tests/ui/nll/get_default.rs

   1 // Basic test for free regions in the NLL code. This test ought to
   2 // report an error due to a reborrowing constraint. Right now, we get
   3 // a variety of errors from the older, AST-based machinery (notably
   4 // borrowck), and then we get the NLL error at the end.
   5
   6 struct Map {
   7 }
   8
   9 impl Map {
  10     fn get(&self) -> Option<&String> { None }
  11     fn set(&mut self, v: String) { }
  12 }
  13
  14 fn ok(map: &mut Map) -> &String {
  15     loop {
  16         match map.get() {
  17             Some(v) => {
  18                 return v;
  19             }
  20             None => {
  21                 map.set(String::new()); // Ideally, this would not error.
  22                 //~^ ERROR borrowed as immutable
  23             }
  24         }
  25     }
  26 }
  27
  28 fn err(map: &mut Map) -> &String {
  29     loop {
  30         match map.get() {
  31             Some(v) => {
  32                 map.set(String::new()); // Both AST and MIR error here
  33                 //~^ ERROR borrowed as immutable
  34                 return v;
  35             }
  36             None => {
  37                 map.set(String::new()); // Ideally, just AST would error here
  38                 //~^ ERROR borrowed as immutable
  39             }
  40         }
  41     }
  42 }
  43
  44 fn main() { }