//-----------------------------------------------------------------------------

 // boost variant/detail/substitute_fwd.hpp header file

 // See http://www.boost.org for updates, documentation, and revision history.

 //-----------------------------------------------------------------------------

 //

 // Copyright (c) 2003

 // Eric Friedman

 //

 // Distributed under the Boost Software License, Version 1.0. (See

 // accompanying file LICENSE_1_0.txt or copy at

 // http://www.boost.org/LICENSE_1_0.txt)

 #ifndef BOOST_VARIANT_DETAIL_SUBSTITUTE_FWD_HPP

 #define BOOST_VARIANT_DETAIL_SUBSTITUTE_FWD_HPP

 #include "boost/mpl/aux_/lambda_arity_param.hpp"

 #include "boost/mpl/aux_/template_arity.hpp"

 #include "boost/mpl/int_fwd.hpp"

 ///////////////////////////////////////////////////////////////////////////////

 // BOOST_VARIANT_DETAIL_NO_SUBSTITUTE

 //

 // Defined if 'substitute' is not implementable on the current compiler.

 //

 #include "boost/mpl/aux_/config/ctps.hpp"

 #include "boost/mpl/aux_/config/ttp.hpp"

 #if defined(BOOST_NO_TEMPLATE_TEMPLATE_PARAMETERS) \

  || defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) \

  && !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)

 #   define BOOST_VARIANT_DETAIL_NO_SUBSTITUTE

 #endif

 namespace boost {

 namespace detail { namespace variant {

 #if !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)

 ///////////////////////////////////////////////////////////////////////////////

 // metafunction substitute

 //

 // Substitutes one type for another in the given type expression.

 //

 template <

       typename T, typename Dest, typename Source

       BOOST_MPL_AUX_LAMBDA_ARITY_PARAM(

           typename Arity = mpl::int_< mpl::aux::template_arity<T>::value >

         )

     >

 struct substitute;

 #endif // !defined(BOOST_VARIANT_DETAIL_NO_SUBSTITUTE)

 }} // namespace detail::variant

 } // namespace boost

 #endif // BOOST_VARIANT_DETAIL_SUBSTITUTE_FWD_HPP