boost/signals2/signal_type.hpp

   1 /*
   2   A meta function which supports using named template type parameters
   3   via Boost.Parameter to specify the template type parameters for
   4   the boost::signals2::signal class.
   5
   6   Author: Frank Mori Hess <fmhess@users.sourceforge.net>
   7   Begin: 2009-01-22
   8 */
   9 // Copyright Frank Mori Hess 2009
  10 // Use, modification and
  11 // distribution is subject to the Boost Software License, Version
  12 // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  13 // http://www.boost.org/LICENSE_1_0.txt)
  14
  15 // For more information, see http://www.boost.org
  16
  17 #ifndef BOOST_SIGNALS2_SIGNAL_TYPE_HPP
  18 #define BOOST_SIGNALS2_SIGNAL_TYPE_HPP
  19
  20 // support for function types is currently broken in Boost.Parameter
  21 // #define BOOST_SIGNALS2_NAMED_SIGNATURE_PARAMETER
  22
  23 #include <boost/signals2/signal.hpp>
  24
  25 #if !defined(BOOST_PARAMETER_MAX_ARITY)
  26 #define BOOST_PARAMETER_MAX_ARITY 7
  27 #else
  28 #if BOOST_PARAMETER_MAX_ARITY < 7
  29 #error This header requires BOOST_PARAMETER_MAX_ARITY to be defined as 7 or greater prior to including Boost.Parameter headers
  30 #endif // BOOST_PARAMETER_MAX_ARITY < 7
  31 #endif // !defined(BOOST_PARAMETER_MAX_ARITY)
  32 #include <boost/parameter.hpp>
  33
  34 #include <boost/type_traits/is_function.hpp>
  35
  36 namespace boost
  37 {
  38   namespace signals2
  39   {
  40     namespace keywords
  41     {
  42 #ifdef BOOST_SIGNALS2_NAMED_SIGNATURE_PARAMETER
  43       BOOST_PARAMETER_TEMPLATE_KEYWORD(signature_type)
  44 #endif
  45       BOOST_PARAMETER_TEMPLATE_KEYWORD(combiner_type)
  46       BOOST_PARAMETER_TEMPLATE_KEYWORD(group_type)
  47       BOOST_PARAMETER_TEMPLATE_KEYWORD(group_compare_type)
  48       BOOST_PARAMETER_TEMPLATE_KEYWORD(slot_function_type)
  49       BOOST_PARAMETER_TEMPLATE_KEYWORD(extended_slot_function_type)
  50       BOOST_PARAMETER_TEMPLATE_KEYWORD(mutex_type)
  51     } // namespace keywords
  52
  53     template <
  54 #ifdef BOOST_SIGNALS2_NAMED_SIGNATURE_PARAMETER
  55         typename A0,
  56 #else
  57         typename Signature,
  58 #endif
  59         typename A1 = parameter::void_,
  60         typename A2 = parameter::void_,
  61         typename A3 = parameter::void_,
  62         typename A4 = parameter::void_,
  63         typename A5 = parameter::void_,
  64         typename A6 = parameter::void_
  65       >
  66     class signal_type
  67     {
  68       typedef parameter::parameters<
  69 #ifdef BOOST_SIGNALS2_NAMED_SIGNATURE_PARAMETER
  70           parameter::required<keywords::tag::signature_type, is_function<boost::mpl::_> >,
  71 #endif
  72           parameter::optional<keywords::tag::combiner_type>,
  73           parameter::optional<keywords::tag::group_type>,
  74           parameter::optional<keywords::tag::group_compare_type>,
  75           parameter::optional<keywords::tag::slot_function_type>,
  76           parameter::optional<keywords::tag::extended_slot_function_type>,
  77           parameter::optional<keywords::tag::mutex_type>
  78         > parameter_spec;
  79
  80     public:
  81       // ArgumentPack
  82       typedef typename
  83         parameter_spec::bind<
  84 #ifdef BOOST_SIGNALS2_NAMED_SIGNATURE_PARAMETER
  85         A0,
  86 #endif
  87         A1, A2, A3, A4, A5, A6>::type
  88         args;
  89
  90 #ifdef BOOST_SIGNALS2_NAMED_SIGNATURE_PARAMETER
  91       typedef typename parameter::value_type<args, keywords::tag::signature_type>::type
  92         signature_type;
  93 #else
  94       typedef Signature signature_type;
  95 #endif
  96
  97       typedef typename parameter::value_type
  98         <
  99           args,
 100           keywords::tag::combiner_type,
 101           optional_last_value
 102             <
 103               typename boost::function_traits<signature_type>::result_type
 104             >
 105         >::type combiner_type;
 106
 107       typedef typename
 108         parameter::value_type<args, keywords::tag::group_type, int>::type group_type;
 109
 110       typedef typename
 111         parameter::value_type<args, keywords::tag::group_compare_type, std::less<group_type> >::type
 112         group_compare_type;
 113
 114       typedef typename
 115         parameter::value_type<args, keywords::tag::slot_function_type, function<signature_type> >::type
 116         slot_function_type;
 117
 118       typedef typename
 119         parameter::value_type
 120           <
 121             args,
 122             keywords::tag::extended_slot_function_type,
 123             typename detail::extended_signature<function_traits<signature_type>::arity, signature_type>::function_type
 124           >::type
 125           extended_slot_function_type;
 126
 127       typedef typename
 128         parameter::value_type<args, keywords::tag::mutex_type, mutex>::type mutex_type;
 129
 130       typedef signal
 131         <
 132           signature_type,
 133           combiner_type,
 134           group_type,
 135           group_compare_type,
 136           slot_function_type,
 137           extended_slot_function_type,
 138           mutex_type
 139         > type;
 140     };
 141   } // namespace signals2
 142 } // namespace boost
 143
 144 #endif // BOOST_SIGNALS2_SIGNAL_TYPE_HPP