ref: 49841bd0fc04490d94cf32c0e6f9d3f4ffabe098
parent: c0e08f308792b15425e10ad494263d77a45ad92d
author: Ben Harris <bjh21@bjh21.me.uk>
date: Tue Jan 31 16:08:05 EST 2023
Mines: Add assertions to range-check conversions to short I think these should be adequately guarded by the new restrictions on grid size, but I'd prefer to be sure.