I think you're exactly right: People who live and breathe JSON and strings don't (and probably shouldn't) care about use cases where the choice between float or double matters...

I also see this with graphics people who live and breathe small (2x2, 3x3, and 4x4) matrices don't care about "type level integers" (as Rust calls them) to make 6x9 matrices efficiently live on the stack or in an array.

> Is it possible that a boxed "Number" type would solve most of the problems?

If you mean it the way I think you do, not for me. I can easily afford to fit a billion 4 byte floats in memory, but I can't afford a billion 8 byte box pointers to a 4 byte box with an n-byte tag, and the cache locality could be horrible.

However, if Go had an elegant macro system (Rust's doesn't seem too bad), I could get by though.