1 // Copyright Daniel Wallin 2006. Use, modification and distribution is

     2 // subject to the Boost Software License, Version 1.0. (See accompanying

     3 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

     4 

     5 #ifndef BOOST_PARAMETER_TEMPLATE_KEYWORD_060203_HPP

     6 # define BOOST_PARAMETER_TEMPLATE_KEYWORD_060203_HPP

     7 

     8 # include <boost/mpl/and.hpp>

     9 # include <boost/mpl/not.hpp>

    10 # include <boost/type_traits/is_convertible.hpp>

    11 # include <boost/type_traits/is_reference.hpp>

    12 

    13 namespace boost { namespace parameter { 

    14 

    15 namespace aux 

    16 {

    17 

    18   struct template_keyword_tag {}; 

    19 

    20   template <class T, class U>

    21   struct is_pointer_convertible

    22     : is_convertible<T*, U*>

    23   {};

    24 

    25   template <class T>

    26   struct is_template_keyword

    27     : mpl::and_<

    28           mpl::not_<is_reference<T> >

    29         , is_pointer_convertible<T, template_keyword_tag>

    30       >

    31   {};

    32 

    33 } // namespace aux

    34 

    35 template <class Tag, class T>

    36 struct template_keyword

    37   : aux::template_keyword_tag

    38 {

    39     typedef Tag key_type;

    40     typedef T value_type;

    41     typedef value_type reference;

    42 };

    43 

    44 }} // namespace boost::parameter

    45 

    46 #endif // BOOST_PARAMETER_TEMPLATE_KEYWORD_060203_HPP

    47