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Diffstat (limited to 'boost/python/data_members.hpp')
| -rw-r--r-- | boost/python/data_members.hpp | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/boost/python/data_members.hpp b/boost/python/data_members.hpp new file mode 100644 index 0000000000..b0851fb1b3 --- /dev/null +++ b/boost/python/data_members.hpp @@ -0,0 +1,318 @@ +// 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 DATA_MEMBERS_DWA2002328_HPP +# define DATA_MEMBERS_DWA2002328_HPP + +# include <boost/python/detail/prefix.hpp> + +# include <boost/python/handle.hpp> + +# include <boost/python/return_value_policy.hpp> +# include <boost/python/return_by_value.hpp> +# include <boost/python/return_internal_reference.hpp> +# include <boost/python/make_function.hpp> + +# include <boost/python/converter/builtin_converters.hpp> + +# include <boost/python/detail/indirect_traits.hpp> +# include <boost/python/detail/not_specified.hpp> +# include <boost/python/detail/value_arg.hpp> + +# include <boost/type_traits/add_const.hpp> +# include <boost/type_traits/add_reference.hpp> +# include <boost/type_traits/is_member_pointer.hpp> + +# if BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003)) +# include <boost/type_traits/remove_cv.hpp> +# endif + +# include <boost/mpl/eval_if.hpp> +# include <boost/mpl/if.hpp> +# include <boost/mpl/vector/vector10.hpp> + +# include <boost/detail/workaround.hpp> + +namespace boost { namespace python { + +// +// This file defines the make_getter and make_setter function +// families, which are responsible for turning pointers, references, +// and pointers-to-data-members into callable Python objects which +// can be used for attribute access on wrapped classes. +// + +namespace detail +{ + + // A small function object which handles the getting and setting of + // data members. + template <class Data, class Class> + struct member + { + public: + member(Data Class::*which) : m_which(which) {} + + Data& operator()(Class& c) const + { + return c.*m_which; + } + + void operator()(Class& c, typename value_arg<Data>::type d) const + { + c.*m_which = d; + } + private: + Data Class::*m_which; + }; + + // A small function object which handles the getting and setting of + // non-member objects. + template <class Data> + struct datum + { + public: + datum(Data *which) : m_which(which) {} + + Data& operator()() const + { + return *m_which; + } + + void operator()(typename value_arg<Data>::type d) const + { + *m_which = d; + } + private: + Data *m_which; + }; + + // + // Helper metafunction for determining the default CallPolicy to use + // for attribute access. If T is a [reference to a] class type X + // whose conversion to python would normally produce a new copy of X + // in a wrapped X class instance (as opposed to types such as + // std::string, which are converted to native Python types, and + // smart pointer types which produce a wrapped class instance of the + // pointee type), to-python conversions will attempt to produce an + // object which refers to the original C++ object, rather than a + // copy. See default_member_getter_policy for rationale. + // + template <class T> + struct default_getter_by_ref + : mpl::and_< + mpl::bool_< + to_python_value< + typename value_arg<T>::type + >::uses_registry + > + , indirect_traits::is_reference_to_class< + typename value_arg<T>::type + > + > + { + }; + + // Metafunction computing the default CallPolicy to use for reading + // data members + // + // If it's a regular class type (not an object manager or other + // type for which we have to_python specializations, use + // return_internal_reference so that we can do things like + // x.y.z = 1 + // and get the right result. + template <class T> + struct default_member_getter_policy + : mpl::if_< + default_getter_by_ref<T> + , return_internal_reference<> + , return_value_policy<return_by_value> + > + {}; + + // Metafunction computing the default CallPolicy to use for reading + // non-member data. + template <class T> + struct default_datum_getter_policy + : mpl::if_< + default_getter_by_ref<T> + , return_value_policy<reference_existing_object> + , return_value_policy<return_by_value> + > + {}; + + // + // make_getter helper function family -- These helpers to + // boost::python::make_getter are used to dispatch behavior. The + // third argument is a workaround for a CWPro8 partial ordering bug + // with pointers to data members. It should be convertible to + // mpl::true_ iff the first argument is a pointer-to-member, and + // mpl::false_ otherwise. The fourth argument is for compilers + // which don't support partial ordering at all and should always be + // passed 0L. + // + +#if BOOST_WORKAROUND(__EDG_VERSION__, <= 238) + template <class D, class P> + inline object make_getter(D& d, P& p, mpl::false_, ...); +#endif + + // Handle non-member pointers with policies + template <class D, class Policies> + inline object make_getter(D* d, Policies const& policies, mpl::false_, int) + { + return python::make_function( + detail::datum<D>(d), policies, mpl::vector1<D&>() + ); + } + + // Handle non-member pointers without policies + template <class D> + inline object make_getter(D* d, not_specified, mpl::false_, long) + { + typedef typename default_datum_getter_policy<D>::type policies; + return detail::make_getter(d, policies(), mpl::false_(), 0); + } + + // Handle pointers-to-members with policies + template <class C, class D, class Policies> + inline object make_getter(D C::*pm, Policies const& policies, mpl::true_, int) + { +#if BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003)) + typedef typename remove_cv<C>::type Class; +#else + typedef C Class; +#endif + return python::make_function( + detail::member<D,Class>(pm) + , policies + , mpl::vector2<D&,Class&>() + ); + } + + // Handle pointers-to-members without policies + template <class C, class D> + inline object make_getter(D C::*pm, not_specified, mpl::true_, long) + { + typedef typename default_member_getter_policy<D>::type policies; + return detail::make_getter(pm, policies(), mpl::true_(), 0); + } + + // Handle references + template <class D, class P> + inline object make_getter(D& d, P& p, mpl::false_, ...) + { + // Just dispatch to the handler for pointer types. + return detail::make_getter(&d, p, mpl::false_(), 0L); + } + + // + // make_setter helper function family -- These helpers to + // boost::python::make_setter are used to dispatch behavior. The + // third argument is for compilers which don't support partial + // ordering at all and should always be passed 0. + // + + + // Handle non-member pointers + template <class D, class Policies> + inline object make_setter(D* p, Policies const& policies, mpl::false_, int) + { + return python::make_function( + detail::datum<D>(p), policies, mpl::vector2<void,D const&>() + ); + } + + // Handle pointers-to-members + template <class C, class D, class Policies> + inline object make_setter(D C::*pm, Policies const& policies, mpl::true_, int) + { + return python::make_function( + detail::member<D,C>(pm) + , policies + , mpl::vector3<void, C&, D const&>() + ); + } + + // Handle references + template <class D, class Policies> + inline object make_setter(D& x, Policies const& policies, mpl::false_, ...) + { + return detail::make_setter(&x, policies, mpl::false_(), 0L); + } +} + +// +// make_getter function family -- build a callable object which +// retrieves data through the first argument and is appropriate for +// use as the `get' function in Python properties . The second, +// policies argument, is optional. We need both D& and D const& +// overloads in order be able to handle rvalues. +// +template <class D, class Policies> +inline object make_getter(D& d, Policies const& policies) +{ + return detail::make_getter(d, policies, is_member_pointer<D>(), 0L); +} + +template <class D, class Policies> +inline object make_getter(D const& d, Policies const& policies) +{ + return detail::make_getter(d, policies, is_member_pointer<D>(), 0L); +} + +template <class D> +inline object make_getter(D& x) +{ + detail::not_specified policy + = detail::not_specified(); // suppress a SunPro warning + return detail::make_getter(x, policy, is_member_pointer<D>(), 0L); +} + +# if !BOOST_WORKAROUND(__EDG_VERSION__, <= 238) && !BOOST_WORKAROUND(BOOST_MSVC, <= 1300) +template <class D> +inline object make_getter(D const& d) +{ + detail::not_specified policy + = detail::not_specified(); // Suppress a SunPro warning + return detail::make_getter(d, policy, is_member_pointer<D>(), 0L); +} +# endif + +// +// make_setter function family -- build a callable object which +// writes data through the first argument and is appropriate for +// use as the `set' function in Python properties . The second, +// policies argument, is optional. We need both D& and D const& +// overloads in order be able to handle rvalues. +// +template <class D, class Policies> +inline object make_setter(D& x, Policies const& policies) +{ + return detail::make_setter(x, policies, is_member_pointer<D>(), 0); +} + +template <class D, class Policies> +inline object make_setter(D const& x, Policies const& policies) +{ + return detail::make_setter(x, policies, is_member_pointer<D>(), 0); +} + +template <class D> +inline object make_setter(D& x) +{ + return detail::make_setter(x, default_call_policies(), is_member_pointer<D>(), 0); +} + +# if !(BOOST_WORKAROUND(BOOST_MSVC, <= 1300) || BOOST_WORKAROUND(__EDG_VERSION__, <= 238)) +template <class D> +inline object make_setter(D const& x) +{ + return detail::make_setter(x, default_call_policies(), is_member_pointer<D>(), 0); +} +# endif + +}} // namespace boost::python + +#endif // DATA_MEMBERS_DWA2002328_HPP |