| // |
| // Copyright (c) Chris Glover, 2016. |
| // |
| // |
| // 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 BOOST_TYPE_INDEX_RUNTIME_CAST_BOOST_SHARED_PTR_CAST_HPP |
| #define BOOST_TYPE_INDEX_RUNTIME_CAST_BOOST_SHARED_PTR_CAST_HPP |
| |
| /// \file boost_shared_ptr_cast.hpp |
| /// \brief Contains the overload of boost::typeindex::runtime_pointer_cast for |
| /// boost::shared_ptr types. |
| |
| #include <boost/type_index/runtime_cast/detail/runtime_cast_impl.hpp> |
| #include <boost/type_traits/is_base_and_derived.hpp> |
| |
| #ifdef BOOST_HAS_PRAGMA_ONCE |
| # pragma once |
| #endif |
| |
| namespace boost { |
| template<class T> class shared_ptr; |
| } |
| |
| namespace boost { namespace typeindex { |
| |
| /// \brief Creates a new instance of std::shared_ptr whose stored pointer is obtained from u's |
| /// stored pointer using a runtime_cast. |
| /// |
| /// The new shared_ptr will share ownership with u, except that it is empty if the runtime_cast |
| /// performed by runtime_pointer_cast returns a null pointer. |
| /// \tparam T The desired target type to return a pointer of. |
| /// \tparam U A complete class type of the source instance pointed to from u. |
| /// \return If there exists a valid conversion from U* to T*, returns a boost::shared_ptr<T> |
| /// that points to an address suitably offset from u. |
| /// If no such conversion exists, returns boost::shared_ptr<T>(); |
| template<typename T, typename U> |
| boost::shared_ptr<T> runtime_pointer_cast(boost::shared_ptr<U> const& u) { |
| T* value = detail::runtime_cast_impl<T>(u.get(), boost::is_base_and_derived<T, U>()); |
| if(value) |
| return boost::shared_ptr<T>(u, value); |
| return boost::shared_ptr<T>(); |
| } |
| |
| }} // namespace boost::typeindex |
| |
| #endif // BOOST_TYPE_INDEX_RUNTIME_CAST_BOOST_SHARED_PTR_CAST_HPP |