Exhaustiveness of pattern matching for numerical values.

[tmielcza]

When I try to compile this code:

fn main() {
    let t: u8 = 3;
    match t {
        0x00...0x100 => (),
    }
}

I got the following error:

src/main.rs:36:5: 38:6 error: non-exhaustive patterns: `_` not covered [E0004]
src/main.rs:36     match t {
src/main.rs:37         0x00...0x100 => (),
src/main.rs:38     }

while 0x00 to 0x100 covers all possible values for a u8.
Why is that?

[jonas-schievink]

This is just not implemented. Last time this was brought up, it was closed in favor of an RFC.

(0x100 is too large for u8 by the way - you want 0xff since ... is inclusive)

[steveklabnik]

Yes, this is a duplicate of #12483, and would require an RFC.