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core: drop unmapped ZSTs in array map#152487

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core: drop unmapped ZSTs in array map#152487
joboet wants to merge 1 commit intorust-lang:mainfrom
joboet:array_map_zst

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@joboet joboet commented Feb 11, 2026 •
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Fixes #152211.
Alternative to #152220 and #152248.

This makes the Drain type use the same ZST-handling strategy as slice::IterMut, which stores the remaining length instead of a one-past-the-end pointer when the type is a ZST. I've also removed the const-generic N parameter from Drain to avoid unnecessary monomorphizations.

@rustbot rustbot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Feb 11, 2026
@joboet joboet marked this pull request as ready for review February 11, 2026 14:30
@rustbot rustbot added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Feb 11, 2026
@rustbot rustbot removed the S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. label Feb 11, 2026
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rustbot commented Feb 11, 2026

r? @scottmcm

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scottmcm commented Apr 18, 2026

I'll flip this to the same reviewer as #147071
r? oli-obk

@rustbot rustbot assigned oli-obk and unassigned scottmcm Apr 18, 2026
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rustbot commented Apr 18, 2026

oli-obk is not on the review rotation at the moment.
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@bors r+ rollup

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rust-bors Bot commented Apr 27, 2026

📌 Commit b9ad3a9 has been approved by oli-obk

It is now in the queue for this repository.

@rust-bors rust-bors Bot 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-review Status: Awaiting review from the assignee but also interested parties. labels Apr 27, 2026
JonathanBrouwer added a commit to JonathanBrouwer/rust that referenced this pull request Apr 27, 2026
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Rollup merge of rust-lang#152487 - joboet:array_map_zst, r=oli-obk
6779e67 
core: drop unmapped ZSTs in array `map`

Fixes rust-lang#152211.
Alternative to rust-lang#152220 and rust-lang#152248.

This makes the `Drain` type use the same ZST-handling strategy as `slice::IterMut`, which stores the remaining length instead of a one-past-the-end pointer when the type is a ZST. I've also removed the const-generic `N` parameter from `Drain` to avoid unnecessary monomorphizations.
@JonathanBrouwer JonathanBrouwer mentioned this pull request Apr 27, 2026
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JonathanBrouwer added a commit to JonathanBrouwer/rust that referenced this pull request Apr 27, 2026
@JonathanBrouwer
Rollup merge of rust-lang#152487 - joboet:array_map_zst, r=oli-obk
76347ce 
core: drop unmapped ZSTs in array `map`

Fixes rust-lang#152211.
Alternative to rust-lang#152220 and rust-lang#152248.

This makes the `Drain` type use the same ZST-handling strategy as `slice::IterMut`, which stores the remaining length instead of a one-past-the-end pointer when the type is a ZST. I've also removed the const-generic `N` parameter from `Drain` to avoid unnecessary monomorphizations.
@JonathanBrouwer JonathanBrouwer mentioned this pull request Apr 27, 2026
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rust-bors Bot pushed a commit that referenced this pull request Apr 27, 2026
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Auto merge of #155872 - JonathanBrouwer:rollup-syHc7Hm, r=JonathanBro…
f81797f 
…uwer

Rollup of 4 pull requests

Successful merges:

 - #152487 (core: drop unmapped ZSTs in array `map`)
 - #155716 (arm64e: set ptrauth ABI subtype on lib.rmeta Mach-O objects)
 - #155864 (Fix panic for doc attributes on where predicates)
 - #155865 (add test for accidentally fixed `binius_field` issue)
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rust-bors Bot commented Apr 27, 2026 •
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⌛ Testing commit b9ad3a9 with merge 44ae6c2...

Workflow: https://github.com/rust-lang/rust/actions/runs/24994532499

rust-bors Bot pushed a commit that referenced this pull request Apr 27, 2026
@bors
Auto merge of #152487 - joboet:array_map_zst, r=oli-obk
44ae6c2 
core: drop unmapped ZSTs in array `map`

Fixes #152211.
Alternative to #152220 and #152248.

This makes the `Drain` type use the same ZST-handling strategy as `slice::IterMut`, which stores the remaining length instead of a one-past-the-end pointer when the type is a ZST. I've also removed the const-generic `N` parameter from `Drain` to avoid unnecessary monomorphizations.
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JonathanBrouwer commented Apr 27, 2026

@bors r-
#155872 (comment)

@rust-bors rust-bors Bot 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-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Apr 27, 2026
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rust-bors Bot commented Apr 27, 2026

This pull request was unapproved.

This PR was contained in a rollup (#155872), which was unapproved.

Auto build was cancelled due to unapproval. Cancelled workflows:

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rustbot commented Apr 30, 2026

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

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joboet commented May 1, 2026

@bors r=@oli-obk

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rust-bors Bot commented May 1, 2026

📌 Commit 14851d2 has been approved by oli-obk

It is now in the queue for this repository.

@rust-bors rust-bors Bot 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 May 1, 2026
GuillaumeGomez added a commit to GuillaumeGomez/rust that referenced this pull request May 1, 2026
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Rollup merge of rust-lang#152487 - joboet:array_map_zst, r=oli-obk
c389685 
core: drop unmapped ZSTs in array `map`

Fixes rust-lang#152211.
Alternative to rust-lang#152220 and rust-lang#152248.

This makes the `Drain` type use the same ZST-handling strategy as `slice::IterMut`, which stores the remaining length instead of a one-past-the-end pointer when the type is a ZST. I've also removed the const-generic `N` parameter from `Drain` to avoid unnecessary monomorphizations.
@GuillaumeGomez GuillaumeGomez mentioned this pull request May 1, 2026
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rust-bors Bot pushed a commit that referenced this pull request May 1, 2026
@bors
Auto merge of #156056 - GuillaumeGomez:rollup-6DdRYmD, r=GuillaumeGomez
4db537e 
Rollup of 7 pull requests

Successful merges:

 - #152487 (core: drop unmapped ZSTs in array `map`)
 - #155940 (refactor rustc_on_unimplemented's filtering)
 - #156020 (Improve source code for `librustdoc/visit_ast.rs`)
 - #156021 (Clean up some traits)
 - #156028 (Add a `Local::arg(i)` helper constructor)
 - #156037 (Add AcceptContext::expect_no_args)
 - #156040 (Add missing alias to mailmap)
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GuillaumeGomez commented May 1, 2026

Failed in #156056 (comment) with:

warning: feature `reentrant_lock` is declared but not used
  --> library/coretests/tests/lib.rs:99:12
   |
99 | #![feature(reentrant_lock)]
   |            ^^^^^^^^^^^^^^
   |
   = note: `#[warn(unused_features)]` (part of `#[warn(unused)]`) on by default

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GuillaumeGomez commented May 1, 2026

@bors r-

@rust-bors rust-bors Bot 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-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels May 1, 2026
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rust-bors Bot commented May 1, 2026

This pull request was unapproved.

This PR was contained in a rollup (#156056), which was unapproved.

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array::map and array::try_map do not drop ZSTs properly

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