Here are some types that support hashing:

  str
  bytes
  int, float
  complex
  tuple
  frozenset

I have crossed that bridge, and I'm telling you (again) that a sorted tuple is not a generic solution.

I'm not saying the problem with tuple doesn't exist, but that there doesn't need to be a built-in way to deal with it. If for some unfortunate reason you've got a mixed-type set that you also want to use as a dict key, you can write a helper.