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// run-pass
#![allow(dead_code)]
#![allow(unused_assignments)]
// Test control flow to follow label_break_value semantics
fn label_break(a: bool, b: bool) -> u32 {
let mut v = 0;
'b: {
v = 1;
if a {
break 'b;
}
v = 2;
if b {
break 'b;
}
v = 3;
}
return v;
}
// Test that values can be returned
fn break_value(a: bool, b: bool) -> u32 {
let result = 'block: {
if a { break 'block 1; }
if b { break 'block 2; }
3
};
result
}
// Test nesting of labeled blocks
// here we only check that it compiles
fn label_break_nested() {
'b: {
println!("hi");
if false {
break 'b;
}
'c: {
if false {
break 'b;
}
break 'c;
}
println!("hello");
if true {
break 'b;
}
}
}
// Tests for mixing labeled blocks with loop constructs
// This function should be the identity function
fn label_break_mixed(v: u32) -> u32 {
let mut r = 0;
'b: {
// Unlabeled break still works
// (only crossing boundaries is an error)
loop {
break;
}
if v == 0 {
break 'b;
}
// Labeled breaking an inner loop still works
'c: loop {
if r == 1 {
break 'c;
}
r += 1;
}
assert_eq!(r, 1);
if v == 1 {
break 'b;
}
// Labeled breaking an outer loop still works
'd: loop {
{
if v == r {
break 'b;
}
if r == 5 {
break 'd;
}
r += 1;
}
}
assert_eq!(r, 5);
assert!(v > r);
// Here we test return from inside a labeled block
return v;
}
r
}
fn label_break_match(c: u8, xe: u8, ye: i8) {
let mut x = 0;
let y = 'a: {
match c {
0 => break 'a 0,
v if { if v % 2 == 0 { break 'a 1; }; v % 3 == 0 } => { x += 1; },
v if { 'b: { break 'b v == 5; } } => { x = 41; },
_ => 'b: {
break 'b ();
},
}
x += 1;
-1
};
assert_eq!(x, xe);
assert_eq!(y, ye);
}
#[allow(unused_labels)]
fn label_break_macro() {
macro_rules! mac1 {
($target:lifetime, $val:expr) => {
break $target $val;
};
}
let x: u8 = 'a: {
'b: {
mac1!('b, 1);
};
0
};
assert_eq!(x, 0);
let x: u8 = 'a: {
'b: {
if true {
mac1!('a, 1);
}
};
0
};
assert_eq!(x, 1);
}
pub fn main() {
assert_eq!(label_break(true, false), 1);
assert_eq!(label_break(false, true), 2);
assert_eq!(label_break(false, false), 3);
assert_eq!(break_value(true, false), 1);
assert_eq!(break_value(false, true), 2);
assert_eq!(break_value(false, false), 3);
assert_eq!(label_break_mixed(0), 0);
assert_eq!(label_break_mixed(1), 1);
assert_eq!(label_break_mixed(2), 2);
assert_eq!(label_break_mixed(3), 3);
assert_eq!(label_break_mixed(4), 4);
assert_eq!(label_break_mixed(5), 5);
assert_eq!(label_break_mixed(6), 6);
label_break_match(0, 0, 0);
label_break_match(1, 1, -1);
label_break_match(2, 0, 1);
label_break_match(3, 2, -1);
label_break_match(5, 42, -1);
label_break_match(7, 1, -1);
label_break_macro();
}
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