Some of us don’t want to wait until the heat death of the universe for the code to compile (not a snipe at boost as a whole - boost units is quite bad iirc). There’s also performance problems if the compiler isn’t able to see through all the templates although that’s true for many things in this space. Finally iirc it doesn’t let you define your own custom units which is a common challenge with dimensional analysis as a library.

If rust ever gets more complete const generics, then things like tiny-uom might work.

Can you provide examples?

Came here to say this. As soon as I saw the first example on the linked web page, I immediately thought of C++. Reinventing the wheel.