If you're just trying to demote a lifetime, you should just be able to specify the lifetime on the variable:

    let values: &'a Vec<Value> = &values;

Lifetimes have variance so that you can always put a "bigger" lifetime in a place expecting a "smaller" one safely and it will treated as the smaller one forever.

Although it can be a bit of a dangerous game trying to "set" lifetimes manually because lifetime variance is hell (at least to me).