This class defines an ATL exception.
Casts the current object to an HRESULT value.
A CAtlException object represents an exception condition related to an ATL operation. The CAtlException class includes a public data member that stores the status code indicating the reason for the exception and a cast operator that allows you to treat the exception as if it were an HRESULT.
In general, you will call AtlThrow rather than creating a CAtlException object directly.