mirror of
https://github.com/rust-lang/rust.git
synced 2025-10-31 04:57:19 +00:00
86 lines
2.8 KiB
Rust
86 lines
2.8 KiB
Rust
// Check that we expand multiple or-patterns from left to right.
|
|
|
|
//@ run-pass
|
|
|
|
fn search(target: (bool, bool, bool)) -> u32 {
|
|
let x = ((false, true), (false, true), (false, true));
|
|
let mut guard_count = 0;
|
|
match x {
|
|
((a, _) | (_, a), (b @ _, _) | (_, b @ _), (c @ false, _) | (_, c @ true))
|
|
if {
|
|
guard_count += 1;
|
|
(a, b, c) == target
|
|
} =>
|
|
{
|
|
guard_count
|
|
}
|
|
_ => unreachable!(),
|
|
}
|
|
}
|
|
|
|
// Equivalent to the above code, but hopefully easier to understand.
|
|
fn search_old_style(target: (bool, bool, bool)) -> u32 {
|
|
let x = ((false, true), (false, true), (false, true));
|
|
let mut guard_count = 0;
|
|
match x {
|
|
((a, _), (b @ _, _), (c @ false, _))
|
|
| ((a, _), (b @ _, _), (_, c @ true))
|
|
| ((a, _), (_, b @ _), (c @ false, _))
|
|
| ((a, _), (_, b @ _), (_, c @ true))
|
|
| ((_, a), (b @ _, _), (c @ false, _))
|
|
| ((_, a), (b @ _, _), (_, c @ true))
|
|
| ((_, a), (_, b @ _), (c @ false, _))
|
|
| ((_, a), (_, b @ _), (_, c @ true))
|
|
if {
|
|
guard_count += 1;
|
|
(a, b, c) == target
|
|
} =>
|
|
{
|
|
guard_count
|
|
}
|
|
_ => unreachable!(),
|
|
}
|
|
}
|
|
|
|
// Check that a dummy or-pattern also leads to running the guard multiple times.
|
|
fn search_with_dummy(target: (bool, bool)) -> u32 {
|
|
let x = ((false, true), (false, true), ());
|
|
let mut guard_count = 0;
|
|
match x {
|
|
((a, _) | (_, a), (b, _) | (_, b), _ | _)
|
|
if {
|
|
guard_count += 1;
|
|
(a, b) == target
|
|
} =>
|
|
{
|
|
guard_count
|
|
}
|
|
_ => unreachable!(),
|
|
}
|
|
}
|
|
|
|
fn main() {
|
|
assert_eq!(search((false, false, false)), 1);
|
|
assert_eq!(search((false, false, true)), 2);
|
|
assert_eq!(search((false, true, false)), 3);
|
|
assert_eq!(search((false, true, true)), 4);
|
|
assert_eq!(search((true, false, false)), 5);
|
|
assert_eq!(search((true, false, true)), 6);
|
|
assert_eq!(search((true, true, false)), 7);
|
|
assert_eq!(search((true, true, true)), 8);
|
|
|
|
assert_eq!(search_old_style((false, false, false)), 1);
|
|
assert_eq!(search_old_style((false, false, true)), 2);
|
|
assert_eq!(search_old_style((false, true, false)), 3);
|
|
assert_eq!(search_old_style((false, true, true)), 4);
|
|
assert_eq!(search_old_style((true, false, false)), 5);
|
|
assert_eq!(search_old_style((true, false, true)), 6);
|
|
assert_eq!(search_old_style((true, true, false)), 7);
|
|
assert_eq!(search_old_style((true, true, true)), 8);
|
|
|
|
assert_eq!(search_with_dummy((false, false)), 1);
|
|
assert_eq!(search_with_dummy((false, true)), 3);
|
|
assert_eq!(search_with_dummy((true, false)), 5);
|
|
assert_eq!(search_with_dummy((true, true)), 7);
|
|
}
|