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>
operator =(T const & rhs) const27 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>
del(proxy<T> const & x)43 inline void del(proxy<T> const& x)
44 {
45 x.del();
46 }
47
48 //
49 // implementation
50 //
51
52 template <class Policies>
proxy(object const & target,key_type const & key)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>
operator object() const58 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>
operator =(typename proxy::assignment_self rhs) const65 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>
del() const90 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
98