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

   1 #![warn(clippy::result_unit_err)]
   2
   3 pub fn returns_unit_error() -> Result<u32, ()> {
   4     Err(())
   5 }
   6
   7 fn private_unit_errors() -> Result<String, ()> {
   8     Err(())
   9 }
  10
  11 pub trait HasUnitError {
  12     fn get_that_error(&self) -> Result<bool, ()>;
  13
  14     fn get_this_one_too(&self) -> Result<bool, ()> {
  15         Err(())
  16     }
  17 }
  18
  19 impl HasUnitError for () {
  20     fn get_that_error(&self) -> Result<bool, ()> {
  21         Ok(true)
  22     }
  23 }
  24
  25 trait PrivateUnitError {
  26     fn no_problem(&self) -> Result<usize, ()>;
  27 }
  28
  29 pub struct UnitErrorHolder;
  30
  31 impl UnitErrorHolder {
  32     pub fn unit_error(&self) -> Result<usize, ()> {
  33         Ok(0)
  34     }
  35 }
  36
  37 // https://github.com/rust-lang/rust-clippy/issues/6546
  38 pub mod issue_6546 {
  39     type ResInv<A, B> = Result<B, A>;
  40
  41     pub fn should_lint() -> ResInv<(), usize> {
  42         Ok(0)
  43     }
  44
  45     pub fn should_not_lint() -> ResInv<usize, ()> {
  46         Ok(())
  47     }
  48
  49     type MyRes<A, B> = Result<(A, B), Box<dyn std::error::Error>>;
  50
  51     pub fn should_not_lint2(x: i32) -> MyRes<i32, ()> {
  52         Ok((x, ()))
  53     }
  54 }
  55
  56 fn main() {}