// Boost.TypeErasure library
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//
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// Copyright 2015 Steven Watanabe
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//
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// Distributed under the Boost Software License Version 1.0. (See
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// accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//
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// $Id$
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#ifndef BOOST_TYPE_ERASURE_DYNAMIC_ANY_CAST_HPP_INCLUDED
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#define BOOST_TYPE_ERASURE_DYNAMIC_ANY_CAST_HPP_INCLUDED
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#include <boost/type_erasure/detail/normalize.hpp>
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#include <boost/type_erasure/binding_of.hpp>
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#include <boost/type_erasure/static_binding.hpp>
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#include <boost/type_erasure/dynamic_binding.hpp>
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#include <boost/type_erasure/concept_of.hpp>
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#include <boost/type_erasure/placeholder_of.hpp>
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#include <boost/type_erasure/any.hpp>
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#include <boost/type_erasure/binding.hpp>
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#include <boost/mpl/vector.hpp>
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#include <boost/mpl/set.hpp>
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#include <boost/mpl/fold.hpp>
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#include <boost/type_traits/add_const.hpp>
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#include <boost/type_traits/add_reference.hpp>
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#include <boost/type_traits/remove_const.hpp>
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#include <boost/type_traits/remove_reference.hpp>
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namespace boost {
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namespace type_erasure {
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namespace detail {
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template<class P, class P2, class Any>
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struct make_ref_placeholder;
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template<class P, class P2, class Any>
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struct make_ref_placeholder<P, P2, const Any&> { typedef const P& type; };
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template<class P, class P2, class Any>
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struct make_ref_placeholder<P, P2, Any&> { typedef P& type; };
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template<class P, class P2, class Any>
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struct make_ref_placeholder<P, P2&, const Any&> { typedef P& type; };
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template<class P, class P2, class Any>
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struct make_ref_placeholder<P, P2&, Any&> { typedef P& type; };
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template<class P, class P2, class Any>
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struct make_ref_placeholder<P, const P2&, const Any&> { typedef const P& type; };
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template<class P, class P2, class Any>
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struct make_ref_placeholder<P, const P2&, Any&> { typedef const P& type; };
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#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
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template<class P, class P2, class Any>
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struct make_ref_placeholder { typedef P&& type; };
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template<class P, class P2, class Any>
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struct make_ref_placeholder<P, P2&, Any> { typedef P& type; };
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template<class P, class P2, class Any>
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struct make_ref_placeholder<P, const P2&, Any> { typedef const P& type; };
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template<class P, class P2, class Any>
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struct make_ref_placeholder<P, P2&&, Any> { typedef P&& type; };
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template<class P, class P2, class Any>
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struct make_ref_placeholder<P, P2&&, const Any&> { typedef const P& type; };
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template<class P, class P2, class Any>
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struct make_ref_placeholder<P, P2&&, Any&> { typedef P& type; };
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#endif
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template<class R, class Tag>
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struct make_result_placeholder_map
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{
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typedef ::boost::mpl::map<
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::boost::mpl::pair<
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typename ::boost::remove_const<
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typename ::boost::remove_reference<
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typename ::boost::type_erasure::placeholder_of<R>::type
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>::type
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>::type,
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typename ::boost::remove_const<
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typename ::boost::remove_reference<
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Tag
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>::type
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>::type
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>
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> type;
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};
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#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
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template<class R, class Any, class Map>
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R dynamic_any_cast_impl(Any&& arg, const static_binding<Map>& map)
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#else
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template<class R, class Any, class Map>
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R dynamic_any_cast_impl(Any& arg, const static_binding<Map>& map)
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#endif
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{
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typedef typename ::boost::remove_const<typename ::boost::remove_reference<Any>::type>::type src_type;
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typedef typename ::boost::type_erasure::detail::normalize_concept<
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typename ::boost::type_erasure::concept_of<src_type>::type
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>::type normalized;
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typedef typename ::boost::mpl::fold<
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normalized,
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#ifndef BOOST_TYPE_ERASURE_USE_MP11
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::boost::mpl::set0<>,
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#else
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::boost::mp11::mp_list<>,
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#endif
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::boost::type_erasure::detail::get_placeholders<
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::boost::mpl::_2,
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::boost::mpl::_1
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>
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>::type placeholders;
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#ifndef BOOST_TYPE_ERASURE_USE_MP11
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typedef ::boost::type_erasure::detail::substitution_map< ::boost::mpl::map0<> > identity_map;
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#else
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typedef ::boost::type_erasure::detail::make_identity_placeholder_map<normalized> identity_map;
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#endif
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::boost::type_erasure::dynamic_binding<placeholders> my_binding(
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::boost::type_erasure::binding_of(arg),
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::boost::type_erasure::make_binding<identity_map>());
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typedef typename ::boost::remove_const<
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typename ::boost::remove_reference<
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typename ::boost::type_erasure::placeholder_of<R>::type
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>::type
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>::type result_placeholder;
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::boost::type_erasure::binding< typename ::boost::type_erasure::concept_of<R>::type> new_binding(
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my_binding,
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map);
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typedef ::boost::type_erasure::any<
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typename ::boost::type_erasure::concept_of<R>::type,
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typename ::boost::type_erasure::detail::make_ref_placeholder<
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result_placeholder,
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typename ::boost::type_erasure::placeholder_of<src_type>::type,
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#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
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Any
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#else
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Any&
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#endif
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>::type
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> result_ref_type;
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#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
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return result_ref_type(std::forward<Any>(arg), new_binding);
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#else
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return result_ref_type(arg, new_binding);
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#endif
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}
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}
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#ifdef BOOST_TYPE_ERASURE_DOXYGEN
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/**
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* Downcasts or crosscasts an @ref any.
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*
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* \pre @c R and @c Any must both be specializations of @ref any.
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* \pre PlaceholderMap must be an MPL map with a key
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* for every non-deduced placeholder used by R.
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* The value associated with each key should
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* be the corresponding placeholder in Any.
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* \pre The concept of Any must include @ref typeid_, for every
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* @ref placeholder which is used by R.
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*
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* The single argument form can only be used when @c R uses
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* a single non-deduced placeholder.
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*
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* \throws bad_any_cast if the concepts used by R were
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* not previously registered via a call to
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* \register_binding.
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*
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* Example:
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* \code
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* // Assume that typeid_<>, copy_constructible<>, and incrementable<>
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* // have all been registered for int.
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* any<mpl::vector<typeid_<>, copy_constructible<> > > x(1);
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* typedef any<
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* mpl::vector<
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* typeid_<>,
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* copy_constructible<>,
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* incrementable<>
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* >
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* > incrementable_any;
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* auto y = dynamic_any_cast<incrementable_any>(x);
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* ++y;
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* assert(any_cast<int>(y) == 2);
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* \endcode
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*/
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template<class R, class Any>
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R dynamic_any_cast(Any&& arg);
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/**
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* \overload
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*/
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template<class R, class Any, class Map>
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R dynamic_any_cast(Any&& arg, const static_binding<Map>&);
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#else
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template<class R, class Concept, class Tag>
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R dynamic_any_cast(const any<Concept, Tag>& arg)
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{
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return ::boost::type_erasure::detail::dynamic_any_cast_impl<R>(arg,
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::boost::type_erasure::make_binding<typename ::boost::type_erasure::detail::make_result_placeholder_map<R, Tag>::type>());
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}
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template<class R, class Concept, class Tag>
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R dynamic_any_cast(any<Concept, Tag>& arg)
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{
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return ::boost::type_erasure::detail::dynamic_any_cast_impl<R>(arg,
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::boost::type_erasure::make_binding<typename ::boost::type_erasure::detail::make_result_placeholder_map<R, Tag>::type>());
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}
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#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
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template<class R, class Concept, class Tag>
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R dynamic_any_cast(any<Concept, Tag>&& arg)
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{
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return ::boost::type_erasure::detail::dynamic_any_cast_impl<R>(::std::move(arg),
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::boost::type_erasure::make_binding<typename ::boost::type_erasure::detail::make_result_placeholder_map<R, Tag>::type>());
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}
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#endif
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template<class R, class Concept, class Tag, class Map>
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R dynamic_any_cast(const any<Concept, Tag>& arg, const static_binding<Map>& map)
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{
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return ::boost::type_erasure::detail::dynamic_any_cast_impl<R>(arg, map);
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}
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template<class R, class Concept, class Tag, class Map>
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R dynamic_any_cast(any<Concept, Tag>& arg, const static_binding<Map>& map)
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{
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return ::boost::type_erasure::detail::dynamic_any_cast_impl<R>(arg, map);
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}
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#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
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template<class R, class Concept, class Tag, class Map>
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R dynamic_any_cast(any<Concept, Tag>&& arg, const static_binding<Map>& map)
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{
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return ::boost::type_erasure::detail::dynamic_any_cast_impl<R>(::std::move(arg), map);
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}
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#endif
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#endif
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}
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}
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#endif
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