mirror of https://github.com/rust-lang/rust
100 lines
2.3 KiB
Rust
100 lines
2.3 KiB
Rust
//@ run-pass
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//@ compile-flags: -Zvalidate-mir
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use std::fmt::Display;
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use std::rc::Rc;
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use std::sync::atomic::{AtomicU8, Ordering};
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static TRACKER: AtomicU8 = AtomicU8::new(0);
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#[derive(Default)]
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struct Droppy {
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inner: u32,
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}
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impl Drop for Droppy {
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fn drop(&mut self) {
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TRACKER.store(1, Ordering::Release);
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println!("I've been dropped");
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}
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}
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fn foo<'a>(x: &'a str) -> Result<impl Display + 'a, ()> {
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Ok(x)
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}
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fn main() {
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assert_eq!(TRACKER.load(Ordering::Acquire), 0);
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let 0 = Droppy::default().inner else { return };
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assert_eq!(TRACKER.load(Ordering::Acquire), 1);
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println!("Should have dropped 👆");
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{
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// cf. https://github.com/rust-lang/rust/pull/99518#issuecomment-1191520030
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struct Foo<'a>(&'a mut u32);
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impl<'a> Drop for Foo<'a> {
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fn drop(&mut self) {
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*self.0 = 0;
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}
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}
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let mut foo = 0;
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let Foo(0) = Foo(&mut foo) else {
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*&mut foo = 1;
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todo!()
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};
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}
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{
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let x = String::from("Hey");
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let Ok(s) = foo(&x) else { panic!() };
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assert_eq!(s.to_string(), x);
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}
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{
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// test let-else drops temps after statement
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let rc = Rc::new(0);
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let 0 = *rc.clone() else { unreachable!() };
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Rc::try_unwrap(rc).unwrap();
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}
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{
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let mut rc = Rc::new(0);
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let mut i = 0;
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loop {
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if i > 3 {
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break;
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}
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let 1 = *rc.clone() else {
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if let Ok(v) = Rc::try_unwrap(rc) {
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rc = Rc::new(v);
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} else {
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panic!()
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}
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i += 1;
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continue
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};
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}
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}
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{
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fn must_pass() {
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let rc = Rc::new(());
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let &None = &Some(Rc::clone(&rc)) else {
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Rc::try_unwrap(rc).unwrap();
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return;
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};
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unreachable!();
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}
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must_pass();
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}
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{
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// test let-else drops temps before else block
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// NOTE: this test has to be the last block in the `main`
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// body.
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let rc = Rc::new(0);
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let 1 = *rc.clone() else {
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Rc::try_unwrap(rc).unwrap();
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return;
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};
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unreachable!();
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}
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}
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