I had a similar idea about forty years ago. Turns out Guy L. Steele and a couple other folks actually did try that, but Fortress was never widely adopted. Later I realized that rather than try to make a whole new language that was different from most existing ones by having that feature, it would be better to have a library that would support units of measurement, ideally in a way that could be translated to other languages. About nineteen years ago, I finally wrote one, for C++. Later I did one for Ruby, putting it aside “temporarily” when I couldn’t decide which of a few approaches to take for some feature I now forget. Now I’m thinking I should do one (or at least check if there is such a thing) for Elixir. 
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