Rust is more restrictive than it needs to be, in this case. What matters is whether it's possible to have a situation where the value of a variable or parameter is not concordant with its type in a given context and what it takes to make that happen.

Of course it's possible to tell the TS type checker to sod off in a given context (cast, use the "any" type, etc.), but without doing that, I think it's hard to contrive a situation such as I described above.

https://www.typescriptlang.org/play?#code/C4TwDgpgBAsiAq5oF4...