string_or_slice.rs

use std::rc::Rc;

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

struct MyString<'a> {
    data: StringOrSlice<'a>,
}

impl<'a> MyString<'a> {
    fn new_owned(data: String) -> Self {
        MyString {
            data: StringOrSlice::Owned(data),
        }
    }

    fn new_borrowed(data: &'a str) -> Self {
        MyString {
            data: StringOrSlice::Borrowed(data),
        }
    }

    fn as_ref(&self) -> &str {
        match &self.data {
            StringOrSlice::Owned(s) => &s,
            StringOrSlice::Borrowed(s) => s,
        }
    }

    fn clone(&self) -> Self {
        match &self.data {
            StringOrSlice::Owned(s) => MyString::new_owned(s.clone()),
            StringOrSlice::Borrowed(s) => MyString::new_borrowed(s),
        }
    }

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