rust/src/test/ui/run-pass/for-loop-while/loop-break-value.rs

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// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![feature(never_type)]
#[allow(unused)]
fn never_returns() {
loop {
break loop {};
}
}
pub fn main() {
let value = 'outer: loop {
if 1 == 1 {
break 13;
} else {
let _never: ! = loop {
break loop {
break 'outer panic!();
}
};
}
};
assert_eq!(value, 13);
let x = [1, 3u32, 5];
let y = [17];
let z = [];
let coerced: &[_] = loop {
match 2 {
1 => break &x,
2 => break &y,
3 => break &z,
_ => (),
}
};
assert_eq!(coerced, &[17u32]);
let trait_unified = loop {
break if true {
break Default::default()
} else {
break [13, 14]
};
};
assert_eq!(trait_unified, [0, 0]);
let trait_unified_2 = loop {
if false {
break [String::from("Hello")]
} else {
break Default::default()
};
};
assert_eq!(trait_unified_2, [""]);
let trait_unified_3 = loop {
break if false {
break [String::from("Hello")]
} else {
["Yes".into()]
};
};
assert_eq!(trait_unified_3, ["Yes"]);
let regular_break = loop {
if true {
break;
} else {
break break Default::default();
}
};
assert_eq!(regular_break, ());
let regular_break_2 = loop {
if true {
break Default::default();
} else {
break;
}
};
assert_eq!(regular_break_2, ());
let regular_break_3 = loop {
break if true {
Default::default()
} else {
break;
}
};
assert_eq!(regular_break_3, ());
let regular_break_4 = loop {
break ();
break;
};
assert_eq!(regular_break_4, ());
let regular_break_5 = loop {
break;
break ();
};
assert_eq!(regular_break_5, ());
let nested_break_value = 'outer2: loop {
let _a: u32 = 'inner: loop {
if true {
break 'outer2 "hello";
} else {
break 'inner 17;
}
};
panic!();
};
assert_eq!(nested_break_value, "hello");
let break_from_while_cond = loop {
'inner_loop: while break 'inner_loop {
panic!();
}
break 123;
};
assert_eq!(break_from_while_cond, 123);
let break_from_while_to_outer = 'outer_loop: loop {
while break 'outer_loop 567 {
panic!("from_inner");
}
panic!("from outer");
};
assert_eq!(break_from_while_to_outer, 567);
let rust = true;
let value = loop {
break rust;
};
assert!(value);
}