CVbString class

CVbString is a wrapper class for the strange Visual Basic 4 string type.

VB4 used ASCII (single-byte) BSTRs. They had to be allocated using the ::SysAllocStringByteLen() function.
Just like the ATL CComBSTR class wraps the UNICODE BSTR, CVbString will wrap the ASCII version with an interface, which is pretty similar to that of CComBSTR.