8ec3116162
(This helps rewrite code that silences Coverity unchecked dynamic_cast warnings,
like 57b89ea1c2 "coverity#704563 Unchecked dynamic
cast", in a way that is cleaner and potentially executes faster.)
Change-Id: I3319c0eeec2aa822f686feacd499a76c8c9b9499
Reviewed-on: https://gerrit.libreoffice.org/80458
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
35 lines
1.2 KiB
C++
35 lines
1.2 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
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/*
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* This file is part of the LibreOffice project.
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*/
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#ifndef INCLUDED_O3TL_UNSAFE_DOWNCAST_HXX
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#define INCLUDED_O3TL_UNSAFE_DOWNCAST_HXX
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#include <cassert>
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#include <type_traits>
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namespace o3tl
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{
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// Do a downcast from polymorphic `BasePtr` to `DerivedPtr` when it is known that `p` is actually
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// pointing to an object of derived type (or is a nullptr). This is potentially cheaper than
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// dynamic_cast and helps to avoid Coverity warnings about unchecked dynamic_cast.
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template <typename DerivedPtr, typename BasePtr>
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std::enable_if_t<
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(std::is_pointer_v<
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DerivedPtr> && std::is_pointer_v<BasePtr> && std::is_base_of_v<std::remove_pointer_t<BasePtr>, std::remove_pointer_t<DerivedPtr>>),
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DerivedPtr>
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unsafe_downcast(BasePtr p)
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{
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assert(p == nullptr || dynamic_cast<DerivedPtr>(p) != nullptr);
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return static_cast<DerivedPtr>(p);
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}
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}
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#endif
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/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
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