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builtin Fn-trait impls: instantiate binder before the return type Sized check #147152

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Merged
merged 3 commits into from
Sep 30, 2025
Merged

builtin Fn-trait impls: instantiate binder before the return type Sized check #147152

merged 3 commits into from
Sep 30, 2025

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lcnr
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@lcnr lcnr commented Sep 29, 2025 •
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@rustbot rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. WG-trait-system-refactor The Rustc Trait System Refactor Initiative (-Znext-solver) labels Sep 29, 2025
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lcnr commented Sep 29, 2025
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tests/ui/traits/next-solver/opaques/overflow-hr-fn-trait-sized-1.rs
// input.
fn flat_map<T, F, I, G>(_: F, _: G)
where
F: FnOnce(T) -> I,
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previously we had to prove for<'a> opaque<'a>: Sized here and each time we tried to prove it resulted in a new opaque<'!a_placeholderN> = ?unconstrained use of the opaque.

This then caused try_evaluate_added_goals to overflow

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lcnr commented Sep 29, 2025

@bors try @rust-timer queue

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rust-bors bot added a commit that referenced this pull request Sep 29, 2025
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Auto merge of #147152 - lcnr:instantiate-pre-sized-check, r=<try>
00ddbc8 
builtin `Fn`-trait impls: instantiate binder before the return type `Sized` check
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@rustbot rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Sep 29, 2025
@lcnr lcnr force-pushed the instantiate-pre-sized-check branch from 2801aa4 to 07806a1 Compare September 29, 2025 13:28
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☀️ Try build successful (CI)
Build commit: 00ddbc8 (00ddbc8af6a270ca7f1f65dc6be53807e42ac754, parent: 128b36a4a48534b048845cc744b9672529d13df1)

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BoxyUwU commented Sep 29, 2025

r=me if perf good

@BoxyUwU BoxyUwU added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Sep 29, 2025
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Finished benchmarking commit (00ddbc8): comparison URL.

Overall result: no relevant changes - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

This benchmark run did not return any relevant results for this metric.

Cycles

Results (secondary 2.7%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

mean range count
Regressions ❌
(primary)		 - - 0
Regressions ❌
(secondary)		 2.7% [2.2%, 3.7%] 5
Improvements ✅
(primary)		 - - 0
Improvements ✅
(secondary)		 - - 0
All ❌✅ (primary) - - 0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 470.851s -> 469.909s (-0.20%)
Artifact size: 387.67 MiB -> 387.69 MiB (0.01%)

@rustbot rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Sep 29, 2025
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lcnr commented Sep 29, 2025

@bors r=BoxyUwU rollup

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bors commented Sep 29, 2025

📌 Commit 07806a1 has been approved by BoxyUwU

It is now in the queue for this repository.

@bors bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Sep 29, 2025
@jhpratt jhpratt mentioned this pull request Sep 30, 2025
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bors added a commit that referenced this pull request Sep 30, 2025
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Auto merge of #147169 - jhpratt:rollup-65ooei8, r=jhpratt
c5dc558 
Rollup of 4 pull requests

Successful merges:

 - #145883 (Make macOS dist build configuration match where reasonable)
 - #146457 (Skip cleanups on unsupported targets)
 - #147152 (builtin `Fn`-trait impls: instantiate binder before the return type `Sized` check)
 - #147153 ([rustdoc] Move doc cfg propagation pass before items stripping passes)

r? `@ghost`
`@rustbot` modify labels: rollup
@bors bors merged commit afd620f into rust-lang:master Sep 30, 2025
10 checks passed
@rustbot rustbot added this to the 1.92.0 milestone Sep 30, 2025
rust-timer added a commit that referenced this pull request Sep 30, 2025
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Unrolled build for #147152
6911204 
Rollup merge of #147152 - lcnr:instantiate-pre-sized-check, r=BoxyUwU

builtin `Fn`-trait impls: instantiate binder before the return type `Sized` check

fixes
- rust-lang/trait-system-refactor-initiative#220
- rust-lang/trait-system-refactor-initiative#204

r? `@BoxyUwU`
This was referenced Sep 30, 2025
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@lcnr lcnr deleted the instantiate-pre-sized-check branch September 30, 2025 08:53
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