[cokernel_hacker]

So let's change it up a bit.

  typedef int (*pfn)(void);
  int g(void);
  int h(void);

  pfn f(double x) {
    switch ((long long)x) {
    case 0:
      return g;
    case 17:
      return h;
    }
  }

If I understand your perspective correctly, `f` should return whatever happens to be in rax if the caller does not pass in a number which truncates to 0 or 17?

[torstenvl]

More or less, yes.

I quibble with "should return" because I don't think it's accurate to say it "should" do anything in any specific set of circumstances. In fact, I'm saying the opposite: it should generate the generic, semantic code translation of what is actually written in source, and if it happens to "return whatever happens to be in rax" (as is likely on x64), then so be it.

In my view, that's what "ignoring the situation completely with unpredictable results" means.