How do I get C++ comments to wrap correctly?

I want to use word-wrap on my C++ comments.

My .vimrc file contains
set tw=75
set fo+=tcjro

But when I type a long C++ style comment, I get
// This object contains the logic (code and data) for making the
first pass over the input

I want the second line to start with a // like the first one.

Ideally I'd like it to also work for sh-style comments:
# stuff
and for javadoc comments
/**
* some stuff that may line-wrap
*/

--
--
You received this message from the "vim_use" maillist.
Do not top-post! Type your reply below the text you are replying to.
For more information, visit http://www.vim.org/maillist.php

---
You received this message because you are subscribed to the Google Groups "vim_use" group.
To unsubscribe from this group and stop receiving emails from it, send an email to vim_use+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.