rust

gistfile1.rs

fn score(hex: &[u8]) -> u8 {
    let mut freq = HashMap::new();
    for byte in hex {
        match freq.get(&byte) {
            Some(count) => freq.insert(byte, *count + 1),
            None        => freq.insert(byte, 1)
        };
    }
    0
}

03-single-byte-xor-cipher.rs:30:28: 30:32 error: cannot borrow `freq` as mutable because it is also borrowed as immutable
03-single-byte-xor-cipher.rs:30             Some(count) => freq.insert(byte, *count + 1),
                                                           ^~~~
03-single-byte-xor-cipher.rs:29:15: 29:19 note: previous borrow of `freq` occurs here; the immutable borrow prevents subsequent moves or mutable borrows of `freq` until the borrow ends
03-single-byte-xor-cipher.rs:29         match freq.get(&byte) {
                                              ^~~~
03-single-byte-xor-cipher.rs:32:10: 32:10 note: previous borrow ends here
03-single-byte-xor-cipher.rs:29         match freq.get(&byte) {
03-single-byte-xor-cipher.rs:30             Some(count) => freq.insert(byte, *count + 1),
03-single-byte-xor-cipher.rs:31             None        => freq.insert(byte, 1)
03-single-byte-xor-cipher.rs:32         };
                                        ^