src/test/ui/did_you_mean/recursion_limit_deref.rs

   1 // Test that the recursion limit can be changed and that the compiler
   2 // suggests a fix. In this case, we have a long chain of Deref impls
   3 // which will cause an overflow during the autoderef loop.
   4 // compile-flags: -Zdeduplicate-diagnostics=yes
   5
   6 #![allow(dead_code)]
   7 #![recursion_limit="10"]
   8
   9 macro_rules! link {
  10     ($outer:ident, $inner:ident) => {
  11         struct $outer($inner);
  12
  13         impl $outer {
  14             fn new() -> $outer {
  15                 $outer($inner::new())
  16             }
  17         }
  18
  19         impl std::ops::Deref for $outer {
  20             type Target = $inner;
  21
  22             fn deref(&self) -> &$inner {
  23                 &self.0
  24             }
  25         }
  26     }
  27 }
  28
  29 struct Bottom;
  30 impl Bottom {
  31     fn new() -> Bottom {
  32         Bottom
  33     }
  34 }
  35
  36 link!(Top, A);
  37 link!(A, B);
  38 link!(B, C);
  39 link!(C, D);
  40 link!(D, E);
  41 link!(E, F);
  42 link!(F, G);
  43 link!(G, H);
  44 link!(H, I);
  45 link!(I, J);
  46 link!(J, K);
  47 link!(K, Bottom);
  48
  49 fn main() {
  50     let t = Top::new();
  51     let x: &Bottom = &t; //~ ERROR mismatched types
  52     //~^ error recursion limit
  53 }