rust/tests/ui/pattern/usefulness/consts-opaque.rs
2024-01-24 07:56:23 +01:00

147 lines
3.4 KiB
Rust

// This file tests the exhaustiveness algorithm on opaque constants. Most of the examples give
// unnecessary warnings because const_to_pat.rs converts a constant pattern to a wildcard when the
// constant is not allowed as a pattern. This is an edge case so we may not care to fix it.
// See also https://github.com/rust-lang/rust/issues/78057
#![deny(unreachable_patterns)]
#[derive(PartialEq)]
struct Foo(i32);
impl Eq for Foo {}
const FOO: Foo = Foo(42);
const FOO_REF: &Foo = &Foo(42);
const FOO_REF_REF: &&Foo = &&Foo(42);
#[derive(PartialEq)]
struct Bar;
impl Eq for Bar {}
const BAR: Bar = Bar;
#[derive(PartialEq)]
enum Baz {
Baz1,
Baz2,
}
impl Eq for Baz {}
const BAZ: Baz = Baz::Baz1;
#[rustfmt::skip]
fn main() {
match FOO {
FOO => {}
_ => {}
}
match FOO_REF {
FOO_REF => {}
Foo(_) => {}
}
// This used to cause an ICE (https://github.com/rust-lang/rust/issues/78071)
match FOO_REF_REF {
FOO_REF_REF => {}
Foo(_) => {}
}
match BAR {
Bar => {}
BAR => {}
//~^ ERROR unreachable pattern
_ => {}
//~^ ERROR unreachable pattern
}
match BAR {
BAR => {}
Bar => {}
//~^ ERROR unreachable pattern
_ => {}
//~^ ERROR unreachable pattern
}
match BAR {
BAR => {}
BAR => {} // should not be emitting unreachable warning
//~^ ERROR unreachable pattern
_ => {} // should not be emitting unreachable warning
//~^ ERROR unreachable pattern
}
match BAZ {
BAZ => {}
Baz::Baz1 => {} // should not be emitting unreachable warning
//~^ ERROR unreachable pattern
_ => {}
}
match BAZ {
Baz::Baz1 => {}
BAZ => {}
//~^ ERROR unreachable pattern
_ => {}
}
match BAZ {
BAZ => {}
Baz::Baz2 => {}
_ => {} // should not be emitting unreachable warning
//~^ ERROR unreachable pattern
}
type Quux = fn(usize, usize) -> usize;
fn quux(a: usize, b: usize) -> usize { a + b }
const QUUX: Quux = quux;
match QUUX {
QUUX => {} //~WARN behave unpredictably
//~| previously accepted
QUUX => {} //~WARN behave unpredictably
//~| previously accepted
_ => {}
}
#[derive(PartialEq, Eq)]
struct Wrap<T>(T);
const WRAPQUUX: Wrap<Quux> = Wrap(quux);
match WRAPQUUX {
WRAPQUUX => {} //~WARN behave unpredictably
//~| previously accepted
WRAPQUUX => {} //~WARN behave unpredictably
//~| previously accepted
Wrap(_) => {}
}
match WRAPQUUX {
Wrap(_) => {}
WRAPQUUX => {} //~WARN behave unpredictably
//~| previously accepted
}
match WRAPQUUX {
Wrap(_) => {}
}
match WRAPQUUX {
//~^ ERROR: non-exhaustive patterns: `Wrap(_)` not covered
WRAPQUUX => {} //~WARN behave unpredictably
//~| previously accepted
}
#[derive(PartialEq, Eq)]
enum WhoKnows<T> {
Yay(T),
Nope,
};
const WHOKNOWSQUUX: WhoKnows<Quux> = WhoKnows::Yay(quux);
match WHOKNOWSQUUX {
WHOKNOWSQUUX => {} //~WARN behave unpredictably
//~| previously accepted
WhoKnows::Yay(_) => {}
WHOKNOWSQUUX => {} //~WARN behave unpredictably
//~| previously accepted
WhoKnows::Nope => {}
}
}