src/tools/clippy/tests/ui/unnecessary_to_owned.fixed

   1 // run-rustfix
   2
   3 #![allow(clippy::ptr_arg)]
   4 #![warn(clippy::unnecessary_to_owned)]
   5 #![feature(custom_inner_attributes)]
   6
   7 use std::borrow::Cow;
   8 use std::ffi::{CStr, CString, OsStr, OsString};
   9 use std::ops::Deref;
  10
  11 #[derive(Clone)]
  12 struct X(String);
  13
  14 impl Deref for X {
  15     type Target = [u8];
  16     fn deref(&self) -> &[u8] {
  17         self.0.as_bytes()
  18     }
  19 }
  20
  21 impl AsRef<str> for X {
  22     fn as_ref(&self) -> &str {
  23         self.0.as_str()
  24     }
  25 }
  26
  27 impl ToString for X {
  28     fn to_string(&self) -> String {
  29         self.0.to_string()
  30     }
  31 }
  32
  33 impl X {
  34     fn join(&self, other: impl AsRef<str>) -> Self {
  35         let mut s = self.0.clone();
  36         s.push_str(other.as_ref());
  37         Self(s)
  38     }
  39 }
  40
  41 #[allow(dead_code)]
  42 #[derive(Clone)]
  43 enum FileType {
  44     Account,
  45     PrivateKey,
  46     Certificate,
  47 }
  48
  49 fn main() {
  50     let c_str = CStr::from_bytes_with_nul(&[0]).unwrap();
  51     let os_str = OsStr::new("x");
  52     let path = std::path::Path::new("x");
  53     let s = "x";
  54     let array = ["x"];
  55     let array_ref = &["x"];
  56     let slice = &["x"][..];
  57     let x = X(String::from("x"));
  58     let x_ref = &x;
  59
  60     require_c_str(&Cow::from(c_str));
  61     require_c_str(c_str);
  62
  63     require_os_str(os_str);
  64     require_os_str(&Cow::from(os_str));
  65     require_os_str(os_str);
  66
  67     require_path(path);
  68     require_path(&Cow::from(path));
  69     require_path(path);
  70
  71     require_str(s);
  72     require_str(&Cow::from(s));
  73     require_str(s);
  74     require_str(x_ref.as_ref());
  75
  76     require_slice(slice);
  77     require_slice(&Cow::from(slice));
  78     require_slice(array.as_ref());
  79     require_slice(array_ref.as_ref());
  80     require_slice(slice);
  81     require_slice(x_ref);
  82
  83     require_x(&Cow::<X>::Owned(x.clone()));
  84     require_x(x_ref);
  85
  86     require_deref_c_str(c_str);
  87     require_deref_os_str(os_str);
  88     require_deref_path(path);
  89     require_deref_str(s);
  90     require_deref_slice(slice);
  91
  92     require_impl_deref_c_str(c_str);
  93     require_impl_deref_os_str(os_str);
  94     require_impl_deref_path(path);
  95     require_impl_deref_str(s);
  96     require_impl_deref_slice(slice);
  97
  98     require_deref_str_slice(s, slice);
  99     require_deref_slice_str(slice, s);
 100
 101     require_as_ref_c_str(c_str);
 102     require_as_ref_os_str(os_str);
 103     require_as_ref_path(path);
 104     require_as_ref_str(s);
 105     require_as_ref_str(&x);
 106     require_as_ref_slice(array);
 107     require_as_ref_slice(array_ref);
 108     require_as_ref_slice(slice);
 109
 110     require_impl_as_ref_c_str(c_str);
 111     require_impl_as_ref_os_str(os_str);
 112     require_impl_as_ref_path(path);
 113     require_impl_as_ref_str(s);
 114     require_impl_as_ref_str(&x);
 115     require_impl_as_ref_slice(array);
 116     require_impl_as_ref_slice(array_ref);
 117     require_impl_as_ref_slice(slice);
 118
 119     require_as_ref_str_slice(s, array);
 120     require_as_ref_str_slice(s, array_ref);
 121     require_as_ref_str_slice(s, slice);
 122     require_as_ref_slice_str(array, s);
 123     require_as_ref_slice_str(array_ref, s);
 124     require_as_ref_slice_str(slice, s);
 125
 126     let _ = x.join(x_ref);
 127
 128     let _ = slice.iter().copied();
 129     let _ = slice.iter().copied();
 130     let _ = [std::path::PathBuf::new()][..].iter().cloned();
 131     let _ = [std::path::PathBuf::new()][..].iter().cloned();
 132
 133     let _ = slice.iter().copied();
 134     let _ = slice.iter().copied();
 135     let _ = [std::path::PathBuf::new()][..].iter().cloned();
 136     let _ = [std::path::PathBuf::new()][..].iter().cloned();
 137
 138     let _ = check_files(&[FileType::Account]);
 139
 140     // negative tests
 141     require_string(&s.to_string());
 142     require_string(&Cow::from(s).into_owned());
 143     require_string(&s.to_owned());
 144     require_string(&x_ref.to_string());
 145
 146     // `X` isn't copy.
 147     require_slice(&x.to_owned());
 148     require_deref_slice(x.to_owned());
 149
 150     // The following should be flagged by `redundant_clone`, but not by this lint.
 151     require_c_str(&CString::from_vec_with_nul(vec![0]).unwrap());
 152     require_os_str(&OsString::from("x"));
 153     require_path(&std::path::PathBuf::from("x"));
 154     require_str(&String::from("x"));
 155 }
 156
 157 fn require_c_str(_: &CStr) {}
 158 fn require_os_str(_: &OsStr) {}
 159 fn require_path(_: &std::path::Path) {}
 160 fn require_str(_: &str) {}
 161 fn require_slice<T>(_: &[T]) {}
 162 fn require_x(_: &X) {}
 163
 164 fn require_deref_c_str<T: Deref<Target = CStr>>(_: T) {}
 165 fn require_deref_os_str<T: Deref<Target = OsStr>>(_: T) {}
 166 fn require_deref_path<T: Deref<Target = std::path::Path>>(_: T) {}
 167 fn require_deref_str<T: Deref<Target = str>>(_: T) {}
 168 fn require_deref_slice<T, U: Deref<Target = [T]>>(_: U) {}
 169
 170 fn require_impl_deref_c_str(_: impl Deref<Target = CStr>) {}
 171 fn require_impl_deref_os_str(_: impl Deref<Target = OsStr>) {}
 172 fn require_impl_deref_path(_: impl Deref<Target = std::path::Path>) {}
 173 fn require_impl_deref_str(_: impl Deref<Target = str>) {}
 174 fn require_impl_deref_slice<T>(_: impl Deref<Target = [T]>) {}
 175
 176 fn require_deref_str_slice<T: Deref<Target = str>, U, V: Deref<Target = [U]>>(_: T, _: V) {}
 177 fn require_deref_slice_str<T, U: Deref<Target = [T]>, V: Deref<Target = str>>(_: U, _: V) {}
 178
 179 fn require_as_ref_c_str<T: AsRef<CStr>>(_: T) {}
 180 fn require_as_ref_os_str<T: AsRef<OsStr>>(_: T) {}
 181 fn require_as_ref_path<T: AsRef<std::path::Path>>(_: T) {}
 182 fn require_as_ref_str<T: AsRef<str>>(_: T) {}
 183 fn require_as_ref_slice<T, U: AsRef<[T]>>(_: U) {}
 184
 185 fn require_impl_as_ref_c_str(_: impl AsRef<CStr>) {}
 186 fn require_impl_as_ref_os_str(_: impl AsRef<OsStr>) {}
 187 fn require_impl_as_ref_path(_: impl AsRef<std::path::Path>) {}
 188 fn require_impl_as_ref_str(_: impl AsRef<str>) {}
 189 fn require_impl_as_ref_slice<T>(_: impl AsRef<[T]>) {}
 190
 191 fn require_as_ref_str_slice<T: AsRef<str>, U, V: AsRef<[U]>>(_: T, _: V) {}
 192 fn require_as_ref_slice_str<T, U: AsRef<[T]>, V: AsRef<str>>(_: U, _: V) {}
 193
 194 // `check_files` is based on:
 195 // https://github.com/breard-r/acmed/blob/1f0dcc32aadbc5e52de6d23b9703554c0f925113/acmed/src/storage.rs#L262
 196 fn check_files(file_types: &[FileType]) -> bool {
 197     for t in file_types {
 198         let path = match get_file_path(t) {
 199             Ok(p) => p,
 200             Err(_) => {
 201                 return false;
 202             },
 203         };
 204         if !path.is_file() {
 205             return false;
 206         }
 207     }
 208     true
 209 }
 210
 211 fn get_file_path(_file_type: &FileType) -> Result<std::path::PathBuf, std::io::Error> {
 212     Ok(std::path::PathBuf::new())
 213 }
 214
 215 fn require_string(_: &String) {}
 216
 217 fn _msrv_1_35() {
 218     #![clippy::msrv = "1.35"]
 219     // `copied` was stabilized in 1.36, so clippy should use `cloned`.
 220     let _ = &["x"][..].iter().cloned();
 221 }
 222
 223 fn _msrv_1_36() {
 224     #![clippy::msrv = "1.36"]
 225     let _ = &["x"][..].iter().copied();
 226 }
 227
 228 // https://github.com/rust-lang/rust-clippy/issues/8507
 229 mod issue_8507 {
 230     #![allow(dead_code)]
 231
 232     struct Opaque<P>(P);
 233
 234     pub trait Abstracted {}
 235
 236     impl<P> Abstracted for Opaque<P> {}
 237
 238     fn build<P>(p: P) -> Opaque<P>
 239     where
 240         P: AsRef<str>,
 241     {
 242         Opaque(p)
 243     }
 244
 245     // Should not lint.
 246     fn test_str(s: &str) -> Box<dyn Abstracted> {
 247         Box::new(build(s.to_string()))
 248     }
 249
 250     // Should not lint.
 251     fn test_x(x: super::X) -> Box<dyn Abstracted> {
 252         Box::new(build(x))
 253     }
 254
 255     #[derive(Clone, Copy)]
 256     struct Y(&'static str);
 257
 258     impl AsRef<str> for Y {
 259         fn as_ref(&self) -> &str {
 260             self.0
 261         }
 262     }
 263
 264     impl ToString for Y {
 265         fn to_string(&self) -> String {
 266             self.0.to_string()
 267         }
 268     }
 269
 270     // Should lint because Y is copy.
 271     fn test_y(y: Y) -> Box<dyn Abstracted> {
 272         Box::new(build(y))
 273     }
 274 }