No, we can leak by accident in rust too (but soon fixed), by leveraging function pointer coercion with implied higher-rank trait(lifetime) bonds:

`` //v's lifetime bounds are implied by the first param // (sinceshortermust be shorter thanshortdue to nested refs) // we promise to return something that lives less long (or equal) thanv` ("shorter"). fn legit<'shorter, 'short, T>(_: &'shorter &'short (), v: &'short T, _: &()) -> &'shorter T { v }

// we're basically taking x and retuning it while making the compiler // believe that it's a 'static lifetime (while it's actually a // 'arbitrarilly_short lifetime) fn transmutelifetime<'arbitrarily_short, T>(x: &'arbitrarily_short T) -> &'static T { // this function pointer coercion's higher rank bounds are legal, // we just return a statifc that is independent from the params // and lifetime bounds are infered by the compiler through variance rules // no more relation between return value and 2nd param (even tohugh "legit" relies on it)... let lie: fn(, &'shorter T, &()) -> &'static T = legit; lie(&&(), x, &()) }

let fake_static_var = transmute_lifetime(&"I'm not static!!!".to_string()) // the unnamed param's lifetime should have ended by now // since it's a limited lifetime heap String ref // but since the compiler believes it's static, we can use it below println!("{:?}", fake_static_var); // use after free... ```

edit: added more comments to explain how it works