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

   1 #![warn(clippy::implicit_clone)]
   2 #![allow(clippy::redundant_clone)]
   3 use std::borrow::Borrow;
   4 use std::ffi::{OsStr, OsString};
   5 use std::path::PathBuf;
   6
   7 fn return_owned_from_slice(slice: &[u32]) -> Vec<u32> {
   8     slice.to_owned()
   9 }
  10
  11 pub fn own_same<T>(v: T) -> T
  12 where
  13     T: ToOwned<Owned = T>,
  14 {
  15     v.to_owned()
  16 }
  17
  18 pub fn own_same_from_ref<T>(v: &T) -> T
  19 where
  20     T: ToOwned<Owned = T>,
  21 {
  22     v.to_owned()
  23 }
  24
  25 pub fn own_different<T, U>(v: T) -> U
  26 where
  27     T: ToOwned<Owned = U>,
  28 {
  29     v.to_owned()
  30 }
  31
  32 #[derive(Copy, Clone)]
  33 struct Kitten;
  34 impl Kitten {
  35     // badly named method
  36     fn to_vec(self) -> Kitten {
  37         Kitten {}
  38     }
  39 }
  40 impl Borrow<BorrowedKitten> for Kitten {
  41     fn borrow(&self) -> &BorrowedKitten {
  42         static VALUE: BorrowedKitten = BorrowedKitten {};
  43         &VALUE
  44     }
  45 }
  46
  47 struct BorrowedKitten;
  48 impl ToOwned for BorrowedKitten {
  49     type Owned = Kitten;
  50     fn to_owned(&self) -> Kitten {
  51         Kitten {}
  52     }
  53 }
  54
  55 mod weird {
  56     #[allow(clippy::ptr_arg)]
  57     pub fn to_vec(v: &Vec<u32>) -> Vec<u32> {
  58         v.clone()
  59     }
  60 }
  61
  62 fn main() {
  63     let vec = vec![5];
  64     let _ = return_owned_from_slice(&vec);
  65     let _ = vec.to_owned();
  66     let _ = vec.to_vec();
  67
  68     let vec_ref = &vec;
  69     let _ = return_owned_from_slice(vec_ref);
  70     let _ = vec_ref.to_owned();
  71     let _ = vec_ref.to_vec();
  72
  73     // we expect no lint for this
  74     let _ = weird::to_vec(&vec);
  75
  76     // we expect no lints for this
  77     let slice: &[u32] = &[1, 2, 3, 4, 5];
  78     let _ = return_owned_from_slice(slice);
  79     let _ = slice.to_owned();
  80     let _ = slice.to_vec();
  81
  82     let str = "hello world".to_string();
  83     let _ = str.to_owned();
  84
  85     // testing w/ an arbitrary type
  86     let kitten = Kitten {};
  87     let _ = kitten.to_owned();
  88     let _ = own_same_from_ref(&kitten);
  89     // this shouln't lint
  90     let _ = kitten.to_vec();
  91
  92     // we expect no lints for this
  93     let borrowed = BorrowedKitten {};
  94     let _ = borrowed.to_owned();
  95
  96     let pathbuf = PathBuf::new();
  97     let _ = pathbuf.to_owned();
  98     let _ = pathbuf.to_path_buf();
  99
 100     let os_string = OsString::from("foo");
 101     let _ = os_string.to_owned();
 102     let _ = os_string.to_os_string();
 103
 104     // we expect no lints for this
 105     let os_str = OsStr::new("foo");
 106     let _ = os_str.to_owned();
 107     let _ = os_str.to_os_string();
 108
 109     // issue #8227
 110     let pathbuf_ref = &pathbuf;
 111     let pathbuf_ref = &pathbuf_ref;
 112     let _ = pathbuf_ref.to_owned(); // Don't lint. Returns `&PathBuf`
 113     let _ = pathbuf_ref.to_path_buf();
 114     let pathbuf_ref = &pathbuf_ref;
 115     let _ = pathbuf_ref.to_owned(); // Don't lint. Returns `&&PathBuf`
 116     let _ = pathbuf_ref.to_path_buf();
 117 }