src/test/ui/regions/region-invariant-static-error-reporting.nll.stderr

   1 error[E0521]: borrowed data escapes outside of function
   2   --> $DIR/region-invariant-static-error-reporting.rs:15:9
   3    |
   4 LL | fn unify<'a>(x: Option<Invariant<'a>>, f: fn(Invariant<'a>)) {
   5    |          --  - `x` is a reference that is only valid in the function body
   6    |          |
   7    |          lifetime `'a` defined here
   8 LL |     let bad = if x.is_some() {
   9 LL |         x.unwrap()
  10    |         ^^^^^^^^^^
  11    |         |
  12    |         `x` escapes the function body here
  13    |         argument requires that `'a` must outlive `'static`
  14    |
  15    = note: requirement occurs because of the type Invariant<'_>, which makes the generic argument '_ invariant
  16    = note: the struct Invariant<'a> is invariant over the parameter 'a
  17    = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
  18
  19 error: aborting due to previous error
  20
  21 For more information about this error, try `rustc --explain E0521`.