How to collapse blocks of code in Eclipse?

Some days ago my Eclipse was working fine and a +/- appeared in every block that could be collapsed (functions, classes, etc.)... but now it does appear, and I don't know how to activate that feature again.

It's Eclipse Helios, running on a Gentoo Linux box.

How do I collapse code in Intellij?

you can use Ctrl+Shift+Minus to collapse all of them and then use Ctrl+Alt+Plus to open one of that recursively.

How do you expand in Eclipse?

Update for Eclipse Mars on Windows 10 (using inside "Search View"): Numpad * - expands all in the selected folder, Numpad + - expands ONE level below the selected folder, Numpad - - collapses previous expanded folder (or if ALL was expanded then next underlying level along WITH the expanded folder down below) in the ...

Preferences -> C++ -> Editor -> Folding ?

Make a right click in the editor window and go to preferences there, then only the editor-relevant section of the preferences dialog will appear. This works for JDT, CDT etc...