/*
Copyright (C) 2012, University of Cambridge, Department of Psychiatry.
Created by Rudolf Cardinal (rnc1001@cam.ac.uk).
This file is part of CamCOPS.
CamCOPS is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
CamCOPS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with CamCOPS. If not, see <https://www.gnu.org/licenses/>.
*/
#pragma once
#include <QSharedPointer>
// UNUSED. For a C++ "clone a class instance" system.
template <typename Base, typename Derived>
class Cloneable : virtual public Base
{
public:
virtual QSharedPointer<Base> clone() const override
{
return QSharedPointer<Base>(
new Derived(static_cast<Derived const &>(*this))
);
}
// Absence of virtual destructor here can lead to a crash,
// even if Base has a virtual destructor? I'm not sure - either that,
// or it was a QMediaPlayer destructor problem.
virtual ~Cloneable()
{}
};
// For multilevel inheritance, because you do not get automatic conversion
// of the QSharedPointer:
template <typename UltimateBase, typename ImmediateBase, typename Derived>
class MutilevelCloneable : virtual public ImmediateBase
{
public:
virtual QSharedPointer<UltimateBase> clone() const override
{
return QSharedPointer<UltimateBase>(
new Derived(static_cast<Derived const &>(*this))
);
}
// (Absence of virtual destructor here can lead to a crash, presumably,
// as above.)
virtual ~MutilevelCloneable()
{}
};