error: lifetime may not live long enough --> $DIR/regions-infer-invariance-due-to-mutability-3.rs:10:5 | LL | fn to_longer_lifetime<'r>(b_isize: Invariant<'r>) -> Invariant<'static> { | -- lifetime `'r` defined here LL | b_isize | ^^^^^^^ returning this value requires that `'r` must outlive `'static` | = note: requirement occurs because of the type `Invariant<'_>`, which makes the generic argument `'_` invariant = note: the struct `Invariant<'a>` is invariant over the parameter `'a` = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance error: aborting due to previous error