[...] The size of () is defined as 0. It sounds absurd for a Storable to
have a size of 0?
This is not absurd at all, there is absolutely no information to be stored. Everything one needs to know is in the type here.
This means that we can read an infinite number of ()
type values out of nothing (no memory location required) or store an
infinite number of () type values without even requiring a memory
location to write to.
Exactly.
[...] Can this be fixed? Is there a compelling argument to keep it like this? [...]
There is nothing to be fixed on the Storable side of things, the fix needs to be in your code, as David has already mentioned. And in addition: I would *strongly* advise to leave the Storable () instance as-is, I'm quite sure that otherwise tons of code will break in mysterious ways, undetected by any compiler.
Cheers,
S.