You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: string.rs
    path of file: ./repos/ruruby/ruruby/src/value
    
    the code of the file until where you have to start completion: use crate::*;
use arrayvec::ArrayString;

pub type SmallString = ArrayString<31>;

const SMALL_STRING_CAPACITY: usize = 31;

#[derive(Clone, PartialEq, Hash)]
pub enum RString {
    Str(String),
    SmallStr(SmallString),
    Bytes(Vec<u8>),
}

use std::fmt;
impl fmt::Debug for RString {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        fn write(s: &str, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            for ch in s.chars() {
                match ch {
                    c @ '\'' | c @ '"' | c @ '\\' => {
                        write!(f, "\\{}", c)?;
                    }
                    c if '\x00' <= c && c <= '\x06' => write!(f, "\\x{:02}", c as u32)?,
                    '\x07' => write!(f, "\\a")?,
                    '\x08' => write!(f, "\\b")?,
                    '\x09' => write!(f, "\\t")?,
                    '\x0a' => write!(f, "\\n")?,
                    '\x0b' => write!(f, "\\v")?,
                    '\x0c' => write!(f, "\\f")?,
                    '\x0d' => write!(f, "\\r")?,
                    '\x1b' => write!(f, "\\e")?,
                    c => write!(f, "{}", c)?,
        
    
    pub(crate) fn append(&mut self, rhs: &RString) {
        use self::RString::*;
        use std::mem;
        *self = match *self {
            Str(ref mut lhs) => match rhs {
                Str(rhs) => {
                    *lhs += rhs;
                    return;
                }
                SmallStr(rhs) => {
                    *lhs += rhs.as_str();
                    return;
                }
                Bytes(rhs) => {
                    let mut bytes = mem::take(lhs).into_bytes();
                    bytes.extend(rhs);
                    RString::from_bytes(bytes)
                }
            },
            SmallStr(ref mut lhs) => {
                let mut lhs = mem::replace(lhs, SmallString::new()).to_string();
                match rhs {
                    Str(rhs) => {
                        lhs += rhs;
                        Str(lhs)
                    }
                    SmallStr(rhs) => {
                        lhs += rhs.as_str();
                        RString::from(lhs)
                    }
                    Bytes(rhs) => {
                        let mut bytes = lhs.into_bytes();
                        bytes.extend(rhs);
                        RString::from_bytes(bytes)
                    }
                }
            }
            Bytes(ref mut lhs) => match rhs {
                Str(rhs) => {
                    let mut bytes = mem::take(lhs);
                    bytes.extend(rhs.as_bytes());
                    RString::from_bytes(bytes)
                }
                SmallStr(rhs) => {
                    let mut bytes = mem::take(lhs);
                    bytes.extend(rhs.as_bytes());
                    RString::from_bytes(bytes)
                }
                Bytes(rhs) => {
                    lhs.extend(rhs);
                    return;
                }
            },
        };
    }