registrations.hpp

来自「Boost provides free peer-reviewed portab」· HPP 代码 · 共 100 行

// 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 REGISTRATIONS_DWA2002223_HPP
# define REGISTRATIONS_DWA2002223_HPP

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

# include <boost/python/type_id.hpp>

# include <boost/python/converter/convertible_function.hpp>
# include <boost/python/converter/constructor_function.hpp>
# include <boost/python/converter/to_python_function_type.hpp>

# include <boost/detail/workaround.hpp>

namespace boost { namespace python { namespace converter { 

struct lvalue_from_python_chain
{
    convertible_function convert;
    lvalue_from_python_chain* next;
};

struct rvalue_from_python_chain
{
    convertible_function convertible;
    constructor_function construct;
    PyTypeObject const* (*expected_pytype)();
    rvalue_from_python_chain* next;
};

struct BOOST_PYTHON_DECL registration
{
 public: // member functions
    explicit registration(type_info target, bool is_shared_ptr = false);
   ~registration();
    
    // Convert the appropriately-typed data to Python
    PyObject* to_python(void const volatile*) const;

    // Return the class object, or raise an appropriate Python
    // exception if no class has been registered.
    PyTypeObject* get_class_object() const;

    // Return common denominator of the python class objects, 
    // convertable to target. Inspects the m_class_object and the value_chains.
    PyTypeObject const* expected_from_python_type() const;
    PyTypeObject const* to_python_target_type() const;

 public: // data members. So sue me.
    const python::type_info target_type;

    // The chain of eligible from_python converters when an lvalue is required
    lvalue_from_python_chain* lvalue_chain;

    // The chain of eligible from_python converters when an rvalue is acceptable
    rvalue_from_python_chain* rvalue_chain;
    
    // The class object associated with this type
    PyTypeObject* m_class_object;

    // The unique to_python converter for the associated C++ type.
    to_python_function_t m_to_python;
    PyTypeObject const* (*m_to_python_target_type)();


    // True iff this type is a shared_ptr.  Needed for special rvalue
    // from_python handling.
    const bool is_shared_ptr;

# if BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
 private:
    void operator=(registration); // This is not defined, and just keeps MWCW happy.
# endif 
};

//
// implementations
//
inline registration::registration(type_info target_type, bool is_shared_ptr)
    : target_type(target_type)
      , lvalue_chain(0)
      , rvalue_chain(0)
      , m_class_object(0)
      , m_to_python(0)
      , m_to_python_target_type(0)
      , is_shared_ptr(is_shared_ptr)
{}

inline bool operator<(registration const& lhs, registration const& rhs)
{
    return lhs.target_type < rhs.target_type;
}

}}} // namespace boost::python::converter

#endif // REGISTRATIONS_DWA2002223_HPP