I'm fairly sure that my xah is co-dependant. His 'characteristics' are sort of opposite mine and I think we 'fit' comfortably at first. Our relationship was so dysfunctional even minus the alcohol. We had no awareness about any of that though, which makes a big difference. I guess just proceed very cautiously.
Here is a quote from Melody Beattie's book "Codependent No More"
Two codependants in a relationship can really play havock with each other. Consider two people-pleasers in a relationship with each other. No consider two people-pleasers in a relationship with each other when they both want out of the relationship. They will, as Earnie Larsen says, do horrible things. They'll nearly destroy each other and themselves before one will stop rescuing and say, "I want out."