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//@ stderr-per-bitwidth
//@ dont-require-annotations: NOTE
#[repr(C)]
union DummyUnion {
unit: (),
u8: u8,
bool: bool,
}
#[repr(C)]
#[derive(Copy, Clone)]
enum Enum {
A,
B,
C,
}
#[derive(Copy, Clone)]
#[repr(C)]
union Foo {
a: bool,
b: Enum,
}
#[repr(C)]
union Bar {
foo: Foo,
u8: u8,
}
// the value is not valid for bools
const BAD_BOOL: bool = unsafe { DummyUnion { u8: 42 }.bool};
//~^ ERROR it is undefined behavior to use this value
const UNINIT_BOOL: bool = unsafe { DummyUnion { unit: () }.bool};
//~^ ERROR evaluation of constant value failed
//~| NOTE uninitialized
// The value is not valid for any union variant, but that's fine
// unions are just a convenient way to transmute bits around
const BAD_UNION: Foo = unsafe { Bar { u8: 42 }.foo };
fn main() {}
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