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// boost polymorphic_pointer_cast.hpp header file ----------------------------------------------//
// (C) Copyright Boris Rasin, 2014-2021.
// (C) Copyright Antony Polukhin, 2014-2025.
// 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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