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- //
- // 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_STD_SHARED_PTR_CAST_HPP
- #define BOOST_TYPE_INDEX_RUNTIME_CAST_STD_SHARED_PTR_CAST_HPP
- /// \file std_shared_ptr_cast.hpp
- /// \brief Contains the overload of boost::typeindex::runtime_pointer_cast for
- /// std::shared_ptr types.
- #include <boost/type_index/runtime_cast/detail/runtime_cast_impl.hpp>
- #include <boost/type_traits/is_base_and_derived.hpp>
- #include <memory>
- #ifdef BOOST_HAS_PRAGMA_ONCE
- # pragma once
- #endif
- 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 std::shared_ptr<T>
- /// that points to an address suitably offset from u.
- /// If no such conversion exists, returns std::shared_ptr<T>();
- template<typename T, typename U>
- std::shared_ptr<T> runtime_pointer_cast(std::shared_ptr<U> const& u) {
- T* value = detail::runtime_cast_impl<T>(u.get(), boost::is_base_and_derived<T, U>());
- if(value)
- return std::shared_ptr<T>(u, value);
- return std::shared_ptr<T>();
- }
- }} // namespace boost::typeindex
- #endif // BOOST_TYPE_INDEX_RUNTIME_CAST_STD_SHARED_PTR_CAST_HPP
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