Tracking Issue for saturating `SystemTime` arithmetic

Feature gate: #![feature(time_saturating_systemtime)]

This is a tracking issue for https://github.com/rust-lang/libs-team/issues/718

This feature adds the following three methods to SystemTime:

• SystemTime::saturating_add
• SystemTime::saturating_sub
• SystemTime::saturating_duration_since

Public API

// std::time

impl SystemTime {
    // ...

    fn saturating_add(&self, rhs: Duration) -> Self {
        self.checked_add(rhs).unwrap_or(SystemTime::MAX)
    }

    fn saturating_sub(&self, rhs: Duration) -> Self {
        self.checked_sub(rhs).unwrap_or(SystemTime::MIN)
    }

    fn saturating_duration_since(&self, rhs: Self) -> Duration {
        self.duration_since(rhs).unwrap_or(Duration::ZERO)
    }
}

Steps / History

(Remember to update the S-tracking-* label when checking boxes.)

• ACP: rust-lang/libs-team#718
• Implementation: #151200
• Final comment period (FCP)^1
• Stabilization PR

Unresolved Questions

• None yet.

Start with the linked implementation PR #151200, the libs-team issue #718, and the feature-lifecycle stabilization guidance referenced in the issue. Review the three SystemTime methods and their completed implementation before determining whether the remaining FCP and stabilization steps are ready; done means the tracking checklist is complete.