llvm-project/libcxx/include/any

693 lines
19 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP_ANY
#define _LIBCPP_ANY
/*
any synopsis
namespace std {
class bad_any_cast : public bad_cast
{
public:
virtual const char* what() const noexcept;
};
class any
{
public:
// 6.3.1 any construct/destruct
any() noexcept;
any(const any& other);
any(any&& other) noexcept;
template <class ValueType>
any(ValueType&& value);
~any();
// 6.3.2 any assignments
any& operator=(const any& rhs);
any& operator=(any&& rhs) noexcept;
template <class ValueType>
any& operator=(ValueType&& rhs);
// 6.3.3 any modifiers
template <class ValueType, class... Args>
decay_t<ValueType>& emplace(Args&&... args);
template <class ValueType, class U, class... Args>
decay_t<ValueType>& emplace(initializer_list<U>, Args&&...);
void reset() noexcept;
void swap(any& rhs) noexcept;
// 6.3.4 any observers
bool has_value() const noexcept;
const type_info& type() const noexcept;
};
// 6.4 Non-member functions
void swap(any& x, any& y) noexcept;
template <class T, class ...Args>
any make_any(Args&& ...args);
template <class T, class U, class ...Args>
any make_any(initializer_list<U>, Args&& ...args);
template<class ValueType>
ValueType any_cast(const any& operand);
template<class ValueType>
ValueType any_cast(any& operand);
template<class ValueType>
ValueType any_cast(any&& operand);
template<class ValueType>
const ValueType* any_cast(const any* operand) noexcept;
template<class ValueType>
ValueType* any_cast(any* operand) noexcept;
} // namespace std
*/
#include <__assert> // all public C++ headers provide the assertion handler
#include <__availability>
#include <__config>
#include <__utility/forward.h>
#include <__utility/in_place.h>
#include <__utility/move.h>
#include <__utility/unreachable.h>
#include <cstdlib>
#include <memory>
#include <type_traits>
#include <typeinfo>
#include <version>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
namespace std {
class _LIBCPP_EXCEPTION_ABI _LIBCPP_AVAILABILITY_BAD_ANY_CAST bad_any_cast : public bad_cast
{
public:
virtual const char* what() const _NOEXCEPT;
};
} // namespace std
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER > 14
_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
void __throw_bad_any_cast()
{
#ifndef _LIBCPP_NO_EXCEPTIONS
throw bad_any_cast();
#else
_VSTD::abort();
#endif
}
// Forward declarations
class _LIBCPP_TEMPLATE_VIS any;
template <class _ValueType>
_LIBCPP_INLINE_VISIBILITY
add_pointer_t<add_const_t<_ValueType>>
any_cast(any const *) _NOEXCEPT;
template <class _ValueType>
_LIBCPP_INLINE_VISIBILITY
add_pointer_t<_ValueType> any_cast(any *) _NOEXCEPT;
namespace __any_imp
{
using _Buffer = aligned_storage_t<3*sizeof(void*), alignment_of<void*>::value>;
template <class _Tp>
using _IsSmallObject = integral_constant<bool
, sizeof(_Tp) <= sizeof(_Buffer)
&& alignment_of<_Buffer>::value
% alignment_of<_Tp>::value == 0
&& is_nothrow_move_constructible<_Tp>::value
>;
enum class _Action {
_Destroy,
_Copy,
_Move,
_Get,
_TypeInfo
};
template <class _Tp> struct _SmallHandler;
template <class _Tp> struct _LargeHandler;
template <class _Tp>
struct _LIBCPP_TEMPLATE_VIS __unique_typeinfo { static constexpr int __id = 0; };
template <class _Tp> constexpr int __unique_typeinfo<_Tp>::__id;
template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
constexpr const void* __get_fallback_typeid() {
return &__unique_typeinfo<remove_cv_t<remove_reference_t<_Tp>>>::__id;
}
template <class _Tp>
inline _LIBCPP_INLINE_VISIBILITY
bool __compare_typeid(type_info const* __id, const void* __fallback_id)
{
#if !defined(_LIBCPP_NO_RTTI)
if (__id && *__id == typeid(_Tp))
return true;
#endif
if (!__id && __fallback_id == __any_imp::__get_fallback_typeid<_Tp>())
return true;
return false;
}
template <class _Tp>
using _Handler = conditional_t<
_IsSmallObject<_Tp>::value, _SmallHandler<_Tp>, _LargeHandler<_Tp>>;
} // namespace __any_imp
class _LIBCPP_TEMPLATE_VIS any
{
public:
// construct/destruct
_LIBCPP_INLINE_VISIBILITY
constexpr any() _NOEXCEPT : __h(nullptr) {}
_LIBCPP_INLINE_VISIBILITY
any(any const & __other) : __h(nullptr)
{
if (__other.__h) __other.__call(_Action::_Copy, this);
}
_LIBCPP_INLINE_VISIBILITY
any(any && __other) _NOEXCEPT : __h(nullptr)
{
if (__other.__h) __other.__call(_Action::_Move, this);
}
template <
class _ValueType
, class _Tp = decay_t<_ValueType>
, class = enable_if_t<
!is_same<_Tp, any>::value &&
!__is_inplace_type<_ValueType>::value &&
is_copy_constructible<_Tp>::value>
>
_LIBCPP_INLINE_VISIBILITY
any(_ValueType && __value);
template <class _ValueType, class ..._Args,
class _Tp = decay_t<_ValueType>,
class = enable_if_t<
is_constructible<_Tp, _Args...>::value &&
is_copy_constructible<_Tp>::value
>
>
_LIBCPP_INLINE_VISIBILITY
explicit any(in_place_type_t<_ValueType>, _Args&&... __args);
template <class _ValueType, class _Up, class ..._Args,
class _Tp = decay_t<_ValueType>,
class = enable_if_t<
is_constructible<_Tp, initializer_list<_Up>&, _Args...>::value &&
is_copy_constructible<_Tp>::value>
>
_LIBCPP_INLINE_VISIBILITY
explicit any(in_place_type_t<_ValueType>, initializer_list<_Up>, _Args&&... __args);
_LIBCPP_INLINE_VISIBILITY
~any() { this->reset(); }
// assignments
_LIBCPP_INLINE_VISIBILITY
any & operator=(any const & __rhs) {
any(__rhs).swap(*this);
return *this;
}
_LIBCPP_INLINE_VISIBILITY
any & operator=(any && __rhs) _NOEXCEPT {
any(_VSTD::move(__rhs)).swap(*this);
return *this;
}
template <
class _ValueType
, class _Tp = decay_t<_ValueType>
, class = enable_if_t<
!is_same<_Tp, any>::value
&& is_copy_constructible<_Tp>::value>
>
_LIBCPP_INLINE_VISIBILITY
any & operator=(_ValueType && __rhs);
template <class _ValueType, class ..._Args,
class _Tp = decay_t<_ValueType>,
class = enable_if_t<
is_constructible<_Tp, _Args...>::value &&
is_copy_constructible<_Tp>::value>
>
_LIBCPP_INLINE_VISIBILITY
_Tp& emplace(_Args&&... args);
template <class _ValueType, class _Up, class ..._Args,
class _Tp = decay_t<_ValueType>,
class = enable_if_t<
is_constructible<_Tp, initializer_list<_Up>&, _Args...>::value &&
is_copy_constructible<_Tp>::value>
>
_LIBCPP_INLINE_VISIBILITY
_Tp& emplace(initializer_list<_Up>, _Args&&...);
// 6.3.3 any modifiers
_LIBCPP_INLINE_VISIBILITY
void reset() _NOEXCEPT { if (__h) this->__call(_Action::_Destroy); }
_LIBCPP_INLINE_VISIBILITY
void swap(any & __rhs) _NOEXCEPT;
// 6.3.4 any observers
_LIBCPP_INLINE_VISIBILITY
bool has_value() const _NOEXCEPT { return __h != nullptr; }
#if !defined(_LIBCPP_NO_RTTI)
_LIBCPP_INLINE_VISIBILITY
const type_info & type() const _NOEXCEPT {
if (__h) {
return *static_cast<type_info const *>(this->__call(_Action::_TypeInfo));
} else {
return typeid(void);
}
}
#endif
private:
typedef __any_imp::_Action _Action;
using _HandleFuncPtr = void* (*)(_Action, any const *, any *, const type_info *,
const void* __fallback_info);
union _Storage {
constexpr _Storage() : __ptr(nullptr) {}
void * __ptr;
__any_imp::_Buffer __buf;
};
_LIBCPP_INLINE_VISIBILITY
void * __call(_Action __a, any * __other = nullptr,
type_info const * __info = nullptr,
const void* __fallback_info = nullptr) const
{
return __h(__a, this, __other, __info, __fallback_info);
}
_LIBCPP_INLINE_VISIBILITY
void * __call(_Action __a, any * __other = nullptr,
type_info const * __info = nullptr,
const void* __fallback_info = nullptr)
{
return __h(__a, this, __other, __info, __fallback_info);
}
template <class>
friend struct __any_imp::_SmallHandler;
template <class>
friend struct __any_imp::_LargeHandler;
template <class _ValueType>
friend add_pointer_t<add_const_t<_ValueType>>
any_cast(any const *) _NOEXCEPT;
template <class _ValueType>
friend add_pointer_t<_ValueType>
any_cast(any *) _NOEXCEPT;
_HandleFuncPtr __h = nullptr;
_Storage __s;
};
namespace __any_imp
{
template <class _Tp>
struct _LIBCPP_TEMPLATE_VIS _SmallHandler
{
_LIBCPP_INLINE_VISIBILITY
static void* __handle(_Action __act, any const * __this, any * __other,
type_info const * __info, const void* __fallback_info)
{
switch (__act)
{
case _Action::_Destroy:
__destroy(const_cast<any &>(*__this));
return nullptr;
case _Action::_Copy:
__copy(*__this, *__other);
return nullptr;
case _Action::_Move:
__move(const_cast<any &>(*__this), *__other);
return nullptr;
case _Action::_Get:
return __get(const_cast<any &>(*__this), __info, __fallback_info);
case _Action::_TypeInfo:
return __type_info();
}
__libcpp_unreachable();
}
template <class ..._Args>
_LIBCPP_INLINE_VISIBILITY
static _Tp& __create(any & __dest, _Args&&... __args) {
typedef allocator<_Tp> _Alloc;
typedef allocator_traits<_Alloc> _ATraits;
_Alloc __a;
_Tp * __ret = static_cast<_Tp*>(static_cast<void*>(&__dest.__s.__buf));
_ATraits::construct(__a, __ret, _VSTD::forward<_Args>(__args)...);
__dest.__h = &_SmallHandler::__handle;
return *__ret;
}
private:
_LIBCPP_INLINE_VISIBILITY
static void __destroy(any & __this) {
typedef allocator<_Tp> _Alloc;
typedef allocator_traits<_Alloc> _ATraits;
_Alloc __a;
_Tp * __p = static_cast<_Tp *>(static_cast<void*>(&__this.__s.__buf));
_ATraits::destroy(__a, __p);
__this.__h = nullptr;
}
_LIBCPP_INLINE_VISIBILITY
static void __copy(any const & __this, any & __dest) {
_SmallHandler::__create(__dest, *static_cast<_Tp const *>(
static_cast<void const *>(&__this.__s.__buf)));
}
_LIBCPP_INLINE_VISIBILITY
static void __move(any & __this, any & __dest) {
_SmallHandler::__create(__dest, _VSTD::move(
*static_cast<_Tp*>(static_cast<void*>(&__this.__s.__buf))));
__destroy(__this);
}
_LIBCPP_INLINE_VISIBILITY
static void* __get(any & __this,
type_info const * __info,
const void* __fallback_id)
{
if (__any_imp::__compare_typeid<_Tp>(__info, __fallback_id))
return static_cast<void*>(&__this.__s.__buf);
return nullptr;
}
_LIBCPP_INLINE_VISIBILITY
static void* __type_info()
{
#if !defined(_LIBCPP_NO_RTTI)
return const_cast<void*>(static_cast<void const *>(&typeid(_Tp)));
#else
return nullptr;
#endif
}
};
template <class _Tp>
struct _LIBCPP_TEMPLATE_VIS _LargeHandler
{
_LIBCPP_INLINE_VISIBILITY
static void* __handle(_Action __act, any const * __this,
any * __other, type_info const * __info,
void const* __fallback_info)
{
switch (__act)
{
case _Action::_Destroy:
__destroy(const_cast<any &>(*__this));
return nullptr;
case _Action::_Copy:
__copy(*__this, *__other);
return nullptr;
case _Action::_Move:
__move(const_cast<any &>(*__this), *__other);
return nullptr;
case _Action::_Get:
return __get(const_cast<any &>(*__this), __info, __fallback_info);
case _Action::_TypeInfo:
return __type_info();
}
__libcpp_unreachable();
}
template <class ..._Args>
_LIBCPP_INLINE_VISIBILITY
static _Tp& __create(any & __dest, _Args&&... __args) {
typedef allocator<_Tp> _Alloc;
typedef allocator_traits<_Alloc> _ATraits;
typedef __allocator_destructor<_Alloc> _Dp;
_Alloc __a;
unique_ptr<_Tp, _Dp> __hold(_ATraits::allocate(__a, 1), _Dp(__a, 1));
_Tp * __ret = __hold.get();
_ATraits::construct(__a, __ret, _VSTD::forward<_Args>(__args)...);
__dest.__s.__ptr = __hold.release();
__dest.__h = &_LargeHandler::__handle;
return *__ret;
}
private:
_LIBCPP_INLINE_VISIBILITY
static void __destroy(any & __this){
typedef allocator<_Tp> _Alloc;
typedef allocator_traits<_Alloc> _ATraits;
_Alloc __a;
_Tp * __p = static_cast<_Tp *>(__this.__s.__ptr);
_ATraits::destroy(__a, __p);
_ATraits::deallocate(__a, __p, 1);
__this.__h = nullptr;
}
_LIBCPP_INLINE_VISIBILITY
static void __copy(any const & __this, any & __dest) {
_LargeHandler::__create(__dest, *static_cast<_Tp const *>(__this.__s.__ptr));
}
_LIBCPP_INLINE_VISIBILITY
static void __move(any & __this, any & __dest) {
__dest.__s.__ptr = __this.__s.__ptr;
__dest.__h = &_LargeHandler::__handle;
__this.__h = nullptr;
}
_LIBCPP_INLINE_VISIBILITY
static void* __get(any & __this, type_info const * __info,
void const* __fallback_info)
{
if (__any_imp::__compare_typeid<_Tp>(__info, __fallback_info))
return static_cast<void*>(__this.__s.__ptr);
return nullptr;
}
_LIBCPP_INLINE_VISIBILITY
static void* __type_info()
{
#if !defined(_LIBCPP_NO_RTTI)
return const_cast<void*>(static_cast<void const *>(&typeid(_Tp)));
#else
return nullptr;
#endif
}
};
} // namespace __any_imp
template <class _ValueType, class _Tp, class>
any::any(_ValueType && __v) : __h(nullptr)
{
__any_imp::_Handler<_Tp>::__create(*this, _VSTD::forward<_ValueType>(__v));
}
template <class _ValueType, class ..._Args, class _Tp, class>
any::any(in_place_type_t<_ValueType>, _Args&&... __args) {
__any_imp::_Handler<_Tp>::__create(*this, _VSTD::forward<_Args>(__args)...);
}
template <class _ValueType, class _Up, class ..._Args, class _Tp, class>
any::any(in_place_type_t<_ValueType>, initializer_list<_Up> __il, _Args&&... __args) {
__any_imp::_Handler<_Tp>::__create(*this, __il, _VSTD::forward<_Args>(__args)...);
}
template <class _ValueType, class, class>
inline _LIBCPP_INLINE_VISIBILITY
any & any::operator=(_ValueType && __v)
{
any(_VSTD::forward<_ValueType>(__v)).swap(*this);
return *this;
}
template <class _ValueType, class ..._Args, class _Tp, class>
inline _LIBCPP_INLINE_VISIBILITY
_Tp& any::emplace(_Args&&... __args) {
reset();
return __any_imp::_Handler<_Tp>::__create(*this, _VSTD::forward<_Args>(__args)...);
}
template <class _ValueType, class _Up, class ..._Args, class _Tp, class>
inline _LIBCPP_INLINE_VISIBILITY
_Tp& any::emplace(initializer_list<_Up> __il, _Args&&... __args) {
reset();
return __any_imp::_Handler<_Tp>::__create(*this, __il, _VSTD::forward<_Args>(__args)...);
}
inline _LIBCPP_INLINE_VISIBILITY
void any::swap(any & __rhs) _NOEXCEPT
{
if (this == &__rhs)
return;
if (__h && __rhs.__h) {
any __tmp;
__rhs.__call(_Action::_Move, &__tmp);
this->__call(_Action::_Move, &__rhs);
__tmp.__call(_Action::_Move, this);
}
else if (__h) {
this->__call(_Action::_Move, &__rhs);
}
else if (__rhs.__h) {
__rhs.__call(_Action::_Move, this);
}
}
// 6.4 Non-member functions
inline _LIBCPP_INLINE_VISIBILITY
void swap(any & __lhs, any & __rhs) _NOEXCEPT
{
__lhs.swap(__rhs);
}
template <class _Tp, class ..._Args>
inline _LIBCPP_INLINE_VISIBILITY
any make_any(_Args&&... __args) {
return any(in_place_type<_Tp>, _VSTD::forward<_Args>(__args)...);
}
template <class _Tp, class _Up, class ..._Args>
inline _LIBCPP_INLINE_VISIBILITY
any make_any(initializer_list<_Up> __il, _Args&&... __args) {
return any(in_place_type<_Tp>, __il, _VSTD::forward<_Args>(__args)...);
}
template <class _ValueType>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
_ValueType any_cast(any const & __v)
{
using _RawValueType = __uncvref_t<_ValueType>;
static_assert(is_constructible<_ValueType, _RawValueType const &>::value,
"ValueType is required to be a const lvalue reference "
"or a CopyConstructible type");
auto __tmp = _VSTD::any_cast<add_const_t<_RawValueType>>(&__v);
if (__tmp == nullptr)
__throw_bad_any_cast();
return static_cast<_ValueType>(*__tmp);
}
template <class _ValueType>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
_ValueType any_cast(any & __v)
{
using _RawValueType = __uncvref_t<_ValueType>;
static_assert(is_constructible<_ValueType, _RawValueType &>::value,
"ValueType is required to be an lvalue reference "
"or a CopyConstructible type");
auto __tmp = _VSTD::any_cast<_RawValueType>(&__v);
if (__tmp == nullptr)
__throw_bad_any_cast();
return static_cast<_ValueType>(*__tmp);
}
template <class _ValueType>
inline _LIBCPP_INLINE_VISIBILITY
_LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
_ValueType any_cast(any && __v)
{
using _RawValueType = __uncvref_t<_ValueType>;
static_assert(is_constructible<_ValueType, _RawValueType>::value,
"ValueType is required to be an rvalue reference "
"or a CopyConstructible type");
auto __tmp = _VSTD::any_cast<_RawValueType>(&__v);
if (__tmp == nullptr)
__throw_bad_any_cast();
return static_cast<_ValueType>(_VSTD::move(*__tmp));
}
template <class _ValueType>
inline _LIBCPP_INLINE_VISIBILITY
add_pointer_t<add_const_t<_ValueType>>
any_cast(any const * __any) _NOEXCEPT
{
static_assert(!is_reference<_ValueType>::value,
"_ValueType may not be a reference.");
return _VSTD::any_cast<_ValueType>(const_cast<any *>(__any));
}
template <class _RetType>
inline _LIBCPP_INLINE_VISIBILITY
_RetType __pointer_or_func_cast(void* __p, /*IsFunction*/false_type) noexcept {
return static_cast<_RetType>(__p);
}
template <class _RetType>
inline _LIBCPP_INLINE_VISIBILITY
_RetType __pointer_or_func_cast(void*, /*IsFunction*/true_type) noexcept {
return nullptr;
}
template <class _ValueType>
add_pointer_t<_ValueType>
any_cast(any * __any) _NOEXCEPT
{
using __any_imp::_Action;
static_assert(!is_reference<_ValueType>::value,
"_ValueType may not be a reference.");
typedef typename add_pointer<_ValueType>::type _ReturnType;
if (__any && __any->__h) {
void *__p = __any->__call(_Action::_Get, nullptr,
#if !defined(_LIBCPP_NO_RTTI)
&typeid(_ValueType),
#else
nullptr,
#endif
__any_imp::__get_fallback_typeid<_ValueType>());
return _VSTD::__pointer_or_func_cast<_ReturnType>(
__p, is_function<_ValueType>{});
}
return nullptr;
}
#endif // _LIBCPP_STD_VER > 14
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP_ANY