The guys who trimmed my trees last week had a very useful widget: a roughly 30-gallon trash can that was flat on one side so you could lay it on its side and rake leaves directly into it, so from the top it was roughly D-shaped. Searches on Google/Amazon/HomeDepot etc yielded zilch, probably because I'm using the wrong search terms.

Any clue what such a thing is called and/or where I would get one?