clone.hpp

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#ifndef CLONE_HPP
#define CLONE_HPP

#include "common/common.hpp"


// NOTE: Duplicate uses shared_ptr so that it can be overloaded to return
// the supplied pointer (as done by SpecificIdentifier). Clone is guaranteed
// to return a new() object.
class Cloner
{
public:
    virtual shared_ptr<Cloner> Clone() const = 0;
    virtual shared_ptr<Cloner> Duplicate( shared_ptr<Cloner> p )
    {
        ASSERT( p.get() == this ); // unfortunate wrinkle: must always call as PX->Duplicate(PX)
      return Clone(); // default duplication is to clone, but can be over-ridden
    }
    template< class TYPE >
    inline static shared_ptr<Cloner> CloneStatic( const TYPE *source )
    {
        shared_ptr<Cloner> clone( new TYPE(*source) );
        *clone = *source; // Copy everything - be aware that this means the clone has links into the source subtree!
        return clone;
    }    
};

#define CLONE_FUNCTION \
    virtual shared_ptr<Cloner> Clone() const  \
    { \
        return Cloner::CloneStatic(this); \
    }
#endif