data_container.rs

use std::rc::Rc;

trait DataContainer<'a, T> {
    fn as_ref(&self) -> &T;
    fn to_owned(&self) -> Self
    where
        T: Clone;
}

enum StringOrRef<'a> {
    Owned(String),
    Borrowed(&'a str),
}

impl<'a> DataContainer<'a, str> for StringOrRef<'a> {
    fn as_ref(&self) -> &str {
        match self {
            StringOrRef::Owned(s) => s.as_str(),
            StringOrRef::Borrowed(s) => s,
        }
    }

    fn to_owned(&self) -> StringOrRef<'static> {
        match self {
            StringOrRef::Owned(s) => StringOrRef::Owned(s.clone()),
            StringOrRef::Borrowed(s) => StringOrRef::Owned(s.to_owned()),
        }
    }
}

enum DataOrRef<'a, T> {
    Owned(T),
    Borrowed(&'a T),
}

impl<'a, T: Clone> DataContainer<'a, T> for DataOrRef<'a, T> {
    fn as_ref(&self) -> &T {
        match self {
            DataOrRef::Owned(d) => d,
            DataOrRef::Borrowed(d) => d,
        }
    }

    fn to_owned(&self) -> DataOrRef<'static, T> {
        match self {
            DataOrRef::Owned(d) => DataOrRef::Owned(d.clone()),
            DataOrRef::Borrowed(d) => DataOrRef::Owned(d.clone()),
        }
    }
}