rust/tests/ui/pattern/usefulness/impl-trait.rs
2024-09-11 18:36:45 +02:00

156 lines
3.3 KiB
Rust

#![feature(never_type)]
#![feature(type_alias_impl_trait)]
#![feature(non_exhaustive_omitted_patterns_lint)]
#![feature(exhaustive_patterns)]
#![deny(unreachable_patterns)]
// Test that the lint traversal handles opaques correctly
#![deny(non_exhaustive_omitted_patterns)]
fn main() {}
#[derive(Copy, Clone)]
enum Void {}
fn return_never_rpit(x: Void) -> impl Copy {
if false {
match return_never_rpit(x) {
_ => {} //~ ERROR unreachable
}
}
x
}
fn friend_of_return_never_rpit(x: Void) {
match return_never_rpit(x) {}
//~^ ERROR non-empty
}
type T = impl Copy;
fn return_never_tait(x: Void) -> T {
if false {
match return_never_tait(x) {
_ => {} //~ ERROR unreachable
}
}
x
}
fn friend_of_return_never_tait(x: Void) {
match return_never_tait(x) {}
//~^ ERROR non-empty
}
fn option_never(x: Void) -> Option<impl Copy> {
if false {
match option_never(x) {
None => {}
Some(_) => {} //~ ERROR unreachable
}
match option_never(x) {
None => {}
_ => {} //~ ERROR unreachable
}
}
Some(x)
}
fn option_never2(x: Void) -> impl Copy {
if false {
match option_never2(x) {
None => {}
Some(_) => {} //~ ERROR unreachable
}
match option_never2(x) {
None => {}
_ => {} //~ ERROR unreachable
}
match option_never2(x) {
None => {}
}
}
Some(x)
}
fn inner_never(x: Void) {
type T = impl Copy;
let y: T = x;
match y {
_ => {} //~ ERROR unreachable
}
}
// This one caused ICE https://github.com/rust-lang/rust/issues/117100.
fn inner_tuple() {
type T = impl Copy;
let foo: T = Some((1u32, 2u32));
match foo {
_ => {}
Some((a, b)) => {} //~ ERROR unreachable
}
}
type U = impl Copy;
fn unify_never(x: Void, u: U) -> U {
if false {
match u {
_ => {} //~ ERROR unreachable
}
}
x
}
type V = impl Copy;
fn infer_in_match(x: Option<V>) {
match x {
None => {}
Some((a, b)) => {}
Some((mut x, mut y)) => {
//~^ ERROR unreachable
x = 42;
y = "foo";
}
}
}
type W = impl Copy;
#[derive(Copy, Clone)]
struct Rec<'a> {
n: u32,
w: Option<&'a W>,
}
fn recursive_opaque() -> W {
if false {
match recursive_opaque() {
// Check for the ol' ICE when the type is recursively opaque.
_ => {}
Rec { n: 0, w: Some(Rec { n: 0, w: _ }) } => {} //~ ERROR unreachable
}
}
let w: Option<&'static W> = None;
Rec { n: 0, w }
}
type X = impl Copy;
struct SecretelyVoid(X);
fn nested_empty_opaque(x: Void) -> X {
if false {
let opaque_void = nested_empty_opaque(x);
let secretely_void = SecretelyVoid(opaque_void);
match secretely_void {
_ => {} //~ ERROR unreachable
}
}
x
}
type Y = (impl Copy, impl Copy);
struct SecretelyDoubleVoid(Y);
fn super_nested_empty_opaque(x: Void) -> Y {
if false {
let opaque_void = super_nested_empty_opaque(x);
let secretely_void = SecretelyDoubleVoid(opaque_void);
match secretely_void {
_ => {} //~ ERROR unreachable
}
}
(x, x)
}