Using Variant to Store Point

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??????Variant is a very powerful data type to store 'any' data. With the help of COM class _variant_t, VARIANT bacomes very easy to use. But _variant_t dosen't support all kinds of data type, for example, point data with two or three elements. Variant can hold pointer, but the memory management becomes a stubborn problem when copying variant. I'm trying to find a better way to solve the problem, but I don't want to rewrite a variant. So,? dose the way exist?

??????Many UI-libs use variant to hold data of properties, such as BCGPControlBar, and they do support point displaying. Actually the point elements are formated to a string so that they be stored into one property. But it's very boring to parse values between points and variant, so it's a good idea to write a adapter for them. This adapter takes charge to format point data to string, extract point data from string, and ex-convert with _variant_t.

if we have a point class like this:

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class ?Point3D
{
public :
Point3D() {}
Point3D( double ?x,? double ?y,? double ?z);
double ?x();
double ?y();
double ?z();
private :
double ?x,?y,?z;
} ;

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we can write our point adapter as following:

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class ?PointAdapter
{
private :
CString?m_strData;
public :
PointAdapter();
PointAdapter( const ?Point3D & ?point);
PointAdapter( const ?_variant_t & ?point);

operator ?Point3D() const ;
operator ?_variant_t() const ;
} ;

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now, we can use the classes:

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Point3D?point( 1 , 2 , 3 );
_variant_t?var? = ?PointAdapter(point);
Point3D?point2? = ?PointAdapter(var);

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