use std::path::Path;

enum Storage<'d> {
    Borrowed(&'d [u8]),
    Owned(String),
}

pub struct Main<'d> {
    storage: Storage<'d>,
    //bytes: Option<&[u8]> // CAN'T DO THIS!
}

impl<'d> Main<'d> {
    pub fn new(binary_data: &[u8]) -> Main {
        // This one uses Borrowed
        Main { storage: Storage::Borrowed(binary_data) }
    }

    pub fn from_file<P: AsRef<Path>>(_file_path: P) -> Main<'static> {
        // This one uses Owned
        Main { storage: Storage::Owned("testdata".to_string()) }
    }

    pub fn get_bytes(&mut self) -> &[u8] {
        let bytes = match self.storage {
            Storage::Borrowed(b) => { b }
            Storage::Owned(ref o) => { o.as_bytes() }
        };

        //self.bytes = Some(bytes) // CAN'T DO THIS!

        bytes
    }
}

fn main() {
    let mut m = Main::from_file("foobar");

    let b = m.get_bytes();

    println!("{:?}", b);

    let b = m.get_bytes();

    println!("{:?}", b);
}