29 #ifndef _GLIBCXX_EXPERIMENTAL_ANY
30 #define _GLIBCXX_EXPERIMENTAL_ANY 1
32 #pragma GCC system_header
34 #if __cplusplus <= 201103L
41 #include <type_traits>
43 namespace std _GLIBCXX_VISIBILITY(default)
45 namespace experimental
47 inline namespace fundamentals_v1
49 _GLIBCXX_BEGIN_NAMESPACE_VERSION
61 #define __cpp_lib_experimental_any 201411
67 class bad_any_cast :
public bad_cast
70 virtual const char* what() const noexcept {
return "bad any_cast"; }
73 [[gnu::noreturn]]
inline void __throw_bad_any_cast()
94 std::aligned_storage<sizeof(_M_ptr), sizeof(_M_ptr)>::type _M_buffer;
97 template<
typename _Tp,
typename _Safe = is_trivially_copyable<_Tp>,
98 bool _Fits = (sizeof(_Tp) <= sizeof(_Storage))>
99 using _Internal = std::
integral_constant<
bool, _Safe::value && _Fits>;
101 template<
typename _Tp>
102 struct _Manager_internal;
104 template<
typename _Tp>
105 struct _Manager_external;
107 template<
typename _Tp>
108 using _Manager = conditional_t<_Internal<_Tp>::value,
109 _Manager_internal<_Tp>,
110 _Manager_external<_Tp>>;
112 template<
typename _Tp,
typename _Decayed = decay_t<_Tp>>
113 using _Decay = enable_if_t<!is_same<_Decayed, any>::value, _Decayed>;
119 any() noexcept : _M_manager(
nullptr) { }
122 any(
const any& __other) : _M_manager(__other._M_manager)
124 if (!__other.empty())
128 _M_manager(_Op_clone, &__other, &__arg);
137 any(
any&& __other) noexcept
138 : _M_manager(__other._M_manager),
139 _M_storage(__other._M_storage)
140 { __other._M_manager =
nullptr; }
143 template <
typename _ValueType,
typename _Tp = _Decay<_ValueType>,
144 typename _Mgr = _Manager<_Tp>>
145 any(_ValueType&& __value)
146 : _M_manager(&_Mgr::_S_manage),
147 _M_storage(_Mgr::_S_create(std::
forward<_ValueType>(__value)))
149 static_assert(is_copy_constructible<_Tp>::value,
150 "The contained object must be CopyConstructible");
159 any& operator=(
const any& __rhs)
161 any(__rhs).swap(*
this);
170 any& operator=(
any&& __rhs) noexcept
172 any(std::move(__rhs)).swap(*
this);
177 template<
typename _ValueType>
178 any& operator=(_ValueType&& __rhs)
180 any(std::forward<_ValueType>(__rhs)).swap(*
this);
187 void clear() noexcept
191 _M_manager(_Op_destroy,
this,
nullptr);
192 _M_manager =
nullptr;
206 bool empty() const noexcept {
return _M_manager ==
nullptr; }
210 const type_info& type() const noexcept
215 _M_manager(_Op_get_type_info,
this, &__arg);
216 return *__arg._M_typeinfo;
220 template<
typename _Tp>
221 static constexpr
bool __is_valid_cast()
222 {
return __or_<is_reference<_Tp>, is_copy_constructible<_Tp>>::value; }
225 enum _Op { _Op_access, _Op_get_type_info, _Op_clone, _Op_destroy };
234 void (*_M_manager)(_Op,
const any*, _Arg*);
237 template<
typename _Tp>
238 friend void* __any_caster(
const any* __any)
240 if (__any->_M_manager != &_Manager<decay_t<_Tp>>::_S_manage)
243 __any->_M_manager(_Op_access, __any, &__arg);
248 template<
typename _Tp>
249 struct _Manager_internal
252 _S_manage(_Op __which,
const any* __anyp, _Arg* __arg);
254 template<
typename _Up>
256 _S_create(_Up&& __value)
259 void* __addr = &__storage._M_buffer;
260 ::new (__addr) _Tp(std::
forward<_Up>(__value));
264 template<typename _Alloc, typename _Up>
266 _S_alloc(const _Alloc&, _Up&& __value)
268 return _S_create(std::forward<_Up>(__value));
273 template<
typename _Tp>
274 struct _Manager_external
277 _S_manage(_Op __which,
const any* __anyp, _Arg* __arg);
279 template<
typename _Up>
281 _S_create(_Up&& __value)
284 __storage._M_ptr =
new _Tp(std::forward<_Up>(__value));
291 inline void swap(
any& __x,
any& __y) noexcept { __x.swap(__y); }
303 template<
typename _ValueType>
304 inline _ValueType any_cast(
const any& __any)
306 static_assert(any::__is_valid_cast<_ValueType>(),
307 "Template argument must be a reference or CopyConstructible type");
308 auto __p = any_cast<add_const_t<remove_reference_t<_ValueType>>>(&__any);
311 __throw_bad_any_cast();
326 template<
typename _ValueType>
327 inline _ValueType any_cast(
any& __any)
329 static_assert(any::__is_valid_cast<_ValueType>(),
330 "Template argument must be a reference or CopyConstructible type");
331 auto __p = any_cast<remove_reference_t<_ValueType>>(&__any);
334 __throw_bad_any_cast();
337 template<
typename _ValueType>
338 inline _ValueType any_cast(
any&& __any)
340 static_assert(any::__is_valid_cast<_ValueType>(),
341 "Template argument must be a reference or CopyConstructible type");
342 auto __p = any_cast<remove_reference_t<_ValueType>>(&__any);
345 __throw_bad_any_cast();
360 template<
typename _ValueType>
361 inline const _ValueType* any_cast(
const any* __any) noexcept
364 return static_cast<_ValueType*
>(__any_caster<_ValueType>(__any));
368 template<
typename _ValueType>
369 inline _ValueType* any_cast(
any* __any) noexcept
372 return static_cast<_ValueType*
>(__any_caster<_ValueType>(__any));
377 template<
typename _Tp>
379 any::_Manager_internal<_Tp>::
380 _S_manage(_Op __which,
const any* __any, _Arg* __arg)
383 auto __ptr =
reinterpret_cast<const _Tp*
>(&__any->_M_storage._M_buffer);
387 __arg->_M_obj =
const_cast<_Tp*
>(__ptr);
389 case _Op_get_type_info:
391 __arg->_M_typeinfo = &
typeid(_Tp);
395 ::new(&__arg->_M_any->_M_storage._M_buffer) _Tp(*__ptr);
403 template<typename _Tp>
405 any::_Manager_external<_Tp>::
406 _S_manage(_Op __which, const
any* __any, _Arg* __arg)
409 auto __ptr =
static_cast<const _Tp*
>(__any->_M_storage._M_ptr);
413 __arg->_M_obj =
const_cast<_Tp*
>(__ptr);
415 case _Op_get_type_info:
417 __arg->_M_typeinfo = &
typeid(_Tp);
421 __arg->_M_any->_M_storage._M_ptr =
new _Tp(*__ptr);
430 _GLIBCXX_END_NAMESPACE_VERSION
437 #endif // _GLIBCXX_EXPERIMENTAL_ANY
void swap(basic_filebuf< _CharT, _Traits > &__x, basic_filebuf< _CharT, _Traits > &__y)
Swap specialization for filebufs.
constexpr _Tp && forward(typename std::remove_reference< _Tp >::type &__t) noexcept
Forward an lvalue.
bool any() const noexcept
Tests whether any of the bits are on.