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- // boost polymorphic_pointer_cast.hpp header file ----------------------------------------------//
- // (C) Copyright Boris Rasin, 2014-2021.
- // (C) Copyright Antony Polukhin, 2014-2024.
- // 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)
- // See http://www.boost.org/libs/conversion for Documentation.
- #ifndef BOOST_CONVERSION_POLYMORPHIC_POINTER_CAST_HPP
- #define BOOST_CONVERSION_POLYMORPHIC_POINTER_CAST_HPP
- #include <boost/config.hpp>
- #ifdef BOOST_HAS_PRAGMA_ONCE
- # pragma once
- #endif
- # include <boost/assert.hpp>
- # include <boost/pointer_cast.hpp>
- # include <boost/throw_exception.hpp>
- namespace boost
- {
- // See the documentation for descriptions of how to choose between
- // static_pointer_cast<>, dynamic_pointer_cast<>, polymorphic_pointer_cast<> and polymorphic_pointer_downcast<>
- // polymorphic_pointer_downcast --------------------------------------------//
- // BOOST_ASSERT() checked polymorphic downcast. Crosscasts prohibited.
- // Supports any type with static_pointer_cast/dynamic_pointer_cast functions:
- // built-in pointers, std::shared_ptr, boost::shared_ptr, boost::intrusive_ptr, etc.
- // WARNING: Because this cast uses BOOST_ASSERT(), it violates
- // the One Definition Rule if used in multiple translation units
- // where BOOST_DISABLE_ASSERTS, BOOST_ENABLE_ASSERT_HANDLER
- // NDEBUG are defined inconsistently.
- // Contributed by Boris Rasin
- template <typename Target, typename Source>
- inline auto polymorphic_pointer_downcast (const Source& x)
- -> decltype(static_pointer_cast<Target>(x))
- {
- BOOST_ASSERT(dynamic_pointer_cast<Target> (x) == x);
- return static_pointer_cast<Target> (x);
- }
- template <typename Target, typename Source>
- inline auto polymorphic_pointer_cast (const Source& x)
- -> decltype(dynamic_pointer_cast<Target>(x))
- {
- auto tmp = dynamic_pointer_cast<Target> (x);
- if ( !tmp ) boost::throw_exception( std::bad_cast() );
- return tmp;
- }
- } // namespace boost
- #endif // BOOST_CONVERSION_POLYMORPHIC_POINTER_CAST_HPP
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