src/test/ui/regions/regions-infer-invariance-due-to-mutability-4.stderr

   1 error: lifetime may not live long enough
   2   --> $DIR/regions-infer-invariance-due-to-mutability-4.rs:10:5
   3    |
   4 LL | fn to_longer_lifetime<'r>(b_isize: Invariant<'r>) -> Invariant<'static> {
   5    |                       -- lifetime `'r` defined here
   6 LL |     b_isize
   7    |     ^^^^^^^ returning this value requires that `'r` must outlive `'static`
   8    |
   9    = note: requirement occurs because of the type `Invariant<'_>`, which makes the generic argument `'_` invariant
  10    = note: the struct `Invariant<'a>` is invariant over the parameter `'a`
  11    = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
  12
  13 error: aborting due to previous error
  14