Auto-comment new line in Vim only for block comments

Question

When I start a new line at the end of a single-line comment in a `.{cpp,h}` file, `vim` is automatically commenting it. For example: ``` // This is a comment<CR> // | <- Cursor is moved to `|`, `//` is automatically inserted. ``` I'm not sure if this is a plugin or a setting. I can't see anything that looks like it'd do this in my `~/.vimrc`, and the loaded plugins are listed below. I like this for `/* */`-style multiline comments, but I don't want my single-line comments running over multiple lines by default. Which setting (or plugin) does this, and can I turn it off for this comment type only? `:scriptnames` gives this: ``` 1: /Users/simont/.vimrc 2: /usr/local/share/vim/vim73/syntax/syntax.vim 3: /usr/local/share/vim/vim73/syntax/synload.vim 4: /usr/local/share/vim/vim73/syntax/syncolor.vim 5: /usr/local/share/vim/vim73/filetype.vim 6: /usr/local/share/vim/vim73/ftplugin.vim 7: /usr/local/share/vim/vim73/syntax/nosyntax.vim 8: /Users/simont/repositories/config-files/vim/colors/sol…

Accepted Answer

```
au FileType c,cpp setlocal comments-=:// comments+=f://
```

In your vimrc should do the trick for `//` without affecting block comments, in {cpp,h} files.

To try it temporarily in the current buffer use:

```
:setlocal comments-=:// comments+=f://
```

Auto-comment new line in Vim only for block comments

Solution

Problem