Recently I noticed a couple of questions (1, 2) where the author had also posted the solution as part of the question. In both cases I asked the author to post the solution as an answer; one of them did, but in the other case I ended up posting it myself (as community wiki, so as not to wrongly claim any reputation for it). But I'm wondering if there's a better, commonly accepted way of handling these cases (or maybe even an official policy)?
I specifically mean cases where the author doesn't repost the solution themselves, because if I post it myself, I can neither accept it nor even upvote it, which means the answer might not get the visibility it deserves, despite it technically being the accepted solution.