/*
 * $Id$
 */

/*
 * Copyright (c) 2016 Brook Milligan.
 * 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)
 */

/*
 * XXX - this is not part of Boost.Proto; instead, it is illustrative
 * of a traits class that would make specializing context::eval
 * classes more straightforward.  See the associated example.
 *
 * NOTE: for practical use, the terminal class should also be
 * specialized in the obvious way for boost::proto::basic_expr.
 */

#ifndef BOOST_PROTO_TRAITS_TERMINAL_HPP
#define BOOST_PROTO_TRAITS_TERMINAL_HPP 1

#include <boost/proto/core.hpp>

namespace boost
{

  namespace proto
  {
    
    namespace type_traits
    {
  
      template < typename Expr >
      struct terminal;

      template < typename T >
      struct terminal< boost::proto::expr< boost::proto::tag::terminal,boost::proto::term<T>,0 > >
      {
	typedef T type;
      };
      
      template < typename T >
      struct terminal< boost::proto::expr< boost::proto::tag::terminal,boost::proto::term<T>,0 > const >
      {
	typedef T type;
      };
      
      template < typename Expr >
      using terminal_t = typename terminal<Expr>::type;
      
    } // namespace type_traits

  } // namespace proto

} // namespace boost

#endif