Re: portability of sed's \{0,1\}?

[Eli Zaretskii]

On Sat, 12 Aug 2000, Paul Eggert wrote:

> The sed FAQ, version 014 <http://www.cornerstonemag.com/sed/sedfaq.html> says:
> 
> * Ultrix 4.3 sed doesn't support \(...\)\{...\} (the idiom used here).
> * Likewise for HHsed v1.5 (by Howard Helman).
> * sedmod v1.0 (by Hern Chen) doesn't support \{...\} at all.

I don't see any work-arounds suggested for these problems.  Does anyone 
know how do you express \(foo\)\{0,1\} portably?