Rust 1.77.0: 70 highlights in 30 minutes

29 днів тому

New changes Rust 1.77.0!
Links:
Rust 1.77.0 Blog Post - blog.rust-lang.org/2024/03/21...
Rust 1.77.1 Blog Post - blog.rust-lang.org/2024/03/28...
async fn calls PR - github.com/rust-lang/rust/pul...
Exhaustiveness: reveal opaque types properly - github.com/rust-lang/rust/pul...
Changes to u128/i128 layout - blog.rust-lang.org/2024/03/30...
Error on incorrect implied bounds in well-formedness check - github.com/rust-lang/rust/pul...
Internal fixes - github.com/rust-lang/rust/pul...
New cargo:: build directive - github.com/rust-lang/cargo/pu...
Cargo documentation updates - github.com/rust-lang/cargo/bl...
The Ferris-the-crab image on today's title picture is by Abi Broom, who is currently the Operations Manager of the Rust Foundation. This Ferris appears to have been hand-drawn in black marker on a piece of paper with hasty strokes for the main body, with a particular jaunty top of the head that evokes the image of a Calvin-and-Hobbes hairdo, with special attention given to providing ferris with adorable shiny eyes. The mouth is reminiscent of Leonardo Da Vinci's Mona Lisa smile, suggesting the artist has been influenced by old Italian culture, and may enjoy pizza and pasta. If you would like to add a copy of this ferris to your collection, you can download the image at foundation.rust-lang.org/img/...
0:21 1. C-string literals
1:02 2. Recursive async fn
2:12 3. offset_of!
2:38 4. std debuginfo is now stripped
3:52 5. incompatible_msrv lint
4:56 Other Rust Changes
5:07 6. Exhaustiveness: reveal opaque types properly
5:31 7. Stabilize THIR unsafeck
6:00 8. New static_mut_refs lint
6:20 9. Undeprecate unstable_features lint
6:38 10. coinductive_overlap_in_coherence promoted to hard error
6:54 11. Eliminate type-driven traversal in const-eval interning
7:22 12. Deny braced macro invocations in let-else statements.
8:12 13. soft_unstable lints now shows up in future breakage reports
8:23 14. Make i128 and u128 16-byte aligned on x86-based targets
8:59 15. Diagnostics now emit more information with --verbose
9:16 16. Improve spacing between printed tokens
9:27 17. Merge unused_tuple_struct_fields into dead_code
9:42 18. Error on incorrect implied bounds in well-formedness check
10:16 19. Fix coverage instrumentation/reports for non-ASCll source code.
10:41 20. Internal fixes
11:06 21. Target Promotions
11:19 22. New Tier 3 Targets
11:55 23. Implement From(&[T; N]) for Cow([T])
12:13 24. Remove special-case handling of Vec::split_off(0)
12:45 Stabilized APIs
12:56 25. array::each_ref & array::each_mut
13:12 26. core::net
13:44 27. round_ties_even for f32 & f64
14:09 28. slice chunk methods
15:29 29. Bound::map
16:00 30. File::create_new
16:37 31. Mutex::clear_poison & RwLock::clear_poison
17:12 Rustdoc
17:17 32. Links allowed in markdown headings
17:24 33. Docs search box supports parens-based type expression syntax
17:44 34. New icon to expand files pane in docs source code view
18:04 35. Prevent JS injection from localStorage
18:21 36. Recommend version-sorting in the Style Guide
18:43 37. More weirdness in weird-exprs .rs
21:00 Cargo
21:03 38. Extend build directive syntax with cargo::
21:28 39. Stabilize id format as PackageIDSpec
21:51 40. cargo-util-schemas
22:09 41. Inherit jobserver from env for all kinds of runner
22:30 42. rustc plugin support deprecated in cargo
22:44 43. Add colors to -Zhelp console output
22:53 44. Add rustc style errors for Cargo.toml parsing
23:05 45. Hold the mutate exclusive lock when vendoring
23:17 46. Set Content-Type: application/json only for requests with a body payload
23:32 47. Set OUT_DIR for all units with build scripts
23:42 48. Fix cargo add selecting the wrong package
23:58 49. cargo fix calls rustc fewer times
24:06 50. Don't inherit workspace if new package is on exclude list
24:17 51. Fix cargo update --precise to accept git branches and tags
24:31 52. Warn about unused keys in the [lints] section of Cargo.toml
24:43 53. Support inserting new lines in cargo fix
24:56 54. Various documentation updates
25:09 Clippy
25:12 55. multiple_crate_versions (feature)
25:34 56. single_call_fn (fix)
25:48 57. unit_arg (fix)
26:02 58. indexing_slicing (fix)
26:24 59. suspicious_open_options
26:44 60. option_as_ref_cloned
26:59 61. thread_local_initializer_can_be_made_const
27:20 62. str_split_at_newline
27:41 63. empty_enum_variants_with_brackets
27:53 64. manual_is_variant_and
28:12 65. pub_underscore_fields
28:34 66. eager_transmute
28:57 67. iter_filter_is_some
29:07 68. iter_filter_is_ok
29:21 69. result_filter_map
29:37 70. unconditional_recursion
Visit ultimaterustcourses.com for Ultimate Rust Crash Course and other Rust courses!

КОМЕНТАРІ: 52

@gamekiller0123 26 днів тому

Recursion is useful for functional-style programming because you can avoid mutable variables. The usual advantages of functional programming apply; being more amenable to tree-like structures and inductive reasoning on them rather than reasoning about state transitions and invariants. The former is often more intuitive and functional code tends to more directly express what is happening at a high level. The usual disadvantages also apply; mainly having to rely on the compiler for performance, which makes it harder to optimize the code.

@NathanStocks 23 дні тому

Thanks! Very concise and informative!

@Im_Ninooo 26 днів тому

*Timestamps* 00:21 1. C-string literals 01:02 2. Recursive async fn 02:12 3. offset_of! 02:38 4. std debuginfo is now stripped 03:52 5. incompatible_msrv lint *Other Rust Changes* 05:07 6. Exhaustiveness: reveal opaque types properly 05:31 7. Stabilize THIR unsafeck 06:00 8. New static_mut_refs lint 06:20 9. Undeprecate unstable_features lint 06:38 10. coinductive_overlap_in_coherence promoted to hard error 06:54 11. Eliminate type-driven traversal in const-eval interning 07:22 12. Deny braced macro invocations in let-else statements. 08:12 13. soft_unstable lints now shows up in future breakage reports 08:23 14. Make i128 and u128 16-byte aligned on x86-based targets 08:59 15. Diagnostics now emit more information with --verbose 09:16 16. Improve spacing between printed tokens 09:27 17. Merge unused_tuple_struct_fields into dead_code 09:42 18. Error on incorrect implied bounds in well-formedness check 10:16 19. Fix coverage instrumentation/reports for non-ASCll source code. 10:41 20. Internal fixes 11:06 21. Target Promotions 11:19 22. New Tier 3 Targets 11:55 23. Implement From for Cow 12:13 24. Remove special-case handling of Vec::split_off(0) *Stabilized APIs* 12:56 25. array::each_ref & array::each_mut 13:12 26. core::net 13:44 27. round_ties_even for f32 & f64 14:09 28. slice chunk methods 15:29 29. Bound::map 16:00 30. File::create_new 16:37 31. Mutex::clear_poison & RwLock::clear_poison *Rustdoc* 17:17 32. Links allowed in markdown headings 17:24 33. Docs search box supports parens-based type expression syntax 17:44 34. New icon to expand files pane in docs source code view 18:04 35. Prevent JS injection from localStorage 18:21 36. Recommend version-sorting in the Style Guide 18:43 37. More weirdness in weird-exprs .rs *Cargo* 21:03 38. Extend build directive syntax with cargo:: 21:28 39. Stabilize id format as PackageIDSpec 21:51 40. cargo-util-schemas 22:09 41. Inherit jobserver from env for all kinds of runner 22:30 42. rustc plugin support deprecated in cargo 22:44 43. Add colors to -Zhelp console output 22:53 44. Add rustc style errors for Cargo.toml parsing 23:05 45. Hold the mutate exclusive lock when vendoring 23:17 46. Set Content-Type: application/json only for requests with a body payload 23:32 47. Set OUT_DIR for all units with build scripts 23:42 48. Fix cargo add selecting the wrong package 23:58 49. cargo fix calls rustc fewer times 24:06 50. Don't inherit workspace if new package is on exclude list 24:17 51. Fix cargo update --precise to accept git branches and tags 24:31 52. Warn about unused keys in the [lints] section of Cargo.toml 24:43 53. Support inserting new lines in cargo fix 24:56 54. Various documentation updates *Clippy* 25:12 55. multiple_crate_versions (feature) 25:34 56. single_call_fn (fix) 25:48 57. unit_arg (fix) 26:02 58. indexing_slicing (fix) 26:24 59. suspicious_open_options 26:44 60. option_as_ref_cloned 26:59 61. thread_local_initializer_can_be_made_const 27:20 62. str_split_at_newline 27:41 63. empty_enum_variants_with_brackets 27:53 64. manual_is_variant_and 28:12 65. pub_underscore_fields 28:34 66. eager_transmute 28:57 67. iter_filter_is_some 29:07 68. iter_filter_is_ok 29:21 69. result_filter_map 29:37 70. unconditional_recursion

@NathanStocks 25 днів тому

You're my new favorite commenter! You just saved me a bunch of time! Thanks!

@Im_Ninooo 25 днів тому

@@NathanStocks you're welcome!

@RobertWHurst 26 днів тому

Thank you for making these Nathan. I very much appreciate the time you put into them - very informative and useful. Do you have a donation link? Would love to buy you a coffee(s) for your hard work.

@NathanStocks 25 днів тому

That would be awesome! I'm up to ~20 hours to produce each of these videos, and its getting really hard to find the time to continue (which is why this video was late). If I could get some sponsors, that would help immensely. Sponsor me on GitHub to support these videos: github.com/sponsors/CleanCut

@kelownatechkid 26 днів тому

Another great video, thank you as always. Awesome to see Josh's great work featured again with a pic this time too - I've been playing around with his cool crate io-mux lately

@NathanStocks 23 дні тому

You're welcome! io-mux looks interesting, thanks for mentioning it!

@JoseLuisQuintana 24 дні тому

Informative and concise. Useful especially for us maintainers. Subscribed!

@NathanStocks 23 дні тому

Thank you! Informative and concise are two things I specifically strive for. Another one is "not boring". Dunno whether I'm accomplishing that one. 😆

@JoseLuisQuintana 23 дні тому

@@NathanStocks definitely "no boring" was the cherry on top!

@haystackdmilith 26 днів тому

Good stuff, makes some features easier to understand. Thanks

@NathanStocks 23 дні тому

You're welcome! I'm glad it helped. 😄

@thornuridbahir8309 26 днів тому

About the recursion vs iteration: There is a whole class of algorithms that are impossible to implement without recursion. Famous example is Ackerman's function, Computerphile has a few great videos about that with prof. Brailsford. Also there are algorithms that are simply easier to implement recursively than iteratively, for example graph/tree exploration. Edit: I have been corrected, apparently all recursion can be implement with loops. But the second part is correct, some of them are so complicated it is way easier and more practical to do them recursively.

@gamekiller0123 26 днів тому

Any recursive function can be written without recursion, for example by simulating the call stack with a vector, though you might need to use while loops. Ackermann's function is one such function that requires while loops (or recursion). This is of theoretical interest because use of general recursion and while loops makes it more difficult to reason about termination and runtime. Well founded recursion can help reason about termination, but not about runtime. This is more of a theoretic consideration though. What's important is the readability, maintainability and utility of production code, which Ackermann's function is not going to be part of. I agree with your tree example.

@thornuridbahir8309 26 днів тому

@@gamekiller0123 Interesting. I was under the impression that there is a class of algorithms that can not be de-recursed, based on this video: ukposts.info/have/v-deo/oWekoW-bsXylpn0.html (especially first 40 seconds). But maybe I misunderstood, I'm not an expert in this area.

@gamekiller0123 26 днів тому

@@thornuridbahir8309 He did explicitly mention for loops a few times. For the final statement "Well, there are some things which are so fundamentally recursive that you just have to do them recursively" he's likely working in a computational model where there are no while loops, or considers while loops comparable to recursion. Or maybe he was just a bit imprecise there.

@thornuridbahir8309 26 днів тому

@@gamekiller0123 oh I see, i didn't differentiate for loop and while loop. Now looking back, it should be obvious that while loops are more powerful. Thanks, I learned something new today.

@stevenhe3462 25 днів тому

All recursion algorithms can be implemented with loops, proof by Turing-completeness. However, the loop implementation is disgusting sometimes.

@lapissea1190 25 днів тому

A quite simple and practical example of why you would use recursive async functions would be to delete a large folder with multiple threads. If you were to do it in a loop you would need to set up a queue and collectors and write logic to determining what files can be deleted when. With a recursive delete you simply iterate over every child of a folder and call delte recursively then finally delete the folder. All of the logic and scheduling is done by recursion implicitly.

@NathanStocks 23 дні тому

Alright. So what I'm hearing is "for algorithmic simplicity". I can buy that.

@lapissea1190 23 дні тому

@@NathanStocks Yep! I mean from my experience recursive vs loop solution usually comes down to... do you have a tree like data structure and are you concerned about stack depth.

@NathanStocks 23 дні тому

@@lapissea1190 I tried recursion a couple times early on in my career in Python -- maxed out stack depth each time. 🤣

@lapissea1190 23 дні тому

@@NathanStocks Oof yeah. I have plenty of bad experiences with python. Maybe because I'm a bit of a performance nut and like to optimize things

@tserica 2 дні тому

One really important use for recursive calls is compilers.

@NathanStocks День тому

Ah, interesting!

@metaltyphoon 26 днів тому

3:23 it seems strip removes debuginfo and symbols. So stack traces won’t have line numbers or function names.

@Luxalpa 25 днів тому

I think the file, line and column numbers will still be in there with strip=true and need -Zlocation-detail=none to get removed

@NathanStocks 23 дні тому

Y'all are going to tantalize me with possibilities until I go and do the research myself to find out for sure, aren't you? 😆

@RobertoGimenez 24 дні тому

Well recursion makes the code simpler in many cases.

@MasterHigure 25 днів тому

If you're depth-first traversing any kind of branched structure, recursion might be a lot simpler to code, because it handles all the backtracking for you correctly, you will at most need to manually code how to undo a single step. No off-by-one errors on how far to step back, no fear of mixing things up when backtracking many messy steps, easier to remember to go down all paths.

@RodrigoCorreaAlves 17 днів тому

Oh boy recursive `async fn` is huge! One use case for recursive fn is when you are talking to another stateful service and needs to 'redirect' the request to another upstream server

@NathanStocks 17 днів тому

Interesting! I haven't considered that case before.

@rolandburgstaller10 25 днів тому

Regarding recursion: NURBS curves and surfaces (massively used in industry) are defined by recursive basis functions, so to evaluate them, it can be useful to do so recursively.

@NathanStocks 23 дні тому

TIL about Non-Uniform Rational B-Splines modeling. Sounds like you are saying that using recursion is a simpler way to model recursive concepts. Makes sense, thanks! 😄

@VivekYadav-ds8oz 24 дні тому

6:43 Isn't that breaking backwards-compatibility?

@DeathSugar 25 днів тому

> Rust logo not affiliated with the Rust Foundation

@NathanStocks 23 дні тому

Are you asking a question? Or...?

@DeathSugar 23 дні тому

@@NathanStocks just memeing around

@JohnPywtorak 24 дні тому

Isn’t Cow clone on write? Not copy. Oops @12 or so min 12:00

@NathanStocks 17 днів тому

Ha! You caught me. It's totally clone-on-write. My bad!

@VivekYadav-ds8oz 24 дні тому

10:08 Anyone else feel uncomfortable by this? If it was an exception for warnings, that would've seemed reasonable. But errors protect the parse and semantic rules of a language. So we're literally breaking the language for a project? It's pragmatic sure, but it feels... wrong and unfair. Should've just not introduced the error till Bevy got patched.

@NathanStocks 17 днів тому

I held off replying to see if we would get any other comments first, but it looks like we're not going to get any. I do not feel that way at all. I view this as *not* breaking the language for a specific project. I'm not sure how breaking a large, popular project unnecessarily would be the "right and fair" choice. Take a look at the projects affected by this change. From what I can tell, the list consists entirely of Bevy and projects that use Bevy: crater-reports.s3.amazonaws.com/pr-109482-1/retry-regressed-list.txt

@joseoncrack 26 днів тому

Rust 1.77! Brand new! Now with even bigger chunks of pineapple!

@NathanStocks 17 днів тому

I'm...at a loss for words. Is this from a meme or something, or just a random statement? I mean, I do like grilled pineapple...😄

@joseoncrack 17 днів тому

@@NathanStocks I don't think it's a meme, or maybe this will be starting one! I was just gently making fun of the Rust development cycle, and the kind of marketing that tends to go around it. Glad you like grilled pineapple, so that has resonated with you at least on some level.😁

@NathanStocks 17 днів тому

@@joseoncrack Ah, okay. I get it. Also, grilled pineapple is a must at any cookout. Pairs well with...everything. 😉