it_bus/nillable.h

#ifndef _IT_BUS_NILLABLE_H_
#define _IT_BUS_NILLABLE_H_

// @Copyright 2003 IONA Technologies, Plc. All Rights Reserved.
//

#include <it_bus/any_type.h>
#include <it_bus/serialization_exception.h>
#include <it_bus/deserialization_exception.h>

namespace IT_Bus
{
    class ComplexTypeWriter;
    class ComplexTypeReader;
    
    class IT_AFC_API Nillable : public virtual AnyType
    {
      public:
        Nillable();

        virtual ~Nillable();

        virtual Boolean
        is_nil() const = 0;

        virtual void
        set_nil() = 0;
        
        virtual void
        read(
            const QName& name,
            ComplexTypeReader& reader
        ) IT_THROW_DECL((IT_Bus::DeserializationException));

        virtual void
        write(
            const QName& name,
            ComplexTypeWriter& writer
        ) const IT_THROW_DECL((IT_Bus::SerializationException));

        virtual AnyType::Kind
        get_kind() const;

        virtual void 
        write_value(
            const QName& name,
            ComplexTypeWriter& writer
        ) const IT_THROW_DECL((SerializationException)) = 0;

        virtual void
        read_value(
            const QName& name,
            ComplexTypeReader& reader
        ) IT_THROW_DECL((DeserializationException)) = 0;
    };


    template <class T>
    Boolean
    equal_or_nil(
        const T* a,
        const T* b
    )
    {
        return (a == 0 && b == 0) || (a != 0 && b != 0 && *a == *b);
    }
}

#endif  

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