Okay, that makes sense. In CVI those features exist, but you have to press a key first. For example, if you press Ctrl+Shift+Space over a function name, you should see its declaration. The only time the declaration pops up automatically is when you type the open parenthesis after the function name.
For auto-completing identifier names, you have to press Ctrl+Space. It works for functions, variables and macros, but it doesn't work for keywords, like "while", "for", etc...
The main restriction with CVI is that for your own identifiers (as opposed to those in the CVI libraries) you will have to compile your project first. I realize that this is not a trivial limitiation, and it is something that we hope to address in the not too distant future.
Thanks again,
Luis