/
nonevalue.h
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/
nonevalue.h
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/*
* The Doomsday Engine Project -- libdeng2
*
* Copyright (c) 2009-2012 Jaakko Keränen <jaakko.keranen@iki.fi>
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* This program 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 this program; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef LIBDENG2_NONEVALUE_H
#define LIBDENG2_NONEVALUE_H
#include "../Value"
namespace de
{
/**
* The NoneValue class is a subclass of Value that does not contain any actual data.
*
* @ingroup data
*/
class DENG2_PUBLIC NoneValue : public Value
{
public:
NoneValue();
Value* duplicate() const;
Text asText() const;
bool isTrue() const;
dint compare(const Value& value) const;
// Implements ISerializable.
void operator >> (Writer& to) const;
void operator << (Reader& from);
};
}
#endif /* LIBDENG2_NONEVALUE_H */