src/test/ui/nll/issue-54779-anon-static-lifetime.rs

   1 // Regression test for #54779, checks if the diagnostics are confusing.
   2
   3 #![feature(nll)]
   4
   5 trait DebugWith<Cx: ?Sized> {
   6     fn debug_with<'me>(&'me self, cx: &'me Cx) -> DebugCxPair<'me, Self, Cx> {
   7         DebugCxPair { value: self, cx }
   8     }
   9
  10     fn fmt_with(&self, cx: &Cx, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result;
  11 }
  12
  13 struct DebugCxPair<'me, Value: ?Sized, Cx: ?Sized>
  14 where
  15     Value: DebugWith<Cx>,
  16 {
  17     value: &'me Value,
  18     cx: &'me Cx,
  19 }
  20
  21 trait DebugContext {}
  22
  23 struct Foo {
  24     bar: Bar,
  25 }
  26
  27 impl DebugWith<dyn DebugContext> for Foo {
  28     fn fmt_with(
  29         &self,
  30         cx: &dyn DebugContext,
  31         fmt: &mut std::fmt::Formatter<'_>,
  32     ) -> std::fmt::Result {
  33         let Foo { bar } = self;
  34         bar.debug_with(cx); //~ ERROR: lifetime may not live long enough
  35         Ok(())
  36     }
  37 }
  38
  39 struct Bar {}
  40
  41 impl DebugWith<dyn DebugContext> for Bar {
  42     fn fmt_with(
  43         &self,
  44         cx: &dyn DebugContext,
  45         fmt: &mut std::fmt::Formatter<'_>,
  46     ) -> std::fmt::Result {
  47         Ok(())
  48     }
  49 }
  50
  51 fn main() {}