In fact, that's exactly what Rust already does today! Option<char> uses the exact same amount of bits to store as plain char, because the compiler has enough in

In fact, that's exactly what Rust already does today! Option<char> uses the exact same amount of bits to store as plain char, because the compiler has enough information to encode the Option-ness of char in what it knows is a garbage bit of the underlying type. https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=56fdd3cb74b645d729d9e49fb7250921 https://play.rust-lang.org/?version=stable&mode=debug&editio...