use std::collections::HashMap;

pub trait Encodable: Sized {}

impl<'a, K, V, S> Encodable for &'a HashMap<K, V, S>
where
    V: 'a,   // It will also crash if we delete this condition
    &'a V: Encodable,
{}

pub trait Inner where for <'a> &'a Self: Encodable {}

pub trait Outer {
    type Inner: Inner;
}

fn main() {}