class.hpp

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// Copyright David Abrahams 2002.
// 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)
#ifndef CLASS_DWA200216_HPP
# define CLASS_DWA200216_HPP

# include <boost/python/detail/prefix.hpp>

# include <boost/noncopyable.hpp>

# include <boost/python/class_fwd.hpp>
# include <boost/python/object/class.hpp>

# include <boost/python/object.hpp>
# include <boost/python/type_id.hpp>
# include <boost/python/data_members.hpp>
# include <boost/python/make_function.hpp>
# include <boost/python/signature.hpp>
# include <boost/python/init.hpp>
# include <boost/python/args_fwd.hpp>

# include <boost/python/object/class_metadata.hpp>
# include <boost/python/object/pickle_support.hpp>
# include <boost/python/object/add_to_namespace.hpp>

# include <boost/python/detail/overloads_fwd.hpp>
# include <boost/python/detail/operator_id.hpp>
# include <boost/python/detail/def_helper.hpp>
# include <boost/python/detail/force_instantiate.hpp>
# include <boost/python/detail/unwrap_type_id.hpp>
# include <boost/python/detail/unwrap_wrapper.hpp>

# include <boost/type_traits/is_same.hpp>
# include <boost/type_traits/is_member_function_pointer.hpp>
# include <boost/type_traits/is_polymorphic.hpp>

# include <boost/mpl/size.hpp>
# include <boost/mpl/for_each.hpp>
# include <boost/mpl/bool.hpp>
# include <boost/mpl/not.hpp>

# include <boost/detail/workaround.hpp>

# if BOOST_WORKAROUND(__MWERKS__, <= 0x3004)                        \
    /* pro9 reintroduced the bug */                                 \
    || (BOOST_WORKAROUND(__MWERKS__, > 0x3100)                      \
        && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3201)))   \
    || BOOST_WORKAROUND(__GNUC__, < 3)

#  define BOOST_PYTHON_NO_MEMBER_POINTER_ORDERING 1

# endif

# ifdef BOOST_PYTHON_NO_MEMBER_POINTER_ORDERING
#  include <boost/mpl/and.hpp>
#  include <boost/type_traits/is_member_pointer.hpp>
# endif

namespace boost { namespace python {

template <class DerivedVisitor> class def_visitor;

enum no_init_t { no_init };

namespace detail
{
  // This function object is used with mpl::for_each to write the id
  // of the type a pointer to which is passed as its 2nd compile-time
  // argument. into the iterator pointed to by its runtime argument
  struct write_type_id
  {
      write_type_id(type_info**p) : p(p) {}

      // Here's the runtime behavior
      template <class T>
      void operator()(T*) const
      {
          *(*p)++ = type_id<T>();
      }

      type_info** p;
  };

  template <class T>
  struct is_data_member_pointer
      : mpl::and_<
            is_member_pointer<T>
          , mpl::not_<is_member_function_pointer<T> >
        >
  {};
  
# ifdef BOOST_PYTHON_NO_MEMBER_POINTER_ORDERING
#  define BOOST_PYTHON_DATA_MEMBER_HELPER(D) , detail::is_data_member_pointer<D>()
#  define BOOST_PYTHON_YES_DATA_MEMBER , mpl::true_
#  define BOOST_PYTHON_NO_DATA_MEMBER , mpl::false_
# elif defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
#  define BOOST_PYTHON_DATA_MEMBER_HELPER(D) , 0
#  define BOOST_PYTHON_YES_DATA_MEMBER , int
#  define BOOST_PYTHON_NO_DATA_MEMBER , ...
# else 
#  define BOOST_PYTHON_DATA_MEMBER_HELPER(D)
#  define BOOST_PYTHON_YES_DATA_MEMBER
#  define BOOST_PYTHON_NO_DATA_MEMBER
# endif
  
  namespace error
  {
    //
    // A meta-assertion mechanism which prints nice error messages and
    // backtraces on lots of compilers. Usage:
    //
    //      assertion<C>::failed
    //
    // where C is an MPL metafunction class
    //
    
    template <class C> struct assertion_failed { };
    template <class C> struct assertion_ok { typedef C failed; };

    template <class C>
    struct assertion
        : mpl::if_<C, assertion_ok<C>, assertion_failed<C> >::type
    {};

    //
    // Checks for validity of arguments used to define virtual
    // functions with default implementations.
    //
    
    template <class Default>
    void not_a_derived_class_member(Default) {}
    
    template <class T, class Fn>
    struct virtual_function_default
    {
        template <class Default>
        static void
        must_be_derived_class_member(Default const&)
        {
            typedef typename assertion<mpl::not_<is_same<Default,Fn> > >::failed test0;
# if !BOOST_WORKAROUND(__MWERKS__, <= 0x2407)
            typedef typename assertion<is_polymorphic<T> >::failed test1;
# endif 
            typedef typename assertion<is_member_function_pointer<Fn> >::failed test2;
            not_a_derived_class_member<Default>(Fn());
        }
    };
  }
}

// This is the primary mechanism through which users will expose
// C++ classes to Python.
template <
    class W // class being wrapped
    , class X1 // = detail::not_specified
    , class X2 // = detail::not_specified
    , class X3 // = detail::not_specified
    >
class class_ : public objects::class_base
{
 public: // types
    typedef objects::class_base base;
    typedef class_<W,X1,X2,X3> self;
    typedef typename objects::class_metadata<W,X1,X2,X3> metadata;
    typedef W wrapped_type;
    
 private: // types

    // A helper class which will contain an array of id objects to be
    // passed to the base class constructor
    struct id_vector
    {
        typedef typename metadata::bases bases;
        
        id_vector()
        {
            // Stick the derived class id into the first element of the array
            ids[0] = detail::unwrap_type_id((W*)0, (W*)0);

            // Write the rest of the elements into succeeding positions.
            type_info* p = ids + 1;
            mpl::for_each(detail::write_type_id(&p), (bases*)0, (add_pointer<mpl::_>*)0);
        }

        BOOST_STATIC_CONSTANT(
            std::size_t, size = mpl::size<bases>::value + 1);
        type_info ids[size];
    };
    friend struct id_vector;

 public: // constructors
    
    // Construct with the class name, with or without docstring, and default __init__() function
    class_(char const* name, char const* doc = 0);

    // Construct with class name, no docstring, and an uncallable __init__ function
    class_(char const* name, no_init_t);

    // Construct with class name, docstring, and an uncallable __init__ function
    class_(char const* name, char const* doc, no_init_t);

    // Construct with class name and init<> function
    template <class DerivedT>
    inline class_(char const* name, init_base<DerivedT> const& i)
        : base(name, id_vector::size, id_vector().ids)
    {
        this->initialize(i);
    }

    // Construct with class name, docstring and init<> function
    template <class DerivedT>
    inline class_(char const* name, char const* doc, init_base<DerivedT> const& i)
        : base(name, id_vector::size, id_vector().ids, doc)
    {
        this->initialize(i);
    }

 public: // member functions
    
    // Generic visitation
    template <class Derived>
    self& def(def_visitor<Derived> const& visitor)
    {
        visitor.visit(*this);
        return *this;
    }

    // Wrap a member function or a non-member function which can take
    // a T, T cv&, or T cv* as its first parameter, a callable
    // python object, or a generic visitor.
    template <class F>
    self& def(char const* name, F f)
    {
        this->def_impl(
            detail::unwrap_wrapper((W*)0)
          , name, f, detail::def_helper<char const*>(0), &f);
        return *this;
    }

    template <class A1, class A2>
    self& def(char const* name, A1 a1, A2 const& a2)
    {
        this->def_maybe_overloads(name, a1, a2, &a2);
        return *this;
    }

    template <class Fn, class A1, class A2>
    self& def(char const* name, Fn fn, A1 const& a1, A2 const& a2)
    {
        //  The arguments are definitely:
        //      def(name, function, policy, doc_string)
        //      def(name, function, doc_string, policy)

        this->def_impl(
            detail::unwrap_wrapper((W*)0)
          , name, fn
          , detail::def_helper<A1,A2>(a1,a2)
          , &fn);

        return *this;
    }

    template <class Fn, class A1, class A2, class A3>
    self& def(char const* name, Fn fn, A1 const& a1, A2 const& a2, A3 const& a3)
    {
        this->def_impl(
            detail::unwrap_wrapper((W*)0)
          , name, fn
          , detail::def_helper<A1,A2,A3>(a1,a2,a3)
          , &fn);

        return *this;
    }

    //
    // Data member access
    //
    template <class D>
    self& def_readonly(char const* name, D const& d)
    {
        return this->def_readonly_impl(name, d BOOST_PYTHON_DATA_MEMBER_HELPER(D));
    }

    template <class D>
    self& def_readwrite(char const* name, D const& d)
    {
        return this->def_readwrite_impl(name, d BOOST_PYTHON_DATA_MEMBER_HELPER(D));
    }
    
    template <class D>
    self& def_readonly(char const* name, D& d)
    {
        return this->def_readonly_impl(name, d BOOST_PYTHON_DATA_MEMBER_HELPER(D));
    }

    template <class D>
    self& def_readwrite(char const* name, D& d)
    {
        return this->def_readwrite_impl(name, d BOOST_PYTHON_DATA_MEMBER_HELPER(D));
    }

    // Property creation
    template <class Get>
    self& add_property(char const* name, Get fget)
    {