;
257        __any_imp::_Buffer __buf;
258    };
259
260    _LIBCPP_ALWAYS_INLINE
261    void * __call(_Action __a, any * __other = nullptr,
262                  type_info const * __info = nullptr) const
263    {
264        return __h(__a, this, __other, __info);
265    }
266
267    _LIBCPP_ALWAYS_INLINE
268    void * __call(_Action __a, any * __other = nullptr,
269                  type_info const * __info = nullptr)
270    {
271        return __h(__a, this, __other, __info);
272    }
273
274    template <class>
275    friend struct __any_imp::_SmallHandler;
276    template <class>
277    friend struct __any_imp::_LargeHandler;
278
279    template <class _ValueType>
280    friend typename add_pointer<typename add_const<_ValueType>::type>::type
281    any_cast(any const *) _NOEXCEPT;
282
283    template <class _ValueType>
284    friend typename add_pointer<_ValueType>::type
285    any_cast(any *) _NOEXCEPT;
286
287    _HandleFuncPtr __h;
288    _Storage __s;
289};
290
291namespace __any_imp
292{
293
294  template <class _Tp>
295  struct _LIBCPP_TEMPLATE_VIS _SmallHandler
296  {
297     _LIBCPP_INLINE_VISIBILITY
298     static void* __handle(_Action __act, any const * __this, any * __other,
299                           type_info const * __info)
300     {
301        switch (__act)
302        {
303        case _Action::_Destroy:
304          __destroy(const_cast<any &>(*__this));
305          return nullptr;
306        case _Action::_Copy:
307            __copy(*__this, *__other);
308            return nullptr;
309        case _Action::_Move:
310          __move(const_cast<any &>(*__this), *__other);
311          return nullptr;
312        case _Action::_Get:
313            return __get(const_cast<any &>(*__this), __info);
314        case _Action::_TypeInfo:
315          return __type_info();
316        }
317    }
318
319    template <class _Up>
320    _LIBCPP_INLINE_VISIBILITY
321    static void __create(any & __dest, _Up && __v)
322    {
323        ::new (static_cast<void*>(&__dest.__s.__buf)) _Tp(_VSTD::forward<_Up>(__v));
324        __dest.__h = &_SmallHandler::__handle;
325    }
326
327  private:
328    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
329    static void __destroy(any & __this)
330    {
331        _Tp & __value = *static_cast<_Tp *>(static_cast<void*>(&__this.__s.__buf));
332        __value.~_Tp();
333        __this.__h = nullptr;
334    }
335
336    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
337    static void __copy(any const & __this, any & __dest)
338    {
339        _SmallHandler::__create(__dest, *static_cast<_Tp const *>(
340            static_cast<void const *>(&__this.__s.__buf)));
341    }
342
343    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
344    static void __move(any & __this, any & __dest)
345    {
346        _SmallHandler::__create(__dest, _VSTD::move(
347            *static_cast<_Tp*>(static_cast<void*>(&__this.__s.__buf))));
348        __destroy(__this);
349    }
350
351    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
352    static void* __get(any & __this, type_info const * __info)
353    {
354#if !defined(_LIBCPP_NO_RTTI)
355        if (typeid(_Tp) == *__info) {
356            return static_cast<void*>(&__this.__s.__buf);
357        }
358        return nullptr;
359#else
360        return static_cast<void*>(&__this.__s.__buf);
361#endif
362    }
363
364    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
365    static void* __type_info()
366    {
367#if !defined(_LIBCPP_NO_RTTI)
368        return const_cast<void*>(static_cast<void const *>(&typeid(_Tp)));
369#else
370        return nullptr;
371#endif
372    }
373  };
374
375  template <class _Tp>
376  struct _LIBCPP_TEMPLATE_VIS _LargeHandler
377  {
378    _LIBCPP_INLINE_VISIBILITY
379    static void* __handle(_Action __act, any const * __this, any * __other,
380                          type_info const * __info)
381    {
382        switch (__act)
383        {
384        case _Action::_Destroy:
385          __destroy(const_cast<any &>(*__this));
386          return nullptr;
387        case _Action::_Copy:
388          __copy(*__this, *__other);
389          return nullptr;
390        case _Action::_Move:
391          __move(const_cast<any &>(*__this), *__other);
392          return nullptr;
393        case _Action::_Get:
394            return __get(const_cast<any &>(*__this), __info);
395        case _Action::_TypeInfo:
396          return __type_info();
397        }
398    }
399
400    template <class _Up>
401    _LIBCPP_INLINE_VISIBILITY
402    static void __create(any & __dest, _Up && __v)
403    {
404        typedef allocator<_Tp> _Alloc;
405        typedef __allocator_destructor<_Alloc> _Dp;
406        _Alloc __a;
407        unique_ptr<_Tp, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
408        ::new ((void*)__hold.get()) _Tp(_VSTD::forward<_Up>(__v));
409        __dest.__s.__ptr = __hold.release();
410        __dest.__h = &_LargeHandler::__handle;
411    }
412
413  private:
414
415    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
416    static void __destroy(any & __this)
417    {
418        delete static_cast<_Tp*>(__this.__s.__ptr);
419        __this.__h = nullptr;
420    }
421
422    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
423    static void __copy(any const & __this, any & __dest)
424    {
425        _LargeHandler::__create(__dest, *static_cast<_Tp const *>(__this.__s.__ptr));
426    }
427
428    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
429    static void __move(any & __this, any & __dest)
430    {
431      __dest.__s.__ptr = __this.__s.__ptr;
432      __dest.__h = &_LargeHandler::__handle;
433      __this.__h = nullptr;
434    }
435
436    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
437    static void* __get(any & __this, type_info const * __info)
438    {
439#if !defined(_LIBCPP_NO_RTTI)
440        if (typeid(_Tp) == *__info) {
441            return static_cast<void*>(__this.__s.__ptr);
442        }
443        return nullptr;
444#else
445        return static_cast<void*>(__this.__s.__ptr);
446#endif
447    }
448
449    _LIBCPP_ALWAYS_INLINE _LIBCPP_INLINE_VISIBILITY
450    static void* __type_info()
451    {
452#if !defined(_LIBCPP_NO_RTTI)
453        return const_cast<void*>(static_cast<void const *>(&typeid(_Tp)));
454#else
455        return nullptr;
456#endif
457    }
458  };
459
460} // namespace __any_imp
461
462
463template <class _ValueType, class>
464any::any(_ValueType && __v) : __h(nullptr)
465{
466  typedef typename decay<_ValueType>::type _Tp;
467  static_assert(is_copy_constructible<_Tp>::value,
468                "_ValueType must be CopyConstructible.");
469  typedef __any_imp::_Handler<_Tp> _HandlerType;
470  _HandlerType::__create(*this, _VSTD::forward<_ValueType>(__v));
471}
472
473template <class _ValueType, class>
474any & any::operator=(_ValueType && __v)
475{
476  typedef typename decay<_ValueType>::type _Tp;
477  static_assert(is_copy_constructible<_Tp>::value,
478                "_ValueType must be CopyConstructible.");
479  any(_VSTD::forward<_ValueType>(__v)).swap(*this);
480  return *this;
481}
482
483inline
484void any::swap(any & __rhs) _NOEXCEPT
485{
486    if (__h && __rhs.__h) {
487        any __tmp;
488        __rhs.__call(_Action::_Move, &__tmp);
489        this->__call(_Action::_Move, &__rhs);
490        __tmp.__call(_Action::_Move, this);
491    }
492    else if (__h) {
493        this->__call(_Action::_Move, &__rhs);
494    }
495    else if (__rhs.__h) {
496        __rhs.__call(_Action::_Move, this);
497    }
498}
499
500// 6.4 Non-member functions
501
502inline _LIBCPP_INLINE_VISIBILITY
503void swap(any & __lhs, any & __rhs) _NOEXCEPT
504{
505    __lhs.swap(__rhs);
506}
507
508template <class _ValueType>
509_LIBCPP_INLINE_VISIBILITY
510_ValueType any_cast(any const & __v)
511{
512    static_assert(
513        is_reference<_ValueType>::value
514        || is_copy_constructible<_ValueType>::value,
515        "_ValueType is required to be a reference or a CopyConstructible type.");
516    typedef typename add_const<typename remove_reference<_ValueType>::type>::type
517            _Tp;
518    _Tp * __tmp = any_cast<_Tp>(&__v);
519    if (__tmp == nullptr)
520        __throw_bad_any_cast();
521    return *__tmp;
522}
523
524template <class _ValueType>
525_LIBCPP_INLINE_VISIBILITY
526_ValueType any_cast(any & __v)
527{
528    static_assert(
529        is_reference<_ValueType>::value
530        || is_copy_constructible<_ValueType>::value,
531        "_ValueType is required to be a reference or a CopyConstructible type.");
532    typedef typename remove_reference<_ValueType>::type _Tp;
533    _Tp * __tmp = any_cast<_Tp>(&__v);
534    if (__tmp == nullptr)
535        __throw_bad_any_cast();
536    return *__tmp;
537}
538
539template <class _ValueType>
540_LIBCPP_INLINE_VISIBILITY
541_ValueType any_cast(any && __v)
542{
543    static_assert(
544        is_reference<_ValueType>::value
545        || is_copy_constructible<_ValueType>::value,
546        "_ValueType is required to be a reference or a CopyConstructible type.");
547    typedef typename remove_reference<_ValueType>::type _Tp;
548    _Tp * __tmp = any_cast<_Tp>(&__v);
549    if (__tmp == nullptr)
550        __throw_bad_any_cast();
551    return *__tmp;
552}
553
554template <class _ValueType>
555inline
556typename add_pointer<typename add_const<_ValueType>::type>::type
557any_cast(any const * __any) _NOEXCEPT
558{
559    static_assert(!is_reference<_ValueType>::value,
560                  "_ValueType may not be a reference.");
561    return any_cast<_ValueType>(const_cast<any *>(__any));
562}
563
564template <class _ValueType>
565typename add_pointer<_ValueType>::type
566any_cast(any * __any) _NOEXCEPT
567{
568    using __any_imp::_Action;
569    static_assert(!is_reference<_ValueType>::value,
570                  "_ValueType may not be a reference.");
571    typedef typename add_pointer<_ValueType>::type _ReturnType;
572    if (__any && __any->__h) {
573
574        return static_cast<_ReturnType>(
575            __any->__call(_Action::_Get, nullptr,
576#if !defined(_LIBCPP_NO_RTTI)
577                &typeid(_ValueType)
578#else
579                nullptr
580#endif
581        ));
582
583    }
584    return nullptr;
585}
586
587#endif // _LIBCPP_STD_VER > 11
588
589_LIBCPP_END_NAMESPACE_LFTS
590
591#endif // _LIBCPP_EXPERIMENTAL_ANY
592