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

   1 #![allow(unused, clippy::redundant_clone, clippy::useless_vec)]
   2 #![warn(clippy::option_as_ref_deref)]
   3
   4 use std::ffi::{CString, OsString};
   5 use std::ops::{Deref, DerefMut};
   6 use std::path::PathBuf;
   7
   8 fn main() {
   9     let mut opt = Some(String::from("123"));
  10
  11     let _ = opt.clone().as_ref().map(Deref::deref).map(str::len);
  12
  13     #[rustfmt::skip]
  14     let _ = opt.clone()
  15         .as_ref().map(
  16             Deref::deref
  17         )
  18         .map(str::len);
  19
  20     let _ = opt.as_mut().map(DerefMut::deref_mut);
  21
  22     let _ = opt.as_ref().map(String::as_str);
  23     let _ = opt.as_ref().map(|x| x.as_str());
  24     let _ = opt.as_mut().map(String::as_mut_str);
  25     let _ = opt.as_mut().map(|x| x.as_mut_str());
  26     let _ = Some(CString::new(vec![]).unwrap()).as_ref().map(CString::as_c_str);
  27     let _ = Some(OsString::new()).as_ref().map(OsString::as_os_str);
  28     let _ = Some(PathBuf::new()).as_ref().map(PathBuf::as_path);
  29     let _ = Some(Vec::<()>::new()).as_ref().map(Vec::as_slice);
  30     let _ = Some(Vec::<()>::new()).as_mut().map(Vec::as_mut_slice);
  31
  32     let _ = opt.as_ref().map(|x| x.deref());
  33     let _ = opt.clone().as_mut().map(|x| x.deref_mut()).map(|x| x.len());
  34
  35     let vc = vec![String::new()];
  36     let _ = Some(1_usize).as_ref().map(|x| vc[*x].as_str()); // should not be linted
  37
  38     let _: Option<&str> = Some(&String::new()).as_ref().map(|x| x.as_str()); // should not be linted
  39
  40     let _ = opt.as_ref().map(|x| &**x);
  41     let _ = opt.as_mut().map(|x| &mut **x);
  42
  43     // Issue #5927
  44     let _ = opt.as_ref().map(std::ops::Deref::deref);
  45 }
  46
  47 #[clippy::msrv = "1.39"]
  48 fn msrv_1_39() {
  49     let opt = Some(String::from("123"));
  50     let _ = opt.as_ref().map(String::as_str);
  51 }
  52
  53 #[clippy::msrv = "1.40"]
  54 fn msrv_1_40() {
  55     let opt = Some(String::from("123"));
  56     let _ = opt.as_ref().map(String::as_str);
  57 }