mirror of
https://github.com/autc04/Retro68.git
synced 2024-09-07 13:54:33 +00:00
530 lines
14 KiB
C++
530 lines
14 KiB
C++
// <experimental/any> -*- C++ -*-
|
|
|
|
// Copyright (C) 2014-2019 Free Software Foundation, Inc.
|
|
//
|
|
// This file is part of the GNU ISO C++ Library. This library is free
|
|
// software; you can redistribute it and/or modify it under the
|
|
// terms of the GNU General Public License as published by the
|
|
// Free Software Foundation; either version 3, or (at your option)
|
|
// any later version.
|
|
|
|
// This library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
|
|
// Under Section 7 of GPL version 3, you are granted additional
|
|
// permissions described in the GCC Runtime Library Exception, version
|
|
// 3.1, as published by the Free Software Foundation.
|
|
|
|
// You should have received a copy of the GNU General Public License and
|
|
// a copy of the GCC Runtime Library Exception along with this program;
|
|
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
|
|
// <http://www.gnu.org/licenses/>.
|
|
|
|
/** @file experimental/any
|
|
* This is a TS C++ Library header.
|
|
*/
|
|
|
|
#ifndef _GLIBCXX_EXPERIMENTAL_ANY
|
|
#define _GLIBCXX_EXPERIMENTAL_ANY 1
|
|
|
|
#pragma GCC system_header
|
|
|
|
#if __cplusplus >= 201402L
|
|
|
|
#include <typeinfo>
|
|
#include <new>
|
|
#include <utility>
|
|
#include <type_traits>
|
|
#include <experimental/bits/lfts_config.h>
|
|
|
|
namespace std _GLIBCXX_VISIBILITY(default)
|
|
{
|
|
_GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|
|
|
namespace experimental
|
|
{
|
|
inline namespace fundamentals_v1
|
|
{
|
|
/**
|
|
* @defgroup any Type-safe container of any type
|
|
* @ingroup experimental
|
|
*
|
|
* A type-safe container for single values of value types, as
|
|
* described in n3804 "Any Library Proposal (Revision 3)".
|
|
*
|
|
* @{
|
|
*/
|
|
|
|
#define __cpp_lib_experimental_any 201411
|
|
|
|
/**
|
|
* @brief Exception class thrown by a failed @c any_cast
|
|
* @ingroup exceptions
|
|
*/
|
|
class bad_any_cast : public bad_cast
|
|
{
|
|
public:
|
|
virtual const char* what() const noexcept { return "bad any_cast"; }
|
|
};
|
|
|
|
[[gnu::noreturn]] inline void __throw_bad_any_cast()
|
|
{
|
|
#if __cpp_exceptions
|
|
throw bad_any_cast{};
|
|
#else
|
|
__builtin_abort();
|
|
#endif
|
|
}
|
|
|
|
/**
|
|
* @brief A type-safe container of any type.
|
|
*
|
|
* An @c any object's state is either empty or it stores a contained object
|
|
* of CopyConstructible type.
|
|
*/
|
|
class any
|
|
{
|
|
// Holds either pointer to a heap object or the contained object itself.
|
|
union _Storage
|
|
{
|
|
// This constructor intentionally doesn't initialize anything.
|
|
_Storage() = default;
|
|
|
|
// Prevent trivial copies of this type, buffer might hold a non-POD.
|
|
_Storage(const _Storage&) = delete;
|
|
_Storage& operator=(const _Storage&) = delete;
|
|
|
|
void* _M_ptr;
|
|
aligned_storage<sizeof(_M_ptr), alignof(void*)>::type _M_buffer;
|
|
};
|
|
|
|
template<typename _Tp, typename _Safe = is_nothrow_move_constructible<_Tp>,
|
|
bool _Fits = (sizeof(_Tp) <= sizeof(_Storage))
|
|
&& (alignof(_Tp) <= alignof(_Storage))>
|
|
using _Internal = std::integral_constant<bool, _Safe::value && _Fits>;
|
|
|
|
template<typename _Tp>
|
|
struct _Manager_internal; // uses small-object optimization
|
|
|
|
template<typename _Tp>
|
|
struct _Manager_external; // creates contained object on the heap
|
|
|
|
template<typename _Tp>
|
|
using _Manager = conditional_t<_Internal<_Tp>::value,
|
|
_Manager_internal<_Tp>,
|
|
_Manager_external<_Tp>>;
|
|
|
|
template<typename _Tp, typename _Decayed = decay_t<_Tp>>
|
|
using _Decay = enable_if_t<!is_same<_Decayed, any>::value, _Decayed>;
|
|
|
|
public:
|
|
// construct/destruct
|
|
|
|
/// Default constructor, creates an empty object.
|
|
any() noexcept : _M_manager(nullptr) { }
|
|
|
|
/// Copy constructor, copies the state of @p __other
|
|
any(const any& __other)
|
|
{
|
|
if (__other.empty())
|
|
_M_manager = nullptr;
|
|
else
|
|
{
|
|
_Arg __arg;
|
|
__arg._M_any = this;
|
|
__other._M_manager(_Op_clone, &__other, &__arg);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @brief Move constructor, transfer the state from @p __other
|
|
*
|
|
* @post @c __other.empty() (this postcondition is a GNU extension)
|
|
*/
|
|
any(any&& __other) noexcept
|
|
{
|
|
if (__other.empty())
|
|
_M_manager = nullptr;
|
|
else
|
|
{
|
|
_Arg __arg;
|
|
__arg._M_any = this;
|
|
__other._M_manager(_Op_xfer, &__other, &__arg);
|
|
}
|
|
}
|
|
|
|
/// Construct with a copy of @p __value as the contained object.
|
|
template <typename _ValueType, typename _Tp = _Decay<_ValueType>,
|
|
typename _Mgr = _Manager<_Tp>,
|
|
typename enable_if<is_constructible<_Tp, _ValueType&&>::value,
|
|
bool>::type = true>
|
|
any(_ValueType&& __value)
|
|
: _M_manager(&_Mgr::_S_manage)
|
|
{
|
|
_Mgr::_S_create(_M_storage, std::forward<_ValueType>(__value));
|
|
static_assert(is_copy_constructible<_Tp>::value,
|
|
"The contained object must be CopyConstructible");
|
|
}
|
|
|
|
/// Construct with a copy of @p __value as the contained object.
|
|
template <typename _ValueType, typename _Tp = _Decay<_ValueType>,
|
|
typename _Mgr = _Manager<_Tp>,
|
|
typename enable_if<!is_constructible<_Tp, _ValueType&&>::value,
|
|
bool>::type = false>
|
|
any(_ValueType&& __value)
|
|
: _M_manager(&_Mgr::_S_manage)
|
|
{
|
|
_Mgr::_S_create(_M_storage, __value);
|
|
static_assert(is_copy_constructible<_Tp>::value,
|
|
"The contained object must be CopyConstructible");
|
|
}
|
|
|
|
/// Destructor, calls @c clear()
|
|
~any() { clear(); }
|
|
|
|
// assignments
|
|
|
|
/// Copy the state of another object.
|
|
any& operator=(const any& __rhs)
|
|
{
|
|
*this = any(__rhs);
|
|
return *this;
|
|
}
|
|
|
|
/**
|
|
* @brief Move assignment operator
|
|
*
|
|
* @post @c __rhs.empty() (not guaranteed for other implementations)
|
|
*/
|
|
any& operator=(any&& __rhs) noexcept
|
|
{
|
|
if (__rhs.empty())
|
|
clear();
|
|
else if (this != &__rhs)
|
|
{
|
|
clear();
|
|
_Arg __arg;
|
|
__arg._M_any = this;
|
|
__rhs._M_manager(_Op_xfer, &__rhs, &__arg);
|
|
}
|
|
return *this;
|
|
}
|
|
|
|
/// Store a copy of @p __rhs as the contained object.
|
|
template<typename _ValueType>
|
|
enable_if_t<!is_same<any, decay_t<_ValueType>>::value, any&>
|
|
operator=(_ValueType&& __rhs)
|
|
{
|
|
*this = any(std::forward<_ValueType>(__rhs));
|
|
return *this;
|
|
}
|
|
|
|
// modifiers
|
|
|
|
/// If not empty, destroy the contained object.
|
|
void clear() noexcept
|
|
{
|
|
if (!empty())
|
|
{
|
|
_M_manager(_Op_destroy, this, nullptr);
|
|
_M_manager = nullptr;
|
|
}
|
|
}
|
|
|
|
/// Exchange state with another object.
|
|
void swap(any& __rhs) noexcept
|
|
{
|
|
if (empty() && __rhs.empty())
|
|
return;
|
|
|
|
if (!empty() && !__rhs.empty())
|
|
{
|
|
if (this == &__rhs)
|
|
return;
|
|
|
|
any __tmp;
|
|
_Arg __arg;
|
|
__arg._M_any = &__tmp;
|
|
__rhs._M_manager(_Op_xfer, &__rhs, &__arg);
|
|
__arg._M_any = &__rhs;
|
|
_M_manager(_Op_xfer, this, &__arg);
|
|
__arg._M_any = this;
|
|
__tmp._M_manager(_Op_xfer, &__tmp, &__arg);
|
|
}
|
|
else
|
|
{
|
|
any* __empty = empty() ? this : &__rhs;
|
|
any* __full = empty() ? &__rhs : this;
|
|
_Arg __arg;
|
|
__arg._M_any = __empty;
|
|
__full->_M_manager(_Op_xfer, __full, &__arg);
|
|
}
|
|
}
|
|
|
|
// observers
|
|
|
|
/// Reports whether there is a contained object or not.
|
|
_GLIBCXX_NODISCARD bool empty() const noexcept { return _M_manager == nullptr; }
|
|
|
|
#if __cpp_rtti
|
|
/// The @c typeid of the contained object, or @c typeid(void) if empty.
|
|
const type_info& type() const noexcept
|
|
{
|
|
if (empty())
|
|
return typeid(void);
|
|
_Arg __arg;
|
|
_M_manager(_Op_get_type_info, this, &__arg);
|
|
return *__arg._M_typeinfo;
|
|
}
|
|
#endif
|
|
|
|
template<typename _Tp>
|
|
static constexpr bool __is_valid_cast()
|
|
{ return __or_<is_reference<_Tp>, is_copy_constructible<_Tp>>::value; }
|
|
|
|
private:
|
|
enum _Op {
|
|
_Op_access, _Op_get_type_info, _Op_clone, _Op_destroy, _Op_xfer
|
|
};
|
|
|
|
union _Arg
|
|
{
|
|
void* _M_obj;
|
|
const std::type_info* _M_typeinfo;
|
|
any* _M_any;
|
|
};
|
|
|
|
void (*_M_manager)(_Op, const any*, _Arg*);
|
|
_Storage _M_storage;
|
|
|
|
template<typename _Tp>
|
|
friend void* __any_caster(const any* __any);
|
|
|
|
// Manage in-place contained object.
|
|
template<typename _Tp>
|
|
struct _Manager_internal
|
|
{
|
|
static void
|
|
_S_manage(_Op __which, const any* __anyp, _Arg* __arg);
|
|
|
|
template<typename _Up>
|
|
static void
|
|
_S_create(_Storage& __storage, _Up&& __value)
|
|
{
|
|
void* __addr = &__storage._M_buffer;
|
|
::new (__addr) _Tp(std::forward<_Up>(__value));
|
|
}
|
|
};
|
|
|
|
// Manage external contained object.
|
|
template<typename _Tp>
|
|
struct _Manager_external
|
|
{
|
|
static void
|
|
_S_manage(_Op __which, const any* __anyp, _Arg* __arg);
|
|
|
|
template<typename _Up>
|
|
static void
|
|
_S_create(_Storage& __storage, _Up&& __value)
|
|
{
|
|
__storage._M_ptr = new _Tp(std::forward<_Up>(__value));
|
|
}
|
|
};
|
|
};
|
|
|
|
/// Exchange the states of two @c any objects.
|
|
inline void swap(any& __x, any& __y) noexcept { __x.swap(__y); }
|
|
|
|
/**
|
|
* @brief Access the contained object.
|
|
*
|
|
* @tparam _ValueType A const-reference or CopyConstructible type.
|
|
* @param __any The object to access.
|
|
* @return The contained object.
|
|
* @throw bad_any_cast If <code>
|
|
* __any.type() != typeid(remove_reference_t<_ValueType>)
|
|
* </code>
|
|
*/
|
|
template<typename _ValueType>
|
|
inline _ValueType any_cast(const any& __any)
|
|
{
|
|
static_assert(any::__is_valid_cast<_ValueType>(),
|
|
"Template argument must be a reference or CopyConstructible type");
|
|
auto __p = any_cast<add_const_t<remove_reference_t<_ValueType>>>(&__any);
|
|
if (__p)
|
|
return *__p;
|
|
__throw_bad_any_cast();
|
|
}
|
|
|
|
/**
|
|
* @brief Access the contained object.
|
|
*
|
|
* @tparam _ValueType A reference or CopyConstructible type.
|
|
* @param __any The object to access.
|
|
* @return The contained object.
|
|
* @throw bad_any_cast If <code>
|
|
* __any.type() != typeid(remove_reference_t<_ValueType>)
|
|
* </code>
|
|
*
|
|
* @{
|
|
*/
|
|
template<typename _ValueType>
|
|
inline _ValueType any_cast(any& __any)
|
|
{
|
|
static_assert(any::__is_valid_cast<_ValueType>(),
|
|
"Template argument must be a reference or CopyConstructible type");
|
|
auto __p = any_cast<remove_reference_t<_ValueType>>(&__any);
|
|
if (__p)
|
|
return *__p;
|
|
__throw_bad_any_cast();
|
|
}
|
|
|
|
template<typename _ValueType,
|
|
typename enable_if<!is_move_constructible<_ValueType>::value
|
|
|| is_lvalue_reference<_ValueType>::value,
|
|
bool>::type = true>
|
|
inline _ValueType any_cast(any&& __any)
|
|
{
|
|
static_assert(any::__is_valid_cast<_ValueType>(),
|
|
"Template argument must be a reference or CopyConstructible type");
|
|
auto __p = any_cast<remove_reference_t<_ValueType>>(&__any);
|
|
if (__p)
|
|
return *__p;
|
|
__throw_bad_any_cast();
|
|
}
|
|
|
|
template<typename _ValueType,
|
|
typename enable_if<is_move_constructible<_ValueType>::value
|
|
&& !is_lvalue_reference<_ValueType>::value,
|
|
bool>::type = false>
|
|
inline _ValueType any_cast(any&& __any)
|
|
{
|
|
static_assert(any::__is_valid_cast<_ValueType>(),
|
|
"Template argument must be a reference or CopyConstructible type");
|
|
auto __p = any_cast<remove_reference_t<_ValueType>>(&__any);
|
|
if (__p)
|
|
return std::move(*__p);
|
|
__throw_bad_any_cast();
|
|
}
|
|
// @}
|
|
|
|
template<typename _Tp>
|
|
void* __any_caster(const any* __any)
|
|
{
|
|
struct _None { };
|
|
using _Up = decay_t<_Tp>;
|
|
using _Vp = conditional_t<is_copy_constructible<_Up>::value, _Up, _None>;
|
|
if (__any->_M_manager != &any::_Manager<_Vp>::_S_manage)
|
|
return nullptr;
|
|
any::_Arg __arg;
|
|
__any->_M_manager(any::_Op_access, __any, &__arg);
|
|
return __arg._M_obj;
|
|
}
|
|
|
|
/**
|
|
* @brief Access the contained object.
|
|
*
|
|
* @tparam _ValueType The type of the contained object.
|
|
* @param __any A pointer to the object to access.
|
|
* @return The address of the contained object if <code>
|
|
* __any != nullptr && __any.type() == typeid(_ValueType)
|
|
* </code>, otherwise a null pointer.
|
|
*
|
|
* @{
|
|
*/
|
|
template<typename _ValueType>
|
|
inline const _ValueType* any_cast(const any* __any) noexcept
|
|
{
|
|
if (__any)
|
|
return static_cast<_ValueType*>(__any_caster<_ValueType>(__any));
|
|
return nullptr;
|
|
}
|
|
|
|
template<typename _ValueType>
|
|
inline _ValueType* any_cast(any* __any) noexcept
|
|
{
|
|
if (__any)
|
|
return static_cast<_ValueType*>(__any_caster<_ValueType>(__any));
|
|
return nullptr;
|
|
}
|
|
// @}
|
|
|
|
template<typename _Tp>
|
|
void
|
|
any::_Manager_internal<_Tp>::
|
|
_S_manage(_Op __which, const any* __any, _Arg* __arg)
|
|
{
|
|
// The contained object is in _M_storage._M_buffer
|
|
auto __ptr = reinterpret_cast<const _Tp*>(&__any->_M_storage._M_buffer);
|
|
switch (__which)
|
|
{
|
|
case _Op_access:
|
|
__arg->_M_obj = const_cast<_Tp*>(__ptr);
|
|
break;
|
|
case _Op_get_type_info:
|
|
#if __cpp_rtti
|
|
__arg->_M_typeinfo = &typeid(_Tp);
|
|
#endif
|
|
break;
|
|
case _Op_clone:
|
|
::new(&__arg->_M_any->_M_storage._M_buffer) _Tp(*__ptr);
|
|
__arg->_M_any->_M_manager = __any->_M_manager;
|
|
break;
|
|
case _Op_destroy:
|
|
__ptr->~_Tp();
|
|
break;
|
|
case _Op_xfer:
|
|
::new(&__arg->_M_any->_M_storage._M_buffer) _Tp
|
|
(std::move(*const_cast<_Tp*>(__ptr)));
|
|
__ptr->~_Tp();
|
|
__arg->_M_any->_M_manager = __any->_M_manager;
|
|
const_cast<any*>(__any)->_M_manager = nullptr;
|
|
break;
|
|
}
|
|
}
|
|
|
|
template<typename _Tp>
|
|
void
|
|
any::_Manager_external<_Tp>::
|
|
_S_manage(_Op __which, const any* __any, _Arg* __arg)
|
|
{
|
|
// The contained object is *_M_storage._M_ptr
|
|
auto __ptr = static_cast<const _Tp*>(__any->_M_storage._M_ptr);
|
|
switch (__which)
|
|
{
|
|
case _Op_access:
|
|
__arg->_M_obj = const_cast<_Tp*>(__ptr);
|
|
break;
|
|
case _Op_get_type_info:
|
|
#if __cpp_rtti
|
|
__arg->_M_typeinfo = &typeid(_Tp);
|
|
#endif
|
|
break;
|
|
case _Op_clone:
|
|
__arg->_M_any->_M_storage._M_ptr = new _Tp(*__ptr);
|
|
__arg->_M_any->_M_manager = __any->_M_manager;
|
|
break;
|
|
case _Op_destroy:
|
|
delete __ptr;
|
|
break;
|
|
case _Op_xfer:
|
|
__arg->_M_any->_M_storage._M_ptr = __any->_M_storage._M_ptr;
|
|
__arg->_M_any->_M_manager = __any->_M_manager;
|
|
const_cast<any*>(__any)->_M_manager = nullptr;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// @} group any
|
|
} // namespace fundamentals_v1
|
|
} // namespace experimental
|
|
|
|
_GLIBCXX_END_NAMESPACE_VERSION
|
|
} // namespace std
|
|
|
|
#endif // C++14
|
|
|
|
#endif // _GLIBCXX_EXPERIMENTAL_ANY
|