https://issues.dlang.org/show_bug.cgi?id=15230
--- Comment #2 from John Colvin <john.loughran.col...@gmail.com> --- (In reply to Jack Stouffer from comment #1) > I would consider this as "working as intended", as the checks are only > supposed to happen in debug mode. In a PR of mine, I asked @schveiguy if it > made any sense to have any checks in a function that is supposed to be > assuming something. He said it's strange, but it's nice to have something > that double checks for you, in debug mode only. It's fine to have extra runtime checks in debug mode that check data, but I think the API should not change. The predicate should either always be verified to be valid or be optional. --