library/core/tests/mem.rs

   1 use core::mem::*;
   2
   3 #[cfg(panic = "unwind")]
   4 use std::rc::Rc;
   5
   6 #[test]
   7 fn size_of_basic() {
   8     assert_eq!(size_of::<u8>(), 1);
   9     assert_eq!(size_of::<u16>(), 2);
  10     assert_eq!(size_of::<u32>(), 4);
  11     assert_eq!(size_of::<u64>(), 8);
  12 }
  13
  14 #[test]
  15 #[cfg(target_pointer_width = "16")]
  16 fn size_of_16() {
  17     assert_eq!(size_of::<usize>(), 2);
  18     assert_eq!(size_of::<*const usize>(), 2);
  19 }
  20
  21 #[test]
  22 #[cfg(target_pointer_width = "32")]
  23 fn size_of_32() {
  24     assert_eq!(size_of::<usize>(), 4);
  25     assert_eq!(size_of::<*const usize>(), 4);
  26 }
  27
  28 #[test]
  29 #[cfg(target_pointer_width = "64")]
  30 fn size_of_64() {
  31     assert_eq!(size_of::<usize>(), 8);
  32     assert_eq!(size_of::<*const usize>(), 8);
  33 }
  34
  35 #[test]
  36 fn size_of_val_basic() {
  37     assert_eq!(size_of_val(&1u8), 1);
  38     assert_eq!(size_of_val(&1u16), 2);
  39     assert_eq!(size_of_val(&1u32), 4);
  40     assert_eq!(size_of_val(&1u64), 8);
  41 }
  42
  43 #[test]
  44 fn align_of_basic() {
  45     assert_eq!(align_of::<u8>(), 1);
  46     assert_eq!(align_of::<u16>(), 2);
  47     assert_eq!(align_of::<u32>(), 4);
  48 }
  49
  50 #[test]
  51 #[cfg(target_pointer_width = "16")]
  52 fn align_of_16() {
  53     assert_eq!(align_of::<usize>(), 2);
  54     assert_eq!(align_of::<*const usize>(), 2);
  55 }
  56
  57 #[test]
  58 #[cfg(target_pointer_width = "32")]
  59 fn align_of_32() {
  60     assert_eq!(align_of::<usize>(), 4);
  61     assert_eq!(align_of::<*const usize>(), 4);
  62 }
  63
  64 #[test]
  65 #[cfg(target_pointer_width = "64")]
  66 fn align_of_64() {
  67     assert_eq!(align_of::<usize>(), 8);
  68     assert_eq!(align_of::<*const usize>(), 8);
  69 }
  70
  71 #[test]
  72 fn align_of_val_basic() {
  73     assert_eq!(align_of_val(&1u8), 1);
  74     assert_eq!(align_of_val(&1u16), 2);
  75     assert_eq!(align_of_val(&1u32), 4);
  76 }
  77
  78 #[test]
  79 fn test_swap() {
  80     let mut x = 31337;
  81     let mut y = 42;
  82     swap(&mut x, &mut y);
  83     assert_eq!(x, 42);
  84     assert_eq!(y, 31337);
  85 }
  86
  87 #[test]
  88 fn test_replace() {
  89     let mut x = Some("test".to_string());
  90     let y = replace(&mut x, None);
  91     assert!(x.is_none());
  92     assert!(y.is_some());
  93 }
  94
  95 #[test]
  96 fn test_transmute_copy() {
  97     assert_eq!(1, unsafe { transmute_copy(&1) });
  98 }
  99
 100 #[test]
 101 fn test_transmute() {
 102     trait Foo {
 103         fn dummy(&self) {}
 104     }
 105     impl Foo for isize {}
 106
 107     let a = box 100isize as Box<dyn Foo>;
 108     unsafe {
 109         let x: ::core::raw::TraitObject = transmute(a);
 110         assert!(*(x.data as *const isize) == 100);
 111         let _x: Box<dyn Foo> = transmute(x);
 112     }
 113
 114     unsafe {
 115         assert_eq!(transmute::<_, Vec<u8>>("L".to_string()), [76]);
 116     }
 117 }
 118
 119 #[test]
 120 #[allow(dead_code)]
 121 fn test_discriminant_send_sync() {
 122     enum Regular {
 123         A,
 124         B(i32),
 125     }
 126     enum NotSendSync {
 127         A(*const i32),
 128     }
 129
 130     fn is_send_sync<T: Send + Sync>() {}
 131
 132     is_send_sync::<Discriminant<Regular>>();
 133     is_send_sync::<Discriminant<NotSendSync>>();
 134 }
 135
 136 #[test]
 137 fn assume_init_good() {
 138     const TRUE: bool = unsafe { MaybeUninit::<bool>::new(true).assume_init() };
 139
 140     assert!(TRUE);
 141 }
 142
 143 #[test]
 144 fn uninit_array_assume_init() {
 145     let mut array: [MaybeUninit<i16>; 5] = MaybeUninit::uninit_array();
 146     array[0].write(3);
 147     array[1].write(1);
 148     array[2].write(4);
 149     array[3].write(1);
 150     array[4].write(5);
 151
 152     let array = unsafe { MaybeUninit::array_assume_init(array) };
 153
 154     assert_eq!(array, [3, 1, 4, 1, 5]);
 155
 156     let [] = unsafe { MaybeUninit::<!>::array_assume_init([]) };
 157 }
 158
 159 #[test]
 160 fn uninit_write_slice() {
 161     let mut dst = [MaybeUninit::new(255); 64];
 162     let src = [0; 64];
 163
 164     assert_eq!(MaybeUninit::write_slice(&mut dst, &src), &src);
 165 }
 166
 167 #[test]
 168 #[should_panic(expected = "source slice length (32) does not match destination slice length (64)")]
 169 fn uninit_write_slice_panic_lt() {
 170     let mut dst = [MaybeUninit::uninit(); 64];
 171     let src = [0; 32];
 172
 173     MaybeUninit::write_slice(&mut dst, &src);
 174 }
 175
 176 #[test]
 177 #[should_panic(expected = "source slice length (128) does not match destination slice length (64)")]
 178 fn uninit_write_slice_panic_gt() {
 179     let mut dst = [MaybeUninit::uninit(); 64];
 180     let src = [0; 128];
 181
 182     MaybeUninit::write_slice(&mut dst, &src);
 183 }
 184
 185 #[test]
 186 fn uninit_clone_from_slice() {
 187     let mut dst = [MaybeUninit::new(255); 64];
 188     let src = [0; 64];
 189
 190     assert_eq!(MaybeUninit::write_slice_cloned(&mut dst, &src), &src);
 191 }
 192
 193 #[test]
 194 #[should_panic(expected = "destination and source slices have different lengths")]
 195 fn uninit_write_slice_cloned_panic_lt() {
 196     let mut dst = [MaybeUninit::uninit(); 64];
 197     let src = [0; 32];
 198
 199     MaybeUninit::write_slice_cloned(&mut dst, &src);
 200 }
 201
 202 #[test]
 203 #[should_panic(expected = "destination and source slices have different lengths")]
 204 fn uninit_write_slice_cloned_panic_gt() {
 205     let mut dst = [MaybeUninit::uninit(); 64];
 206     let src = [0; 128];
 207
 208     MaybeUninit::write_slice_cloned(&mut dst, &src);
 209 }
 210
 211 #[test]
 212 #[cfg(panic = "unwind")]
 213 fn uninit_write_slice_cloned_mid_panic() {
 214     use std::panic;
 215
 216     enum IncrementOrPanic {
 217         Increment(Rc<()>),
 218         ExpectedPanic,
 219         UnexpectedPanic,
 220     }
 221
 222     impl Clone for IncrementOrPanic {
 223         fn clone(&self) -> Self {
 224             match self {
 225                 Self::Increment(rc) => Self::Increment(rc.clone()),
 226                 Self::ExpectedPanic => panic!("expected panic on clone"),
 227                 Self::UnexpectedPanic => panic!("unexpected panic on clone"),
 228             }
 229         }
 230     }
 231
 232     let rc = Rc::new(());
 233
 234     let mut dst = [
 235         MaybeUninit::uninit(),
 236         MaybeUninit::uninit(),
 237         MaybeUninit::uninit(),
 238         MaybeUninit::uninit(),
 239     ];
 240
 241     let src = [
 242         IncrementOrPanic::Increment(rc.clone()),
 243         IncrementOrPanic::Increment(rc.clone()),
 244         IncrementOrPanic::ExpectedPanic,
 245         IncrementOrPanic::UnexpectedPanic,
 246     ];
 247
 248     let err = panic::catch_unwind(panic::AssertUnwindSafe(|| {
 249         MaybeUninit::write_slice_cloned(&mut dst, &src);
 250     }));
 251
 252     drop(src);
 253
 254     match err {
 255         Ok(_) => unreachable!(),
 256         Err(payload) => {
 257             payload
 258                 .downcast::<&'static str>()
 259                 .and_then(|s| if *s == "expected panic on clone" { Ok(s) } else { Err(s) })
 260                 .unwrap_or_else(|p| panic::resume_unwind(p));
 261
 262             assert_eq!(Rc::strong_count(&rc), 1)
 263         }
 264     }
 265 }
 266
 267 #[test]
 268 fn uninit_write_slice_cloned_no_drop() {
 269     #[derive(Clone)]
 270     struct Bomb;
 271
 272     impl Drop for Bomb {
 273         fn drop(&mut self) {
 274             panic!("dropped a bomb! kaboom")
 275         }
 276     }
 277
 278     let mut dst = [MaybeUninit::uninit()];
 279     let src = [Bomb];
 280
 281     MaybeUninit::write_slice_cloned(&mut dst, &src);
 282
 283     forget(src);
 284 }
 285
 286 #[test]
 287 fn uninit_const_assume_init_read() {
 288     const FOO: u32 = unsafe { MaybeUninit::new(42).assume_init_read() };
 289     assert_eq!(FOO, 42);
 290 }