In Java, I could do this.
int diff = \'Z\' - \'A\'; // 25
I have tried the same in Rust:
The operation is meaningless in a Unicode world, and barely ever meaningful in an ASCII world, this is why Rust doesn't provide it directly, but there are two ways to do this depending on your use case:
'Z' as u32 - 'A' as u32
b'Z' - b'A'