I don't think you can; in my experience that's a feature of various code-golfing sites, as seeing others' solutions would give you a rather unfair advantage.

Past Perl golfing contests often (always?) had a deadline after which solutions would be revealed and a post-mortem prepared so everyone could compare their solutions, learn, and improve on them still. (I remember a very nice and rather huge PDF collecting all these, from various contests/sites.) Unfortunately this appears to have fallen out of style.