123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342 |
- // See http://www.boost.org/libs/any for Documentation.
- #ifndef BOOST_ANY_INCLUDED
- #define BOOST_ANY_INCLUDED
- #if defined(_MSC_VER)
- # pragma once
- #endif
- // what: variant type boost::any
- // who: contributed by Kevlin Henney,
- // with features contributed and bugs found by
- // Antony Polukhin, Ed Brey, Mark Rodgers,
- // Peter Dimov, and James Curran
- // when: July 2001, April 2013 - 2019
- #include <algorithm>
- #include <boost/config.hpp>
- #include <boost/type_index.hpp>
- #include <boost/type_traits/remove_reference.hpp>
- #include <boost/type_traits/decay.hpp>
- #include <boost/type_traits/remove_cv.hpp>
- #include <boost/type_traits/add_reference.hpp>
- #include <boost/type_traits/is_reference.hpp>
- #include <boost/type_traits/is_const.hpp>
- #include <boost/throw_exception.hpp>
- #include <boost/static_assert.hpp>
- #include <boost/utility/enable_if.hpp>
- #include <boost/core/addressof.hpp>
- #include <boost/type_traits/is_same.hpp>
- #include <boost/type_traits/is_const.hpp>
- #include <boost/type_traits/conditional.hpp>
- namespace boost
- {
- class any
- {
- public: // structors
- BOOST_CONSTEXPR any() BOOST_NOEXCEPT
- : content(0)
- {
- }
- template<typename ValueType>
- any(const ValueType & value)
- : content(new holder<
- BOOST_DEDUCED_TYPENAME remove_cv<BOOST_DEDUCED_TYPENAME decay<const ValueType>::type>::type
- >(value))
- {
- }
- any(const any & other)
- : content(other.content ? other.content->clone() : 0)
- {
- }
- #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
- // Move constructor
- any(any&& other) BOOST_NOEXCEPT
- : content(other.content)
- {
- other.content = 0;
- }
- // Perfect forwarding of ValueType
- template<typename ValueType>
- any(ValueType&& value
- , typename boost::disable_if<boost::is_same<any&, ValueType> >::type* = 0 // disable if value has type `any&`
- , typename boost::disable_if<boost::is_const<ValueType> >::type* = 0) // disable if value has type `const ValueType&&`
- : content(new holder< typename decay<ValueType>::type >(static_cast<ValueType&&>(value)))
- {
- }
- #endif
- ~any() BOOST_NOEXCEPT
- {
- delete content;
- }
- public: // modifiers
- any & swap(any & rhs) BOOST_NOEXCEPT
- {
- std::swap(content, rhs.content);
- return *this;
- }
- #ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
- template<typename ValueType>
- any & operator=(const ValueType & rhs)
- {
- any(rhs).swap(*this);
- return *this;
- }
- any & operator=(any rhs)
- {
- rhs.swap(*this);
- return *this;
- }
- #else
- any & operator=(const any& rhs)
- {
- any(rhs).swap(*this);
- return *this;
- }
- // move assignment
- any & operator=(any&& rhs) BOOST_NOEXCEPT
- {
- rhs.swap(*this);
- any().swap(rhs);
- return *this;
- }
- // Perfect forwarding of ValueType
- template <class ValueType>
- any & operator=(ValueType&& rhs)
- {
- any(static_cast<ValueType&&>(rhs)).swap(*this);
- return *this;
- }
- #endif
- public: // queries
- bool empty() const BOOST_NOEXCEPT
- {
- return !content;
- }
- void clear() BOOST_NOEXCEPT
- {
- any().swap(*this);
- }
- const boost::typeindex::type_info& type() const BOOST_NOEXCEPT
- {
- return content ? content->type() : boost::typeindex::type_id<void>().type_info();
- }
- #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
- private: // types
- #else
- public: // types (public so any_cast can be non-friend)
- #endif
- class BOOST_SYMBOL_VISIBLE placeholder
- {
- public: // structors
- virtual ~placeholder()
- {
- }
- public: // queries
- virtual const boost::typeindex::type_info& type() const BOOST_NOEXCEPT = 0;
- virtual placeholder * clone() const = 0;
- };
- template<typename ValueType>
- class holder
- #ifndef BOOST_NO_CXX11_FINAL
- final
- #endif
- : public placeholder
- {
- public: // structors
- holder(const ValueType & value)
- : held(value)
- {
- }
- #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
- holder(ValueType&& value)
- : held(static_cast< ValueType&& >(value))
- {
- }
- #endif
- public: // queries
- virtual const boost::typeindex::type_info& type() const BOOST_NOEXCEPT
- {
- return boost::typeindex::type_id<ValueType>().type_info();
- }
- virtual placeholder * clone() const
- {
- return new holder(held);
- }
- public: // representation
- ValueType held;
- private: // intentionally left unimplemented
- holder & operator=(const holder &);
- };
- #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
- private: // representation
- template<typename ValueType>
- friend ValueType * any_cast(any *) BOOST_NOEXCEPT;
- template<typename ValueType>
- friend ValueType * unsafe_any_cast(any *) BOOST_NOEXCEPT;
- #else
- public: // representation (public so any_cast can be non-friend)
- #endif
- placeholder * content;
- };
-
- inline void swap(any & lhs, any & rhs) BOOST_NOEXCEPT
- {
- lhs.swap(rhs);
- }
- class BOOST_SYMBOL_VISIBLE bad_any_cast :
- #ifndef BOOST_NO_RTTI
- public std::bad_cast
- #else
- public std::exception
- #endif
- {
- public:
- virtual const char * what() const BOOST_NOEXCEPT_OR_NOTHROW
- {
- return "boost::bad_any_cast: "
- "failed conversion using boost::any_cast";
- }
- };
- template<typename ValueType>
- ValueType * any_cast(any * operand) BOOST_NOEXCEPT
- {
- return operand && operand->type() == boost::typeindex::type_id<ValueType>()
- ? boost::addressof(
- static_cast<any::holder<BOOST_DEDUCED_TYPENAME remove_cv<ValueType>::type> *>(operand->content)->held
- )
- : 0;
- }
- template<typename ValueType>
- inline const ValueType * any_cast(const any * operand) BOOST_NOEXCEPT
- {
- return any_cast<ValueType>(const_cast<any *>(operand));
- }
- template<typename ValueType>
- ValueType any_cast(any & operand)
- {
- typedef BOOST_DEDUCED_TYPENAME remove_reference<ValueType>::type nonref;
- nonref * result = any_cast<nonref>(boost::addressof(operand));
- if(!result)
- boost::throw_exception(bad_any_cast());
- // Attempt to avoid construction of a temporary object in cases when
- // `ValueType` is not a reference. Example:
- // `static_cast<std::string>(*result);`
- // which is equal to `std::string(*result);`
- typedef BOOST_DEDUCED_TYPENAME boost::conditional<
- boost::is_reference<ValueType>::value,
- ValueType,
- BOOST_DEDUCED_TYPENAME boost::add_reference<ValueType>::type
- >::type ref_type;
- #ifdef BOOST_MSVC
- # pragma warning(push)
- # pragma warning(disable: 4172) // "returning address of local variable or temporary" but *result is not local!
- #endif
- return static_cast<ref_type>(*result);
- #ifdef BOOST_MSVC
- # pragma warning(pop)
- #endif
- }
- template<typename ValueType>
- inline ValueType any_cast(const any & operand)
- {
- typedef BOOST_DEDUCED_TYPENAME remove_reference<ValueType>::type nonref;
- return any_cast<const nonref &>(const_cast<any &>(operand));
- }
- #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
- template<typename ValueType>
- inline ValueType any_cast(any&& operand)
- {
- BOOST_STATIC_ASSERT_MSG(
- boost::is_rvalue_reference<ValueType&&>::value /*true if ValueType is rvalue or just a value*/
- || boost::is_const< typename boost::remove_reference<ValueType>::type >::value,
- "boost::any_cast shall not be used for getting nonconst references to temporary objects"
- );
- return any_cast<ValueType>(operand);
- }
- #endif
- // Note: The "unsafe" versions of any_cast are not part of the
- // public interface and may be removed at any time. They are
- // required where we know what type is stored in the any and can't
- // use typeid() comparison, e.g., when our types may travel across
- // different shared libraries.
- template<typename ValueType>
- inline ValueType * unsafe_any_cast(any * operand) BOOST_NOEXCEPT
- {
- return boost::addressof(
- static_cast<any::holder<ValueType> *>(operand->content)->held
- );
- }
- template<typename ValueType>
- inline const ValueType * unsafe_any_cast(const any * operand) BOOST_NOEXCEPT
- {
- return unsafe_any_cast<ValueType>(const_cast<any *>(operand));
- }
- }
- // Copyright Kevlin Henney, 2000, 2001, 2002. All rights reserved.
- // Copyright Antony Polukhin, 2013-2019.
- //
- // Distributed under the Boost Software License, Version 1.0. (See
- // accompanying file LICENSE_1_0.txt or copy at
- // http://www.boost.org/LICENSE_1_0.txt)
- #endif
|