src/test/ui/lifetimes/issue-77175.rs

   1 #[deny(single_use_lifetimes)]
   2 // edition:2018
   3 // check-pass
   4
   5 // Prior to the fix, the compiler complained that the 'a lifetime was only used
   6 // once. This was obviously wrong since the lifetime is used twice: For the s3
   7 // parameter and the return type. The issue was caused by the compiler
   8 // desugaring the async function into a generator that uses only a single
   9 // lifetime, which then the validator complained about becauase of the
  10 // single_use_lifetimes constraints.
  11 async fn bar<'a>(s1: String, s2: &'_ str, s3: &'a str) -> &'a str {
  12     s3
  13 }
  14
  15 fn foo<'a>(s1: String, s2: &'_ str, s3: &'a str) -> &'a str {
  16     s3
  17 }
  18
  19 fn main() {}