error: lifetime may not live long enough --> $DIR/copy_modulo_regions.rs:12:5 | LL | fn foo<'a>() -> [Foo<'a>; 100] { | -- lifetime `'a` defined here LL | [mk_foo::<'a>(); 100] | ^^^^^^^^^^^^^^^^^^^^^ returning this value requires that `'a` must outlive `'static` | = note: requirement occurs because of the type `Foo<'_>`, which makes the generic argument `'_` invariant = note: the struct `Foo<'a>` is invariant over the parameter `'a` = help: see for more information about variance error: aborting due to previous error