Variant Streaming Code
Posted
by Kenneth Kasajian
Overview
This code provides two global functions, WriteVariantToStream and ReadVariantFromStream, that enable you to read and write a variant to a stream. In addition, there are two other global functions, ReadVariantFromBlob and WriteVariantToBlob, for reading and writing a variant to a BLOB.Highlights
Here are some of the main advantages of these functions:- Uses any given IStream to stream the Variant into and out of.
- Data is streamed in efficient binary form.
- Stream is versioned for backwards compatibility.
- Supports arbitrary size and arbitrary dimension safe-arrays.
- Object streaming is supported if the object in variant supports IPersistStream[Init].
- All code is in one header file (VariantStream.h) and only two routines are exposed: WriteVariantToStream and ReadVariantFromStream.
- Comes with supporting test code that tests the header file -- in case code is modified
- Does not use C++ exception handling. Test project has EH flag turned..
- Doesn't use the CRT.
- Does not use any Direct-To-COM (VC++'s comdef.h, such as _variant_t, _bstr_t, _com_ptr, _com_error)
- Works in both Unicode and ANSI
