cpp/lib/common/ExceptionHolder.h

#ifndef _qpid_ExceptionHolder_h
#define _qpid_ExceptionHolder_h

/*
 *
 * Copyright (c) 2006 The Apache Software Foundation
 *
 * Licensed 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
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include <Exception.h>
#include <boost/shared_ptr.hpp>

namespace qpid {

/**
 * Holder for a heap-allocated exc eption that can be stack allocated
 * and thrown safely.
 *
 * Basically this is a shared_ptr with the Exception functions added
 * so the catcher need not be aware that it is a pointer rather than a
 * reference.
 * 
 * shared_ptr is chosen over auto_ptr because it has normal 
 * copy semantics. 
 */
class ExceptionHolder : public Exception, public boost::shared_ptr<Exception>
{
  public:
    typedef boost::shared_ptr<Exception> shared_ptr;

    ExceptionHolder() throw() {}
    ExceptionHolder(Exception* p) throw() : shared_ptr(p) {}
    ExceptionHolder(shared_ptr p) throw() : shared_ptr(p) {}

    ExceptionHolder(const Exception& e) throw() : shared_ptr(e.clone()) {}
    ExceptionHolder(const std::exception& e);

    ~ExceptionHolder() throw() {}

    const char* what() const throw() { return (*this)->what(); }
    std::string toString() const throw() { return (*this)->toString(); }
    virtual Exception* clone() const throw() { return (*this)->clone(); }
    virtual void throwSelf() const { (*this)->throwSelf(); }
};

} // namespace qpid



#endif  /*!_qpid_ExceptionHolder_h*/