CODEWITHSUNDEEP
rustbyteliterals
Dominus
Dominus

Reputation: 998

Is it possible to write literal byte strings with values larger than 127 in rust?

I've noticed that in Rust, we can't use the byte notation for values larger than 128, that is 

let x = "\x01\x17\x7f"

is fine since all chars are < 128, but 

let x = "\x01\x17\x80"

will fail since \x80 = 128.

Is there any way to still write string-like objects in that format?

Upvotes: 0

Views: 1070

Answers (1)

mcarton
mcarton

Reputation: 29991

Above 127 you enter the realm of Unicode and must use the \u{codepoint} escape sequence:

let x = "\u{80}";

Note however that 0x80 by itself isn't a valid byte in a UTF-8 string, so this turns out as two bytes:

let x = "\u{80}";

for b in x.bytes() {
    println!("{:X}", b);
}

prints

C2
80

If you instead need the value 0x80, you can't use a string and must use a byte slice:

fn main() {
    let x = b"\x80";

    for b in x {
        println!("{:X}", b);
    }
}

prints

80

Upvotes: 4

Related Questions