src/tools/clippy/tests/ui/for_loops_over_fallibles.rs

   1 #![warn(clippy::for_loops_over_fallibles)]
   2
   3 fn for_loops_over_fallibles() {
   4     let option = Some(1);
   5     let mut result = option.ok_or("x not found");
   6     let v = vec![0, 1, 2];
   7
   8     // check over an `Option`
   9     for x in option {
  10         println!("{}", x);
  11     }
  12
  13     // check over an `Option`
  14     for x in option.iter() {
  15         println!("{}", x);
  16     }
  17
  18     // check over a `Result`
  19     for x in result {
  20         println!("{}", x);
  21     }
  22
  23     // check over a `Result`
  24     for x in result.iter_mut() {
  25         println!("{}", x);
  26     }
  27
  28     // check over a `Result`
  29     for x in result.into_iter() {
  30         println!("{}", x);
  31     }
  32
  33     for x in option.ok_or("x not found") {
  34         println!("{}", x);
  35     }
  36
  37     // make sure LOOP_OVER_NEXT lint takes clippy::precedence when next() is the last call
  38     // in the chain
  39     for x in v.iter().next() {
  40         println!("{}", x);
  41     }
  42
  43     // make sure we lint when next() is not the last call in the chain
  44     for x in v.iter().next().and(Some(0)) {
  45         println!("{}", x);
  46     }
  47
  48     for x in v.iter().next().ok_or("x not found") {
  49         println!("{}", x);
  50     }
  51
  52     // check for false positives
  53
  54     // for loop false positive
  55     for x in v {
  56         println!("{}", x);
  57     }
  58
  59     // while let false positive for Option
  60     while let Some(x) = option {
  61         println!("{}", x);
  62         break;
  63     }
  64
  65     // while let false positive for Result
  66     while let Ok(x) = result {
  67         println!("{}", x);
  68         break;
  69     }
  70 }
  71
  72 fn main() {}