35 lines
1.2 KiB
C++
35 lines
1.2 KiB
C++
/* Copyright (c) 2012-2021 The ANTLR Project. All rights reserved.
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* Use of this file is governed by the BSD 3-clause license that
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* can be found in the LICENSE.txt file in the project root.
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*/
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#pragma once
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#include <cassert>
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#include <memory>
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#include <type_traits>
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namespace antlrcpp {
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template <typename To, typename From>
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To downCast(From* from) {
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static_assert(std::is_pointer_v<To>, "Target type not a pointer.");
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static_assert(std::is_base_of_v<From, std::remove_pointer_t<To>>, "Target type not derived from source type.");
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#if !defined(__GNUC__) || defined(__GXX_RTTI)
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assert(from == nullptr || dynamic_cast<To>(from) != nullptr);
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#endif
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return static_cast<To>(from);
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}
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template <typename To, typename From>
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To downCast(From& from) {
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static_assert(std::is_lvalue_reference_v<To>, "Target type not a lvalue reference.");
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static_assert(std::is_base_of_v<From, std::remove_reference_t<To>>, "Target type not derived from source type.");
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#if !defined(__GNUC__) || defined(__GXX_RTTI)
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assert(dynamic_cast<std::add_pointer_t<std::remove_reference_t<To>>>(std::addressof(from)) != nullptr);
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#endif
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return static_cast<To>(from);
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}
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}
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