TIL

The F# language has built in support for annotating numeric values with units, and for such values it appears will do some dimensional analysis and statically complain if units are incorrect.

It’s unclear if there’s a large benefit in having this functionality in the core language rather than a library, which is more common across other languages, but anecdotally in those other languages (e.g. Python) it certainly isn’t common to use these libraries in arbitrary code.