src/test/ui/variance/variance-use-covariant-struct-2.rs

   1 // Test that a covariant struct permits the lifetime of a reference to
   2 // be shortened.
   3
   4 #![allow(dead_code)]
   5 // build-pass (FIXME(62277): could be check-pass?)
   6
   7 struct SomeStruct<T>(T);
   8
   9 fn foo<'min,'max>(v: SomeStruct<&'max ()>)
  10                   -> SomeStruct<&'min ()>
  11     where 'max : 'min
  12 {
  13     v
  14 }
  15
  16 fn main() { }