Tracking Issue for constify-ing non-trait `Duration` methods #72440

marmeladema · 2020-05-21T22:30:07Z

This is a tracking issue for constify-ing non-trait Duration methods

The feature gates for the issueis #![feature(duration_consts_float)]. The methods covered by that are:

Duration::as_secs_f64
Duration::as_secs_f32
Duration::as_millis_f64
Duration::as_millis_f32
Duration::div_duration_f64
Duration::div_duration_f32

Steps

Adjust documentation (see instructions on rustc-dev-guide)
Stabilization PR (see instructions on rustc-dev-guide)

Unresolved Questions

XXX --- list all the "unresolved questions" found in the RFC to ensure they are
not forgotten

Implementation history

Constify most non-trait Duration methods as described: Constify most non-trait Duration methods as described in #72440 #72481
Make all methods of Duration unstably const: Make all methods of Duration unstably const #76335
Partially stabilize duration_consts_2: Partially stabilize duration_consts_2 #89542

The text was updated successfully, but these errors were encountered:

marmeladema · 2020-05-21T22:33:13Z

I also would like to add a Duration::MAX associated const. Should it be part of the same tracking issue?

Mark-Simulacrum · 2020-05-21T22:52:47Z

I don't think so -- adding a new constant seems pretty orthogonal to me.

marmeladema · 2020-05-22T07:26:18Z

I don't think so -- adding a new constant seems pretty orthogonal to me.

It's orthogonal but depends on Duration::new being const so I thought having a tracking issue just for one associated const might be overkill.

RalfJung · 2020-05-22T20:03:26Z

Because they end up calling f32|64::is_finite which ultimately call mem::transmute which is not const.

FWIW, #72449 makes the other safe transmute wrappers const. Once that lands, abs_private and is_finite could also be made const.

RalfJung · 2020-05-23T17:43:45Z

All right, #72449 will make is_finite const as well, so you should be able to use that.

marmeladema · 2020-05-23T17:47:37Z

Great! I'll wait for #72449 to land and update my PR accordingly.

…72440

RalfJung · 2020-05-30T15:06:37Z

The tracking issue should also notice that stabilizing any of the f32/f64 methods is blocked on stabilizing floating point in const at all (#57241).

…i-obk Constify most non-trait `Duration` methods as described in rust-lang#72440 The remaining methods could probably be made const once rust-lang#72449 lands with support for `f<32|64>::is_finite()`.

…72440

Constify most non-trait `Duration` methods as described in rust-lang#72440 The remaining methods could probably be made const once rust-lang#72449 lands with support for `f<32|64>::is_finite()`.

Make the following methods of `Duration` unstable const under `duration_const_2`: - `from_secs_f64` - `from_secs_f32` - `mul_f64` - `mul_f32` - `div_f64` - `div_f32` This results in all methods of `Duration` being (unstable) const. Also adds tests for these methods in a const context, moved the test to `library` as part of rust-lang#76268. Possible because of rust-lang#72449, which made the relevant `f32` and `f64` methods const. Tracking issue: rust-lang#72440

@ecstatic-morse

…orse Make all methods of `Duration` unstably const Make the following methods of `Duration` unstable const under `duration_const_2`: - `from_secs_f64` - `from_secs_f32` - `mul_f64` - `mul_f32` - `div_f64` - `div_f32` This results in all methods of `Duration` being (unstable) const. Moved the tests to `library` as part of rust-lang#76268. Possible because of rust-lang#72449, which made the relevant `f32` and `f64` methods const. Tracking issue: rust-lang#72440 r? @ecstatic-morse

@ecstatic-morse

…orse Make all methods of `Duration` unstably const Make the following methods of `Duration` unstable const under `duration_const_2`: - `from_secs_f64` - `from_secs_f32` - `mul_f64` - `mul_f32` - `div_f64` - `div_f32` This results in all methods of `Duration` being (unstable) const. Moved the tests to `library` as part of rust-lang#76268. Possible because of rust-lang#72449, which made the relevant `f32` and `f64` methods const. Tracking issue: rust-lang#72440 r? @ecstatic-morse

@ecstatic-morse

…orse Make all methods of `Duration` unstably const Make the following methods of `Duration` unstable const under `duration_const_2`: - `from_secs_f64` - `from_secs_f32` - `mul_f64` - `mul_f32` - `div_f64` - `div_f32` This results in all methods of `Duration` being (unstable) const. Moved the tests to `library` as part of rust-lang#76268. Possible because of rust-lang#72449, which made the relevant `f32` and `f64` methods const. Tracking issue: rust-lang#72440 r? @ecstatic-morse

@ecstatic-morse

…orse Make all methods of `Duration` unstably const Make the following methods of `Duration` unstable const under `duration_const_2`: - `from_secs_f64` - `from_secs_f32` - `mul_f64` - `mul_f32` - `div_f64` - `div_f32` This results in all methods of `Duration` being (unstable) const. Moved the tests to `library` as part of rust-lang#76268. Possible because of rust-lang#72449, which made the relevant `f32` and `f64` methods const. Tracking issue: rust-lang#72440 r? @ecstatic-morse

…on-try-from-secs-float, r=dtolnay Stabilize `duration_checked_float` ## Stabilization Report This stabilization report is for a stabilization of `duration_checked_float`, tracking issue: rust-lang#83400. ### Implementation History - rust-lang#82179 - rust-lang#90247 - rust-lang#96051 - Changed error type to `FromFloatSecsError` in rust-lang#90247 - rust-lang#96051 changes the rounding mode to round-to-nearest instead of truncate. ## API Summary This stabilization report proposes the following API to be stabilized in `core`, along with their re-exports in `std`: ```rust // core::time impl Duration { pub const fn try_from_secs_f32(secs: f32) -> Result<Duration, TryFromFloatSecsError>; pub const fn try_from_secs_f64(secs: f64) -> Result<Duration, TryFromFloatSecsError>; } #[derive(Debug, Clone, PartialEq, Eq)] pub struct TryFromFloatSecsError { ... } impl core::fmt::Display for TryFromFloatSecsError { ... } impl core::error::Error for TryFromFloatSecsError { ... } ``` These functions are made const unstable under `duration_consts_float`, tracking issue rust-lang#72440. There is an open question in the tracking issue around what the error type should be called which I was hoping to resolve in the context of an FCP. In this stabilization PR, I have altered the name of the error type to `TryFromFloatSecsError`. In my opinion, the error type shares the name of the method (adjusted to accommodate both types of floats), which is consistent with other error types in `core`, `alloc` and `std` like `TryReserveError` and `TryFromIntError`. ## Experience Report Code such as this is ready to be converted to a checked API to ensure it is panic free: ```rust impl Time { pub fn checked_add_f64(&self, seconds: f64) -> Result<Self, TimeError> { // Fail safely during `f64` conversion to duration if seconds.is_nan() || seconds.is_infinite() { return Err(TzOutOfRangeError::new().into()); } if seconds.is_sign_positive() { self.checked_add(Duration::from_secs_f64(seconds)) } else { self.checked_sub(Duration::from_secs_f64(-seconds)) } } } ``` See: artichoke/artichoke#2194. `@rustbot` label +T-libs-api -T-libs cc `@mbartlett21`

…on-try-from-secs-float, r=dtolnay Stabilize `duration_checked_float` ## Stabilization Report This stabilization report is for a stabilization of `duration_checked_float`, tracking issue: rust-lang#83400. ### Implementation History - rust-lang#82179 - rust-lang#90247 - rust-lang#96051 - Changed error type to `FromFloatSecsError` in rust-lang#90247 - rust-lang#96051 changes the rounding mode to round-to-nearest instead of truncate. ## API Summary This stabilization report proposes the following API to be stabilized in `core`, along with their re-exports in `std`: ```rust // core::time impl Duration { pub const fn try_from_secs_f32(secs: f32) -> Result<Duration, TryFromFloatSecsError>; pub const fn try_from_secs_f64(secs: f64) -> Result<Duration, TryFromFloatSecsError>; } #[derive(Debug, Clone, PartialEq, Eq)] pub struct TryFromFloatSecsError { ... } impl core::fmt::Display for TryFromFloatSecsError { ... } impl core::error::Error for TryFromFloatSecsError { ... } ``` These functions are made const unstable under `duration_consts_float`, tracking issue rust-lang#72440. There is an open question in the tracking issue around what the error type should be called which I was hoping to resolve in the context of an FCP. In this stabilization PR, I have altered the name of the error type to `TryFromFloatSecsError`. In my opinion, the error type shares the name of the method (adjusted to accommodate both types of floats), which is consistent with other error types in `core`, `alloc` and `std` like `TryReserveError` and `TryFromIntError`. ## Experience Report Code such as this is ready to be converted to a checked API to ensure it is panic free: ```rust impl Time { pub fn checked_add_f64(&self, seconds: f64) -> Result<Self, TimeError> { // Fail safely during `f64` conversion to duration if seconds.is_nan() || seconds.is_infinite() { return Err(TzOutOfRangeError::new().into()); } if seconds.is_sign_positive() { self.checked_add(Duration::from_secs_f64(seconds)) } else { self.checked_sub(Duration::from_secs_f64(-seconds)) } } } ``` See: artichoke/artichoke#2194. ``@rustbot`` label +T-libs-api -T-libs cc ``@mbartlett21``

MoSal · 2023-04-27T20:04:33Z

Didn't see this mentioned anywhere with a quick search, but Duration::from_secs_f64 is not const anymore?

Is #![feature(duration_consts_float)] no-op now?

MoSal · 2023-04-29T13:11:15Z

Didn't see this mentioned anywhere with a quick search, but Duration::from_secs_f64 is not const anymore?

Is #![feature(duration_consts_float)] no-op now?

Looking at this closer today, the from_* and try_from_* float functions were no longer
const after #110393. That's because the try_from_secs macro makes use of $int_ty::from($expr), the trait impls of which are no longer const.

The from calls can be replaced with ($expr as $int_ty) if it is desired to restore the const impls.

…, r=scottmcm Implement `Duration::as_millis_{f64,f32}` Implementation of rust-lang#122451. Linked const-unstability to rust-lang#72440, so the post there should probably be updated to mentions the 2 new methods when/if this PR is merged.

Rollup merge of rust-lang#122479 - GrigorenkoPV:duration_millis_float, r=scottmcm Implement `Duration::as_millis_{f64,f32}` Implementation of rust-lang#122451. Linked const-unstability to rust-lang#72440, so the post there should probably be updated to mentions the 2 new methods when/if this PR is merged.

RalfJung · 2024-09-08T07:17:47Z

@rust-lang/libs-api With #57241 being stable now, I think we can proceed with stabilizing these as well? :)

EDIT: I updated the function list; some things listed there were actually not even unstably const any more.

dtolnay · 2024-09-09T19:49:47Z

@rfcbot fcp merge

const for these 6 already-stable Duration methods, unblocked by #128596 in Rust 1.82 (current beta).

rfcbot · 2024-09-09T19:49:48Z

Team member @dtolnay has proposed to merge this. The next step is review by the rest of the tagged team members:

No concerns currently listed.

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for info about what commands tagged team members can give me.

rfcbot · 2024-10-01T14:53:18Z

🔔 This is now entering its final comment period, as per the review above. 🔔

rfcbot · 2024-10-11T16:16:06Z

The final comment period, with a disposition to merge, as per the review above, is now complete.

As the automated representative of the governance process, I would like to thank the author for their work and everyone else who contributed.

This will be merged soon.

Rollup merge of rust-lang#131289 - RalfJung:duration_consts_float, r=tgross35 stabilize duration_consts_float Waiting for FCP in rust-lang#72440 to pass. `as_millis_f32` and `as_millis_f64` are not stable at all yet, so I moved their const-stability together with their regular stability (tracked at rust-lang#122451). Fixes rust-lang#72440

stabilize duration_consts_float Waiting for FCP in rust-lang/rust#72440 to pass. `as_millis_f32` and `as_millis_f64` are not stable at all yet, so I moved their const-stability together with their regular stability (tracked at rust-lang/rust#122451). Fixes rust-lang/rust#72440

marmeladema added the C-tracking-issue Category: An issue tracking the progress of sth. like the implementation of an RFC label May 21, 2020

jonas-schievink added A-const-fn T-libs-api Relevant to the library API team, which will review and decide on the PR/issue. labels May 21, 2020

RalfJung mentioned this issue May 22, 2020

Const floating point bitcasts and classification #72449

Merged

marmeladema added a commit to marmeladema/rust that referenced this issue May 30, 2020

Constify most non-trait Duration methods as described in rust-lang#…

7527409

…72440

marmeladema changed the title ~~Tracking Issue for constify-ing most non-trait Duration methods~~ Tracking Issue for constify-ing non-trait Duration methods May 30, 2020

Dylan-DPC-zz mentioned this issue Jul 14, 2020

Rollup of 11 pull requests #74322

Closed

Manishearth mentioned this issue Jul 14, 2020

Rollup of 15 pull requests #74329

Closed

marmeladema added a commit to marmeladema/rust that referenced this issue Jul 15, 2020

Constify most non-trait Duration methods as described in rust-lang#…

4a96800

…72440

KodrAus added the Libs-Tracked Libs issues that are tracked on the team's project board. label Jul 29, 2020

CDirkx mentioned this issue Sep 4, 2020

Make all methods of Duration unstably const #76335

Merged

lopopolo mentioned this issue Sep 25, 2022

Stabilize duration_checked_float #102271

Merged

GrigorenkoPV mentioned this issue Mar 14, 2024

Implement Duration::as_millis_{f64,f32} #122479

Merged

RalfJung added the I-libs-api-nominated Nominated for discussion during a libs-api team meeting. label Sep 8, 2024

rfcbot added proposed-final-comment-period Proposed to merge/close by relevant subteam, see T-<team> label. Will enter FCP once signed off. disposition-merge This issue / PR is in PFCP or FCP with a disposition to merge it. labels Sep 9, 2024

dtolnay removed the I-libs-api-nominated Nominated for discussion during a libs-api team meeting. label Sep 9, 2024

rfcbot added the final-comment-period In the final comment period and will be merged soon unless new substantive objections are raised. label Oct 1, 2024

rfcbot removed the proposed-final-comment-period Proposed to merge/close by relevant subteam, see T-<team> label. Will enter FCP once signed off. label Oct 1, 2024

RalfJung mentioned this issue Oct 5, 2024

stabilize duration_consts_float #131289

Merged

rustbot mentioned this issue Oct 11, 2024

Tracking issue for release notes of #72440: Tracking Issue for constify-ing non-trait Duration methods #131554

Closed

3 tasks

bors closed this as completed in 3e16b77 Oct 12, 2024

apiraino removed the to-announce Announce this issue on triage meeting label Oct 17, 2024

RalfJung added the A-const-eval Area: Constant evaluation, covers all const contexts (static, const fn, ...) label Dec 1, 2024

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Tracking Issue for constify-ing non-trait `Duration` methods #72440

Tracking Issue for constify-ing non-trait `Duration` methods #72440

marmeladema commented May 21, 2020 •

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Tracking Issue for constify-ing non-trait Duration methods #72440

Tracking Issue for constify-ing non-trait Duration methods #72440

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Tracking Issue for constify-ing non-trait `Duration` methods #72440

Tracking Issue for constify-ing non-trait `Duration` methods #72440

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