Chris@16: // See http://www.boost.org/libs/any for Documentation.
Chris@16: 
Chris@16: #ifndef BOOST_ANY_INCLUDED
Chris@16: #define BOOST_ANY_INCLUDED
Chris@16: 
Chris@101: #if defined(_MSC_VER)
Chris@16: # pragma once
Chris@16: #endif
Chris@16: 
Chris@16: // what:  variant type boost::any
Chris@16: // who:   contributed by Kevlin Henney,
Chris@16: //        with features contributed and bugs found by
Chris@16: //        Antony Polukhin, Ed Brey, Mark Rodgers, 
Chris@16: //        Peter Dimov, and James Curran
Chris@16: // when:  July 2001, April 2013 - May 2013
Chris@16: 
Chris@16: #include <algorithm>
Chris@16: 
Chris@16: #include "boost/config.hpp"
Chris@101: #include <boost/type_index.hpp>
Chris@16: #include <boost/type_traits/remove_reference.hpp>
Chris@16: #include <boost/type_traits/decay.hpp>
Chris@101: #include <boost/type_traits/remove_cv.hpp>
Chris@16: #include <boost/type_traits/add_reference.hpp>
Chris@16: #include <boost/type_traits/is_reference.hpp>
Chris@16: #include <boost/type_traits/is_const.hpp>
Chris@16: #include <boost/throw_exception.hpp>
Chris@16: #include <boost/static_assert.hpp>
Chris@16: #include <boost/utility/enable_if.hpp>
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: #include <boost/type_traits/is_const.hpp>
Chris@101: #include <boost/mpl/if.hpp>
Chris@16: 
Chris@16: namespace boost
Chris@16: {
Chris@16:     class any
Chris@16:     {
Chris@16:     public: // structors
Chris@16: 
Chris@16:         any() BOOST_NOEXCEPT
Chris@16:           : content(0)
Chris@16:         {
Chris@16:         }
Chris@16: 
Chris@16:         template<typename ValueType>
Chris@16:         any(const ValueType & value)
Chris@101:           : content(new holder<
Chris@101:                 BOOST_DEDUCED_TYPENAME remove_cv<BOOST_DEDUCED_TYPENAME decay<const ValueType>::type>::type
Chris@101:             >(value))
Chris@16:         {
Chris@16:         }
Chris@16: 
Chris@16:         any(const any & other)
Chris@16:           : content(other.content ? other.content->clone() : 0)
Chris@16:         {
Chris@16:         }
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:         // Move constructor
Chris@16:         any(any&& other) BOOST_NOEXCEPT
Chris@16:           : content(other.content)
Chris@16:         {
Chris@16:             other.content = 0;
Chris@16:         }
Chris@16: 
Chris@16:         // Perfect forwarding of ValueType
Chris@16:         template<typename ValueType>
Chris@16:         any(ValueType&& value
Chris@16:             , typename boost::disable_if<boost::is_same<any&, ValueType> >::type* = 0 // disable if value has type `any&`
Chris@16:             , typename boost::disable_if<boost::is_const<ValueType> >::type* = 0) // disable if value has type `const ValueType&&`
Chris@16:           : content(new holder< typename decay<ValueType>::type >(static_cast<ValueType&&>(value)))
Chris@16:         {
Chris@16:         }
Chris@16: #endif
Chris@16: 
Chris@16:         ~any() BOOST_NOEXCEPT
Chris@16:         {
Chris@16:             delete content;
Chris@16:         }
Chris@16: 
Chris@16:     public: // modifiers
Chris@16: 
Chris@16:         any & swap(any & rhs) BOOST_NOEXCEPT
Chris@16:         {
Chris@16:             std::swap(content, rhs.content);
Chris@16:             return *this;
Chris@16:         }
Chris@16: 
Chris@16: 
Chris@16: #ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:         template<typename ValueType>
Chris@16:         any & operator=(const ValueType & rhs)
Chris@16:         {
Chris@16:             any(rhs).swap(*this);
Chris@16:             return *this;
Chris@16:         }
Chris@16: 
Chris@16:         any & operator=(any rhs)
Chris@16:         {
Chris@16:             any(rhs).swap(*this);
Chris@16:             return *this;
Chris@16:         }
Chris@16: 
Chris@16: #else 
Chris@16:         any & operator=(const any& rhs)
Chris@16:         {
Chris@16:             any(rhs).swap(*this);
Chris@16:             return *this;
Chris@16:         }
Chris@16: 
Chris@16:         // move assignement
Chris@16:         any & operator=(any&& rhs) BOOST_NOEXCEPT
Chris@16:         {
Chris@16:             rhs.swap(*this);
Chris@16:             any().swap(rhs);
Chris@16:             return *this;
Chris@16:         }
Chris@16: 
Chris@16:         // Perfect forwarding of ValueType
Chris@16:         template <class ValueType>
Chris@16:         any & operator=(ValueType&& rhs)
Chris@16:         {
Chris@16:             any(static_cast<ValueType&&>(rhs)).swap(*this);
Chris@16:             return *this;
Chris@16:         }
Chris@16: #endif
Chris@16: 
Chris@16:     public: // queries
Chris@16: 
Chris@16:         bool empty() const BOOST_NOEXCEPT
Chris@16:         {
Chris@16:             return !content;
Chris@16:         }
Chris@16: 
Chris@16:         void clear() BOOST_NOEXCEPT
Chris@16:         {
Chris@16:             any().swap(*this);
Chris@16:         }
Chris@16: 
Chris@101:         const boost::typeindex::type_info& type() const BOOST_NOEXCEPT
Chris@16:         {
Chris@101:             return content ? content->type() : boost::typeindex::type_id<void>().type_info();
Chris@16:         }
Chris@16: 
Chris@16: #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
Chris@16:     private: // types
Chris@16: #else
Chris@16:     public: // types (public so any_cast can be non-friend)
Chris@16: #endif
Chris@16: 
Chris@16:         class placeholder
Chris@16:         {
Chris@16:         public: // structors
Chris@16: 
Chris@16:             virtual ~placeholder()
Chris@16:             {
Chris@16:             }
Chris@16: 
Chris@16:         public: // queries
Chris@16: 
Chris@101:             virtual const boost::typeindex::type_info& type() const BOOST_NOEXCEPT = 0;
Chris@16: 
Chris@16:             virtual placeholder * clone() const = 0;
Chris@16: 
Chris@16:         };
Chris@16: 
Chris@16:         template<typename ValueType>
Chris@16:         class holder : public placeholder
Chris@16:         {
Chris@16:         public: // structors
Chris@16: 
Chris@16:             holder(const ValueType & value)
Chris@16:               : held(value)
Chris@16:             {
Chris@16:             }
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:             holder(ValueType&& value)
Chris@16:               : held(static_cast< ValueType&& >(value))
Chris@16:             {
Chris@16:             }
Chris@16: #endif
Chris@16:         public: // queries
Chris@16: 
Chris@101:             virtual const boost::typeindex::type_info& type() const BOOST_NOEXCEPT
Chris@16:             {
Chris@101:                 return boost::typeindex::type_id<ValueType>().type_info();
Chris@16:             }
Chris@16: 
Chris@16:             virtual placeholder * clone() const
Chris@16:             {
Chris@16:                 return new holder(held);
Chris@16:             }
Chris@16: 
Chris@16:         public: // representation
Chris@16: 
Chris@16:             ValueType held;
Chris@16: 
Chris@16:         private: // intentionally left unimplemented
Chris@16:             holder & operator=(const holder &);
Chris@16:         };
Chris@16: 
Chris@16: #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
Chris@16: 
Chris@16:     private: // representation
Chris@16: 
Chris@16:         template<typename ValueType>
Chris@16:         friend ValueType * any_cast(any *) BOOST_NOEXCEPT;
Chris@16: 
Chris@16:         template<typename ValueType>
Chris@16:         friend ValueType * unsafe_any_cast(any *) BOOST_NOEXCEPT;
Chris@16: 
Chris@16: #else
Chris@16: 
Chris@16:     public: // representation (public so any_cast can be non-friend)
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16:         placeholder * content;
Chris@16: 
Chris@16:     };
Chris@16:  
Chris@16:     inline void swap(any & lhs, any & rhs) BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         lhs.swap(rhs);
Chris@16:     }
Chris@16: 
Chris@101:     class BOOST_SYMBOL_VISIBLE bad_any_cast :
Chris@101: #ifndef BOOST_NO_RTTI
Chris@101:         public std::bad_cast
Chris@101: #else
Chris@101:         public std::exception
Chris@101: #endif
Chris@16:     {
Chris@16:     public:
Chris@16:         virtual const char * what() const BOOST_NOEXCEPT_OR_NOTHROW
Chris@16:         {
Chris@16:             return "boost::bad_any_cast: "
Chris@16:                    "failed conversion using boost::any_cast";
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     template<typename ValueType>
Chris@16:     ValueType * any_cast(any * operand) BOOST_NOEXCEPT
Chris@16:     {
Chris@101:         return operand && operand->type() == boost::typeindex::type_id<ValueType>()
Chris@101:             ? &static_cast<any::holder<BOOST_DEDUCED_TYPENAME remove_cv<ValueType>::type> *>(operand->content)->held
Chris@16:             : 0;
Chris@16:     }
Chris@16: 
Chris@16:     template<typename ValueType>
Chris@16:     inline const ValueType * any_cast(const any * operand) BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         return any_cast<ValueType>(const_cast<any *>(operand));
Chris@16:     }
Chris@16: 
Chris@16:     template<typename ValueType>
Chris@16:     ValueType any_cast(any & operand)
Chris@16:     {
Chris@16:         typedef BOOST_DEDUCED_TYPENAME remove_reference<ValueType>::type nonref;
Chris@16: 
Chris@16: 
Chris@16:         nonref * result = any_cast<nonref>(&operand);
Chris@16:         if(!result)
Chris@16:             boost::throw_exception(bad_any_cast());
Chris@16: 
Chris@16:         // Attempt to avoid construction of a temporary object in cases when 
Chris@16:         // `ValueType` is not a reference. Example:
Chris@16:         // `static_cast<std::string>(*result);` 
Chris@16:         // which is equal to `std::string(*result);`
Chris@16:         typedef BOOST_DEDUCED_TYPENAME boost::mpl::if_<
Chris@16:             boost::is_reference<ValueType>,
Chris@16:             ValueType,
Chris@16:             BOOST_DEDUCED_TYPENAME boost::add_reference<ValueType>::type
Chris@16:         >::type ref_type;
Chris@16: 
Chris@16:         return static_cast<ref_type>(*result);
Chris@16:     }
Chris@16: 
Chris@16:     template<typename ValueType>
Chris@16:     inline ValueType any_cast(const any & operand)
Chris@16:     {
Chris@16:         typedef BOOST_DEDUCED_TYPENAME remove_reference<ValueType>::type nonref;
Chris@16:         return any_cast<const nonref &>(const_cast<any &>(operand));
Chris@16:     }
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:     template<typename ValueType>
Chris@101:     inline ValueType any_cast(any&& operand)
Chris@16:     {
Chris@16:         BOOST_STATIC_ASSERT_MSG(
Chris@101:             boost::is_rvalue_reference<ValueType&&>::value /*true if ValueType is rvalue or just a value*/
Chris@16:             || boost::is_const< typename boost::remove_reference<ValueType>::type >::value,
Chris@16:             "boost::any_cast shall not be used for getting nonconst references to temporary objects" 
Chris@16:         );
Chris@101:         return any_cast<ValueType>(operand);
Chris@16:     }
Chris@16: #endif
Chris@16: 
Chris@16: 
Chris@16:     // Note: The "unsafe" versions of any_cast are not part of the
Chris@16:     // public interface and may be removed at any time. They are
Chris@16:     // required where we know what type is stored in the any and can't
Chris@16:     // use typeid() comparison, e.g., when our types may travel across
Chris@16:     // different shared libraries.
Chris@16:     template<typename ValueType>
Chris@16:     inline ValueType * unsafe_any_cast(any * operand) BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         return &static_cast<any::holder<ValueType> *>(operand->content)->held;
Chris@16:     }
Chris@16: 
Chris@16:     template<typename ValueType>
Chris@16:     inline const ValueType * unsafe_any_cast(const any * operand) BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         return unsafe_any_cast<ValueType>(const_cast<any *>(operand));
Chris@16:     }
Chris@16: }
Chris@16: 
Chris@16: // Copyright Kevlin Henney, 2000, 2001, 2002. All rights reserved.
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #endif