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Diffstat (limited to 'include/comphelper/flagguard.hxx')
-rw-r--r-- | include/comphelper/flagguard.hxx | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/include/comphelper/flagguard.hxx b/include/comphelper/flagguard.hxx new file mode 100644 index 000000000..14eee07a8 --- /dev/null +++ b/include/comphelper/flagguard.hxx @@ -0,0 +1,80 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ + +#ifndef INCLUDED_COMPHELPER_FLAGGUARD_HXX +#define INCLUDED_COMPHELPER_FLAGGUARD_HXX + +#include <comphelper/scopeguard.hxx> +#include <utility> + +namespace comphelper +{ + + //= ValueRestorationGuard + + // note: can't store the originalValue in a ValueRestorationGuard member, + // because it will be used from base class dtor + template <typename T> struct ValueRestorationGuard_Impl + { + T& rVal; + T const originalValue; + ValueRestorationGuard_Impl(T& i_valRef) + : rVal(i_valRef), originalValue(i_valRef) {} + void operator()() + { + rVal = originalValue; + } + }; + + template <typename T> + class ValueRestorationGuard : public ScopeGuard<ValueRestorationGuard_Impl<T>> + { + public: + template <typename T1> + ValueRestorationGuard(T& i_valRef, T1&& i_temporaryValue) + : ScopeGuard<ValueRestorationGuard_Impl<T>>(ValueRestorationGuard_Impl(i_valRef)) + { + i_valRef = std::forward<T1>(i_temporaryValue); + } + }; + + typedef ValueRestorationGuard<bool> FlagRestorationGuard; + + //= FlagGuard + + // Guarantees that the flag is true within the scope of the guard, and is set to false after + // its destruction, regardless of initial flag value + class FlagGuard : public FlagRestorationGuard + { + public: + // Set flag to false before passing its reference to base class ctor, so that it would be + // reset back to false in base class dtor + explicit FlagGuard(bool& i_flagRef) + : FlagRestorationGuard((i_flagRef = false), true) + { + } + }; + + +} // namespace comphelper + + +#endif // INCLUDED_COMPHELPER_FLAGGUARD_HXX + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |