/******************************************************************************** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).** All rights reserved.** Contact: Nokia Corporation (qt-info@nokia.com)**** This file is part of the QtXmlPatterns module of the Qt Toolkit.**** $QT_BEGIN_LICENSE:LGPL$** No Commercial Usage** This file contains pre-release code and may not be distributed.** You may use this file in accordance with the terms and conditions** contained in the Technology Preview License Agreement accompanying** this package.**** GNU Lesser General Public License Usage** Alternatively, this file may be used under the terms of the GNU Lesser** General Public License version 2.1 as published by the Free Software** Foundation and appearing in the file LICENSE.LGPL included in the** packaging of this file. Please review the following information to** ensure the GNU Lesser General Public License version 2.1 requirements** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.**** In addition, as a special exception, Nokia gives you certain additional** rights. These rights are described in the Nokia Qt LGPL Exception** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.**** If you have questions regarding the use of this file, please contact** Nokia at qt-info@nokia.com.****************** $QT_END_LICENSE$******************************************************************************///// W A R N I N G// -------------//// This file is not part of the Qt API. It exists purely as an// implementation detail. This header file may change from version to// version without notice, or even be removed.//// We mean it.#ifndef Patternist_EmptyContainer_H#define Patternist_EmptyContainer_H#include "qexpression_p.h"QT_BEGIN_HEADERQT_BEGIN_NAMESPACEnamespace QPatternist{ /** * @short Base class for expressions that has no operands. * * @author Frans Englich <frans.englich@nokia.com> * @ingroup Patternist_expressions */ class Q_AUTOTEST_EXPORT EmptyContainer : public Expression { public: /** * @returns always an empty list. */ virtual Expression::List operands() const; /** * Does nothing, since sub-classes has no operands. Calling * it makes hence no sense, and it also results in an assert crash. */ virtual void setOperands(const Expression::List &); protected: /** * @returns always @c true */ virtual bool compressOperands(const StaticContext::Ptr &context); /** * @returns always an empty list since it has no operands. */ virtual SequenceType::List expectedOperandTypes() const; };}QT_END_NAMESPACEQT_END_HEADER#endif