How to add components based on a component.

[coolcatcoder]

I don't know how to phrase this. Basically, I occasionally need to add some components to an entity based on another component. What is the best way of doing this? The 2 obvious approaches that I can see, would be to either use a generic component, and have a generic system, or to use an enum that has variants for every single component I would want to add. Is there a better way, or are either of these okay?
(Also, if this doesn't make sense, I'm happy to try re-explain!)
(Also posted in #help on the discord: 1270282512714694706)

[coolcatcoder]

Resolved by discord thread.