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Diffstat (limited to 'library/std/src/time/tests.rs')
| -rw-r--r-- | library/std/src/time/tests.rs | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/library/std/src/time/tests.rs b/library/std/src/time/tests.rs index 6229556c8..2e64ae59a 100644 --- a/library/std/src/time/tests.rs +++ b/library/std/src/time/tests.rs @@ -88,6 +88,14 @@ fn instant_math_is_associative() { // Changing the order of instant math shouldn't change the results, // especially when the expression reduces to X + identity. assert_eq!((now + offset) - now, (now - now) + offset); + + // On any platform, `Instant` should have the same resolution as `Duration` (e.g. 1 nanosecond) + // or better. Otherwise, math will be non-associative (see #91417). + let now = Instant::now(); + let provided_offset = Duration::from_nanos(1); + let later = now + provided_offset; + let measured_offset = later - now; + assert_eq!(measured_offset, provided_offset); } #[test] |