Since all of the expressions just wrap a None, I wouldn’t be surprised if the transmutes basically get compiled to 0, making the assertion at the end assert_eq!(0 * 0, 0).
That’s kind of wild, I double-checked and it’s true.
Although I disagree with the second part, the Rust folks wouldn’t care about the in-memory representation as long as the compilation is on point.
Looking closer at the final enum, I guess it’s because there are nine possible cases for it, making the compiler pack it into 4 bits, with one number representing each? I checked and None is represented as 8, while 7 Somes containing a None is 0 and the full 8 Somes is represented by 1.
Since all of the expressions just wrap a
None, I wouldn’t be surprised if the transmutes basically get compiled to0, making the assertion at the endassert_eq!(0 * 0, 0).Nah these are the actual integer representations. Otherwise you would have
Some(None) == Some(Some(None))which is way too Javascripty for Rust folks.That’s kind of wild, I double-checked and it’s true.
Although I disagree with the second part, the Rust folks wouldn’t care about the in-memory representation as long as the compilation is on point.
Looking closer at the final enum, I guess it’s because there are nine possible cases for it, making the compiler pack it into 4 bits, with one number representing each? I checked and
Noneis represented as8, while 7Somes containing aNoneis 0 and the full 8Somes is represented by1.Well I can’t speak for everyone, but Rust is very intentional about supporting things like
repr(C). At least some of us care a lot.