Remove unnecessary `get_unchecked` by ChrisDenton · Pull Request #155855 · rust-lang/rust

ChrisDenton · 2026-04-27T03:29:27Z

My benchmarking did not show any issue with using the safe method instead so I assume this isn't an issue any more. But let's do a perf run to be sure.

rustbot · 2026-04-27T03:29:32Z

r? @Mark-Simulacrum

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Owners of files modified in this PR: @scottmcm, libs
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ChrisDenton · 2026-04-27T03:29:37Z

@bors try @rust-timer queue

Remove unnecessary `get_unchecked`

rust-bors · 2026-04-27T05:39:50Z

☀️ Try build successful (CI)
Build commit: 6395398 (6395398753df5c5854178b39b30e9b7692892504, parent: ca9a134e0985765ded9cfdde4030a5df4db7e2bd)

rust-timer · 2026-04-27T06:19:33Z

Finished benchmarking commit (6395398): comparison URL.

Overall result: no relevant changes - no action needed

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

This perf run didn't have relevant results for this metric.

Max RSS (memory usage)

Results (primary 2.2%, secondary 0.5%)

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

	mean	range	count
Regressions ❌ (primary)	2.2%	[2.2%, 2.2%]	1
Regressions ❌ (secondary)	2.8%	[2.8%, 2.8%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.9%	[-1.9%, -1.9%]	1
All ❌✅ (primary)	2.2%	[2.2%, 2.2%]	1

Cycles

Results (primary -2.5%, secondary 3.2%)

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)	3.2%	[2.0%, 4.2%]	8
Improvements ✅ (primary)	-2.5%	[-2.5%, -2.5%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-2.5%	[-2.5%, -2.5%]	1

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 488.117s -> 486.46s (-0.34%)
Artifact size: 393.52 MiB -> 393.51 MiB (-0.00%)

Mark-Simulacrum · 2026-05-04T13:27:53Z

I'd guess there's very little dependency on this from the compiler, so probably not super meaningful results in perf. I'm OK approving it though given your local benchmarking.

@bors r+

rust-bors · 2026-05-04T13:27:56Z

📌 Commit 69cc5fa has been approved by Mark-Simulacrum

It is now in the queue for this repository.

…ark-Simulacrum Remove unnecessary `get_unchecked` My benchmarking did not show any issue with using the safe method instead so I assume this isn't an issue any more. But let's do a perf run to be sure.

…uwer Rollup of 10 pull requests Successful merges: - #155848 ([doc]: Revert `core::io::ErrorKind` doc changes) - #155855 (Remove unnecessary `get_unchecked`) - #156062 (Added command-line argument support for `wasm32-wali-linux-musl`) - #155543 (docs(unstable-book): Document const generics features) - #156043 (c-variadic: gate `va_arg` on `c_variadic_experimental_arch`) - #156082 (Move tests associated types) - #156092 (Clean up `TyCtxt::needs_crate_hash` usage and rename it to `needs_hir_hash`.) - #156104 (Relax `T: Sized` bound on `try_as_dyn` / `try_as_dyn_mut`) - #156128 (.mailmap: prefer matching just based on commit emails) - #156135 (Remove most uses of def_id_to_node_id)

…ark-Simulacrum Remove unnecessary `get_unchecked` My benchmarking did not show any issue with using the safe method instead so I assume this isn't an issue any more. But let's do a perf run to be sure.

…uwer Rollup of 10 pull requests Successful merges: - #155848 ([doc]: Revert `core::io::ErrorKind` doc changes) - #155855 (Remove unnecessary `get_unchecked`) - #155543 (docs(unstable-book): Document const generics features) - #155962 (`rustc`: `target_features`: allow for `cfg`-only stable `target_features`) - #156043 (c-variadic: gate `va_arg` on `c_variadic_experimental_arch`) - #156082 (Move tests associated types) - #156092 (Clean up `TyCtxt::needs_crate_hash` usage and rename it to `needs_hir_hash`.) - #156104 (Relax `T: Sized` bound on `try_as_dyn` / `try_as_dyn_mut`) - #156128 (.mailmap: prefer matching just based on commit emails) - #156135 (Remove most uses of def_id_to_node_id)

…ark-Simulacrum Remove unnecessary `get_unchecked` My benchmarking did not show any issue with using the safe method instead so I assume this isn't an issue any more. But let's do a perf run to be sure.

…uwer Rollup of 12 pull requests Successful merges: - #155848 ([doc]: Revert `core::io::ErrorKind` doc changes) - #155855 (Remove unnecessary `get_unchecked`) - #155543 (docs(unstable-book): Document const generics features) - #155962 (`rustc`: `target_features`: allow for `cfg`-only stable `target_features`) - #156043 (c-variadic: gate `va_arg` on `c_variadic_experimental_arch`) - #156082 (Move tests associated types) - #156092 (Clean up `TyCtxt::needs_crate_hash` usage and rename it to `needs_hir_hash`.) - #156103 (Fix E0040 suggestion for explicit `Drop::drop` UFCS calls) - #156104 (Relax `T: Sized` bound on `try_as_dyn` / `try_as_dyn_mut`) - #156128 (.mailmap: prefer matching just based on commit emails) - #156135 (Remove most uses of def_id_to_node_id) - #156152 (Update books)

…ark-Simulacrum Remove unnecessary `get_unchecked` My benchmarking did not show any issue with using the safe method instead so I assume this isn't an issue any more. But let's do a perf run to be sure.

Rollup of 16 pull requests Successful merges: - #155848 ([doc]: Revert `core::io::ErrorKind` doc changes) - #155855 (Remove unnecessary `get_unchecked`) - #155543 (docs(unstable-book): Document const generics features) - #155962 (`rustc`: `target_features`: allow for `cfg`-only stable `target_features`) - #156043 (c-variadic: gate `va_arg` on `c_variadic_experimental_arch`) - #156082 (Move tests associated types) - #156087 (Improve `&pin` reference-pattern suggestions) - #156092 (Clean up `TyCtxt::needs_crate_hash` usage and rename it to `needs_hir_hash`.) - #156103 (Fix E0040 suggestion for explicit `Drop::drop` UFCS calls) - #156104 (Relax `T: Sized` bound on `try_as_dyn` / `try_as_dyn_mut`) - #156122 (Add a `doc_cfg` regression test to ensure foreign types impls are working as expected) - #156128 (.mailmap: prefer matching just based on commit emails) - #156135 (Remove most uses of def_id_to_node_id) - #156152 (Update books) - #156154 (tests: mark import UI tests as check-pass) - #156162 (Update `browser-ui-test` version to `0.23.5`)

Remove unnecessary get_unchecked

69cc5fa

My benchmarking did not show any issue with using the safe method instead so I assume this isn't an issue any more. But let's do a perf run to be sure.

rustbot assigned Mark-Simulacrum Apr 27, 2026

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Apr 27, 2026

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rustbot added the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Apr 27, 2026

rust-bors Bot pushed a commit that referenced this pull request Apr 27, 2026

Auto merge of #155855 - ChrisDenton:remove-unsafe-get, r=<try>

6395398

Remove unnecessary `get_unchecked`

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rustbot removed the S-waiting-on-perf Status: Waiting on a perf run to be completed. label Apr 27, 2026

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 May 4, 2026

JonathanBrouwer mentioned this pull request May 4, 2026

Rollup of 9 pull requests #156149

Closed

JonathanBrouwer mentioned this pull request May 4, 2026

Rollup of 10 pull requests #156150

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JonathanBrouwer mentioned this pull request May 4, 2026

Rollup of 10 pull requests #156153

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JonathanBrouwer mentioned this pull request May 4, 2026

Rollup of 12 pull requests #156158

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GuillaumeGomez mentioned this pull request May 5, 2026

Rollup of 16 pull requests #156166

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Remove unnecessary `get_unchecked`#155855

Remove unnecessary `get_unchecked`#155855
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ChrisDenton:remove-unsafe-get

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rust-timer commented Apr 27, 2026

Overall result: no relevant changes - no action needed

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Mark-Simulacrum commented May 4, 2026

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