| 1 | // |
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| 2 | // Copyright (c) Chris Glover, 2016. |
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| 3 | // |
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| 4 | // |
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| 5 | // Distributed under the Boost Software License, Version 1.0. (See accompanying |
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| 6 | // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
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| 7 | // |
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| 8 | |
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| 9 | #ifndef BOOST_TYPE_INDEX_RUNTIME_CAST_DETAIL_RUNTIME_CAST_IMPL_HPP |
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| 10 | #define BOOST_TYPE_INDEX_RUNTIME_CAST_DETAIL_RUNTIME_CAST_IMPL_HPP |
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| 11 | |
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| 12 | /// \file runtime_cast_impl.hpp |
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| 13 | /// \brief Contains the overload of boost::typeindex::runtime_cast for |
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| 14 | /// pointer types. |
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| 15 | /// |
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| 16 | /// boost::typeindex::runtime_cast can be used to emulate dynamic_cast |
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| 17 | /// functionality on platorms that don't provide it or should the user |
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| 18 | /// desire opt in functionality instead of enabling it system wide. |
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| 19 | |
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| 20 | #include <boost/type_index.hpp> |
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| 21 | |
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| 22 | #include <type_traits> |
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| 23 | |
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| 24 | #ifdef BOOST_HAS_PRAGMA_ONCE |
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| 25 | # pragma once |
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| 26 | #endif |
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| 27 | |
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| 28 | namespace boost { namespace typeindex { |
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| 29 | |
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| 30 | namespace detail { |
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| 31 | |
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| 32 | template<typename T, typename U> |
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| 33 | T* runtime_cast_impl(U* u, std::integral_constant<bool, true>) noexcept { |
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| 34 | return u; |
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| 35 | } |
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| 36 | |
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| 37 | template<typename T, typename U> |
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| 38 | T const* runtime_cast_impl(U const* u, std::integral_constant<bool, true>) noexcept { |
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| 39 | return u; |
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| 40 | } |
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| 41 | |
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| 42 | template<typename T, typename U> |
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| 43 | T* runtime_cast_impl(U* u, std::integral_constant<bool, false>) noexcept { |
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| 44 | return const_cast<T*>(static_cast<T const*>( |
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| 45 | u->boost_type_index_find_instance_(boost::typeindex::type_id<T>()) |
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| 46 | )); |
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| 47 | } |
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| 48 | |
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| 49 | template<typename T, typename U> |
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| 50 | T const* runtime_cast_impl(U const* u, std::integral_constant<bool, false>) noexcept { |
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| 51 | return static_cast<T const*>(u->boost_type_index_find_instance_(boost::typeindex::type_id<T>())); |
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| 52 | } |
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| 53 | |
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| 54 | } // namespace detail |
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| 55 | |
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| 56 | }} // namespace boost::typeindex |
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| 57 | |
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| 58 | #endif // BOOST_TYPE_INDEX_RUNTIME_CAST_DETAIL_RUNTIME_CAST_IMPL_HPP |
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| 59 | |
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