Shared via Rust Playground

playground.rs

use std::marker::PhantomData;

struct Env;
#[derive(Clone, Copy)]
struct Term<'a> {
    life: PhantomData<&'a Env>,
}

// Decodes a Term to a rust value. This interfaces with native code.
trait Decoder: Sized {
    fn decode(env: &Env, term: Term) -> Option<Self>;
}

// The str this returns would only be valid for the lifetime of env.
// Is there any way to give the returned &str an intersection with the lifetime
// of the env?
// (Calls into C)
impl<'a> Decoder for &'a str {
    fn decode(env: &'a Env, term: Term) -> Option<Self> {
        None
    }
}

fn main() {}