diff options
Diffstat (limited to 'library/std/src/time/tests.rs')
-rw-r--r-- | library/std/src/time/tests.rs | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/library/std/src/time/tests.rs b/library/std/src/time/tests.rs index 2e64ae59aff..6ed84806e6d 100644 --- a/library/std/src/time/tests.rs +++ b/library/std/src/time/tests.rs @@ -1,4 +1,5 @@ use super::{Duration, Instant, SystemTime, UNIX_EPOCH}; +use core::fmt::Debug; #[cfg(not(target_arch = "wasm32"))] use test::{black_box, Bencher}; @@ -201,6 +202,32 @@ fn since_epoch() { assert!(a < hundred_twenty_years); } +#[test] +fn big_math() { + // Check that the same result occurs when adding/subtracting each duration one at a time as when + // adding/subtracting them all at once. + #[track_caller] + fn check<T: Eq + Copy + Debug>(start: Option<T>, op: impl Fn(&T, Duration) -> Option<T>) { + const DURATIONS: [Duration; 2] = + [Duration::from_secs(i64::MAX as _), Duration::from_secs(50)]; + if let Some(start) = start { + assert_eq!( + op(&start, DURATIONS.into_iter().sum()), + DURATIONS.into_iter().try_fold(start, |t, d| op(&t, d)) + ) + } + } + + check(SystemTime::UNIX_EPOCH.checked_sub(Duration::from_secs(100)), SystemTime::checked_add); + check(SystemTime::UNIX_EPOCH.checked_add(Duration::from_secs(100)), SystemTime::checked_sub); + + let instant = Instant::now(); + check(instant.checked_sub(Duration::from_secs(100)), Instant::checked_add); + check(instant.checked_sub(Duration::from_secs(i64::MAX as _)), Instant::checked_add); + check(instant.checked_add(Duration::from_secs(100)), Instant::checked_sub); + check(instant.checked_add(Duration::from_secs(i64::MAX as _)), Instant::checked_sub); +} + macro_rules! bench_instant_threaded { ($bench_name:ident, $thread_count:expr) => { #[bench] |