src/test/ui/variance/variance-contravariant-arg-object.rs

   1 #![allow(dead_code)]
   2
   3 // Test that even when `T` is only used in contravariant position, it
   4 // is treated as invariant.
   5
   6 trait Get<T> : 'static {
   7     fn get(&self, t: T);
   8 }
   9
  10 fn get_min_from_max<'min, 'max>(v: Box<dyn Get<&'max i32>>)
  11                                 -> Box<dyn Get<&'min i32>>
  12     where 'max : 'min
  13 {
  14     v
  15     //~^ ERROR lifetime may not live long enough
  16 }
  17
  18 fn get_max_from_min<'min, 'max>(v: Box<dyn Get<&'min i32>>)
  19                                 -> Box<dyn Get<&'max i32>>
  20     where 'max : 'min
  21 {
  22     // Previously OK:
  23     v
  24     //~^ ERROR lifetime may not live long enough
  25 }
  26
  27 fn main() { }