You trigger the Code completion feature when you call Content Assist (such as when you type Ctrl+Space), but it is auto-activated when you type ".", "->" or "::".
implies there is no way for it to "auto activate" on its own -- like it would in every other IDE I have ever used (at least a half dozen).
Hmmm. Really? No one else in the Eclipse universe has ever expected auto-complete to auto-activate?
Well, thanks. I poked around the help, but at first glance assumed I was just missing something.