office-gobmx/include/comphelper/flagguard.hxx
Mike Kaganski 00748b3066 Introduce comphelper::ValueRestorationGuard extending FlagRestorationGuard
... to any value type.

Change-Id: I808f4729478cb3f90a86ef30be8158ebc40a6b96
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/91428
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
2020-03-31 18:11:45 +02:00

80 lines
2.6 KiB
C++

/* -*- 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: */