luabind/detail/compute_score.hpp

   1 // Copyright Daniel Wallin 2008. 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 LUABIND_COMPUTE_RANK_081006_HPP
   6 # define LUABIND_COMPUTE_RANK_081006_HPP
   7
   8 # include <luabind/config.hpp>
   9 # include <luabind/detail/policy.hpp>
  10 # include <boost/mpl/apply_wrap.hpp>
  11 # include <boost/mpl/begin_end.hpp>
  12 # include <boost/mpl/int.hpp>
  13 # include <boost/mpl/next.hpp>
  14
  15 namespace luabind { namespace detail {
  16
  17 namespace mpl = boost::mpl;
  18
  19 template <class Idx, class Iter, class End, class Policies>
  20 int compute_score_aux(
  21     lua_State*L, int index, Idx, Iter, End end, Policies const& policies)
  22 {
  23     typedef typename Iter::type arg_type;
  24     typedef typename find_conversion_policy<Idx::value, Policies>::type
  25         conversion_policy;
  26     typedef typename mpl::apply_wrap2<
  27         conversion_policy, arg_type, lua_to_cpp>::type converter;
  28
  29     int score = converter::match(L, LUABIND_DECORATE_TYPE(arg_type), index);
  30
  31     if (score < 0)
  32         return score;
  33
  34     if (conversion_policy::has_arg)
  35         ++index;
  36
  37     int next = compute_score_aux(
  38         L
  39       , index
  40       , typename mpl::next<Idx>::type()
  41       , typename mpl::next<Iter>::type()
  42       , end
  43       , policies
  44     );
  45
  46     if (next < 0)
  47         return next;
  48
  49     return score + next;
  50 }
  51
  52 template <class Idx, class End, class Policies>
  53 int compute_score_aux(lua_State*, int, Idx, End, End, Policies const&)
  54 {
  55     return 0;
  56 }
  57
  58 template <class Signature, class Policies>
  59 int compute_score(lua_State* L, Signature, Policies const& policies)
  60 {
  61     return compute_score_aux(
  62         L
  63       , 1
  64       , mpl::int_<1>()
  65       , typename mpl::next<typename mpl::begin<Signature>::type>::type()
  66       , typename mpl::end<Signature>::type()
  67       , policies
  68     );
  69 }
  70
  71 template <class Iter, class End, class Idx, class Policies>
  72 int compute_arity_aux(Iter, End end, Idx, Policies const& policies)
  73 {
  74     typedef typename find_conversion_policy<Idx::value, Policies>::type
  75         conversion_policy;
  76
  77     int next = compute_arity_aux(
  78         typename mpl::next<Iter>::type()
  79       , end
  80       , typename mpl::next<Idx>::type()
  81       , policies
  82     );
  83
  84     return (conversion_policy::has_arg ? 1 : 0) + next;
  85 }
  86
  87 template <class End, class Idx, class Policies>
  88 int compute_arity_aux(End, End, Idx, Policies const&)
  89 {
  90     return 0;
  91 }
  92
  93 template <class Signature, class Policies>
  94 int compute_arity(Signature, Policies const& policies)
  95 {
  96     return compute_arity_aux(
  97         typename mpl::next<typename mpl::begin<Signature>::type>::type()
  98       , typename mpl::end<Signature>::type()
  99       , mpl::int_<1>()
 100       , policies
 101     );
 102 }
 103
 104 }} // namespace luabind::detail
 105
 106 #endif // LUABIND_COMPUTE_RANK_081006_HPP