rust-lang/nomicon

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The Dark Arts of Advanced and Unsafe Rust Programming

Stars: 2.3k
Forks: 325
Open beginner issues: 0
Indexed issues: 81

Dominant language: CSS
License: Apache-2.0
Last GitHub push: Aug 17, 2026
Latest indexed: Sep 19, 2026
Contributing guide: No contributing guide
Code of conduct: No code of conduct
Beginner labels: help wanted good first issue
PR merge metrics: No merged PRs in 30d

Beginner friendly Everything

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81 open issues indexed

"Improperly reduced borrows" can be updated soon. Open

Difficulty 2/5 1-3 hours Newbie friendliness 76/100

rust-lang/nomicon#527 · 1 reaction · Opened Aug 27, 2026
How can the null-pointer optimization apply to fieldless enums Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

rust-lang/nomicon#524 · Opened Aug 7, 2026
Follow up on #269 Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

rust-lang/nomicon#522 · Opened May 6, 2026
It would be nice to clarify "dangling" definition Open

Difficulty 4/5 3-5 days Newbie friendliness 38/100

rust-lang/nomicon#521 · Opened Mar 26, 2026
Exception safety statement regarding Box contradicted by std docs Open

Difficulty 1/5 Under an hour Newbie friendliness 48/100

rust-lang/nomicon#509 · 1 reaction · Opened Nov 6, 2025
A note that a macro in a #![forbid(unsafe_code)] library can emit unsafe code Open

Difficulty 2/5 1-3 hours Newbie friendliness 48/100

rust-lang/nomicon#506 · 1 reaction · Opened Oct 27, 2025
Phrasing of Sync and Send Open

Difficulty 1/5 Under an hour Newbie friendliness 55/100

rust-lang/nomicon#503 · 4 comments · 4 reactions · Opened Oct 3, 2025
You can't actually `impl !Send` or `impl !Sync` (yet) Open

Difficulty 1/5 Under an hour Newbie friendliness 55/100

rust-lang/nomicon#497 · Opened Jul 16, 2025
[Pre-PR Contribution] Structured Rustonomicon Dataset (JSONL + SQLite) for Intelligent Tooling Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

rust-lang/nomicon#490 · Opened May 13, 2025
[feedback] docs unclear for: higher ranked trait bounds Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

rust-lang/nomicon#480 · 2 reactions · Opened Feb 7, 2025
Incorrect explanation of Sequential Consistency Open

Difficulty 1/5 Under an hour Newbie friendliness 55/100

rust-lang/nomicon#479 · Opened Jan 31, 2025
A tiny error in "Atomics" Open

Difficulty 1/5 Under an hour Newbie friendliness 90/100

rust-lang/nomicon#473 · 1 reaction · Opened Jan 4, 2025
Clarification needed in unwinding section Open

Difficulty 2/5 1-3 hours Newbie friendliness 45/100

rust-lang/nomicon#463 · 1 comment · Opened Sep 23, 2024
Can undefined behavior that is theoretically reachable, but not reached in practice cause problems? Open

Difficulty 4/5 3-5 days Newbie friendliness 25/100

rust-lang/nomicon#454 · 4 comments · Opened Jun 15, 2024
8.2 "Send and Sync" appears to misdefine "Send" Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

rust-lang/nomicon#453 · 1 comment · 7 reactions · Opened Jun 3, 2024
Description about `Layout::array` differs from std Open

Difficulty 1/5 Under an hour Newbie friendliness 55/100

rust-lang/nomicon#451 · Opened May 22, 2024
Confused about lifetime Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

rust-lang/nomicon#442 · Opened Mar 3, 2024
10.1.2. Base Code / Send and Sync. "Sync + Send" Open

Difficulty 2/5 1-3 hours Newbie friendliness 45/100

rust-lang/nomicon#436 · 3 comments · Opened Dec 13, 2023
"Working With Uninitialized Memory" makes overly broad claims Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

rust-lang/nomicon#435 · Opened Dec 12, 2023
Keep "Concurrency" and "Arc and Mutex" closer Open

Difficulty 1/5 Under an hour Newbie friendliness 45/100

rust-lang/nomicon#434 · Opened Dec 9, 2023
"9. Implementing Vec": Dangling pointer overflow? Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

rust-lang/nomicon#433 · Opened Dec 4, 2023
Add an elided bound example in unbounded lifetimes section to make stuff clearer Open

Difficulty 2/5 1-3 hours Newbie friendliness 45/100

rust-lang/nomicon#422 · Opened Sep 27, 2023
Higher Ranked Trait Bounds (HRTB) article appears to be out of date Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

rust-lang/nomicon#412 · 3 comments · 1 reaction · Opened Jun 10, 2023
Section `Unchecked Uninitialized Memory` could now mention `array::from_fn` Open

Difficulty 1/5 Under an hour Newbie friendliness 50/100

rust-lang/nomicon#407 · Opened May 3, 2023
atomics part has misleading statements about hardware reordering caused by cache Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

rust-lang/nomicon#400 · Opened Feb 8, 2023
Suggestion to rewrite variance in fuction arguments explanation Open

Difficulty 2/5 1-3 hours Newbie friendliness 48/100

rust-lang/nomicon#394 · 2 comments · Opened Jan 8, 2023
Discuss the `WrapperStruct(UnsafeCell<some_c_struct>)`FFI pattern Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

rust-lang/nomicon#385 · Opened Nov 11, 2022
Reference and nomicon contradict each other on `ManuallyDrop` Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

rust-lang/nomicon#383 · Opened Oct 26, 2022
example uses deprecated `compare_and_swap` Open

rust-lang/nomicon#382 · 2 reactions · 1 assignee · Opened Oct 20, 2022
panic_handler isn't just for no_std applications Open

Difficulty 1/5 Under an hour Newbie friendliness 45/100

rust-lang/nomicon#373 · 2 comments · Opened Jul 9, 2022
what is heap::deallocate? Open

Difficulty 3/5 1-2 days Newbie friendliness 35/100

rust-lang/nomicon#370 · 10 comments · Opened Jun 25, 2022
clarify what is leaked even more Open

Difficulty 1/5 Under an hour Newbie friendliness 72/100

rust-lang/nomicon#369 · Opened Jun 25, 2022
Issues in destructor Open

Difficulty 1/5 Under an hour Newbie friendliness 72/100

rust-lang/nomicon#356 · Opened May 5, 2022
confusion about PhantomData & T: 'a Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

rust-lang/nomicon#348 · 1 comment · Opened Apr 30, 2022
Can we use non_exhausive attr instead of zero length array in "Representing Opaque Structs" Open

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

rust-lang/nomicon#342 · 4 comments · Opened Feb 20, 2022
The Subtyping and Variance chapter is confusing Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

rust-lang/nomicon#339 · 1 comment · 3 reactions · Opened Feb 9, 2022
Subtyping and Variance - Trait variance not covered Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

rust-lang/nomicon#338 · Opened Feb 9, 2022
Dubious justification for using `NonNull` in `Arc` Open

Difficulty 2/5 1-3 hours Newbie friendliness 45/100

rust-lang/nomicon#323 · Opened Nov 10, 2021
Splitting up src/ffi.md Open

C-meta

Difficulty 5/5 Over a week Newbie friendliness 20/100

rust-lang/nomicon#321 · Opened Oct 20, 2021
guideline for unsafe comments and how to get more people understanding `unsafe` semantics Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

rust-lang/nomicon#312 · 2 reactions · Opened Sep 21, 2021
the Atomics page left me confused about "relaxed". What is it for? Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

rust-lang/nomicon#309 · 7 comments · Opened Sep 9, 2021
Send and Sync page has a confusing start Open

Difficulty 1/5 Under an hour Newbie friendliness 35/100

rust-lang/nomicon#307 · Opened Sep 2, 2021
trivial: if Vec::into_iter() mispelled the comments ? Open

Difficulty 1/5 Under an hour Newbie friendliness 55/100

rust-lang/nomicon#304 · 4 comments · Opened Aug 30, 2021
Include brief explainer of C patterns and idioms in the FFI section Open

Difficulty 4/5 3-5 days Newbie friendliness 38/100

rust-lang/nomicon#300 · Opened Aug 18, 2021
Review and update the "as of ..." references Open

C-outdated

Difficulty 3/5 1-2 days Newbie friendliness 35/100

rust-lang/nomicon#295 · Opened Jul 27, 2021
Steal information from the "Crust of Rust: Subtyping and Variance" video (or just add a link to it) Open

C-enhancement

Difficulty 3/5 1-2 days Newbie friendliness 35/100

rust-lang/nomicon#293 · 1 comment · Opened Jul 16, 2021
Consider using mdbook's include anchors feature for some examples Open

C-meta

Difficulty 5/5 Over a week Newbie friendliness 30/100

rust-lang/nomicon#289 · Opened Jul 1, 2021
Prefer "one sentense per line" rule Open

C-meta

Difficulty 3/5 1-2 days Newbie friendliness 30/100

rust-lang/nomicon#281 · 1 comment · Opened Jun 18, 2021
Move the (duplicate) lists of rules to the reference Open

C-meta

Difficulty 3/5 1-2 days Newbie friendliness 35/100

rust-lang/nomicon#279 · 4 comments · Opened Jun 16, 2021
Add code example about how to write robust unsafe rust Open

I-needs-decision

Difficulty 4/5 3-5 days Newbie friendliness 42/100

rust-lang/nomicon#270 · 1 comment · Opened Jun 3, 2021

rust-lang/nomicon

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