Yup, a decent quality (i.e. not cheap) diamond core drill should cope with pretty well anything. I recently hired a big drill (i.e. much bigger than my SDS plus one, to drill a 162mm diameter hole through very hard bricks, and thence into middling blockwork. I'd imagine a good 40mm core drill should be manageable by an SDS plus drill. Mine says 28mm max for solid drills, and 50mm for core drills, and I've used it with ease for a 40mm TCT core drill in hard-ish bricks. A TCT core drill takes a lot more effort than a diamond one, as its cutting away far more material.
On a related note, I checked the blurb on my disc cutter diamond blade, which insisted it could not be used for cutting granite. What, those granite setts over there, that I cut in half with it last year? I was forewarned about granite dust not being nice, so wore respirator and eye protection.