rust/tests/ui/transmutability/enums/uninhabited_optimization.rs

33 lines
593 B
Rust

//@ check-pass
//! Tests that we do not regress rust-lang/rust#125811
#![feature(transmutability)]
fn assert_transmutable<T>()
where
(): std::mem::TransmuteFrom<T>
{}
enum Uninhabited {}
enum SingleInhabited {
X,
Y(Uninhabited)
}
enum SingleUninhabited {
X(Uninhabited),
Y(Uninhabited),
}
enum MultipleUninhabited {
X(u8, Uninhabited),
Y(Uninhabited, u16),
}
fn main() {
assert_transmutable::<Uninhabited>();
assert_transmutable::<SingleInhabited>();
assert_transmutable::<SingleUninhabited>();
assert_transmutable::<MultipleUninhabited>();
}