> This is yet another reason why I say bare numbers can be poison in a sufficiently complicated system.

In Racket, I tended to use keyword arguments, and include the units in the keyword argument. For example, one library used `:velocity-mm/s`. (The `/` character is an identifier constituent, not some special operator syntax.)

In Rust, I'm going to try out using language features for static checking of some units (with 0 runtime cost).