Tracking Issue for Duration::as_millis_{f64,f32} · Issue #122451 · rust-lang/rust (original) (raw)

Feature gate: #![feature(duration_millis_float)]

This is a tracking issue for

• Duration::as_millis_f64
• Duration::as_millis_f32

Public API

impl Duration { /// Returns the number of milliseconds contained by this Duration as f64. /// /// The returned value does include the fractional (nanosecond) part of the duration. /// /// # Examples /// /// use std::time::Duration; /// /// let dur = Duration::new(2, 67_890_000); /// assert_eq!(dur.as_millis_f64(), 2678.9); /// pub const fn as_millis_f64(self);

/// Returns the number of milliseconds contained by this `Duration` as `f32`.
///
/// The returned value does include the fractional (nanosecond) part of the duration.
///
/// # Examples
/// ```
/// use std::time::Duration;
///
/// let dur = Duration::new(2, 67_890_000);
/// assert_eq!(dur.as_millis_f32(), 2678.9);
/// ```
pub const fn as_millis_f32(self);

}

Steps / History

• ACP: Add as_millis_{f64,f32} helper functions for Duration libs-team#349
• Implementation: Implement Duration::as_millis_{f64,f32} #122479
• Related lint: Add lint which checks that duration conversion aren't losing precision rust-clippy#12539
• Final comment period (FCP)1
• Stabilization PR

Unresolved Questions

• The implementation is using floating-point division; would we be ok with changing it to multiplication-by-reciprocal at the cost of a ½ULP but being faster? as_secs_f32 uses division, so maybe not.

1. https://std-dev-guide.rust-lang.org/feature-lifecycle/stabilization.html ↩