mirror of
https://github.com/rust-lang/rust.git
synced 2024-12-04 20:54:13 +00:00
76 lines
1.3 KiB
Rust
76 lines
1.3 KiB
Rust
// run-pass
|
|
// adapted from tests/ui/binding/if-let.rs
|
|
|
|
#![allow(dead_code)]
|
|
|
|
fn none() -> bool {
|
|
let None = Some("test") else {
|
|
return true;
|
|
};
|
|
false
|
|
}
|
|
|
|
fn ok() -> bool {
|
|
let Ok(()) = Err::<(),&'static str>("test") else {
|
|
return true;
|
|
};
|
|
false
|
|
}
|
|
|
|
pub fn main() {
|
|
let x = Some(3);
|
|
let Some(y) = x else {
|
|
panic!("let-else panicked");
|
|
};
|
|
assert_eq!(y, 3);
|
|
let Some(_) = x else {
|
|
panic!("bad match");
|
|
};
|
|
assert!(none());
|
|
assert!(ok());
|
|
|
|
assert!((|| {
|
|
let 1 = 2 else {
|
|
return true;
|
|
};
|
|
false
|
|
})());
|
|
|
|
enum Foo {
|
|
One,
|
|
Two(usize),
|
|
Three(String, isize),
|
|
}
|
|
|
|
let foo = Foo::Three("three".to_string(), 42);
|
|
let one = || {
|
|
let Foo::One = foo else {
|
|
return true;
|
|
};
|
|
false
|
|
};
|
|
assert!(one());
|
|
let two = || {
|
|
let Foo::Two(_x) = foo else {
|
|
return true;
|
|
};
|
|
false
|
|
};
|
|
assert!(two());
|
|
let three = || {
|
|
let Foo::Three(s, _x) = foo else {
|
|
return false;
|
|
};
|
|
s == "three"
|
|
};
|
|
assert!(three());
|
|
|
|
let a@Foo::Two(_) = Foo::Two(42_usize) else {
|
|
panic!("bad match")
|
|
};
|
|
let Foo::Two(b) = a else {
|
|
panic!("panic in nested `if let`");
|
|
};
|
|
assert_eq!(b, 42_usize);
|
|
}
|