src/test/ui/suggestions/impl-trait-missing-lifetime-gated.rs

   1 // edition:2021
   2 // gate-test-anonymous_lifetime_in_impl_trait
   3 // Verify the behaviour of `feature(anonymous_lifetime_in_impl_trait)`.
   4
   5 fn f(_: impl Iterator<Item = &'_ ()>) {}
   6 //~^ ERROR anonymous lifetimes in `impl Trait` are unstable
   7
   8 fn g(x: impl Iterator<Item = &'_ ()>) -> Option<&'_ ()> { x.next() }
   9 //~^ ERROR anonymous lifetimes in `impl Trait` are unstable
  10 //~| ERROR missing lifetime specifier
  11
  12 // Anonymous lifetimes in async fn are already allowed.
  13 // This is understood as `fn foo<'_1>(_: impl Iterator<Item = &'_1 ()>) {}`.
  14 async fn h(_: impl Iterator<Item = &'_ ()>) {}
  15
  16 // Anonymous lifetimes in async fn are already allowed.
  17 // But that lifetime does not participate in resolution.
  18 async fn i(x: impl Iterator<Item = &'_ ()>) -> Option<&'_ ()> { x.next() }
  19 //~^ ERROR missing lifetime specifier
  20
  21 fn main() {}