[Inkscape-devel] Link help

I added a class called SPTRefReference, similar to SPUseReference. It extends URIReference. When I try to instantiate it in my tref struct's init function (tref->ref = new SPTRefReference(SP_OBJECT(tref));), just as the SPUse struct does, it won't link. Something about missing definition for SPTRefReference's vtable. Anyone know what step I am missing? Probably something small or maybe related to this particular compiler (which I have not used before; at least not on Windows).

Much appreciated, Gail