// 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 PROXY_DWA2002615_HPP
# define PROXY_DWA2002615_HPP
# include <boost/python/detail/prefix.hpp>
# include <boost/python/object_core.hpp>
# include <boost/python/object_operators.hpp>

namespace boost { namespace python { namespace api {

template <class Policies>
class proxy : public object_operators<proxy<Policies> >
{
 typedef typename Policies::key_type key_type;
 
 typedef proxy const& assignment_self;
 public:
 proxy(object const& target, key_type const& key);
 operator object() const;

 // to support a[b] = c[d]
 proxy const& operator=(assignment_self) const;
 
 template <class T>
 inline proxy const& operator=(T const& rhs) const
 {
 Policies::set(m_target, m_key, object(rhs));
 return *this;
 }

 public: // implementation detail
 void del() const;
 
 private:
 object m_target;
 key_type m_key;
};


template <class T>
inline void del(proxy<T> const& x)
{
 x.del();
}

//
// implementation
//

template <class Policies>
inline proxy<Policies>::proxy(object const& target, key_type const& key)
 : m_target(target), m_key(key)
{}

template <class Policies>
inline proxy<Policies>::operator object() const
{
 return Policies::get(m_target, m_key);
}

// to support a[b] = c[d]
template <class Policies>
inline proxy<Policies> const& proxy<Policies>::operator=(typename proxy::assignment_self rhs) const
{
 return *this = python::object(rhs);
}

# define BOOST_PYTHON_PROXY_INPLACE(op) \
template <class Policies, class R> \
proxy<Policies> const& operator op(proxy<Policies> const& lhs, R const& rhs) \
{ \
 object old(lhs); \
 return lhs = (old op rhs); \
} 
BOOST_PYTHON_PROXY_INPLACE(+=)
BOOST_PYTHON_PROXY_INPLACE(-=)
BOOST_PYTHON_PROXY_INPLACE(*=)
BOOST_PYTHON_PROXY_INPLACE(/=)
BOOST_PYTHON_PROXY_INPLACE(%=)
BOOST_PYTHON_PROXY_INPLACE(<<=)
BOOST_PYTHON_PROXY_INPLACE(>>=)
BOOST_PYTHON_PROXY_INPLACE(&=)
BOOST_PYTHON_PROXY_INPLACE(^=)
BOOST_PYTHON_PROXY_INPLACE(|=)
# undef BOOST_PYTHON_PROXY_INPLACE

template <class Policies>
inline void proxy<Policies>::del() const
{
 Policies::del(m_target, m_key);
}

}}} // namespace boost::python::api

#endif // PROXY_DWA2002615_HPP