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Move from boost-sanbox [ JDG ]
[SVN r18958]
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Joel de Guzman
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include/boost/iterator/indirect_iterator.hpp
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include/boost/iterator/indirect_iterator.hpp
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// (C) Copyright David Abrahams 2002.
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// (C) Copyright Jeremy Siek 2002.
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// (C) Copyright Thomas Witt 2002.
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// Permission to copy, use, modify,
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// sell and distribute this software is granted provided this
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// copyright notice appears in all copies. This software is provided
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// "as is" without express or implied warranty, and with no claim as
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// to its suitability for any purpose.
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#ifndef BOOST_INDIRECT_ITERATOR_23022003THW_HPP
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#define BOOST_INDIRECT_ITERATOR_23022003THW_HPP
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#include <boost/iterator.hpp>
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#include <boost/iterator/iterator_adaptor.hpp>
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#include <boost/iterator/iterator_traits.hpp>
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#include <boost/python/detail/indirect_traits.hpp>
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#include <boost/mpl/not.hpp>
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#include <boost/mpl/aux_/has_xxx.hpp>
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#ifdef BOOST_NO_MPL_AUX_HAS_XXX
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# include <boost/shared_ptr.hpp>
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# include <boost/scoped_ptr.hpp>
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# include <boost/mpl/bool.hpp>
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# include <memory>
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#endif
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#include <boost/iterator/detail/config_def.hpp> // must be last #include
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namespace boost
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{
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template <class Iter, class Value, class Category, class Reference, class Difference>
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struct indirect_iterator;
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namespace detail
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{
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struct unspecified {};
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//
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// Detection for whether a type has a nested `element_type'
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// typedef. Used to detect smart pointers. For compilers not
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// supporting mpl's has_xxx, we supply specializations. However, we
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// really ought to have a specializable is_pointer template which
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// can be used instead with something like
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// boost/python/pointee.hpp to find the value_type.
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//
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# ifndef BOOST_NO_MPL_AUX_HAS_XXX
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namespace aux
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{
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BOOST_MPL_HAS_XXX_TRAIT_DEF(element_type)
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}
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template <class T>
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struct has_element_type
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: mpl::bool_<
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mpl::if_<
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is_class<T>
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, ::boost::detail::aux::has_element_type<T>
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, mpl::false_
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>::type::value
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>
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{
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};
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# else
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template <class T>
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struct has_element_type
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: mpl::false_ {};
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template <class T>
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struct has_element_type<boost::shared_ptr<T> >
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: mpl::true_ {};
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template <class T>
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struct has_element_type<boost::scoped_ptr<T> >
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: mpl::true_ {};
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template <class T>
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struct has_element_type<std::auto_ptr<T> >
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: mpl::true_ {};
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# endif
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// Metafunction returning the nested element_type typedef
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template <class T>
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struct smart_pointer_value : remove_const<typename T::element_type>
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{};
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template <class T>
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struct iterator_is_mutable
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: mpl::not_<
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boost::python::detail::is_reference_to_const<
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typename iterator_reference<T>::type
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>
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>
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{
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};
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template <class T>
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struct not_int_impl
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{
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template <class U>
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struct apply {
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typedef T type;
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};
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};
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template <>
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struct not_int_impl<int> {};
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template <class T, class U>
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struct not_int
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: not_int_impl<T>::template apply<U> {};
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// If the Value parameter is unspecified, we use this metafunction
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// to deduce the default types
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template <class Iter, class Value, class Category, class Reference, class Difference>
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struct indirect_base
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{
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typedef typename iterator_value<Iter>::type dereferenceable;
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typedef mpl::and_<
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is_class<dereferenceable>
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, has_element_type<dereferenceable>
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> is_smart_ptr;
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typedef typename mpl::apply_if<
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is_smart_ptr
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, smart_pointer_value<dereferenceable>
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, iterator_value<dereferenceable>
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>::type value_type;
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typedef typename mpl::if_<
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mpl::or_<
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is_smart_ptr
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, iterator_is_mutable<dereferenceable>
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>
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, value_type
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, value_type const
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>::type cv_value_type;
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typedef iterator_adaptor<
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indirect_iterator<Iter, Value, Category, Reference, Difference>
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, Iter
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, cv_value_type
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, Category
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, Reference
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, Difference
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> type;
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};
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template <>
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struct indirect_base<int, int, int, int, int> {};
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} // namespace detail
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template <
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class Iterator
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, class Value = use_default
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, class Category = use_default
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, class Reference = use_default
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, class Difference = use_default
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>
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class indirect_iterator
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: public detail::indirect_base<
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Iterator, Value, Category, Reference, Difference
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>::type
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{
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typedef typename detail::indirect_base<
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Iterator, Value, Category, Reference, Difference
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>::type super_t;
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friend class iterator_core_access;
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public:
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indirect_iterator() {}
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indirect_iterator(Iterator iter)
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: super_t(iter) {}
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template <
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class Iterator2, class Value2, class Category2
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, class Reference2, class Difference2
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>
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indirect_iterator(
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indirect_iterator<
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Iterator2, Value2, Category2, Reference2, Difference2
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> const& y
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, typename enable_if_convertible<Iterator2, Iterator>::type* = 0
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)
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: super_t(y.base())
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{}
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private:
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typename super_t::reference dereference() const
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{
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# if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551))
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return const_cast<super_t::reference>(**this->base());
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# else
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return **this->base();
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# endif
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}
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};
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template <class Iter>
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inline
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indirect_iterator<Iter> make_indirect_iterator(Iter x)
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{
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return indirect_iterator<Iter>(x);
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}
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template <class Traits, class Iter>
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inline
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indirect_iterator<Iter,Traits> make_indirect_iterator(Iter x, Traits* = 0)
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{
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return indirect_iterator<Iter, Traits>(x);
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}
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} // namespace boost
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#include <boost/iterator/detail/config_undef.hpp>
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#endif // BOOST_INDIRECT_ITERATOR_23022003THW_HPP
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