Chris@16: //-----------------------------------------------------------------------------
Chris@16: // boost variant/variant.hpp header file
Chris@16: // See http://www.boost.org for updates, documentation, and revision history.
Chris@16: //-----------------------------------------------------------------------------
Chris@16: //
Chris@16: // Copyright (c) 2002-2003 Eric Friedman, Itay Maman
Chris@101: // Copyright (c) 2012-2014 Antony Polukhin
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: // Thanks to Adam Romanek for providing patches for exception-disabled env.
Chris@16: 
Chris@16: #ifndef BOOST_VARIANT_VARIANT_HPP
Chris@16: #define BOOST_VARIANT_VARIANT_HPP
Chris@16: 
Chris@16: #include <cstddef> // for std::size_t
Chris@16: #include <new> // for placement new
Chris@16: 
Chris@101: #include "boost/type_index.hpp"
Chris@16: 
Chris@16: #include "boost/variant/detail/config.hpp"
Chris@16: #include "boost/mpl/aux_/value_wknd.hpp"
Chris@16: 
Chris@16: #include "boost/variant/variant_fwd.hpp"
Chris@16: #include "boost/variant/detail/backup_holder.hpp"
Chris@16: #include "boost/variant/detail/enable_recursive_fwd.hpp"
Chris@16: #include "boost/variant/detail/forced_return.hpp"
Chris@16: #include "boost/variant/detail/initializer.hpp"
Chris@16: #include "boost/variant/detail/make_variant_list.hpp"
Chris@16: #include "boost/variant/detail/over_sequence.hpp"
Chris@16: #include "boost/variant/detail/visitation_impl.hpp"
Chris@16: #include "boost/variant/detail/hash_variant.hpp"
Chris@16: 
Chris@16: #include "boost/variant/detail/generic_result_type.hpp"
Chris@16: #include "boost/variant/detail/move.hpp"
Chris@16: 
Chris@16: #include "boost/detail/no_exceptions_support.hpp"
Chris@16: #include "boost/detail/reference_content.hpp"
Chris@16: #include "boost/aligned_storage.hpp"
Chris@16: #include "boost/blank.hpp"
Chris@16: #include "boost/math/common_factor_ct.hpp"
Chris@16: #include "boost/static_assert.hpp"
Chris@16: #include "boost/preprocessor/cat.hpp"
Chris@16: #include "boost/preprocessor/repeat.hpp"
Chris@16: #include "boost/type_traits/alignment_of.hpp"
Chris@16: #include "boost/type_traits/add_const.hpp"
Chris@16: #include "boost/type_traits/has_nothrow_constructor.hpp"
Chris@16: #include "boost/type_traits/has_nothrow_copy.hpp"
Chris@101: #include "boost/type_traits/is_nothrow_move_assignable.hpp"
Chris@16: #include "boost/type_traits/is_nothrow_move_constructible.hpp"
Chris@16: #include "boost/type_traits/is_const.hpp"
Chris@16: #include "boost/type_traits/is_same.hpp"
Chris@16: #include "boost/type_traits/is_rvalue_reference.hpp"
Chris@16: #include "boost/utility/enable_if.hpp"
Chris@16: #include "boost/utility/declval.hpp"
Chris@16: #include "boost/variant/recursive_wrapper_fwd.hpp"
Chris@16: #include "boost/variant/static_visitor.hpp"
Chris@16: 
Chris@16: #include "boost/mpl/assert.hpp"
Chris@16: #include "boost/mpl/begin_end.hpp"
Chris@16: #include "boost/mpl/bool.hpp"
Chris@16: #include "boost/mpl/deref.hpp"
Chris@16: #include "boost/mpl/empty.hpp"
Chris@16: #include "boost/mpl/eval_if.hpp"
Chris@16: #include "boost/mpl/find_if.hpp"
Chris@16: #include "boost/mpl/fold.hpp"
Chris@16: #include "boost/mpl/front.hpp"
Chris@16: #include "boost/mpl/identity.hpp"
Chris@16: #include "boost/mpl/if.hpp"
Chris@16: #include "boost/mpl/int.hpp"
Chris@16: #include "boost/mpl/is_sequence.hpp"
Chris@16: #include "boost/mpl/iterator_range.hpp"
Chris@16: #include "boost/mpl/iter_fold_if.hpp"
Chris@16: #include "boost/mpl/logical.hpp"
Chris@16: #include "boost/mpl/max_element.hpp"
Chris@16: #include "boost/mpl/next.hpp"
Chris@16: #include "boost/mpl/not.hpp"
Chris@16: #include "boost/mpl/pair.hpp"
Chris@16: #include "boost/mpl/protect.hpp"
Chris@16: #include "boost/mpl/push_front.hpp"
Chris@16: #include "boost/mpl/same_as.hpp"
Chris@16: #include "boost/mpl/size_t.hpp"
Chris@16: #include "boost/mpl/sizeof.hpp"
Chris@16: #include "boost/mpl/transform.hpp"
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // Implementation Macros:
Chris@16: //
Chris@16: // BOOST_VARIANT_VISITATION_UNROLLING_LIMIT
Chris@16: //   Defined in boost/variant/detail/visitation_impl.hpp.
Chris@16: //
Chris@16: // BOOST_VARIANT_MINIMIZE_SIZE
Chris@16: //   When #defined, implementation employs all known means to minimize the
Chris@16: //   size of variant obje   cts. However, often unsuccessful due to alignment
Chris@16: //   issues, and potentially harmful to runtime speed, so not enabled by
Chris@16: //   default. (TODO: Investigate further.)
Chris@16: 
Chris@16: #if defined(BOOST_VARIANT_MINIMIZE_SIZE)
Chris@16: #   include <climits> // for SCHAR_MAX
Chris@16: #   include "boost/mpl/eval_if.hpp"
Chris@16: #   include "boost/mpl/equal_to.hpp"
Chris@16: #   include "boost/mpl/identity.hpp"
Chris@16: #   include "boost/mpl/int.hpp"
Chris@16: #   include "boost/mpl/if.hpp"
Chris@16: #   include "boost/mpl/less.hpp"
Chris@16: #   include "boost/mpl/long.hpp"
Chris@16: #   include "boost/mpl/O1_size.hpp"
Chris@16: #endif
Chris@16: 
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: namespace detail { namespace variant {
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) metafunction max_value
Chris@16: //
Chris@16: // Finds the maximum value of the unary metafunction F over Sequence.
Chris@16: //
Chris@16: template <typename Sequence, typename F>
Chris@16: struct max_value
Chris@16: {
Chris@16: private: // helpers, for metafunction result (below)
Chris@16: 
Chris@16:     typedef typename mpl::transform1<Sequence, F>::type transformed_;
Chris@16:     typedef typename mpl::max_element<transformed_
Chris@16:           
Chris@16:         >::type max_it;
Chris@16: 
Chris@16: public: // metafunction result
Chris@16: 
Chris@16:     typedef typename mpl::deref<max_it>::type
Chris@16:         type;
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: struct add_alignment
Chris@16: {
Chris@16:     template <typename State, typename Item>
Chris@16:     struct apply
Chris@16:         : mpl::size_t<
Chris@16:               ::boost::math::static_lcm<
Chris@16:                   BOOST_MPL_AUX_VALUE_WKND(State)::value
Chris@16:                 , ::boost::alignment_of<Item>::value
Chris@16:                 >::value
Chris@16:             >
Chris@16:     {};
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) metafunction find_fallback_type
Chris@16: //
Chris@16: // Provides a fallback (i.e., nothrow default-constructible) type from the
Chris@16: // specified sequence, or no_fallback_type if not found.
Chris@16: //
Chris@16: // This implementation is designed to prefer boost::blank over other potential
Chris@16: // fallback types, regardless of its position in the specified sequence.
Chris@16: //
Chris@16: 
Chris@16: class no_fallback_type;
Chris@16: 
Chris@16: struct find_fallback_type_pred
Chris@16: {
Chris@16:     template <typename Iterator>
Chris@16:     struct apply
Chris@16:     {
Chris@16:     private:
Chris@16:         typedef typename mpl::deref<Iterator>::type t_;
Chris@16: 
Chris@16:     public:
Chris@16:         typedef mpl::not_< has_nothrow_constructor<t_> > type;
Chris@16:     };
Chris@16: };
Chris@16: 
Chris@16: template <typename Types>
Chris@16: struct find_fallback_type
Chris@16: {
Chris@16: private: // helpers, for metafunction result (below)
Chris@16: 
Chris@16:     typedef typename mpl::end<Types>::type end_it;
Chris@16: 
Chris@16:     // [Find the first suitable fallback type...]
Chris@16: 
Chris@16:     typedef typename mpl::iter_fold_if<
Chris@16:           Types
Chris@16:         , mpl::int_<0>, mpl::protect< mpl::next<> >
Chris@16:         , mpl::protect< find_fallback_type_pred >
Chris@16:         >::type first_result_;
Chris@16: 
Chris@16:     typedef typename first_result_::first first_result_index;
Chris@16:     typedef typename first_result_::second first_result_it;
Chris@16: 
Chris@16:     // [...now search the rest of the sequence for boost::blank...]
Chris@16: 
Chris@16:     typedef typename mpl::iter_fold_if<
Chris@16:           mpl::iterator_range< first_result_it,end_it >
Chris@16:         , first_result_index, mpl::protect< mpl::next<> >
Chris@16:         , mpl::protect< mpl::not_same_as<boost::blank> >
Chris@16:         >::type second_result_;
Chris@16: 
Chris@16:     typedef typename second_result_::second second_result_it;
Chris@16: 
Chris@16: public: // metafunction result
Chris@16: 
Chris@16:     // [...and return the results of the search:]
Chris@16:     typedef typename mpl::eval_if<
Chris@16:           is_same< second_result_it,end_it >
Chris@16:         , mpl::if_<
Chris@16:               is_same< first_result_it,end_it >
Chris@16:             , mpl::pair< no_fallback_type,no_fallback_type >
Chris@16:             , first_result_
Chris@16:             >
Chris@16:         , mpl::identity< second_result_ >
Chris@16:         >::type type;
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_NOEXCEPT
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@101: // (detail) metafunction is_variant_move_noexcept_constructible
Chris@16: //
Chris@16: // Returns true_type if all the types are nothrow move constructible.
Chris@16: //
Chris@16: template <class Types>
Chris@101: struct is_variant_move_noexcept_constructible {
Chris@16:     typedef typename boost::mpl::find_if<
Chris@16:         Types, mpl::not_<boost::is_nothrow_move_constructible<boost::mpl::_1> >
Chris@16:     >::type iterator_t;
Chris@16: 
Chris@16:     typedef typename boost::mpl::end<Types>::type end_t;
Chris@16:     typedef typename boost::is_same<
Chris@16:         iterator_t, end_t
Chris@16:     >::type type;
Chris@16: };
Chris@101: 
Chris@101: ///////////////////////////////////////////////////////////////////////////////
Chris@101: // (detail) metafunction is_variant_move_noexcept_assignable
Chris@101: //
Chris@101: // Returns true_type if all the types are nothrow move constructible.
Chris@101: //
Chris@101: template <class Types>
Chris@101: struct is_variant_move_noexcept_assignable {
Chris@101:     typedef typename boost::mpl::find_if<
Chris@101:         Types, mpl::not_<boost::is_nothrow_move_assignable<boost::mpl::_1> >
Chris@101:     >::type iterator_t;
Chris@101: 
Chris@101:     typedef typename boost::mpl::end<Types>::type end_t;
Chris@101:     typedef typename boost::is_same<
Chris@101:         iterator_t, end_t
Chris@101:     >::type type;
Chris@101: };
Chris@16: #endif // BOOST_NO_CXX11_NOEXCEPT
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) metafunction make_storage
Chris@16: //
Chris@16: // Provides an aligned storage type capable of holding any of the types
Chris@16: // specified in the given type-sequence.
Chris@16: //
Chris@16: 
Chris@16: template <typename Types, typename NeverUsesBackupFlag>
Chris@16: struct make_storage
Chris@16: {
Chris@16: private: // helpers, for metafunction result (below)
Chris@16: 
Chris@16:     typedef typename mpl::eval_if<
Chris@16:           NeverUsesBackupFlag
Chris@16:         , mpl::identity< Types >
Chris@16:         , mpl::push_front<
Chris@16:               Types, backup_holder<void*>
Chris@16:             >
Chris@16:         >::type types;
Chris@16: 
Chris@16:     typedef typename max_value<
Chris@16:           types, mpl::sizeof_<mpl::_1>
Chris@16:         >::type max_size;
Chris@16: 
Chris@16: #if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0551))
Chris@16: 
Chris@16:     typedef typename mpl::fold<
Chris@16:           types
Chris@16:         , mpl::size_t<1>
Chris@16:         , add_alignment
Chris@16:         >::type max_alignment;
Chris@16: 
Chris@16: #else // borland
Chris@16: 
Chris@16:     // temporary workaround -- use maximal alignment
Chris@16:     typedef mpl::size_t< -1 > max_alignment;
Chris@16: 
Chris@16: #endif // borland workaround
Chris@16: 
Chris@16: public: // metafunction result
Chris@16: 
Chris@16:     typedef ::boost::aligned_storage<
Chris@16:           BOOST_MPL_AUX_VALUE_WKND(max_size)::value
Chris@16:         , BOOST_MPL_AUX_VALUE_WKND(max_alignment)::value
Chris@16:         > type;
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class destroyer
Chris@16: //
Chris@16: // Internal visitor that destroys the value it visits.
Chris@16: //
Chris@16: struct destroyer
Chris@16:     : public static_visitor<>
Chris@16: {
Chris@16: public: // visitor interfaces
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@101:     internal_visit(T& operand, int) const BOOST_NOEXCEPT
Chris@16:     {
Chris@101:         operand.~T(); // must be noexcept
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0551)) || \
Chris@16:     BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600))
Chris@16:         operand; // suppresses warnings
Chris@16: #endif
Chris@16: 
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class template known_get
Chris@16: //
Chris@16: // Visitor that returns a reference to content of the specified type.
Chris@16: //
Chris@16: // Precondition: visited variant MUST contain logical content of type T.
Chris@16: //
Chris@16: template <typename T>
Chris@16: class known_get
Chris@16:     : public static_visitor<T&>
Chris@16: {
Chris@16: 
Chris@16: public: // visitor interface
Chris@16: 
Chris@16:     T& operator()(T& operand) const BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         return operand;
Chris@16:     }
Chris@16: 
Chris@16:     template <typename U>
Chris@16:     T& operator()(U&) const
Chris@16:     {
Chris@16:         // logical error to be here: see precondition above
Chris@16:         return ::boost::detail::variant::forced_return< T& >();
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class copy_into
Chris@16: //
Chris@16: // Internal visitor that copies the value it visits into the given buffer.
Chris@16: //
Chris@16: class copy_into
Chris@16:     : public static_visitor<>
Chris@16: {
Chris@16: private: // representation
Chris@16: 
Chris@16:     void* storage_;
Chris@16: 
Chris@16: public: // structors
Chris@16: 
Chris@16:     explicit copy_into(void* storage) BOOST_NOEXCEPT
Chris@16:         : storage_(storage)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16: public: // internal visitor interface
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@16:     internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const
Chris@16:     {
Chris@16:         new(storage_) T( operand.get() );
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@16:     internal_visit(const boost::detail::variant::backup_holder<T>& operand, long) const
Chris@16:     {
Chris@16:         new(storage_) T( operand.get() );
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@16:     internal_visit(const T& operand, int) const
Chris@16:     {
Chris@16:         new(storage_) T(operand);
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class move_into
Chris@16: //
Chris@16: // Internal visitor that moves the value it visits into the given buffer.
Chris@16: //
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16: class move_into
Chris@16:     : public static_visitor<>
Chris@16: {
Chris@16: private: // representation
Chris@16: 
Chris@16:     void* storage_;
Chris@16: 
Chris@16: public: // structors
Chris@16: 
Chris@16:     explicit move_into(void* storage) BOOST_NOEXCEPT
Chris@16:         : storage_(storage)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16: public: // internal visitor interface
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@16:     internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const
Chris@16:     {
Chris@16:         new(storage_) T( ::boost::detail::variant::move(operand.get()) );
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@16:     internal_visit(T& operand, int) const BOOST_NOEXCEPT_IF(BOOST_NOEXCEPT_EXPR(T(boost::declval<T>())))
Chris@16:     {
Chris@16:         new(storage_) T(::boost::detail::variant::move(operand));
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: };
Chris@16: #endif
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class assign_storage
Chris@16: //
Chris@16: // Internal visitor that assigns the given storage (which must be a
Chris@16: // constructed value of the same type) to the value it visits.
Chris@16: //
Chris@16: struct assign_storage
Chris@16:     : public static_visitor<>
Chris@16: {
Chris@16: private: // representation
Chris@16: 
Chris@16:     const void* rhs_storage_;
Chris@16: 
Chris@16: public: // structors
Chris@16: 
Chris@16:     explicit assign_storage(const void* rhs_storage) BOOST_NOEXCEPT
Chris@16:         : rhs_storage_(rhs_storage)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16: public: // internal visitor interfaces
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@16:     internal_visit(backup_holder<T>& lhs_content, long) const
Chris@16:     {
Chris@16:         lhs_content.get()
Chris@16:             = static_cast< const backup_holder<T>* >(rhs_storage_)->get();
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@16:     internal_visit(const backup_holder<T>& lhs_content, long) const
Chris@16:     {
Chris@16:         lhs_content.get()
Chris@16:             = static_cast< const backup_holder<T>* >(rhs_storage_)->get();
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@16:     internal_visit(T& lhs_content, int) const
Chris@16:     {
Chris@16:         // NOTE TO USER :
Chris@16:         // Compile error here indicates one of variant's bounded types does
Chris@16:         // not meet the requirements of the Assignable concept. Thus,
Chris@16:         // variant is not Assignable.
Chris@16:         //
Chris@16:         // Hint: Are any of the bounded types const-qualified or references?
Chris@16:         //
Chris@16:         lhs_content = *static_cast< const T* >(rhs_storage_);
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class move_storage
Chris@16: //
Chris@16: // Internal visitor that moves the given storage (which must be a
Chris@16: // constructed value of the same type) to the value it visits.
Chris@16: //
Chris@16: struct move_storage
Chris@16:     : public static_visitor<>
Chris@16: {
Chris@16: private: // representation
Chris@16: 
Chris@16:     void* rhs_storage_;
Chris@16: 
Chris@16: public: // structors
Chris@16: 
Chris@16:     explicit move_storage(void* rhs_storage) BOOST_NOEXCEPT
Chris@16:         : rhs_storage_(rhs_storage)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16: public: // internal visitor interfaces
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@16:     internal_visit(backup_holder<T>& lhs_content, long) const
Chris@16:     {
Chris@16:         lhs_content.get()
Chris@16:             = ::boost::detail::variant::move(static_cast<backup_holder<T>* >(rhs_storage_)->get());
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@16:     internal_visit(const backup_holder<T>& lhs_content, long) const
Chris@16:     {
Chris@16:         lhs_content.get()
Chris@16:             = ::boost::detail::variant::move(static_cast<backup_holder<T>* >(rhs_storage_)->get());
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@16:     internal_visit(T& lhs_content, int) const
Chris@16:     {
Chris@16:         // NOTE TO USER :
Chris@16:         // Compile error here indicates one of variant's bounded types does
Chris@16:         // not meet the requirements of the Assignable concept. Thus,
Chris@16:         // variant is not Assignable.
Chris@16:         //
Chris@16:         // Hint: Are any of the bounded types const-qualified or references?
Chris@16:         //
Chris@16:         lhs_content = ::boost::detail::variant::move(*static_cast<T* >(rhs_storage_));
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class direct_assigner
Chris@16: //
Chris@16: // Generic static visitor that: if and only if the visited value is of the
Chris@16: // specified type, assigns the given value to the visited value and returns
Chris@16: // true; else returns false.
Chris@16: //
Chris@16: template <typename T>
Chris@16: class direct_assigner
Chris@16:     : public static_visitor<bool>
Chris@16: {
Chris@16: private: // representation
Chris@16: 
Chris@16:     const T& rhs_;
Chris@16: 
Chris@16: public: // structors
Chris@16: 
Chris@16:     explicit direct_assigner(const T& rhs) BOOST_NOEXCEPT
Chris@16:         : rhs_(rhs)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16: public: // visitor interface
Chris@16: 
Chris@16:     bool operator()(T& lhs)
Chris@16:     {
Chris@16:         lhs = rhs_;
Chris@16:         return true;
Chris@16:     }
Chris@16: 
Chris@16:     template <typename U>
Chris@16:     bool operator()(U&) BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         return false;
Chris@16:     }
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600))
Chris@16: private:
Chris@16:     // silence MSVC warning C4512: assignment operator could not be generated
Chris@16:     direct_assigner& operator= (direct_assigner const&);
Chris@16: #endif
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class direct_mover
Chris@16: //
Chris@16: // Generic static visitor that: if and only if the visited value is of the
Chris@16: // specified type, move assigns the given value to the visited value and returns
Chris@16: // true; else returns false.
Chris@16: //
Chris@16: template <typename T>
Chris@16: class direct_mover
Chris@16:     : public static_visitor<bool>
Chris@16: {
Chris@16: private: // representation
Chris@16: 
Chris@16:     T& rhs_;
Chris@16: 
Chris@16: public: // structors
Chris@16: 
Chris@16:     explicit direct_mover(T& rhs) BOOST_NOEXCEPT
Chris@16:         : rhs_(rhs)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16: public: // visitor interface
Chris@16: 
Chris@16:     bool operator()(T& lhs)
Chris@16:     {
Chris@16:         lhs = ::boost::detail::variant::move(rhs_);
Chris@16:         return true;
Chris@16:     }
Chris@16: 
Chris@16:     template <typename U>
Chris@16:     bool operator()(U&) BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         return false;
Chris@16:     }
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600))
Chris@16: private:
Chris@16:     // silence MSVC warning C4512: assignment operator could not be generated
Chris@16:     direct_mover& operator= (direct_mover const&);
Chris@16: #endif
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class backup_assigner
Chris@16: //
Chris@16: // Internal visitor that "assigns" the given value to the visited value,
Chris@16: // using backup to recover if the destroy-copy sequence fails.
Chris@16: //
Chris@16: // NOTE: This needs to be a friend of variant, as it needs access to
Chris@16: // indicate_which, indicate_backup_which, etc.
Chris@16: //
Chris@16: template <typename Variant>
Chris@16: class backup_assigner
Chris@16:     : public static_visitor<>
Chris@16: {
Chris@16: private: // representation
Chris@16: 
Chris@16:     Variant& lhs_;
Chris@16:     int rhs_which_;
Chris@16:     const void* rhs_content_;
Chris@16:     void (*copy_rhs_content_)(void*, const void*);
Chris@16: 
Chris@16: public: // structors
Chris@16: 
Chris@16:     template<class RhsT>
Chris@16:     backup_assigner(Variant& lhs, int rhs_which, const RhsT& rhs_content)
Chris@16:         : lhs_(lhs)
Chris@16:         , rhs_which_(rhs_which)
Chris@16:         , rhs_content_(&rhs_content)
Chris@16:         , copy_rhs_content_(&construct_impl<RhsT>)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16: private: // helpers, for visitor interface (below)
Chris@16: 
Chris@16:     template<class RhsT>
Chris@16:     static void construct_impl(void* addr, const void* obj)
Chris@16:     {
Chris@16:         new(addr) RhsT(*static_cast<const RhsT*>(obj));
Chris@16:     }
Chris@16: 
Chris@16:     template <typename LhsT>
Chris@16:     void backup_assign_impl(
Chris@101:           backup_holder<LhsT>& lhs_content
Chris@101:         , mpl::false_ // is_nothrow_move_constructible
Chris@101:         , long
Chris@101:         )
Chris@101:     {
Chris@101:         // Move lhs content to backup...
Chris@101:         backup_holder<LhsT> backup_lhs_content(0);
Chris@101:         backup_lhs_content.swap(lhs_content); // nothrow
Chris@101: 
Chris@101:         // ...destroy lhs content...
Chris@101:         lhs_content.~backup_holder<LhsT>(); // nothrow
Chris@101: 
Chris@101:         BOOST_TRY
Chris@101:         {
Chris@101:             // ...and attempt to copy rhs content into lhs storage:
Chris@101:             copy_rhs_content_(lhs_.storage_.address(), rhs_content_);
Chris@101:         }
Chris@101:         BOOST_CATCH (...)
Chris@101:         {
Chris@101:             // In case of failure, copy backup pointer to lhs storage...
Chris@101:             new(lhs_.storage_.address())
Chris@101:                     backup_holder<LhsT>( 0 ); // nothrow
Chris@101: 
Chris@101:             static_cast<backup_holder<LhsT>* >(lhs_.storage_.address())
Chris@101:                     ->swap(backup_lhs_content); // nothrow
Chris@101: 
Chris@101:             // ...and rethrow:
Chris@101:             BOOST_RETHROW;
Chris@101:         }
Chris@101:         BOOST_CATCH_END
Chris@101: 
Chris@101:         // In case of success, indicate new content type:
Chris@101:         lhs_.indicate_which(rhs_which_); // nothrow
Chris@101:     }
Chris@101: 
Chris@101:     template <typename LhsT>
Chris@101:     void backup_assign_impl(
Chris@16:           LhsT& lhs_content
Chris@16:         , mpl::true_ // is_nothrow_move_constructible
Chris@101:         , int
Chris@16:         )
Chris@16:     {
Chris@16:         // Move lhs content to backup...
Chris@16:         LhsT backup_lhs_content(
Chris@16:               ::boost::detail::variant::move(lhs_content)
Chris@16:             ); // nothrow
Chris@16: 
Chris@16:         // ...destroy lhs content...
Chris@16:         lhs_content.~LhsT(); // nothrow
Chris@16: 
Chris@16:         BOOST_TRY
Chris@16:         {
Chris@16:             // ...and attempt to copy rhs content into lhs storage:
Chris@16:             copy_rhs_content_(lhs_.storage_.address(), rhs_content_);
Chris@16:         }
Chris@16:         BOOST_CATCH (...)
Chris@16:         {
Chris@16:             // In case of failure, restore backup content to lhs storage...
Chris@16:             new(lhs_.storage_.address())
Chris@16:                 LhsT(
Chris@16:                       ::boost::detail::variant::move(backup_lhs_content)
Chris@16:                     ); // nothrow
Chris@16: 
Chris@16:             // ...and rethrow:
Chris@16:             BOOST_RETHROW;
Chris@16:         }
Chris@16:         BOOST_CATCH_END
Chris@16: 
Chris@16:         // In case of success, indicate new content type:
Chris@16:         lhs_.indicate_which(rhs_which_); // nothrow
Chris@16:     }
Chris@16: 
Chris@16:     template <typename LhsT>
Chris@16:     void backup_assign_impl(
Chris@16:           LhsT& lhs_content
Chris@16:         , mpl::false_ // is_nothrow_move_constructible
Chris@101:         , int
Chris@16:         )
Chris@16:     {
Chris@16:         // Backup lhs content...
Chris@16:         LhsT* backup_lhs_ptr = new LhsT(lhs_content);
Chris@16: 
Chris@16:         // ...destroy lhs content...
Chris@16:         lhs_content.~LhsT(); // nothrow
Chris@16: 
Chris@16:         BOOST_TRY
Chris@16:         {
Chris@16:             // ...and attempt to copy rhs content into lhs storage:
Chris@16:             copy_rhs_content_(lhs_.storage_.address(), rhs_content_);
Chris@16:         }
Chris@16:         BOOST_CATCH (...)
Chris@16:         {
Chris@16:             // In case of failure, copy backup pointer to lhs storage...
Chris@16:             new(lhs_.storage_.address())
Chris@16:                 backup_holder<LhsT>( backup_lhs_ptr ); // nothrow
Chris@16: 
Chris@16:             // ...indicate now using backup...
Chris@16:             lhs_.indicate_backup_which( lhs_.which() ); // nothrow
Chris@16: 
Chris@16:             // ...and rethrow:
Chris@16:             BOOST_RETHROW;
Chris@16:         }
Chris@16:         BOOST_CATCH_END
Chris@16: 
Chris@16:         // In case of success, indicate new content type...
Chris@16:         lhs_.indicate_which(rhs_which_); // nothrow
Chris@16: 
Chris@16:         // ...and delete backup:
Chris@16:         delete backup_lhs_ptr; // nothrow
Chris@16:     }
Chris@16: 
Chris@16: public: // visitor interface
Chris@16: 
Chris@16:     template <typename LhsT>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@16:     internal_visit(LhsT& lhs_content, int)
Chris@16:     {
Chris@16:         typedef typename is_nothrow_move_constructible<LhsT>::type
Chris@16:             nothrow_move;
Chris@16: 
Chris@101:         backup_assign_impl( lhs_content, nothrow_move(), 1L);
Chris@16: 
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600))
Chris@16: private:
Chris@16:     // silence MSVC warning C4512: assignment operator could not be generated
Chris@16:     backup_assigner& operator= (backup_assigner const&);
Chris@16: #endif
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class swap_with
Chris@16: //
Chris@16: // Visitor that swaps visited value with content of given variant.
Chris@16: //
Chris@16: // Precondition: Given variant MUST have same logical type as visited value.
Chris@16: //
Chris@16: template <typename Variant>
Chris@16: struct swap_with
Chris@16:     : public static_visitor<>
Chris@16: {
Chris@16: private: // representation
Chris@16: 
Chris@16:     Variant& toswap_;
Chris@16: 
Chris@16: public: // structors
Chris@16: 
Chris@101:     explicit swap_with(Variant& toswap) BOOST_NOEXCEPT
Chris@16:         : toswap_(toswap)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16: public: // internal visitor interfaces
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     void operator()(T& operand) const
Chris@16:     {
Chris@16:         // Since the precondition ensures types are same, get T...
Chris@16:         known_get<T> getter;
Chris@16:         T& other = toswap_.apply_visitor(getter);
Chris@16: 
Chris@16:         // ...and swap:
Chris@16:         ::boost::detail::variant::move_swap( operand, other );
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     swap_with& operator=(const swap_with&);
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class reflect
Chris@16: //
Chris@16: // Generic static visitor that performs a typeid on the value it visits.
Chris@16: //
Chris@16: 
Chris@16: class reflect
Chris@101:     : public static_visitor<const boost::typeindex::type_info&>
Chris@16: {
Chris@16: public: // visitor interfaces
Chris@16: 
Chris@16:     template <typename T>
Chris@101:     const boost::typeindex::type_info& operator()(const T&) const BOOST_NOEXCEPT
Chris@16:     {
Chris@101:         return boost::typeindex::type_id<T>().type_info();
Chris@16:     }
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class comparer
Chris@16: //
Chris@16: // Generic static visitor that compares the content of the given lhs variant
Chris@16: // with the visited rhs content using Comp.
Chris@16: //
Chris@16: // Precondition: lhs.which() == rhs.which()
Chris@16: //
Chris@16: template <typename Variant, typename Comp>
Chris@16: class comparer
Chris@16:     : public static_visitor<bool>
Chris@16: {
Chris@16: private: // representation
Chris@16: 
Chris@16:     const Variant& lhs_;
Chris@16: 
Chris@16: public: // structors
Chris@16: 
Chris@16:     explicit comparer(const Variant& lhs) BOOST_NOEXCEPT
Chris@16:         : lhs_(lhs)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16: public: // visitor interfaces
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     bool operator()(const T& rhs_content) const
Chris@16:     {
Chris@16:         // Since the precondition ensures lhs and rhs types are same, get T...
Chris@16:         known_get<const T> getter;
Chris@16:         const T& lhs_content = lhs_.apply_visitor(getter);
Chris@16: 
Chris@16:         // ...and compare lhs and rhs contents:
Chris@16:         return Comp()(lhs_content, rhs_content);
Chris@16:     }
Chris@16: 
Chris@16: private:
Chris@16:     comparer& operator=(const comparer&);
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class equal_comp
Chris@16: //
Chris@16: // Generic function object compares lhs with rhs using operator==.
Chris@16: //
Chris@16: struct equal_comp
Chris@16: {
Chris@16:     template <typename T>
Chris@16:     bool operator()(const T& lhs, const T& rhs) const
Chris@16:     {
Chris@16:         return lhs == rhs;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class less_comp
Chris@16: //
Chris@16: // Generic function object compares lhs with rhs using operator<.
Chris@16: //
Chris@16: struct less_comp
Chris@16: {
Chris@16:     template <typename T>
Chris@16:     bool operator()(const T& lhs, const T& rhs) const
Chris@16:     {
Chris@16:         return lhs < rhs;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // (detail) class template invoke_visitor
Chris@16: //
Chris@16: // Internal visitor that invokes the given visitor using:
Chris@16: //  * for wrappers (e.g., recursive_wrapper), the wrapper's held value.
Chris@16: //  * for all other values, the value itself.
Chris@16: //
Chris@16: template <typename Visitor>
Chris@16: class invoke_visitor
Chris@16: {
Chris@16: private: // representation
Chris@16: 
Chris@16:     Visitor& visitor_;
Chris@16: 
Chris@16: public: // visitor typedefs
Chris@16: 
Chris@16:     typedef typename Visitor::result_type
Chris@16:         result_type;
Chris@16: 
Chris@16: public: // structors
Chris@16: 
Chris@16:     explicit invoke_visitor(Visitor& visitor) BOOST_NOEXCEPT
Chris@16:         : visitor_(visitor)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16: #if !defined(BOOST_NO_VOID_RETURNS)
Chris@16: 
Chris@16: public: // internal visitor interfaces
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     result_type internal_visit(T& operand, int)
Chris@16:     {
Chris@16:         return visitor_(operand);
Chris@16:     }
Chris@16: 
Chris@16: #   if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0564))
Chris@16:     template <typename T>
Chris@16:     result_type internal_visit(const T& operand, int)
Chris@16:     {
Chris@16:         return visitor_(operand);
Chris@16:     }
Chris@16: #   endif
Chris@16: 
Chris@16: #else // defined(BOOST_NO_VOID_RETURNS)
Chris@16: 
Chris@16: private: // helpers, for internal visitor interfaces (below)
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
Chris@16:     visit_impl(T& operand, mpl::false_)
Chris@16:     {
Chris@16:         return visitor_(operand);
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@16:     visit_impl(T& operand, mpl::true_)
Chris@16:     {
Chris@16:         visitor_(operand);
Chris@16:         BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:     }
Chris@16: 
Chris@16: public: // internal visitor interfaces
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
Chris@16:     internal_visit(T& operand, int)
Chris@16:     {
Chris@16:         typedef typename is_same<result_type, void>::type
Chris@16:             has_void_result_type;
Chris@16: 
Chris@16:         return visit_impl(operand, has_void_result_type());
Chris@16:     }
Chris@16: 
Chris@16: #endif // BOOST_NO_VOID_RETURNS) workaround
Chris@16: 
Chris@16: public: // internal visitor interfaces, cont.
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
Chris@16:     internal_visit(boost::recursive_wrapper<T>& operand, long)
Chris@16:     {
Chris@16:         return internal_visit( operand.get(), 1L );
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
Chris@16:     internal_visit(const boost::recursive_wrapper<T>& operand, long)
Chris@16:     {
Chris@16:         return internal_visit( operand.get(), 1L );
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
Chris@16:     internal_visit(boost::detail::reference_content<T>& operand, long)
Chris@16:     {
Chris@16:         return internal_visit( operand.get(), 1L );
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
Chris@16:     internal_visit(const boost::detail::reference_content<T>& operand, long)
Chris@16:     {
Chris@16:         return internal_visit( operand.get(), 1L );
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
Chris@16:     internal_visit(boost::detail::variant::backup_holder<T>& operand, long)
Chris@16:     {
Chris@16:         return internal_visit( operand.get(), 1L );
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:         BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(result_type)
Chris@16:     internal_visit(const boost::detail::variant::backup_holder<T>& operand, long)
Chris@16:     {
Chris@16:         return internal_visit( operand.get(), 1L );
Chris@16:     }
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600))
Chris@16: private:
Chris@16:     // silence MSVC warning C4512: assignment operator could not be generated
Chris@16:     invoke_visitor& operator= (invoke_visitor const&);
Chris@16: #endif
Chris@16: };
Chris@16: 
Chris@16: }} // namespace detail::variant
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // class template variant (concept inspired by Andrei Alexandrescu)
Chris@16: //
Chris@16: // See docs and boost/variant/variant_fwd.hpp for more information.
Chris@16: //
Chris@16: template <
Chris@16:       typename T0_
Chris@16:     , BOOST_VARIANT_ENUM_SHIFTED_PARAMS(typename T)
Chris@16:     >
Chris@16: class variant
Chris@16: {
Chris@16: private: // helpers, for typedefs (below)
Chris@16: 
Chris@16:     typedef variant wknd_self_t;
Chris@16: 
Chris@16:     struct is_recursive_
Chris@16:         : detail::variant::is_recursive_flag<T0_>
Chris@16:     {
Chris@16:     };
Chris@16: 
Chris@16:     typedef typename mpl::eval_if<
Chris@16:           is_recursive_
Chris@16:         , T0_
Chris@16:         , mpl::identity< T0_ >
Chris@16:         >::type unwrapped_T0_;
Chris@16: 
Chris@16:     struct is_sequence_based_
Chris@16:         : detail::variant::is_over_sequence<unwrapped_T0_>
Chris@16:     {
Chris@16:     };
Chris@16: 
Chris@16: #if !defined(BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT)
Chris@16: 
Chris@16: private: // helpers, for typedefs (below)
Chris@16: 
Chris@16:     typedef typename mpl::eval_if<
Chris@16:           is_sequence_based_
Chris@16:         , unwrapped_T0_ // over_sequence<...>::type
Chris@16:         , detail::variant::make_variant_list<
Chris@16:               unwrapped_T0_
Chris@16:             , BOOST_VARIANT_ENUM_SHIFTED_PARAMS(T)
Chris@16:             >
Chris@16:         >::type specified_types;
Chris@16: 
Chris@16:     BOOST_STATIC_ASSERT((
Chris@16:           ::boost::mpl::not_< mpl::empty<specified_types> >::value
Chris@16:         ));
Chris@16: 
Chris@16:     typedef typename mpl::eval_if<
Chris@16:           is_recursive_
Chris@16:         , mpl::transform<
Chris@16:               specified_types
Chris@16:             , mpl::protect<
Chris@16:                   detail::variant::quoted_enable_recursive<wknd_self_t>
Chris@16:                 >
Chris@16:             >
Chris@16:         , mpl::identity< specified_types >
Chris@16:         >::type recursive_enabled_types;
Chris@16: 
Chris@16: public: // public typedefs
Chris@16: 
Chris@16:     typedef typename mpl::transform<
Chris@16:           recursive_enabled_types
Chris@16:         , unwrap_recursive<mpl::_1>
Chris@16:         >::type types;
Chris@16: 
Chris@16: private: // internal typedefs
Chris@16: 
Chris@16:     typedef typename mpl::transform<
Chris@16:           recursive_enabled_types
Chris@16:         , mpl::protect< detail::make_reference_content<> >
Chris@16:         >::type internal_types;
Chris@16: 
Chris@16:     typedef typename mpl::front<
Chris@16:           internal_types
Chris@16:         >::type internal_T0;
Chris@16: 
Chris@16: #else // defined(BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT)
Chris@16: 
Chris@16: private: // helpers, for typedefs (below)
Chris@16: 
Chris@16:     typedef unwrapped_T0_ T0;
Chris@16: 
Chris@16:     #define BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS(z,N,_) \
Chris@16:         typedef typename mpl::eval_if< \
Chris@16:               is_recursive_ \
Chris@16:             , detail::variant::enable_recursive< \
Chris@16:                   BOOST_PP_CAT(T,N) \
Chris@16:                 , wknd_self_t \
Chris@16:                 > \
Chris@16:             , mpl::identity< BOOST_PP_CAT(T,N) > \
Chris@16:             >::type BOOST_PP_CAT(recursive_enabled_T,N); \
Chris@16:         /**/
Chris@16: 
Chris@16:     BOOST_PP_REPEAT(
Chris@16:           BOOST_VARIANT_LIMIT_TYPES
Chris@16:         , BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS
Chris@16:         , _
Chris@16:         )
Chris@16: 
Chris@16:     #undef BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS
Chris@16: 
Chris@16:     #define BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS(z,N,_) \
Chris@16:         typedef typename unwrap_recursive< \
Chris@16:               BOOST_PP_CAT(recursive_enabled_T,N) \
Chris@16:             >::type BOOST_PP_CAT(public_T,N); \
Chris@16:         /**/
Chris@16: 
Chris@16:     BOOST_PP_REPEAT(
Chris@16:           BOOST_VARIANT_LIMIT_TYPES
Chris@16:         , BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS
Chris@16:         , _
Chris@16:         )
Chris@16: 
Chris@16:     #undef BOOST_VARIANT_AUX_UNWRAP_RECURSIVE_TYPEDEFS
Chris@16: 
Chris@16: public: // public typedefs
Chris@16: 
Chris@16:     typedef typename detail::variant::make_variant_list<
Chris@16:           BOOST_VARIANT_ENUM_PARAMS(public_T)
Chris@16:         >::type types;
Chris@16: 
Chris@16: private: // helpers, for internal typedefs (below)
Chris@16: 
Chris@16:     #define BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS(z,N,_) \
Chris@16:         typedef detail::make_reference_content< \
Chris@16:               BOOST_PP_CAT(recursive_enabled_T,N) \
Chris@16:             >::type BOOST_PP_CAT(internal_T,N); \
Chris@16:         /**/
Chris@16: 
Chris@16:     BOOST_PP_REPEAT(
Chris@16:           BOOST_VARIANT_LIMIT_TYPES
Chris@16:         , BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS
Chris@16:         , _
Chris@16:         )
Chris@16: 
Chris@16:     #undef BOOST_VARIANT_AUX_MAKE_REFERENCE_CONTENT_TYPEDEFS
Chris@16: 
Chris@16: private: // internal typedefs
Chris@16: 
Chris@16:     typedef typename detail::variant::make_variant_list<
Chris@16:           BOOST_VARIANT_ENUM_PARAMS(internal_T)
Chris@16:         >::type internal_types;
Chris@16: 
Chris@16: private: // static precondition assertions
Chris@16: 
Chris@16:     // NOTE TO USER :
Chris@16:     // variant< type-sequence > syntax is not supported on this compiler!
Chris@16:     //
Chris@16:     BOOST_MPL_ASSERT_NOT(( is_sequence_based_ ));
Chris@16: 
Chris@16: #endif // BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT workaround
Chris@16: 
Chris@16: private: // helpers, for representation (below)
Chris@16: 
Chris@16:     typedef typename detail::variant::find_fallback_type<
Chris@16:           internal_types
Chris@16:         >::type fallback_type_result_;
Chris@16: 
Chris@16:     typedef typename fallback_type_result_::first
Chris@16:         fallback_type_index_;
Chris@16:     typedef typename fallback_type_result_::second
Chris@16:         fallback_type_;
Chris@16: 
Chris@16:     struct has_fallback_type_
Chris@16:         : mpl::not_<
Chris@16:               is_same< fallback_type_, detail::variant::no_fallback_type >
Chris@16:             >
Chris@16:     {
Chris@16:     };
Chris@16: 
Chris@16:     typedef has_fallback_type_
Chris@16:         never_uses_backup_flag;
Chris@16: 
Chris@16:     typedef typename detail::variant::make_storage<
Chris@16:           internal_types, never_uses_backup_flag
Chris@16:         >::type storage_t;
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_NOEXCEPT
Chris@101:     typedef typename detail::variant::is_variant_move_noexcept_constructible<
Chris@16:         internal_types
Chris@101:     > variant_move_noexcept_constructible;
Chris@101: 
Chris@101:     typedef typename detail::variant::is_variant_move_noexcept_assignable<
Chris@101:         internal_types
Chris@101:     > variant_move_noexcept_assignable;
Chris@101: 
Chris@16: #endif
Chris@16: 
Chris@16: private: // helpers, for representation (below)
Chris@16: 
Chris@16:     // which_ on:
Chris@16:     // * [0,  size<internal_types>) indicates stack content
Chris@16:     // * [-size<internal_types>, 0) indicates pointer to heap backup
Chris@16:     // if which_ >= 0:
Chris@16:     // * then which() -> which_
Chris@16:     // * else which() -> -(which_ + 1)
Chris@16: 
Chris@16: #if !defined(BOOST_VARIANT_MINIMIZE_SIZE)
Chris@16: 
Chris@16:     typedef int which_t;
Chris@16: 
Chris@16: #else // defined(BOOST_VARIANT_MINIMIZE_SIZE)
Chris@16: 
Chris@16:     // [if O1_size available, then attempt which_t size optimization...]
Chris@16:     // [select signed char if fewer than SCHAR_MAX types, else signed int:]
Chris@16:     typedef typename mpl::eval_if<
Chris@16:           mpl::equal_to< mpl::O1_size<internal_types>, mpl::long_<-1> >
Chris@16:         , mpl::identity< int >
Chris@16:         , mpl::if_<
Chris@16:               mpl::less< mpl::O1_size<internal_types>, mpl::int_<SCHAR_MAX> >
Chris@16:             , signed char
Chris@16:             , int
Chris@16:             >
Chris@16:         >::type which_t;
Chris@16: 
Chris@16: #endif // BOOST_VARIANT_MINIMIZE_SIZE switch
Chris@16: 
Chris@16: // representation -- private when possible
Chris@16: #if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
Chris@16:     private:
Chris@16: #else
Chris@16:     public:
Chris@16: #endif
Chris@16: 
Chris@16:     which_t which_;
Chris@16:     storage_t storage_;
Chris@16: 
Chris@16:     void indicate_which(int which_arg) BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         which_ = static_cast<which_t>( which_arg );
Chris@16:     }
Chris@16: 
Chris@16:     void indicate_backup_which(int which_arg) BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         which_ = static_cast<which_t>( -(which_arg + 1) );
Chris@16:     }
Chris@16: 
Chris@16: private: // helpers, for queries (below)
Chris@16: 
Chris@16:     bool using_backup() const BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         return which_ < 0;
Chris@16:     }
Chris@16: 
Chris@16: public: // queries
Chris@16: 
Chris@16:     int which() const BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         // If using heap backup...
Chris@16:         if (using_backup())
Chris@16:             // ...then return adjusted which_:
Chris@16:             return -(which_ + 1);
Chris@16: 
Chris@16:         // Otherwise, return which_ directly:
Chris@16:         return which_;
Chris@16:     }
Chris@16: 
Chris@16: private: // helpers, for structors (below)
Chris@16: 
Chris@16:     struct initializer
Chris@16:         : BOOST_VARIANT_AUX_INITIALIZER_T(
Chris@16:               recursive_enabled_types, recursive_enabled_T
Chris@16:             )
Chris@16:     {
Chris@16:     };
Chris@16: 
Chris@101:     void destroy_content() BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         detail::variant::destroyer visitor;
Chris@16:         this->internal_apply_visitor(visitor);
Chris@16:     }
Chris@16: 
Chris@16: public: // structors
Chris@16: 
Chris@16:     ~variant() BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         destroy_content();
Chris@16:     }
Chris@16: 
Chris@101:     variant() BOOST_NOEXCEPT_IF(boost::has_nothrow_constructor<internal_T0>::value)
Chris@16:     {
Chris@101: #ifdef _MSC_VER
Chris@101: #pragma warning( push )
Chris@101: // behavior change: an object of POD type constructed with an initializer of the form () will be default-initialized 
Chris@101: #pragma warning( disable : 4345 ) 
Chris@101: #endif
Chris@16:         // NOTE TO USER :
Chris@16:         // Compile error from here indicates that the first bound
Chris@16:         // type is not default-constructible, and so variant cannot
Chris@16:         // support its own default-construction.
Chris@16:         //
Chris@16:         new( storage_.address() ) internal_T0();
Chris@16:         indicate_which(0); // zero is the index of the first bounded type
Chris@101: #ifdef _MSC_VER
Chris@101: #pragma warning( pop )
Chris@101: #endif
Chris@16:     }
Chris@16: 
Chris@16: private: // helpers, for structors, cont. (below)
Chris@16: 
Chris@16:     class convert_copy_into
Chris@16:         : public static_visitor<int>
Chris@16:     {
Chris@16:     private: // representation
Chris@16: 
Chris@16:         void* storage_;
Chris@16: 
Chris@16:     public: // structors
Chris@16: 
Chris@16:         explicit convert_copy_into(void* storage) BOOST_NOEXCEPT
Chris@16:             : storage_(storage)
Chris@16:         {
Chris@16:         }
Chris@16: 
Chris@16:     public: // internal visitor interfaces (below)
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(T& operand, int) const
Chris@16:         {
Chris@16:             // NOTE TO USER :
Chris@16:             // Compile error here indicates one of the source variant's types 
Chris@16:             // cannot be unambiguously converted to the destination variant's
Chris@16:             // types (or that no conversion exists).
Chris@16:             //
Chris@16:             return initializer::initialize(storage_, operand);
Chris@16:         }
Chris@16: 
Chris@16: #   if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x0564))
Chris@16:         template <typename T>
Chris@16:         result_type internal_visit(const T& operand, int) const
Chris@16:         {
Chris@16:             return initializer::initialize(storage_, operand);
Chris@16:         }
Chris@16: #   endif
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(boost::detail::reference_content<T>& operand, long) const
Chris@16:         {
Chris@16:             return internal_visit( operand.get(), 1L );
Chris@16:         }
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(const boost::detail::reference_content<T>& operand, long) const
Chris@16:         {
Chris@16:             return internal_visit( operand.get(), 1L );
Chris@16:         }
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const
Chris@16:         {
Chris@16:             return internal_visit( operand.get(), 1L );
Chris@16:         }
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(const boost::detail::variant::backup_holder<T>& operand, long) const
Chris@16:         {
Chris@16:             return internal_visit( operand.get(), 1L );
Chris@16:         }
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(boost::recursive_wrapper<T>& operand, long) const
Chris@16:         {
Chris@16:             return internal_visit( operand.get(), 1L );
Chris@16:         }
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(const boost::recursive_wrapper<T>& operand, long) const
Chris@16:         {
Chris@16:             return internal_visit( operand.get(), 1L );
Chris@16:         }
Chris@16: 
Chris@16:     };
Chris@16: 
Chris@16:     friend class convert_copy_into;
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:     class convert_move_into
Chris@16:         : public static_visitor<int>
Chris@16:     {
Chris@16:     private: // representation
Chris@16: 
Chris@16:         void* storage_;
Chris@16: 
Chris@16:     public: // structors
Chris@16: 
Chris@16:         explicit convert_move_into(void* storage) BOOST_NOEXCEPT
Chris@16:             : storage_(storage)
Chris@16:         {
Chris@16:         }
Chris@16: 
Chris@16:     public: // internal visitor interfaces (below)
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(T& operand, int) const
Chris@16:         {
Chris@16:             // NOTE TO USER :
Chris@16:             // Compile error here indicates one of the source variant's types 
Chris@16:             // cannot be unambiguously converted to the destination variant's
Chris@16:             // types (or that no conversion exists).
Chris@16:             //
Chris@16:             return initializer::initialize(storage_, detail::variant::move(operand) );
Chris@16:         }
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(boost::detail::reference_content<T>& operand, long) const
Chris@16:         {
Chris@16:             return internal_visit( operand.get(), 1L );
Chris@16:         }
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(const boost::detail::reference_content<T>& operand, long) const
Chris@16:         {
Chris@16:             return internal_visit( operand.get(), 1L );
Chris@16:         }
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(boost::detail::variant::backup_holder<T>& operand, long) const
Chris@16:         {
Chris@16:             return internal_visit( operand.get(), 1L );
Chris@16:         }
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(const boost::detail::variant::backup_holder<T>& operand, long) const
Chris@16:         {
Chris@16:             return internal_visit( operand.get(), 1L );
Chris@16:         }
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(boost::recursive_wrapper<T>& operand, long) const
Chris@16:         {
Chris@16:             return internal_visit( operand.get(), 1L );
Chris@16:         }
Chris@16: 
Chris@16:         template <typename T>
Chris@16:         int internal_visit(const boost::recursive_wrapper<T>& operand, long) const
Chris@16:         {
Chris@16:             return internal_visit( operand.get(), 1L );
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     friend class convert_move_into;
Chris@16: #endif
Chris@16: 
Chris@16: private: // helpers, for structors, below 
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     void convert_construct(
Chris@16:           T& operand
Chris@16:         , int
Chris@16:         , mpl::false_ = mpl::false_() // is_foreign_variant
Chris@16:         )
Chris@16:     {
Chris@16:         // NOTE TO USER :
Chris@16:         // Compile error here indicates that the given type is not 
Chris@16:         // unambiguously convertible to one of the variant's types
Chris@16:         // (or that no conversion exists).
Chris@16:         //
Chris@16:         indicate_which(
Chris@16:               initializer::initialize(
Chris@16:                   storage_.address()
Chris@16:                 , operand
Chris@16:                 )
Chris@16:             );
Chris@16:     }
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:     template <typename T>
Chris@16:     typename boost::enable_if<boost::is_rvalue_reference<T&&> >::type convert_construct(
Chris@16:           T&& operand
Chris@16:         , int
Chris@16:         , mpl::false_ = mpl::false_() // is_foreign_variant
Chris@16:         )
Chris@16:     {
Chris@16:         // NOTE TO USER :
Chris@16:         // Compile error here indicates that the given type is not 
Chris@16:         // unambiguously convertible to one of the variant's types
Chris@16:         // (or that no conversion exists).
Chris@16:         //
Chris@16:         indicate_which(
Chris@16:               initializer::initialize(
Chris@16:                   storage_.address()
Chris@16:                 , detail::variant::move(operand)
Chris@16:                 )
Chris@16:             );
Chris@16:     }
Chris@16: #endif
Chris@16: 
Chris@16:     template <typename Variant>
Chris@16:     void convert_construct(
Chris@16:           Variant& operand
Chris@16:         , long
Chris@16:         , mpl::true_// is_foreign_variant
Chris@16:         )
Chris@16:     {
Chris@16:         convert_copy_into visitor(storage_.address());
Chris@16:         indicate_which(
Chris@16:               operand.internal_apply_visitor(visitor)
Chris@16:             );
Chris@16:     }
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:     template <typename Variant>
Chris@16:     typename boost::enable_if<boost::is_rvalue_reference<Variant&&> >::type convert_construct(
Chris@16:           Variant&& operand
Chris@16:         , long
Chris@16:         , mpl::true_// is_foreign_variant
Chris@16:         )
Chris@16:     {
Chris@16:         convert_move_into visitor(storage_.address());
Chris@16:         indicate_which(
Chris@16:               operand.internal_apply_visitor(visitor)
Chris@16:             );
Chris@16:     }
Chris@16: #endif
Chris@16: 
Chris@16:     template <typename Variant>
Chris@16:     void convert_construct_variant(Variant& operand)
Chris@16:     {
Chris@16:         // [Determine if the given variant is itself a bounded type, or if its
Chris@16:         //  content needs to be converted (i.e., it is a 'foreign' variant):]
Chris@16:         //
Chris@16: 
Chris@16:         typedef typename mpl::find_if<
Chris@16:               types
Chris@16:             , is_same<
Chris@16:                   add_const<mpl::_1>
Chris@16:                 , const Variant
Chris@16:                 >
Chris@16:             >::type found_it;
Chris@16: 
Chris@16:         typedef typename mpl::end<types>::type not_found;
Chris@16:         typedef typename is_same<
Chris@16:               found_it, not_found
Chris@16:             >::type is_foreign_variant;
Chris@16: 
Chris@16:         // Convert construct from operand:
Chris@16:         convert_construct(
Chris@16:               operand, 1L
Chris@16:             , is_foreign_variant()
Chris@16:             );
Chris@16:     }
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:     template <typename Variant>
Chris@16:     typename boost::enable_if<boost::is_rvalue_reference<Variant&&> >::type convert_construct_variant(Variant&& operand)
Chris@16:     {
Chris@16:         // [Determine if the given variant is itself a bounded type, or if its
Chris@16:         //  content needs to be converted (i.e., it is a 'foreign' variant):]
Chris@16:         //
Chris@16: 
Chris@16:         typedef typename mpl::find_if<
Chris@16:               types
Chris@16:             , is_same<
Chris@16:                   add_const<mpl::_1>
Chris@16:                 , const Variant
Chris@16:                 >
Chris@16:             >::type found_it;
Chris@16: 
Chris@16:         typedef typename mpl::end<types>::type not_found;
Chris@16:         typedef typename is_same<
Chris@16:               found_it, not_found
Chris@16:             >::type is_foreign_variant;
Chris@16: 
Chris@16:         // Convert move construct from operand:
Chris@16:         convert_construct(
Chris@16:               detail::variant::move(operand), 1L
Chris@16:             , is_foreign_variant()
Chris@16:             );
Chris@16:     }
Chris@16: #endif
Chris@16: 
Chris@16:     template <BOOST_VARIANT_ENUM_PARAMS(typename U)>
Chris@16:     void convert_construct(
Chris@16:           boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>& operand
Chris@16:         , long
Chris@16:         )
Chris@16:     {
Chris@16:         convert_construct_variant(operand);
Chris@16:     }
Chris@16: 
Chris@16:     template <BOOST_VARIANT_ENUM_PARAMS(typename U)>
Chris@16:     void convert_construct(
Chris@16:           const boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>& operand
Chris@16:         , long
Chris@16:         )
Chris@16:     {
Chris@16:         convert_construct_variant(operand);    
Chris@16:     }
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:     template <BOOST_VARIANT_ENUM_PARAMS(typename U)>
Chris@16:     void convert_construct(
Chris@16:           boost::variant<BOOST_VARIANT_ENUM_PARAMS(U)>&& operand
Chris@16:         , long
Chris@16:         )
Chris@16:     {
Chris@16:         convert_construct_variant( detail::variant::move(operand) );    
Chris@16:     }
Chris@16: #endif
Chris@16: 
Chris@16: public: // structors, cont.
Chris@16: 
Chris@16: #if !defined(BOOST_VARIANT_AUX_BROKEN_CONSTRUCTOR_TEMPLATE_ORDERING)
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     variant(const T& operand)
Chris@16:     {
Chris@16:         convert_construct(operand, 1L);
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     variant(T& operand)
Chris@16:     {
Chris@16:         convert_construct(operand, 1L);
Chris@16:     }
Chris@16: 
Chris@16: #elif defined(BOOST_VARIANT_AUX_HAS_CONSTRUCTOR_TEMPLATE_ORDERING_SFINAE_WKND)
Chris@16: 
Chris@16:     // For compilers that cannot distinguish between T& and const T& in
Chris@16:     // template constructors, but do fully support SFINAE, we can workaround:
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     variant(const T& operand)
Chris@16:     {
Chris@16:         convert_construct(operand, 1L);
Chris@16:     }
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     variant(
Chris@16:           T& operand
Chris@16:         , typename enable_if<
Chris@16:               mpl::not_< is_const<T> >
Chris@16:             , void
Chris@16:             >::type* = 0
Chris@16:         )
Chris@16:     {
Chris@16:         convert_construct(operand, 1L);
Chris@16:     }
Chris@16: 
Chris@16: #else // !defined(BOOST_VARIANT_AUX_HAS_CONSTRUCTOR_TEMPLATE_ORDERING_SFINAE_WKND)
Chris@16: 
Chris@16:     // For compilers that cannot distinguish between T& and const T& in
Chris@16:     // template constructors, and do NOT support SFINAE, we can't workaround:
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     variant(const T& operand)
Chris@16:     {
Chris@16:         convert_construct(operand, 1L);
Chris@16:     }
Chris@16: #endif // BOOST_VARIANT_AUX_BROKEN_CONSTRUCTOR_TEMPLATE_ORDERING workarounds
Chris@16:     
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:     template <class T>
Chris@16:     variant(T&& operand, typename boost::enable_if<boost::is_rvalue_reference<T&&> >::type* = 0, 
Chris@16:         typename boost::disable_if<boost::is_const<T> >::type* = 0)
Chris@16:     {
Chris@16:         convert_construct( detail::variant::move(operand), 1L);
Chris@16:     }
Chris@16: #endif
Chris@16: 
Chris@16: public: // structors, cont.
Chris@16: 
Chris@16:     // [MSVC6 requires copy constructor appear after template constructors]
Chris@16:     variant(const variant& operand)
Chris@16:     {
Chris@16:         // Copy the value of operand into *this...
Chris@16:         detail::variant::copy_into visitor( storage_.address() );
Chris@16:         operand.internal_apply_visitor(visitor);
Chris@16: 
Chris@16:         // ...and activate the *this's primary storage on success:
Chris@16:         indicate_which(operand.which());
Chris@16:     }
Chris@16:     
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@101:     variant(variant&& operand) BOOST_NOEXCEPT_IF(variant_move_noexcept_constructible::type::value)
Chris@16:     {
Chris@16:         // Move the value of operand into *this...
Chris@16:         detail::variant::move_into visitor( storage_.address() );
Chris@16:         operand.internal_apply_visitor(visitor);
Chris@16: 
Chris@16:         // ...and activate the *this's primary storage on success:
Chris@16:         indicate_which(operand.which());
Chris@16:     }
Chris@16: #endif
Chris@16: 
Chris@16: private: // helpers, for modifiers (below)
Chris@16: 
Chris@16: #   if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
Chris@16:     template <typename Variant>
Chris@16:     friend class detail::variant::backup_assigner;
Chris@16: #   endif
Chris@16: 
Chris@16:     // class assigner
Chris@16:     //
Chris@16:     // Internal visitor that "assigns" the visited value to the given variant
Chris@16:     // by appropriate destruction and copy-construction.
Chris@16:     //
Chris@16: 
Chris@16:     class assigner
Chris@16:         : public static_visitor<>
Chris@16:     {
Chris@101:     protected: // representation
Chris@16: 
Chris@16:         variant& lhs_;
Chris@101:         const int rhs_which_;
Chris@16: 
Chris@16:     public: // structors
Chris@16: 
Chris@16:         assigner(variant& lhs, int rhs_which) BOOST_NOEXCEPT
Chris@16:             : lhs_(lhs)
Chris@16:             , rhs_which_(rhs_which)
Chris@16:         {
Chris@16:         }
Chris@16: 
Chris@101:     protected: // helpers, for internal visitor interface (below)
Chris@16: 
Chris@16:         template <typename RhsT, typename B1, typename B2>
Chris@16:         void assign_impl(
Chris@16:               const RhsT& rhs_content
Chris@16:             , mpl::true_ // has_nothrow_copy
Chris@16:             , B1 // is_nothrow_move_constructible
Chris@16:             , B2 // has_fallback_type
Chris@101:             ) const BOOST_NOEXCEPT
Chris@16:         {
Chris@16:             // Destroy lhs's content...
Chris@16:             lhs_.destroy_content(); // nothrow
Chris@16: 
Chris@16:             // ...copy rhs content into lhs's storage...
Chris@16:             new(lhs_.storage_.address())
Chris@16:                 RhsT( rhs_content ); // nothrow
Chris@16: 
Chris@16:             // ...and indicate new content type:
Chris@16:             lhs_.indicate_which(rhs_which_); // nothrow
Chris@16:         }
Chris@16: 
Chris@16:         template <typename RhsT, typename B>
Chris@16:         void assign_impl(
Chris@16:               const RhsT& rhs_content
Chris@16:             , mpl::false_ // has_nothrow_copy
Chris@16:             , mpl::true_ // is_nothrow_move_constructible
Chris@16:             , B // has_fallback_type
Chris@101:             ) const
Chris@16:         {
Chris@16:             // Attempt to make a temporary copy (so as to move it below)...
Chris@16:             RhsT temp(rhs_content);
Chris@16: 
Chris@16:             // ...and upon success destroy lhs's content...
Chris@16:             lhs_.destroy_content(); // nothrow
Chris@16: 
Chris@16:             // ...move the temporary copy into lhs's storage...
Chris@16:             new(lhs_.storage_.address())
Chris@16:                 RhsT( detail::variant::move(temp) ); // nothrow
Chris@16: 
Chris@16:             // ...and indicate new content type:
Chris@16:             lhs_.indicate_which(rhs_which_); // nothrow
Chris@16:         }
Chris@16: 
Chris@101:         void construct_fallback() const BOOST_NOEXCEPT {
Chris@101:             // In case of failure, default-construct fallback type in lhs's storage...
Chris@101:             new (lhs_.storage_.address())
Chris@101:                 fallback_type_; // nothrow
Chris@101: 
Chris@101:             // ...indicate construction of fallback type...
Chris@101:             lhs_.indicate_which(
Chris@101:                   BOOST_MPL_AUX_VALUE_WKND(fallback_type_index_)::value
Chris@101:                 ); // nothrow
Chris@101:         }
Chris@101: 
Chris@16:         template <typename RhsT>
Chris@16:         void assign_impl(
Chris@16:               const RhsT& rhs_content
Chris@16:             , mpl::false_ // has_nothrow_copy
Chris@16:             , mpl::false_ // is_nothrow_move_constructible
Chris@16:             , mpl::true_ // has_fallback_type
Chris@101:             ) const
Chris@16:         {
Chris@16:             // Destroy lhs's content...
Chris@16:             lhs_.destroy_content(); // nothrow
Chris@16: 
Chris@16:             BOOST_TRY
Chris@16:             {
Chris@16:                 // ...and attempt to copy rhs's content into lhs's storage:
Chris@16:                 new(lhs_.storage_.address())
Chris@16:                     RhsT( rhs_content );
Chris@16:             }
Chris@16:             BOOST_CATCH (...)
Chris@16:             {
Chris@101:                 construct_fallback();
Chris@16: 
Chris@16:                 // ...and rethrow:
Chris@16:                 BOOST_RETHROW;
Chris@16:             }
Chris@16:             BOOST_CATCH_END
Chris@16: 
Chris@16:             // In the event of success, indicate new content type:
Chris@16:             lhs_.indicate_which(rhs_which_); // nothrow
Chris@16:         }
Chris@16: 
Chris@16:         template <typename RhsT>
Chris@16:         void assign_impl(
Chris@16:               const RhsT& rhs_content
Chris@16:             , mpl::false_ // has_nothrow_copy
Chris@16:             , mpl::false_ // is_nothrow_move_constructible
Chris@16:             , mpl::false_ // has_fallback_type
Chris@101:             ) const
Chris@16:         {
Chris@16:             detail::variant::backup_assigner<wknd_self_t>
Chris@16:                 visitor(lhs_, rhs_which_, rhs_content);
Chris@16:             lhs_.internal_apply_visitor(visitor);
Chris@16:         }
Chris@16: 
Chris@16:     public: // internal visitor interfaces
Chris@16: 
Chris@16:         template <typename RhsT>
Chris@16:             BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@101:         internal_visit(const RhsT& rhs_content, int) const
Chris@16:         {
Chris@16:             typedef typename has_nothrow_copy<RhsT>::type
Chris@16:                 nothrow_copy;
Chris@16:             typedef typename mpl::or_< // reduces compile-time
Chris@16:                   nothrow_copy
Chris@16:                 , is_nothrow_move_constructible<RhsT>
Chris@16:                 >::type nothrow_move_constructor;
Chris@16: 
Chris@16:             assign_impl(
Chris@16:                   rhs_content
Chris@16:                 , nothrow_copy()
Chris@16:                 , nothrow_move_constructor()
Chris@16:                 , has_fallback_type_()
Chris@16:                 );
Chris@16: 
Chris@16:             BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:         }
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600))
Chris@16:     private:
Chris@16:         // silence MSVC warning C4512: assignment operator could not be generated
Chris@16:         assigner& operator= (assigner const&);
Chris@16: #endif
Chris@16:     };
Chris@16:     
Chris@16:     friend class assigner;
Chris@16:    
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:     // class move_assigner
Chris@16:     //
Chris@16:     // Internal visitor that "move assigns" the visited value to the given variant
Chris@16:     // by appropriate destruction and move-construction.
Chris@16:     //
Chris@16: 
Chris@16:     class move_assigner
Chris@101:         : public assigner
Chris@16:     {
Chris@16:     public: // structors
Chris@16: 
Chris@16:         move_assigner(variant& lhs, int rhs_which) BOOST_NOEXCEPT
Chris@101:             : assigner(lhs, rhs_which)
Chris@16:         {
Chris@16:         }
Chris@16: 
Chris@16:     private: // helpers, for internal visitor interface (below)
Chris@101:         
Chris@16:         template <typename RhsT, typename B2>
Chris@16:         void assign_impl(
Chris@16:               RhsT& rhs_content
Chris@16:             , mpl::true_ // has_nothrow_copy
Chris@16:             , mpl::false_ // is_nothrow_move_constructible
Chris@16:             , B2 // has_fallback_type
Chris@101:             ) const BOOST_NOEXCEPT
Chris@16:         {
Chris@101:             assigner::assign_impl(rhs_content, mpl::true_(), mpl::false_(), B2());
Chris@16:         }
Chris@16: 
Chris@101:         template <typename RhsT, typename B, typename B2>
Chris@16:         void assign_impl(
Chris@16:               RhsT& rhs_content
Chris@101:             , B // has_nothrow_copy
Chris@16:             , mpl::true_ // is_nothrow_move_constructible
Chris@101:             , B2 // has_fallback_type
Chris@101:             ) const BOOST_NOEXCEPT
Chris@16:         {
Chris@16:             // ...destroy lhs's content...
Chris@101:             assigner::lhs_.destroy_content(); // nothrow
Chris@16: 
Chris@16:             // ...move the rhs_content into lhs's storage...
Chris@101:             new(assigner::lhs_.storage_.address())
Chris@16:                 RhsT( detail::variant::move(rhs_content) ); // nothrow
Chris@16: 
Chris@16:             // ...and indicate new content type:
Chris@101:             assigner::lhs_.indicate_which(assigner::rhs_which_); // nothrow
Chris@16:         }
Chris@16: 
Chris@16:         template <typename RhsT>
Chris@16:         void assign_impl(
Chris@16:               RhsT& rhs_content
Chris@16:             , mpl::false_ // has_nothrow_copy
Chris@16:             , mpl::false_ // is_nothrow_move_constructible
Chris@16:             , mpl::true_ // has_fallback_type
Chris@101:             ) const
Chris@16:         {
Chris@16:             // Destroy lhs's content...
Chris@101:             assigner::lhs_.destroy_content(); // nothrow
Chris@16: 
Chris@16:             BOOST_TRY
Chris@16:             {
Chris@16:                 // ...and attempt to copy rhs's content into lhs's storage:
Chris@101:                 new(assigner::lhs_.storage_.address())
Chris@16:                     RhsT( detail::variant::move(rhs_content) );
Chris@16:             }
Chris@16:             BOOST_CATCH (...)
Chris@16:             {
Chris@101:                 assigner::construct_fallback();
Chris@16: 
Chris@16:                 // ...and rethrow:
Chris@16:                 BOOST_RETHROW;
Chris@16:             }
Chris@16:             BOOST_CATCH_END
Chris@16: 
Chris@16:             // In the event of success, indicate new content type:
Chris@101:             assigner::lhs_.indicate_which(assigner::rhs_which_); // nothrow
Chris@16:         }
Chris@101:         
Chris@16:         template <typename RhsT>
Chris@16:         void assign_impl(
Chris@101:               RhsT& rhs_content
Chris@16:             , mpl::false_ // has_nothrow_copy
Chris@16:             , mpl::false_ // is_nothrow_move_constructible
Chris@16:             , mpl::false_ // has_fallback_type
Chris@101:             ) const
Chris@16:         {
Chris@101:             assigner::assign_impl(rhs_content, mpl::false_(), mpl::false_(), mpl::false_());
Chris@16:         }
Chris@16: 
Chris@16:     public: // internal visitor interfaces
Chris@16: 
Chris@16:         template <typename RhsT>
Chris@16:             BOOST_VARIANT_AUX_RETURN_VOID_TYPE
Chris@101:         internal_visit(RhsT& rhs_content, int) const
Chris@16:         {
Chris@16:             typedef typename is_nothrow_move_constructible<RhsT>::type
Chris@16:                 nothrow_move_constructor;
Chris@16:             typedef typename mpl::or_< // reduces compile-time
Chris@16:                   nothrow_move_constructor
Chris@16:                 , has_nothrow_copy<RhsT>
Chris@16:                 >::type nothrow_copy;
Chris@16: 
Chris@16:             assign_impl(
Chris@16:                   rhs_content
Chris@16:                 , nothrow_copy()
Chris@16:                 , nothrow_move_constructor()
Chris@16:                 , has_fallback_type_()
Chris@16:                 );
Chris@16: 
Chris@16:             BOOST_VARIANT_AUX_RETURN_VOID;
Chris@16:         }
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600))
Chris@16:     private:
Chris@16:         // silence MSVC warning C4512: assignment operator could not be generated
Chris@16:         move_assigner& operator= (move_assigner const&);
Chris@16: #endif
Chris@16:     };
Chris@16: 
Chris@16:     friend class move_assigner;
Chris@16: #endif // BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16: 
Chris@16:     void variant_assign(const variant& rhs)
Chris@16:     {
Chris@16:         // If the contained types are EXACTLY the same...
Chris@16:         if (which_ == rhs.which_)
Chris@16:         {
Chris@16:             // ...then assign rhs's storage to lhs's content:
Chris@16:             detail::variant::assign_storage visitor(rhs.storage_.address());
Chris@16:             this->internal_apply_visitor(visitor);
Chris@16:         }
Chris@16:         else
Chris@16:         {
Chris@16:             // Otherwise, perform general (copy-based) variant assignment:
Chris@16:             assigner visitor(*this, rhs.which());
Chris@16:             rhs.internal_apply_visitor(visitor); 
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:     void variant_assign(variant&& rhs)
Chris@16:     {
Chris@16:         // If the contained types are EXACTLY the same...
Chris@16:         if (which_ == rhs.which_)
Chris@16:         {
Chris@16:             // ...then move rhs's storage to lhs's content:
Chris@16:             detail::variant::move_storage visitor(rhs.storage_.address());
Chris@16:             this->internal_apply_visitor(visitor);
Chris@16:         }
Chris@16:         else
Chris@16:         {
Chris@16:             // Otherwise, perform general (move-based) variant assignment:
Chris@16:             move_assigner visitor(*this, rhs.which());
Chris@16:             rhs.internal_apply_visitor(visitor); 
Chris@16:         }
Chris@16:     }
Chris@16: #endif // BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16: 
Chris@16: private: // helpers, for modifiers (below)
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     void assign(const T& rhs)
Chris@16:     {
Chris@16:         // If direct T-to-T assignment is not possible...
Chris@16:         detail::variant::direct_assigner<T> direct_assign(rhs);
Chris@16:         if (this->apply_visitor(direct_assign) == false)
Chris@16:         {
Chris@16:             // ...then convert rhs to variant and assign:
Chris@16:             //
Chris@16:             // While potentially inefficient, the following construction of a
Chris@16:             // variant allows T as any type convertible to one of the bounded
Chris@16:             // types without excessive code redundancy.
Chris@16:             //
Chris@16:             variant temp(rhs);
Chris@16:             variant_assign( detail::variant::move(temp) );
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:     template <typename T>
Chris@16:     void move_assign(T&& rhs)
Chris@16:     {
Chris@16:         // If direct T-to-T move assignment is not possible...
Chris@16:         detail::variant::direct_mover<T> direct_move(rhs);
Chris@16:         if (this->apply_visitor(direct_move) == false)
Chris@16:         {
Chris@16:             // ...then convert rhs to variant and assign:
Chris@16:             //
Chris@16:             // While potentially inefficient, the following construction of a
Chris@16:             // variant allows T as any type convertible to one of the bounded
Chris@16:             // types without excessive code redundancy.
Chris@16:             //
Chris@16:             variant temp( detail::variant::move(rhs) );
Chris@16:             variant_assign( detail::variant::move(temp) );
Chris@16:         }
Chris@16:     }
Chris@16: #endif // BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16: 
Chris@16: public: // modifiers
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16:     template <class T>
Chris@16:     typename boost::enable_if_c<boost::is_rvalue_reference<T&&>::value && !boost::is_const<T>::value, variant& >::type 
Chris@101:         operator=(T&& rhs) 
Chris@16:     {
Chris@16:         move_assign( detail::variant::move(rhs) );
Chris@16:         return *this;
Chris@16:     }
Chris@16: #endif // BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16: 
Chris@16:     template <typename T>
Chris@16:     variant& operator=(const T& rhs)
Chris@16:     {
Chris@16:         assign(rhs);
Chris@16:         return *this;
Chris@16:     }
Chris@16: 
Chris@16:     // [MSVC6 requires copy assign appear after templated operator=]
Chris@16:     variant& operator=(const variant& rhs)
Chris@16:     {
Chris@16:         variant_assign(rhs);
Chris@16:         return *this;
Chris@16:     }
Chris@16: 
Chris@16: #ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@101:     variant& operator=(variant&& rhs) 
Chris@101: #if !defined(__GNUC__) || (__GNUC__ != 4) || (__GNUC_MINOR__ > 6)
Chris@101:         BOOST_NOEXCEPT_IF(variant_move_noexcept_constructible::type::value && variant_move_noexcept_assignable::type::value)
Chris@101: #endif
Chris@16:     {
Chris@16:         variant_assign( detail::variant::move(rhs) );
Chris@16:         return *this;
Chris@16:     }
Chris@16: #endif // BOOST_NO_CXX11_RVALUE_REFERENCES
Chris@16: 
Chris@16:     void swap(variant& rhs)
Chris@16:     {
Chris@16:         // If the contained types are the same...
Chris@16:         if (which() == rhs.which())
Chris@16:         {
Chris@16:             // ...then swap the values directly:
Chris@16:             detail::variant::swap_with<variant> visitor(rhs);
Chris@16:             this->apply_visitor(visitor);
Chris@16:         }
Chris@16:         else
Chris@16:         {
Chris@16:             // ...otherwise, perform general variant swap:
Chris@16:             variant tmp( detail::variant::move(rhs) );
Chris@16:             rhs = detail::variant::move(*this);
Chris@16:             *this = detail::variant::move(tmp);
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16: public: // queries
Chris@16: 
Chris@16:     //
Chris@16:     // NOTE: member which() defined above.
Chris@16:     //
Chris@16: 
Chris@16:     bool empty() const BOOST_NOEXCEPT
Chris@16:     {
Chris@16:         return false;
Chris@16:     }
Chris@16: 
Chris@101:     const boost::typeindex::type_info& type() const
Chris@16:     {
Chris@16:         detail::variant::reflect visitor;
Chris@16:         return this->apply_visitor(visitor);
Chris@16:     }
Chris@16: 
Chris@16: public: // prevent comparison with foreign types
Chris@16: 
Chris@101: // Obsolete. Remove.
Chris@16: #   define BOOST_VARIANT_AUX_FAIL_COMPARISON_RETURN_TYPE \
Chris@16:     void
Chris@16: 
Chris@16:     template <typename U>
Chris@101:     void operator==(const U&) const
Chris@16:     {
Chris@16:         BOOST_STATIC_ASSERT( false && sizeof(U) );
Chris@16:     }
Chris@16: 
Chris@16:     template <typename U>
Chris@101:     void operator<(const U&) const
Chris@101:     {
Chris@101:         BOOST_STATIC_ASSERT( false && sizeof(U) );
Chris@101:     }
Chris@101: 
Chris@101:     template <typename U>
Chris@101:     void operator!=(const U&) const
Chris@101:     {
Chris@101:         BOOST_STATIC_ASSERT( false && sizeof(U) );
Chris@101:     }
Chris@101: 
Chris@101:     template <typename U>
Chris@101:     void operator>(const U&) const
Chris@101:     {
Chris@101:         BOOST_STATIC_ASSERT( false && sizeof(U) );
Chris@101:     }
Chris@101: 
Chris@101:     template <typename U>
Chris@101:     void operator<=(const U&) const
Chris@101:     {
Chris@101:         BOOST_STATIC_ASSERT( false && sizeof(U) );
Chris@101:     }
Chris@101: 
Chris@101:     template <typename U>
Chris@101:     void operator>=(const U&) const
Chris@16:     {
Chris@16:         BOOST_STATIC_ASSERT( false && sizeof(U) );
Chris@16:     }
Chris@16: 
Chris@16: public: // comparison operators
Chris@16: 
Chris@16:     // [MSVC6 requires these operators appear after template operators]
Chris@16: 
Chris@16:     bool operator==(const variant& rhs) const
Chris@16:     {
Chris@16:         if (this->which() != rhs.which())
Chris@16:             return false;
Chris@16: 
Chris@16:         detail::variant::comparer<
Chris@16:               variant, detail::variant::equal_comp
Chris@16:             > visitor(*this);
Chris@16:         return rhs.apply_visitor(visitor);
Chris@16:     }
Chris@16: 
Chris@16:     bool operator<(const variant& rhs) const
Chris@16:     {
Chris@16:         //
Chris@16:         // Dirk Schreib suggested this collating order.
Chris@16:         //
Chris@16: 
Chris@16:         if (this->which() != rhs.which())
Chris@16:             return this->which() < rhs.which();
Chris@16: 
Chris@16:         detail::variant::comparer<
Chris@16:               variant, detail::variant::less_comp
Chris@16:             > visitor(*this);
Chris@16:         return rhs.apply_visitor(visitor);
Chris@16:     }
Chris@16: 
Chris@101:     ///////////////////////////////////////////////////////////////////////////////
Chris@101:     // comparison operators != > <= >=
Chris@101:     inline bool operator!=(const variant& rhs) const
Chris@101:     {
Chris@101:         return !(*this == rhs);
Chris@101:     }
Chris@101: 
Chris@101:     inline bool operator>(const variant& rhs) const
Chris@101:     {
Chris@101:         return rhs < *this;
Chris@101:     }
Chris@101: 
Chris@101:     inline bool operator<=(const variant& rhs) const
Chris@101:     {
Chris@101:         return !(*this > rhs);
Chris@101:     }
Chris@101: 
Chris@101:     inline bool operator>=(const variant& rhs) const
Chris@101:     {
Chris@101:         return !(*this < rhs);
Chris@101:     }
Chris@101: 
Chris@16: // helpers, for visitation support (below) -- private when possible
Chris@16: #if !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
Chris@16: 
Chris@16:     template < BOOST_VARIANT_ENUM_PARAMS(typename U) >
Chris@16:     friend class variant;
Chris@16: 
Chris@16: private:
Chris@16: 
Chris@16: #else// defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
Chris@16: 
Chris@16: public:
Chris@16: 
Chris@16: #endif// !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
Chris@16: 
Chris@16:     template <typename Visitor, typename VoidPtrCV>
Chris@16:     static
Chris@16:         BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(
Chris@16:               typename Visitor::result_type
Chris@16:             )
Chris@16:     internal_apply_visitor_impl(
Chris@16:           int internal_which
Chris@16:         , int logical_which
Chris@16:         , Visitor& visitor
Chris@16:         , VoidPtrCV storage
Chris@16:         )
Chris@16:     {
Chris@16:         typedef mpl::int_<0> first_which;
Chris@16:         typedef typename mpl::begin<internal_types>::type first_it;
Chris@16:         typedef typename mpl::end<internal_types>::type last_it;
Chris@16: 
Chris@16:         typedef detail::variant::visitation_impl_step<
Chris@16:               first_it, last_it
Chris@16:             > first_step;
Chris@16: 
Chris@16:         return detail::variant::visitation_impl(
Chris@16:               internal_which, logical_which
Chris@16:             , visitor, storage, mpl::false_()
Chris@16:             , never_uses_backup_flag()
Chris@16:             , static_cast<first_which*>(0), static_cast<first_step*>(0)
Chris@16:             );
Chris@16:     }
Chris@16: 
Chris@16:     template <typename Visitor>
Chris@16:         BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(
Chris@16:               typename Visitor::result_type
Chris@16:             )
Chris@16:     internal_apply_visitor(Visitor& visitor)
Chris@16:     {
Chris@16:         return internal_apply_visitor_impl(
Chris@16:               which_, which(), visitor, storage_.address()
Chris@16:             );
Chris@16:     }
Chris@16: 
Chris@16:     template <typename Visitor>
Chris@16:         BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(
Chris@16:               typename Visitor::result_type
Chris@16:             )
Chris@16:     internal_apply_visitor(Visitor& visitor) const
Chris@16:     {
Chris@16:         return internal_apply_visitor_impl(
Chris@16:               which_, which(), visitor, storage_.address()
Chris@16:             );
Chris@16:     }
Chris@16: 
Chris@16: public: // visitation support
Chris@16: 
Chris@16:     template <typename Visitor>
Chris@16:         BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(
Chris@16:               typename Visitor::result_type
Chris@16:             )
Chris@16:     apply_visitor(Visitor& visitor)
Chris@16:     {
Chris@16:         detail::variant::invoke_visitor<Visitor> invoker(visitor);
Chris@16:         return this->internal_apply_visitor(invoker);
Chris@16:     }
Chris@16: 
Chris@16:     template <typename Visitor>
Chris@16:         BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(
Chris@16:               typename Visitor::result_type
Chris@16:             )
Chris@16:     apply_visitor(Visitor& visitor) const
Chris@16:     {
Chris@16:         detail::variant::invoke_visitor<Visitor> invoker(visitor);
Chris@16:         return this->internal_apply_visitor(invoker);
Chris@16:     }
Chris@16: 
Chris@16: }; // class variant
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // metafunction make_variant_over
Chris@16: //
Chris@16: // See docs and boost/variant/variant_fwd.hpp for more information.
Chris@16: //
Chris@16: template <typename Types>
Chris@16: struct make_variant_over
Chris@16: {
Chris@16: private: // precondition assertions
Chris@16: 
Chris@16:     BOOST_STATIC_ASSERT(( ::boost::mpl::is_sequence<Types>::value ));
Chris@16: 
Chris@16: public: // metafunction result
Chris@16: 
Chris@16:     typedef variant<
Chris@16:           detail::variant::over_sequence< Types >
Chris@16:         > type;
Chris@16: 
Chris@16: };
Chris@16: 
Chris@101: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // function template swap
Chris@16: //
Chris@16: // Swaps two variants of the same type (i.e., identical specification).
Chris@16: //
Chris@16: template < BOOST_VARIANT_ENUM_PARAMS(typename T) >
Chris@16: inline void swap(
Chris@16:       variant< BOOST_VARIANT_ENUM_PARAMS(T) >& lhs
Chris@16:     , variant< BOOST_VARIANT_ENUM_PARAMS(T) >& rhs
Chris@16:     )
Chris@16: {
Chris@16:     lhs.swap(rhs);
Chris@16: }
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: // implementation additions
Chris@16: 
Chris@16: #if !defined(BOOST_NO_IOSTREAM)
Chris@16: #include "boost/variant/detail/variant_io.hpp"
Chris@16: #endif // BOOST_NO_IOSTREAM
Chris@16: 
Chris@16: #endif // BOOST_VARIANT_VARIANT_HPP