Re: Is it possible to clone an object
John <John@discussions.microsoft.com> wrote:
Is it possible to clone (i.e. copy operator) an ATL object?
Say for instance I create the following object;
////////
// create an instance of some object and set some properties
///////
double d = 1.234;
float f = 5.678;
long l = 3;
CComPtr<ISomeObject> m_SomeObj1;
m_SomeObj1.CoCreateInstance(__uuidof(SomeObject));
m_SomeObj1->put_DoubleValue(d);
m_SomeObj1->put_FloatValue(f);
m_SomeObj1->put_LongValue(l);
//////
// Now I want to create a copy of this object with the current
// parameters into another object;
//////
CComPtr<ISomeObject> m_SomeObj2;
m_SomeObj2 = m_SomeObj1;
This would work, but it doesn't clone anything, it simply AddRef's the
old instance.
In general, you cannot clone an arbitrary COM object. An object may of
course provide a Clone() method or similar, returning a copy of itself.
Objects that support persistence can usually be cloned by serializing
them into a stream, then deserializing into a fresh instance.
--
With best wishes,
Igor Tandetnik
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