1 // ignore-tidy-linelength
2 #![feature(const_transmute)]
3 #![allow(const_err, invalid_value)] // make sure we cannot allow away the errors tested here
7 const UNALIGNED: &u16 = unsafe { mem::transmute(&[0u8; 4]) };
8 //~^ ERROR it is undefined behavior to use this value
9 //~^^ type validation failed: encountered unaligned reference (required 2 byte alignment but found 1)
11 const NULL: &u16 = unsafe { mem::transmute(0usize) };
12 //~^ ERROR it is undefined behavior to use this value
14 // It is very important that we reject this: We do promote `&(4 * REF_AS_USIZE)`,
15 // but that would fail to compile; so we ended up breaking user code that would
16 // have worked fine had we not promoted.
17 const REF_AS_USIZE: usize = unsafe { mem::transmute(&0) };
18 //~^ ERROR it is undefined behavior to use this value
20 const REF_AS_USIZE_SLICE: &[usize] = &[unsafe { mem::transmute(&0) }];
21 //~^ ERROR it is undefined behavior to use this value
23 const USIZE_AS_REF: &'static u8 = unsafe { mem::transmute(1337usize) };
24 //~^ ERROR it is undefined behavior to use this value