rust/tests/ui/enum-discriminant/actually_not_an_enum-discriminant.rs
2023-01-11 09:32:08 +00:00

50 lines
1.2 KiB
Rust

// run-pass
#![feature(core_intrinsics)]
use std::intrinsics::discriminant_value;
struct Zst;
struct Struct {
_a: u32,
}
union Union {
_a: u32,
}
fn check(v: u8) {
assert_eq!(v, 0);
}
pub fn generic<T>()
where
for<'a> T: Fn(&'a isize),
{
let v: Vec<T> = Vec::new();
let _: u8 = discriminant_value(&v);
}
fn main() {
// check that we use `u8` as the discriminant value
// for everything that is not an enum.
check(discriminant_value(&true));
check(discriminant_value(&'a'));
check(discriminant_value(&7));
check(discriminant_value(&7.0));
check(discriminant_value(&Zst));
check(discriminant_value(&Struct { _a: 7 }));
check(discriminant_value(&Union { _a: 7 }));
check(discriminant_value(&[7, 77]));
check(discriminant_value(&(7 as *const ())));
check(discriminant_value(&(7 as *mut ())));
check(discriminant_value(&&7));
check(discriminant_value(&&mut 7));
check(discriminant_value(&check));
let fn_ptr: fn(u8) = check;
check(discriminant_value(&fn_ptr));
let hrtb: for<'a> fn(&'a str) -> &'a str = |x| x;
check(discriminant_value(&hrtb));
check(discriminant_value(&(7, 77, 777)));
}