rust/tests/ui/uninhabited/uninhabited-irrefutable.rs

40 lines
985 B
Rust

//@ revisions: min_exhaustive_patterns exhaustive_patterns
#![cfg_attr(exhaustive_patterns, feature(exhaustive_patterns))]
#![cfg_attr(min_exhaustive_patterns, feature(min_exhaustive_patterns))]
#![feature(never_type)]
mod foo {
pub struct SecretlyEmpty {
_priv: !,
}
pub struct NotSoSecretlyEmpty {
pub _pub: !,
}
}
struct NotSoSecretlyEmpty {
_priv: !,
}
enum Foo {
//~^ NOTE `Foo` defined here
A(foo::SecretlyEmpty),
//~^ NOTE not covered
B(foo::NotSoSecretlyEmpty),
C(NotSoSecretlyEmpty),
D(u32, u32),
}
fn main() {
let x: Foo = Foo::D(123, 456);
let Foo::D(_y, _z) = x;
//~^ ERROR refutable pattern in local binding
//~| `Foo::A(_)` not covered
//~| NOTE `let` bindings require an "irrefutable pattern"
//~| NOTE for more information
//~| NOTE pattern `Foo::A(_)` is currently uninhabited
//~| NOTE the matched value is of type `Foo`
//~| HELP you might want to use `let else`
}