ceph/src/boost/libs/python/include/boost/python/proxy.hpp

   1 // Copyright David Abrahams 2002.
   2 // Distributed under the Boost Software License, Version 1.0. (See
   3 // accompanying file LICENSE_1_0.txt or copy at
   4 // http://www.boost.org/LICENSE_1_0.txt)
   5 #ifndef PROXY_DWA2002615_HPP
   6 # define PROXY_DWA2002615_HPP
   7 # include <boost/python/detail/prefix.hpp>
   8 # include <boost/python/object_core.hpp>
   9 # include <boost/python/object_operators.hpp>
  10
  11 namespace boost { namespace python { namespace api {
  12
  13 template <class Policies>
  14 class proxy : public object_operators<proxy<Policies> >
  15 {
  16     typedef typename Policies::key_type key_type;
  17
  18     typedef proxy const& assignment_self;
  19  public:
  20     proxy(object const& target, key_type const& key);
  21     operator object() const;
  22
  23     // to support a[b] = c[d]
  24     proxy const& operator=(assignment_self) const;
  25
  26     template <class T>
  27     inline proxy const& operator=(T const& rhs) const
  28     {
  29         Policies::set(m_target, m_key, object(rhs));
  30         return *this;
  31     }
  32
  33  public: // implementation detail
  34     void del() const;
  35
  36  private:
  37     object m_target;
  38     key_type m_key;
  39 };
  40
  41
  42 template <class T>
  43 inline void del(proxy<T> const& x)
  44 {
  45     x.del();
  46 }
  47
  48 //
  49 // implementation
  50 //
  51
  52 template <class Policies>
  53 inline proxy<Policies>::proxy(object const& target, key_type const& key)
  54     : m_target(target), m_key(key)
  55 {}
  56
  57 template <class Policies>
  58 inline proxy<Policies>::operator object() const
  59 {
  60     return Policies::get(m_target, m_key);
  61 }
  62
  63 // to support a[b] = c[d]
  64 template <class Policies>
  65 inline proxy<Policies> const& proxy<Policies>::operator=(typename proxy::assignment_self rhs) const
  66 {
  67     return *this = python::object(rhs);
  68 }
  69
  70 # define BOOST_PYTHON_PROXY_INPLACE(op)                                         \
  71 template <class Policies, class R>                                              \
  72 proxy<Policies> const& operator op(proxy<Policies> const& lhs, R const& rhs)    \
  73 {                                                                               \
  74     object old(lhs);                                                            \
  75     return lhs = (old op rhs);                                                  \
  76 }
  77 BOOST_PYTHON_PROXY_INPLACE(+=)
  78 BOOST_PYTHON_PROXY_INPLACE(-=)
  79 BOOST_PYTHON_PROXY_INPLACE(*=)
  80 BOOST_PYTHON_PROXY_INPLACE(/=)
  81 BOOST_PYTHON_PROXY_INPLACE(%=)
  82 BOOST_PYTHON_PROXY_INPLACE(<<=)
  83 BOOST_PYTHON_PROXY_INPLACE(>>=)
  84 BOOST_PYTHON_PROXY_INPLACE(&=)
  85 BOOST_PYTHON_PROXY_INPLACE(^=)
  86 BOOST_PYTHON_PROXY_INPLACE(|=)
  87 # undef BOOST_PYTHON_PROXY_INPLACE
  88
  89 template <class Policies>
  90 inline void proxy<Policies>::del() const
  91 {
  92     Policies::del(m_target, m_key);
  93 }
  94
  95 }}} // namespace boost::python::api
  96
  97 #endif // PROXY_DWA2002615_HPP