UnsafeStorage

UnsafeStorage is used to mark that there are some arbitrary invariants which must be maintained in storing its inner value. Therefore, creation and modifying of the inner value is an "unsafe" behavior. Although it might not be unsafe in traditional Rust terms (no memory unsafety), behavior might be "undefined"—or at least undocumented, because invariants are expected to be upheld.

This is useful in macros which do not encapsulate their storage in modules. This makes the macros for the end-user more ergonomic, as they can use the macro multiple times in a single module.