LaTeX "stretch" equivalent

Hello,

I'm afraid I've hit another snag. How would I go about getting two
rules to the left and right of a centred object?

Like this: [---------------- text ----------------].

I've tried using "|" and "&" with various combinations of
@FullWidthRule and @LocalWidthRule, but I can't figure it out.

Sorry for being so annoying. An answer in the form of the (obvious? :/
) page (or approximate section) in one of the guides would more than
suffice.

Thank you, Matej