diff -r 000000000000 -r 1918ee327afb src/xmlpatterns/expr/qtreatas.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/expr/qtreatas.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,92 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 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.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qcommonsequencetypes_p.h"
+#include "qtypechecker_p.h"
+
+#include "qtreatas_p.h"
+
+QT_BEGIN_NAMESPACE
+
+using namespace QPatternist;
+
+TreatAs::TreatAs(const Expression::Ptr &operand,
+                 const SequenceType::Ptr &reqType) : SingleContainer(operand),
+                                                     m_reqType(reqType)
+{
+    Q_ASSERT(reqType);
+}
+
+Expression::Ptr TreatAs::typeCheck(const StaticContext::Ptr &context,
+                                   const SequenceType::Ptr &reqType)
+{
+    Q_ASSERT(context);
+    Q_ASSERT(reqType);
+
+    /* Apply function conversion with the special error code XPDY0050. After that, we
+     * let the regular typeCheck() function be invoked on the operand before we rewrite
+     * to it. Hence is applyFunctionConversion() called twice, which doesn't break anything,
+     * but indeed is redundant. */
+    const Expression::Ptr treated(TypeChecker::applyFunctionConversion(m_operand,
+                                                                       m_reqType,
+                                                                       context,
+                                                                       ReportContext::XPDY0050));
+    return treated->typeCheck(context, reqType);
+}
+
+ExpressionVisitorResult::Ptr TreatAs::accept(const ExpressionVisitor::Ptr &visitor) const
+{
+    return visitor->visit(this);
+}
+
+SequenceType::Ptr TreatAs::staticType() const
+{
+    return m_reqType;
+}
+
+SequenceType::List TreatAs::expectedOperandTypes() const
+{
+    SequenceType::List result;
+    result.append(CommonSequenceTypes::ZeroOrMoreItems);
+    return result;
+}
+
+QT_END_NAMESPACE