sl@0: //-----------------------------------------------------------------------------
sl@0: // boost variant/recursive_variant.hpp header file
sl@0: // See http://www.boost.org for updates, documentation, and revision history.
sl@0: //-----------------------------------------------------------------------------
sl@0: //
sl@0: // Copyright (c) 2003
sl@0: // Eric Friedman
sl@0: //
sl@0: // Distributed under the Boost Software License, Version 1.0. (See
sl@0: // accompanying file LICENSE_1_0.txt or copy at
sl@0: // http://www.boost.org/LICENSE_1_0.txt)
sl@0: 
sl@0: #ifndef BOOST_VARIANT_RECURSIVE_VARIANT_HPP
sl@0: #define BOOST_VARIANT_RECURSIVE_VARIANT_HPP
sl@0: 
sl@0: #include "boost/variant/variant_fwd.hpp"
sl@0: #include "boost/variant/detail/enable_recursive.hpp"
sl@0: #include "boost/variant/detail/substitute_fwd.hpp"
sl@0: #include "boost/variant/detail/make_variant_list.hpp"
sl@0: #include "boost/variant/detail/over_sequence.hpp"
sl@0: 
sl@0: #include "boost/mpl/aux_/lambda_arity_param.hpp"
sl@0: 
sl@0: #if !defined(BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT)
sl@0: #   include "boost/mpl/eval_if.hpp"
sl@0: #   include "boost/mpl/identity.hpp"
sl@0: #   include "boost/mpl/protect.hpp"
sl@0: #   include "boost/mpl/transform.hpp"
sl@0: #else
sl@0: #   include "boost/preprocessor/cat.hpp"
sl@0: #   include "boost/preprocessor/repeat.hpp"
sl@0: #endif
sl@0: 
sl@0: #include "boost/mpl/bool.hpp"
sl@0: #include "boost/mpl/is_sequence.hpp"
sl@0: #include "boost/variant/variant.hpp"
sl@0: 
sl@0: namespace boost {
sl@0: 
sl@0: namespace detail { namespace variant {
sl@0: 
sl@0: ///////////////////////////////////////////////////////////////////////////////
sl@0: // (detail) metafunction specialization substitute
sl@0: //
sl@0: // Handles embedded variant types when substituting for recursive_variant_.
sl@0: //
sl@0: 
sl@0: #if !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
sl@0: 
sl@0: template <
sl@0:       BOOST_VARIANT_ENUM_PARAMS(typename T)
sl@0:     , typename RecursiveVariant
sl@0:       BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(typename Arity)
sl@0:     >
sl@0: struct substitute<
sl@0:       ::boost::variant<
sl@0:           recursive_flag< T0 >
sl@0:         , BOOST_VARIANT_ENUM_SHIFTED_PARAMS(T)
sl@0:         >
sl@0:     , RecursiveVariant
sl@0:     , ::boost::recursive_variant_
sl@0:       BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(Arity)
sl@0:     >
sl@0: {
sl@0:     typedef ::boost::variant<
sl@0:           recursive_flag< T0 >
sl@0:         , BOOST_VARIANT_ENUM_SHIFTED_PARAMS(T)
sl@0:         > type;
sl@0: };
sl@0: 
sl@0: template <
sl@0:       BOOST_VARIANT_ENUM_PARAMS(typename T)
sl@0:     , typename RecursiveVariant
sl@0:       BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(typename Arity)
sl@0:     >
sl@0: struct substitute<
sl@0:       ::boost::variant< BOOST_VARIANT_ENUM_PARAMS(T) >
sl@0:     , RecursiveVariant
sl@0:     , ::boost::recursive_variant_
sl@0:       BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(Arity)
sl@0:     >
sl@0: {
sl@0: 
sl@0: #if !defined(BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT)
sl@0: 
sl@0: private: // helpers, for metafunction result (below)
sl@0: 
sl@0:     typedef typename mpl::eval_if<
sl@0:           ::boost::detail::variant::is_over_sequence<T0>
sl@0:         , mpl::identity< T0 >
sl@0:         , make_variant_list< BOOST_VARIANT_ENUM_PARAMS(T) >
sl@0:         >::type initial_types;
sl@0: 
sl@0:     typedef typename mpl::transform<
sl@0:           initial_types
sl@0:         , mpl::protect< quoted_enable_recursive<RecursiveVariant,mpl::true_> >
sl@0:         >::type types;
sl@0: 
sl@0: public: // metafunction result
sl@0: 
sl@0:     typedef ::boost::variant< types > type;
sl@0: 
sl@0: #else // defined(BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT)
sl@0: 
sl@0: private: // helpers, for metafunction result (below)
sl@0: 
sl@0:     #define BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS(z,N,_)  \
sl@0:         typedef typename enable_recursive<   \
sl@0:               BOOST_PP_CAT(T,N)              \
sl@0:             , RecursiveVariant               \
sl@0:             , mpl::true_                     \
sl@0:             >::type BOOST_PP_CAT(wknd_T,N);  \
sl@0:         /**/
sl@0: 
sl@0:     BOOST_PP_REPEAT(
sl@0:           BOOST_VARIANT_LIMIT_TYPES
sl@0:         , BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS
sl@0:         , _
sl@0:         )
sl@0: 
sl@0:     #undef BOOST_VARIANT_AUX_ENABLE_RECURSIVE_TYPEDEFS
sl@0: 
sl@0: public: // metafunction result
sl@0: 
sl@0:     typedef ::boost::variant< BOOST_VARIANT_ENUM_PARAMS(wknd_T) > type;
sl@0: 
sl@0: #endif // BOOST_VARIANT_NO_TYPE_SEQUENCE_SUPPORT workaround
sl@0: 
sl@0: };
sl@0: 
sl@0: #else // defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
sl@0: 
sl@0: //
sl@0: // no specializations: embedded variants unsupported on these compilers!
sl@0: //
sl@0: 
sl@0: #endif // !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)
sl@0: 
sl@0: }} // namespace detail::variant
sl@0: 
sl@0: ///////////////////////////////////////////////////////////////////////////////
sl@0: // metafunction make_recursive_variant
sl@0: //
sl@0: // See docs and boost/variant/variant_fwd.hpp for more information.
sl@0: //
sl@0: template < BOOST_VARIANT_ENUM_PARAMS(typename T) >
sl@0: struct make_recursive_variant
sl@0: {
sl@0: public: // metafunction result
sl@0: 
sl@0:     typedef boost::variant<
sl@0:           detail::variant::recursive_flag< T0 >
sl@0:         , BOOST_VARIANT_ENUM_SHIFTED_PARAMS(T)
sl@0:         > type;
sl@0: 
sl@0: };
sl@0: 
sl@0: ///////////////////////////////////////////////////////////////////////////////
sl@0: // metafunction make_recursive_variant_over
sl@0: //
sl@0: // See docs and boost/variant/variant_fwd.hpp for more information.
sl@0: //
sl@0: template <typename Types>
sl@0: struct make_recursive_variant_over
sl@0: {
sl@0: private: // precondition assertions
sl@0: 
sl@0: #if !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)
sl@0:     BOOST_STATIC_ASSERT(( ::boost::mpl::is_sequence<Types>::value ));
sl@0: #endif
sl@0: 
sl@0: public: // metafunction result
sl@0: 
sl@0:     typedef typename make_recursive_variant<
sl@0:           detail::variant::over_sequence< Types >
sl@0:         >::type type;
sl@0: 
sl@0: };
sl@0: 
sl@0: } // namespace boost
sl@0: 
sl@0: #endif // BOOST_VARIANT_RECURSIVE_VARIANT_HPP