Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //
Chris@16: // Copyright David Abrahams 2002, Joel de Guzman, 2002.
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: #ifndef INIT_JDG20020820_HPP
Chris@16: #define INIT_JDG20020820_HPP
Chris@16: 
Chris@16: # include <boost/python/detail/prefix.hpp>
Chris@16: 
Chris@16: #include <boost/python/detail/type_list.hpp>
Chris@16: #include <boost/python/args_fwd.hpp>
Chris@16: #include <boost/python/detail/make_keyword_range_fn.hpp>
Chris@16: #include <boost/python/def_visitor.hpp>
Chris@16: 
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: #include <boost/mpl/eval_if.hpp>
Chris@16: #include <boost/mpl/size.hpp>
Chris@16: #include <boost/mpl/iterator_range.hpp>
Chris@16: #include <boost/mpl/empty.hpp>
Chris@16: #include <boost/mpl/begin_end.hpp>
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/mpl/prior.hpp>
Chris@16: #include <boost/mpl/joint_view.hpp>
Chris@16: #include <boost/mpl/back.hpp>
Chris@16: 
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: 
Chris@16: #include <boost/preprocessor/enum_params_with_a_default.hpp>
Chris@16: #include <boost/preprocessor/enum_params.hpp>
Chris@16: 
Chris@16: #include <utility>
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: #define BOOST_PYTHON_OVERLOAD_TYPES_WITH_DEFAULT                                \
Chris@16:     BOOST_PP_ENUM_PARAMS_WITH_A_DEFAULT(                                        \
Chris@16:         BOOST_PYTHON_MAX_ARITY,                                                 \
Chris@16:         class T,                                                                \
Chris@16:         mpl::void_)                                                             \
Chris@16: 
Chris@16: #define BOOST_PYTHON_OVERLOAD_TYPES                                             \
Chris@16:     BOOST_PP_ENUM_PARAMS_Z(1,                                                   \
Chris@16:         BOOST_PYTHON_MAX_ARITY,                                                 \
Chris@16:         class T)                                                                \
Chris@16: 
Chris@16: #define BOOST_PYTHON_OVERLOAD_ARGS                                              \
Chris@16:     BOOST_PP_ENUM_PARAMS_Z(1,                                                   \
Chris@16:         BOOST_PYTHON_MAX_ARITY,                                                 \
Chris@16:         T)                                                                      \
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace boost { namespace python {
Chris@16: 
Chris@16: template <BOOST_PYTHON_OVERLOAD_TYPES_WITH_DEFAULT>
Chris@16: class init; // forward declaration
Chris@16: 
Chris@16: 
Chris@16: template <BOOST_PYTHON_OVERLOAD_TYPES_WITH_DEFAULT>
Chris@16: struct optional; // forward declaration
Chris@16: 
Chris@16: namespace detail
Chris@16: {
Chris@16:   namespace error
Chris@16:   {
Chris@16:     template <int keywords, int init_args>
Chris@16:     struct more_keywords_than_init_arguments
Chris@16:     {
Chris@16:         typedef char too_many_keywords[init_args - keywords >= 0 ? 1 : -1];
Chris@16:     };
Chris@16:   }
Chris@16: 
Chris@16:   //  is_optional<T>::value
Chris@16:   //
Chris@16:   //      This metaprogram checks if T is an optional
Chris@16:   //
Chris@16: #if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
Chris@16: 
Chris@16:     template <class T>
Chris@16:     struct is_optional {
Chris@16: 
Chris@16:     private:
Chris@16: 
Chris@16:         template <BOOST_PYTHON_OVERLOAD_TYPES>
Chris@16:         static boost::type_traits::yes_type f(optional<BOOST_PYTHON_OVERLOAD_ARGS>);
Chris@16:         static boost::type_traits::no_type f(...);
Chris@16:         static T t();
Chris@16: 
Chris@16:     public:
Chris@16: 
Chris@16:         BOOST_STATIC_CONSTANT(
Chris@16:             bool, value =
Chris@16:                 sizeof(f(t())) == sizeof(::boost::type_traits::yes_type));
Chris@16:         typedef mpl::bool_<value> type;
Chris@16:     };
Chris@16: 
Chris@16: #else
Chris@16: 
Chris@16:     template <class T>
Chris@16:     struct is_optional
Chris@16:       : mpl::false_
Chris@16:     {};
Chris@16: 
Chris@16:     template <BOOST_PYTHON_OVERLOAD_TYPES>
Chris@16:     struct is_optional<optional<BOOST_PYTHON_OVERLOAD_ARGS> >
Chris@16:       : mpl::true_
Chris@16:     {};
Chris@16:   
Chris@16: #endif
Chris@16: 
Chris@16:   template <int NDefaults>
Chris@16:   struct define_class_init_helper;
Chris@16: 
Chris@16: } // namespace detail
Chris@16: 
Chris@16: template <class DerivedT>
Chris@16: struct init_base : def_visitor<DerivedT>
Chris@16: {
Chris@16:     init_base(char const* doc_, detail::keyword_range const& keywords_)
Chris@16:         : m_doc(doc_), m_keywords(keywords_)
Chris@16:     {}
Chris@16:         
Chris@16:     init_base(char const* doc_)
Chris@16:         : m_doc(doc_)
Chris@16:     {}
Chris@16: 
Chris@16:     DerivedT const& derived() const
Chris@16:     {
Chris@16:         return *static_cast<DerivedT const*>(this);
Chris@16:     }
Chris@16:     
Chris@16:     char const* doc_string() const
Chris@16:     {
Chris@16:         return m_doc;
Chris@16:     }
Chris@16: 
Chris@16:     detail::keyword_range const& keywords() const
Chris@16:     {
Chris@16:         return m_keywords;
Chris@16:     }
Chris@16: 
Chris@16:     static default_call_policies call_policies()
Chris@16:     {
Chris@16:         return default_call_policies();
Chris@16:     }
Chris@16: 
Chris@16:  private:
Chris@16:     //  visit
Chris@16:     //
Chris@16:     //      Defines a set of n_defaults + 1 constructors for its
Chris@16:     //      class_<...> argument. Each constructor after the first has
Chris@16:     //      one less argument to its right. Example:
Chris@16:     //
Chris@16:     //          init<int, optional<char, long, double> >
Chris@16:     //
Chris@16:     //      Defines:
Chris@16:     //
Chris@16:     //          __init__(int, char, long, double)
Chris@16:     //          __init__(int, char, long)
Chris@16:     //          __init__(int, char)
Chris@16:     //          __init__(int)
Chris@16:     template <class classT>
Chris@16:     void visit(classT& cl) const
Chris@16:     {
Chris@16:         typedef typename DerivedT::signature signature;
Chris@16:         typedef typename DerivedT::n_arguments n_arguments;
Chris@16:         typedef typename DerivedT::n_defaults n_defaults;
Chris@16:     
Chris@16:         detail::define_class_init_helper<n_defaults::value>::apply(
Chris@16:             cl
Chris@16:           , derived().call_policies()
Chris@16:           , signature()
Chris@16:           , n_arguments()
Chris@16:           , derived().doc_string()
Chris@16:           , derived().keywords());
Chris@16:     }
Chris@16:     
Chris@16:     friend class python::def_visitor_access;
Chris@16:     
Chris@16:  private: // data members
Chris@16:     char const* m_doc;
Chris@16:     detail::keyword_range m_keywords;
Chris@16: };
Chris@16: 
Chris@16: template <class CallPoliciesT, class InitT>
Chris@16: class init_with_call_policies
Chris@16:     : public init_base<init_with_call_policies<CallPoliciesT, InitT> >
Chris@16: {
Chris@16:     typedef init_base<init_with_call_policies<CallPoliciesT, InitT> > base;
Chris@16:  public:
Chris@16:     typedef typename InitT::n_arguments n_arguments;
Chris@16:     typedef typename InitT::n_defaults n_defaults;
Chris@16:     typedef typename InitT::signature signature;
Chris@16: 
Chris@16:     init_with_call_policies(
Chris@16:         CallPoliciesT const& policies_
Chris@16:         , char const* doc_
Chris@16:         , detail::keyword_range const& keywords
Chris@16:         )
Chris@16:         : base(doc_, keywords)
Chris@16:         , m_policies(policies_)
Chris@16:     {}
Chris@16: 
Chris@16:     CallPoliciesT const& call_policies() const
Chris@16:     {
Chris@16:         return this->m_policies;
Chris@16:     }
Chris@16:     
Chris@16:  private: // data members
Chris@16:     CallPoliciesT m_policies;
Chris@16: };
Chris@16: 
Chris@16: //
Chris@16: // drop1<S> is the initial length(S) elements of S
Chris@16: //
Chris@16: namespace detail
Chris@16: {
Chris@16:   template <class S>
Chris@16:   struct drop1
Chris@16:     : mpl::iterator_range<
Chris@16:           typename mpl::begin<S>::type
Chris@16:         , typename mpl::prior<
Chris@16:               typename mpl::end<S>::type
Chris@16:           >::type
Chris@16:       >
Chris@16:   {};
Chris@16: }
Chris@16: 
Chris@16: template <BOOST_PYTHON_OVERLOAD_TYPES>
Chris@16: class init : public init_base<init<BOOST_PYTHON_OVERLOAD_ARGS> >
Chris@16: {
Chris@16:     typedef init_base<init<BOOST_PYTHON_OVERLOAD_ARGS> > base;
Chris@16:  public:
Chris@16:     typedef init<BOOST_PYTHON_OVERLOAD_ARGS> self_t;
Chris@16: 
Chris@16:     init(char const* doc_ = 0)
Chris@16:         : base(doc_)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     template <std::size_t N>
Chris@16:     init(char const* doc_, detail::keywords<N> const& kw)
Chris@16:         : base(doc_, kw.range())
Chris@16:     {
Chris@16:         typedef typename detail::error::more_keywords_than_init_arguments<
Chris@16:             N, n_arguments::value + 1
Chris@16:             >::too_many_keywords assertion;
Chris@16:     }
Chris@16: 
Chris@16:     template <std::size_t N>
Chris@16:     init(detail::keywords<N> const& kw, char const* doc_ = 0)
Chris@16:         : base(doc_, kw.range())
Chris@16:     {
Chris@16:         typedef typename detail::error::more_keywords_than_init_arguments<
Chris@16:             N, n_arguments::value + 1
Chris@16:             >::too_many_keywords assertion;
Chris@16:     }
Chris@16: 
Chris@16:     template <class CallPoliciesT>
Chris@16:     init_with_call_policies<CallPoliciesT, self_t>
Chris@16:     operator[](CallPoliciesT const& policies) const
Chris@16:     {
Chris@16:         return init_with_call_policies<CallPoliciesT, self_t>(
Chris@16:             policies, this->doc_string(), this->keywords());
Chris@16:     }
Chris@16: 
Chris@16:     typedef detail::type_list<BOOST_PYTHON_OVERLOAD_ARGS> signature_;
Chris@16: 
Chris@16:     typedef detail::is_optional<
Chris@16:         typename mpl::eval_if<
Chris@16:             mpl::empty<signature_>
Chris@16:           , mpl::false_
Chris@16:           , mpl::back<signature_>
Chris@16:         >::type
Chris@16:     > back_is_optional;
Chris@16:     
Chris@16:     typedef typename mpl::eval_if<
Chris@16:         back_is_optional
Chris@16:       , mpl::back<signature_>
Chris@16:       , mpl::vector0<>
Chris@16:     >::type optional_args;
Chris@16: 
Chris@16:     typedef typename mpl::eval_if<
Chris@16:         back_is_optional
Chris@16:       , mpl::if_<
Chris@16:             mpl::empty<optional_args>
Chris@16:           , detail::drop1<signature_>
Chris@16:           , mpl::joint_view<
Chris@16:                 detail::drop1<signature_>
Chris@16:               , optional_args
Chris@16:             >
Chris@16:         >
Chris@16:       , signature_
Chris@16:     >::type signature;
Chris@16: 
Chris@16:     // TODO: static assert to make sure there are no other optional elements
Chris@16: 
Chris@16:     // Count the number of default args
Chris@16:     typedef mpl::size<optional_args> n_defaults;
Chris@16:     typedef mpl::size<signature> n_arguments;
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //
Chris@16: //  optional
Chris@16: //
Chris@16: //      optional<T0...TN>::type returns a typelist.
Chris@16: //
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: template <BOOST_PYTHON_OVERLOAD_TYPES>
Chris@16: struct optional
Chris@16:     : detail::type_list<BOOST_PYTHON_OVERLOAD_ARGS>
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: namespace detail
Chris@16: {
Chris@16:   template <class ClassT, class CallPoliciesT, class Signature, class NArgs>
Chris@16:   inline void def_init_aux(
Chris@16:       ClassT& cl
Chris@16:       , Signature const&
Chris@16:       , NArgs
Chris@16:       , CallPoliciesT const& policies
Chris@16:       , char const* doc
Chris@16:       , detail::keyword_range const& keywords_
Chris@16:       )
Chris@16:   {
Chris@16:       cl.def(
Chris@16:           "__init__"
Chris@16:         , detail::make_keyword_range_constructor<Signature,NArgs>(
Chris@16:               policies
Chris@16:             , keywords_
Chris@16:             , (typename ClassT::metadata::holder*)0
Chris@16:           )
Chris@16:         , doc
Chris@16:       );
Chris@16:   }
Chris@16: 
Chris@16:   ///////////////////////////////////////////////////////////////////////////////
Chris@16:   //
Chris@16:   //  define_class_init_helper<N>::apply
Chris@16:   //
Chris@16:   //      General case
Chris@16:   //
Chris@16:   //      Accepts a class_ and an arguments list. Defines a constructor
Chris@16:   //      for the class given the arguments and recursively calls
Chris@16:   //      define_class_init_helper<N-1>::apply with one fewer argument (the
Chris@16:   //      rightmost argument is shaved off)
Chris@16:   //
Chris@16:   ///////////////////////////////////////////////////////////////////////////////
Chris@16:   template <int NDefaults>
Chris@16:   struct define_class_init_helper
Chris@16:   {
Chris@16: 
Chris@16:       template <class ClassT, class CallPoliciesT, class Signature, class NArgs>
Chris@16:       static void apply(
Chris@16:           ClassT& cl
Chris@16:           , CallPoliciesT const& policies
Chris@16:           , Signature const& args
Chris@16:           , NArgs
Chris@16:           , char const* doc
Chris@16:           , detail::keyword_range keywords)
Chris@16:       {
Chris@16:           detail::def_init_aux(cl, args, NArgs(), policies, doc, keywords);
Chris@16: 
Chris@16:           if (keywords.second > keywords.first)
Chris@16:               --keywords.second;
Chris@16: 
Chris@16:           typedef typename mpl::prior<NArgs>::type next_nargs;
Chris@16:           define_class_init_helper<NDefaults-1>::apply(
Chris@16:               cl, policies, Signature(), next_nargs(), doc, keywords);
Chris@16:       }
Chris@16:   };
Chris@16: 
Chris@16:   ///////////////////////////////////////////////////////////////////////////////
Chris@16:   //
Chris@16:   //  define_class_init_helper<0>::apply
Chris@16:   //
Chris@16:   //      Terminal case
Chris@16:   //
Chris@16:   //      Accepts a class_ and an arguments list. Defines a constructor
Chris@16:   //      for the class given the arguments.
Chris@16:   //
Chris@16:   ///////////////////////////////////////////////////////////////////////////////
Chris@16:   template <>
Chris@16:   struct define_class_init_helper<0> {
Chris@16: 
Chris@16:       template <class ClassT, class CallPoliciesT, class Signature, class NArgs>
Chris@16:       static void apply(
Chris@16:           ClassT& cl
Chris@16:         , CallPoliciesT const& policies
Chris@16:         , Signature const& args
Chris@16:         , NArgs
Chris@16:         , char const* doc
Chris@16:         , detail::keyword_range const& keywords)
Chris@16:       {
Chris@16:           detail::def_init_aux(cl, args, NArgs(), policies, doc, keywords);
Chris@16:       }
Chris@16:   };
Chris@16: }
Chris@16: 
Chris@16: }} // namespace boost::python
Chris@16: 
Chris@16: #undef BOOST_PYTHON_OVERLOAD_TYPES_WITH_DEFAULT
Chris@16: #undef BOOST_PYTHON_OVERLOAD_TYPES
Chris@16: #undef BOOST_PYTHON_OVERLOAD_ARGS
Chris@16: #undef BOOST_PYTHON_IS_OPTIONAL_VALUE
Chris@16: #undef BOOST_PYTHON_APPEND_TO_INIT
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: #endif // INIT_JDG20020820_HPP
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: