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use std::borrow::Cow;
use std::fmt;
use std::ops::Deref;
use std::rc::Rc;
#[derive(Debug, Clone, Hash, PartialOrd, Ord, PartialEq, Eq)]
pub enum Cons<'el> {
Borrowed(&'el str),
Rc(Rc<String>),
}
impl<'a> AsRef<str> for Cons<'a> {
fn as_ref(&self) -> &str {
use self::Cons::*;
match *self {
Borrowed(value) => value,
Rc(ref value) => value.as_ref(),
}
}
}
impl<'a> Deref for Cons<'a> {
type Target = str;
fn deref(&self) -> &str {
self.as_ref()
}
}
impl<'el> From<String> for Cons<'el> {
fn from(value: String) -> Self {
Cons::Rc(Rc::new(value))
}
}
impl<'el> From<&'el str> for Cons<'el> {
fn from(value: &'el str) -> Self {
Cons::Borrowed(value)
}
}
impl<'el> From<Rc<String>> for Cons<'el> {
fn from(value: Rc<String>) -> Self {
Cons::Rc(value)
}
}
impl<'el> From<Cow<'el, str>> for Cons<'el> {
fn from(value: Cow<'el, str>) -> Self {
use self::Cow::*;
match value {
Owned(string) => Cons::Rc(Rc::new(string)),
Borrowed(string) => Cons::Borrowed(string),
}
}
}
impl<'el> fmt::Display for Cons<'el> {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
self.as_ref().fmt(fmt)
}
}