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 #[allow(dead_code)]
 102 fn test_discriminant_send_sync() {
 103     enum Regular {
 104         A,
 105         B(i32),
 106     }
 107     enum NotSendSync {
 108         A(*const i32),
 109     }
 110
 111     fn is_send_sync<T: Send + Sync>() {}
 112
 113     is_send_sync::<Discriminant<Regular>>();
 114     is_send_sync::<Discriminant<NotSendSync>>();
 115 }
 116
 117 #[test]
 118 fn assume_init_good() {
 119     const TRUE: bool = unsafe { MaybeUninit::<bool>::new(true).assume_init() };
 120
 121     assert!(TRUE);
 122 }
 123
 124 #[test]
 125 fn uninit_array_assume_init() {
 126     let mut array: [MaybeUninit<i16>; 5] = MaybeUninit::uninit_array();
 127     array[0].write(3);
 128     array[1].write(1);
 129     array[2].write(4);
 130     array[3].write(1);
 131     array[4].write(5);
 132
 133     let array = unsafe { MaybeUninit::array_assume_init(array) };
 134
 135     assert_eq!(array, [3, 1, 4, 1, 5]);
 136
 137     let [] = unsafe { MaybeUninit::<!>::array_assume_init([]) };
 138 }
 139
 140 #[test]
 141 fn uninit_write_slice() {
 142     let mut dst = [MaybeUninit::new(255); 64];
 143     let src = [0; 64];
 144
 145     assert_eq!(MaybeUninit::write_slice(&mut dst, &src), &src);
 146 }
 147
 148 #[test]
 149 #[should_panic(expected = "source slice length (32) does not match destination slice length (64)")]
 150 fn uninit_write_slice_panic_lt() {
 151     let mut dst = [MaybeUninit::uninit(); 64];
 152     let src = [0; 32];
 153
 154     MaybeUninit::write_slice(&mut dst, &src);
 155 }
 156
 157 #[test]
 158 #[should_panic(expected = "source slice length (128) does not match destination slice length (64)")]
 159 fn uninit_write_slice_panic_gt() {
 160     let mut dst = [MaybeUninit::uninit(); 64];
 161     let src = [0; 128];
 162
 163     MaybeUninit::write_slice(&mut dst, &src);
 164 }
 165
 166 #[test]
 167 fn uninit_clone_from_slice() {
 168     let mut dst = [MaybeUninit::new(255); 64];
 169     let src = [0; 64];
 170
 171     assert_eq!(MaybeUninit::write_slice_cloned(&mut dst, &src), &src);
 172 }
 173
 174 #[test]
 175 #[should_panic(expected = "destination and source slices have different lengths")]
 176 fn uninit_write_slice_cloned_panic_lt() {
 177     let mut dst = [MaybeUninit::uninit(); 64];
 178     let src = [0; 32];
 179
 180     MaybeUninit::write_slice_cloned(&mut dst, &src);
 181 }
 182
 183 #[test]
 184 #[should_panic(expected = "destination and source slices have different lengths")]
 185 fn uninit_write_slice_cloned_panic_gt() {
 186     let mut dst = [MaybeUninit::uninit(); 64];
 187     let src = [0; 128];
 188
 189     MaybeUninit::write_slice_cloned(&mut dst, &src);
 190 }
 191
 192 #[test]
 193 #[cfg(panic = "unwind")]
 194 fn uninit_write_slice_cloned_mid_panic() {
 195     use std::panic;
 196
 197     enum IncrementOrPanic {
 198         Increment(Rc<()>),
 199         ExpectedPanic,
 200         UnexpectedPanic,
 201     }
 202
 203     impl Clone for IncrementOrPanic {
 204         fn clone(&self) -> Self {
 205             match self {
 206                 Self::Increment(rc) => Self::Increment(rc.clone()),
 207                 Self::ExpectedPanic => panic!("expected panic on clone"),
 208                 Self::UnexpectedPanic => panic!("unexpected panic on clone"),
 209             }
 210         }
 211     }
 212
 213     let rc = Rc::new(());
 214
 215     let mut dst = [
 216         MaybeUninit::uninit(),
 217         MaybeUninit::uninit(),
 218         MaybeUninit::uninit(),
 219         MaybeUninit::uninit(),
 220     ];
 221
 222     let src = [
 223         IncrementOrPanic::Increment(rc.clone()),
 224         IncrementOrPanic::Increment(rc.clone()),
 225         IncrementOrPanic::ExpectedPanic,
 226         IncrementOrPanic::UnexpectedPanic,
 227     ];
 228
 229     let err = panic::catch_unwind(panic::AssertUnwindSafe(|| {
 230         MaybeUninit::write_slice_cloned(&mut dst, &src);
 231     }));
 232
 233     drop(src);
 234
 235     match err {
 236         Ok(_) => unreachable!(),
 237         Err(payload) => {
 238             payload
 239                 .downcast::<&'static str>()
 240                 .and_then(|s| if *s == "expected panic on clone" { Ok(s) } else { Err(s) })
 241                 .unwrap_or_else(|p| panic::resume_unwind(p));
 242
 243             assert_eq!(Rc::strong_count(&rc), 1)
 244         }
 245     }
 246 }
 247
 248 #[test]
 249 fn uninit_write_slice_cloned_no_drop() {
 250     #[derive(Clone)]
 251     struct Bomb;
 252
 253     impl Drop for Bomb {
 254         fn drop(&mut self) {
 255             panic!("dropped a bomb! kaboom")
 256         }
 257     }
 258
 259     let mut dst = [MaybeUninit::uninit()];
 260     let src = [Bomb];
 261
 262     MaybeUninit::write_slice_cloned(&mut dst, &src);
 263
 264     forget(src);
 265 }
 266
 267 #[test]
 268 fn uninit_const_assume_init_read() {
 269     const FOO: u32 = unsafe { MaybeUninit::new(42).assume_init_read() };
 270     assert_eq!(FOO, 42);
 271 }