8a74ae6c9d
We had new failure on MinGW with GCC believing that some pointer returned by down_cast could be NULL; and the down_cast function was in the global namespace. * spot/misc/casts.hh: Rewrite. * NEWS: Mention the small issues. * tests/core/ikwiad.cc, tests/core/ngraph.cc: Adjust to use spot::down_cast instead of down_cast.
69 lines
2 KiB
C++
69 lines
2 KiB
C++
// -*- coding: utf-8 -*-
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// Copyright (C) 2011, 2015-2018 Laboratoire de Recherche et Développement
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// de l'Epita (LRDE).
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//
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// This file is part of Spot, a model checking library.
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//
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// Spot is free software; you can redistribute it and/or modify it
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// under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 3 of the License, or
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// (at your option) any later version.
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//
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// Spot is distributed in the hope that it will be useful, but WITHOUT
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// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
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// License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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#pragma once
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#include <memory>
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#include <type_traits>
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// We usually write code like
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// subtypename* i = down_cast<subtypename*>(m);
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// ... use i ...
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// When NDEBUG is set, the down_cast is a fast static_cast.
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// Otherwise, the down_cast is a dynamic_cast and may return 0
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// on error, which is caught by an assert in the down_cast function.
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//
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// NB: It is valid to use down_cast with non-pointer template argument:
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// subtypename& i = down_cast<subtypename&>(m);
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// If an error occurs during the cast, an exception is thrown.
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//
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// NB: down_cast can also be used on shared_ptr.
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namespace spot
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{
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template<typename T, typename U>
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inline
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T down_cast(U* u) noexcept
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{
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SPOT_ASSERT(dynamic_cast<T>(u));
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return static_cast<T>(u);
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}
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template<typename T, typename U>
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inline
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T down_cast(const std::shared_ptr<U>& u) noexcept
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{
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SPOT_ASSERT(std::dynamic_pointer_cast<typename T::element_type>(u));
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return std::static_pointer_cast<typename T::element_type>(u);
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}
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template<typename T, typename U>
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inline
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T down_cast(U u)
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#ifdef NDEBUG
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noexcept
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#endif
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{
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#ifdef NDEBUG
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return static_cast<T>(u);
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#else
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return dynamic_cast<T>(u);
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#endif
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}
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} // namespace spot
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