Can I create a fusion drive with an HDD that already has a boot camp partition? I'm planning to replace the optical drive in my MacBook Pro 9,1 (mid-2012, non-retina) with an SSD and make the two internal drives into a fusion drive, and I know that creating a boot camp partition on a Mac without an optical drive can be a challenge. So I want to create my boot camp partition before I create my fusion drive.

I couldn't find an answer to this in my googling. I know that you can create a Boot Camp partition if you already have a fusion drive.

Can I create a fusion drive using an HDD that already has a boot camp partition on it?
From my hands-on experience, I'd have to say, "negative".

I've created a couple of fusion drives on a 2008 Mac Pro from devices with preexisting partitions. Building the fusion in Core Storage destroyed all partitions on the media.