mirror of https://github.com/rust-lang/rust
37 lines
784 B
Rust
37 lines
784 B
Rust
type Field1 = i32;
|
|
type Field2 = f32;
|
|
type Field3 = i64;
|
|
|
|
#[repr(C)]
|
|
union DummyUnion {
|
|
field1: Field1,
|
|
field2: Field2,
|
|
field3: Field3,
|
|
}
|
|
|
|
const FLOAT1_AS_I32: i32 = 1065353216;
|
|
const UNION: DummyUnion = DummyUnion { field1: FLOAT1_AS_I32 };
|
|
|
|
const fn read_field1() -> Field1 {
|
|
const FIELD1: Field1 = unsafe { UNION.field1 };
|
|
FIELD1
|
|
}
|
|
|
|
const fn read_field2() -> Field2 {
|
|
const FIELD2: Field2 = unsafe { UNION.field2 };
|
|
FIELD2
|
|
}
|
|
|
|
const fn read_field3() -> Field3 {
|
|
const FIELD3: Field3 = unsafe { UNION.field3 };
|
|
//~^ ERROR evaluation of constant value failed
|
|
//~| uninitialized
|
|
FIELD3
|
|
}
|
|
|
|
fn main() {
|
|
assert_eq!(read_field1(), FLOAT1_AS_I32);
|
|
assert_eq!(read_field2(), 1.0);
|
|
assert_eq!(read_field3(), unsafe { UNION.field3 });
|
|
}
|