I was wondering any of you has successfully done that before?
If yes, is anything I need to pay attention to?
I was wondering any of you has successfully done that before?
If yes, is anything I need to pay attention to?
That idea is a non-starter.
The VC6 static library will need to link against the same CRT as the VC9 one in order to avoid multiply defined symbols, mismatching heap implementations and other nastiness. That won't be an easy task as the VC compilers make assumptions about the contents of the CRT.
The layout of structs and classes will differ between VC6 and VC9, even though the declarations may match exactly, the objects won't be compatible.
If you need to do this, your best bet would be to wrap the VC6 static library in a VC6 dynamic library that provides a c-style interface and access that from VC9.