Fix parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp` #139357

miried · 2025-04-04T08:14:45Z

We saw a regression introduced in version 1.86 that seems to be coming from switching the order of v1 and v2 when calling comparison functions in min_by / max_by / minmax_by (cf. this PR: #136307)

When the compare function is not symmetric in the arguments, this leads to false results. Apparently, the test cases do not cover this scenario currently. While asymmetric comparison may be an edge case, but current behavior is unexpected nevertheless.

rustbot · 2025-04-04T08:14:49Z

r? @thomcc

rustbot has assigned @thomcc.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

miried · 2025-04-22T08:13:45Z

@thomcc please let me know if you have any suggestions

thomcc · 2025-04-24T17:13:58Z

Can you add a test covering this?

thomcc · 2025-04-24T17:19:29Z

Hi, I've nominated this because it's a behavioral change. I gather it reverts an earlier behavioral change that we made unintentionally.

miried · 2025-04-29T09:04:29Z

doctest added & rebased on latest master

Amanieu · 2025-04-30T18:55:38Z

We discussed this in the libs meeting. We would like to make this a documented guarantee. Could you update the documentation to actually guarantee that the ordering is preserved when passed to the closure?

@rfcbot merge

rfcbot · 2025-04-30T18:55:39Z

Team member @Amanieu has proposed to merge this. The next step is review by the rest of the tagged team members:

No concerns currently listed.

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for info about what commands tagged team members can give me.

scottmcm · 2025-05-01T17:49:06Z

I just want to emphasize that violating duality like this is already explicitly called out as "a logic error" in the trait documentation, and thus anyone writing things like this should expect that their garbage in will result in garbage out in various situations.

It's ok if we want to give something stronger for these functions, since we know that they only need one check (to the extent that the _by ones use FnOnce), but this should not be considered a more general guarantee about the order in which comparisons will be done in the library.

Also, this was an intentional change, since historically lt has worked better than le, as seen by things like #106107.

Hopefully it's better now, as a bunch of work has happened in rust and LLVM to try to improve things, but...

Amanieu · 2025-05-03T11:04:32Z

I just want to emphasize that violating duality like this is already explicitly called out as "a logic error" in the trait documentation, and thus anyone writing things like this should expect that their garbage in will result in garbage out in various situations.

These specific methods don't actually use the Ord trait: they use the given function to compare the arguments and produce an Ordering. Hence why we felt comfortable with providing this guarantee.

hanna-kruppe · 2025-05-03T12:11:51Z

Other similar methods like sort_by and binary_search_by (should) require the closure to work like a correct Ord::cmp method. It’s just {min,max}_by that can easily dispense with it because they can be boiled down to a single binary choice (cf. is_sorted_by where the closure literally returns a bool).

rfcbot · 2025-05-03T12:58:53Z

🔔 This is now entering its final comment period, as per the review above. 🔔

…n `std::cmp`

teor2345 · 2025-05-10T01:03:26Z

library/core/src/cmp.rs

 /// let result = cmp::min_by(1, -1, abs_cmp);
 /// assert_eq!(result, 1);
+///
+/// let rhs_abs_cmp = |x: &i32, y: &i32| x.cmp(&y.abs());


Should this be called out as an invalid comparison function?

The documentation currently does not rule it out explicitly, as far as I can tell. But it is better to clarify it either way.

I remember a way of marking code docs as a "bad example", but maybe that was the Rust Book only?

This example should just be removed. Examples should show how APIs are intended to be used and avoid bad examples. The line in the documentation is enough.

Amanieu · 2025-08-13T15:42:35Z

ping @miried

Could you please remove the examples that you added. We don't want to encourage bad patterns in our examples. The extra paragraph in the docs is enough.

Amanieu · 2025-08-13T15:42:40Z

@rustbot author

rustbot · 2025-08-13T15:42:44Z

Reminder, once the PR becomes ready for a review, use @rustbot ready.

rustbot · 2025-08-19T09:07:00Z

⚠️ Warning ⚠️

This PR is based on an upstream commit that is older than 28 days.

It's recommended to update your branch according to the rustc-dev-guide.

miried · 2025-08-19T11:06:20Z

@rustbot ready

Amanieu · 2025-08-19T14:13:54Z

@bors r+

bors · 2025-08-19T14:17:21Z

📌 Commit 36d309e has been approved by Amanieu

It is now in the queue for this repository.

Fix parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp` We saw a regression introduced in version `1.86` that seems to be coming from switching the order of `v1` and `v2` when calling `comparison` functions in `min_by` / `max_by` / `minmax_by` (cf. this PR: rust-lang#136307) When the `compare` function is not symmetric in the arguments, this leads to false results. Apparently, the test cases do not cover this scenario currently. While asymmetric comparison may be an edge case, but current behavior is unexpected nevertheless.

Rollup of 13 pull requests Successful merges: - #139357 (Fix parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp`) - #140314 (Rustdoc: typecheck scrape-examples.js) - #140794 (mention lint group in default level lint note) - #145006 (Clarify EOF handling for `BufRead::skip_until`) - #145252 (Demote x86_64-apple-darwin to Tier 2 with host tools) - #145359 (Fix bug where `rustdoc-js` tester would not pick the right `search.js` file if there is more than one) - #145381 (Implement feature `int_lowest_highest_one` for integer and NonZero types) - #145417 (std_detect: RISC-V platform guide documentation) - #145531 (Add runtime detection for APX-F and AVX10) - #145619 (`std_detect`: Use `rustc-std-workspace-*` to pull in `compiler-builtins`) - #145622 (Remove the std workspace patch for `compiler-builtins`) - #145623 (Pretty print the name of an future from calling async closure) - #145626 (add a fallback implementation for the `prefetch_*` intrinsics ) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of #139357 - miried:master, r=Amanieu Fix parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp` We saw a regression introduced in version `1.86` that seems to be coming from switching the order of `v1` and `v2` when calling `comparison` functions in `min_by` / `max_by` / `minmax_by` (cf. this PR: #136307) When the `compare` function is not symmetric in the arguments, this leads to false results. Apparently, the test cases do not cover this scenario currently. While asymmetric comparison may be an edge case, but current behavior is unexpected nevertheless.

Rollup of 13 pull requests Successful merges: - rust-lang/rust#139357 (Fix parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp`) - rust-lang/rust#140314 (Rustdoc: typecheck scrape-examples.js) - rust-lang/rust#140794 (mention lint group in default level lint note) - rust-lang/rust#145006 (Clarify EOF handling for `BufRead::skip_until`) - rust-lang/rust#145252 (Demote x86_64-apple-darwin to Tier 2 with host tools) - rust-lang/rust#145359 (Fix bug where `rustdoc-js` tester would not pick the right `search.js` file if there is more than one) - rust-lang/rust#145381 (Implement feature `int_lowest_highest_one` for integer and NonZero types) - rust-lang/rust#145417 (std_detect: RISC-V platform guide documentation) - rust-lang/rust#145531 (Add runtime detection for APX-F and AVX10) - rust-lang/rust#145619 (`std_detect`: Use `rustc-std-workspace-*` to pull in `compiler-builtins`) - rust-lang/rust#145622 (Remove the std workspace patch for `compiler-builtins`) - rust-lang/rust#145623 (Pretty print the name of an future from calling async closure) - rust-lang/rust#145626 (add a fallback implementation for the `prefetch_*` intrinsics ) r? `@ghost` `@rustbot` modify labels: rollup

Fix parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp` We saw a regression introduced in version `1.86` that seems to be coming from switching the order of `v1` and `v2` when calling `comparison` functions in `min_by` / `max_by` / `minmax_by` (cf. this PR: rust-lang#136307) When the `compare` function is not symmetric in the arguments, this leads to false results. Apparently, the test cases do not cover this scenario currently. While asymmetric comparison may be an edge case, but current behavior is unexpected nevertheless.

This MR contains the following updates: | Package | Update | Change | |---|---|---| | [rust](https://github.com/rust-lang/rust) | minor | `1.90.0` -> `1.91.0` | MR created with the help of [el-capitano/tools/renovate-bot](https://gitlab.com/el-capitano/tools/renovate-bot). **Proposed changes to behavior should be submitted there as MRs.** --- ### Release Notes <details> <summary>rust-lang/rust (rust)</summary> ### [`v1.91.0`](https://github.com/rust-lang/rust/blob/HEAD/RELEASES.md#Version-1910-2025-10-30) [Compare Source](rust-lang/rust@1.90.0...1.91.0) \========================== <a id="1.91.0-Language"></a> ## Language - [Lower pattern bindings in the order they're written and base drop order on primary bindings' order](rust-lang/rust#143764) - [Stabilize declaration of C-style variadic functions for `sysv64`, `win64`, `efiapi`, and `aapcs` ABIs](rust-lang/rust#144066). This brings these ABIs in line with the C ABI: variadic functions can be declared in extern blocks but not defined. - [Add `dangling_pointers_from_locals` lint to warn against dangling pointers from local variables](rust-lang/rust#144322) - [Upgrade `semicolon_in_expressions_from_macros` from warn to deny](rust-lang/rust#144369) - [Stabilize LoongArch32 inline assembly](rust-lang/rust#144402) - [Add warn-by-default `integer_to_ptr_transmutes` lint against integer-to-pointer transmutes](rust-lang/rust#144531) - [Stabilize `sse4a` and `tbm` target features](rust-lang/rust#144542) - [Add `target_env = "macabi"` and `target_env = "sim"` cfgs](rust-lang/rust#139451) as replacements for the `target_abi` cfgs with the same values. <a id="1.91.0-Compiler"></a> ## Compiler - [Don't warn on never-to-any `as` casts as unreachable](rust-lang/rust#144804) <a id="1.91.0-Platform-Support"></a> ## Platform Support - [Promote `aarch64-pc-windows-gnullvm` and `x86_64-pc-windows-gnullvm` to Tier 2 with host tools.](rust-lang/rust#143031) Note: llvm-tools and MSI installers are missing but will be added in future releases. - [Promote `aarch64-pc-windows-msvc` to Tier 1](rust-lang/rust#145682) Refer to Rust's [platform support page][platform-support-doc] for more information on Rust's tiered platform support. [platform-support-doc]: https://doc.rust-lang.org/rustc/platform-support.html <a id="1.91.0-Libraries"></a> ## Libraries - [Print thread ID in panic message](rust-lang/rust#115746) - [Fix overly restrictive lifetime in `core::panic::Location::file` return type](rust-lang/rust#132087) - [Guarantee parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp`](rust-lang/rust#139357) - [Document assumptions about `Clone` and `Eq` traits](rust-lang/rust#144330) - [`std::thread`: Return error if setting thread stack size fails](rust-lang/rust#144210) This used to panic within the standard library. <a id="1.91.0-Stabilized-APIs"></a> ## Stabilized APIs - [`Path::file_prefix`](https://doc.rust-lang.org/stable/std/path/struct.Path.html#method.file_prefix) - [`AtomicPtr::fetch_ptr_add`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_ptr_add) - [`AtomicPtr::fetch_ptr_sub`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_ptr_sub) - [`AtomicPtr::fetch_byte_add`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_byte_add) - [`AtomicPtr::fetch_byte_sub`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_byte_sub) - [`AtomicPtr::fetch_or`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_or) - [`AtomicPtr::fetch_and`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_and) - [`AtomicPtr::fetch_xor`](https://doc.rust-lang.org/stable/std/sync/atomic/struct.AtomicPtr.html#method.fetch_xor) - [`{integer}::strict_add`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_add) - [`{integer}::strict_sub`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_sub) - [`{integer}::strict_mul`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_mul) - [`{integer}::strict_div`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.strict_div) - [`{integer}::strict_div_euclid`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.strict_div_euclid) - [`{integer}::strict_rem`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.strict_rem) - [`{integer}::strict_rem_euclid`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.strict_rem_euclid) - [`{integer}::strict_neg`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_neg) - [`{integer}::strict_shl`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_shl) - [`{integer}::strict_shr`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_shr) - [`{integer}::strict_pow`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_pow) - [`i{N}::strict_add_unsigned`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.strict_add_unsigned) - [`i{N}::strict_sub_unsigned`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.strict_sub_unsigned) - [`i{N}::strict_abs`](https://doc.rust-lang.org/stable/std/primitive.i32.html#method.strict_abs) - [`u{N}::strict_add_signed`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_add_signed) - [`u{N}::strict_sub_signed`](https://doc.rust-lang.org/stable/std/primitive.u32.html#method.strict_sub_signed) - [`PanicHookInfo::payload_as_str`](https://doc.rust-lang.org/stable/std/panic/struct.PanicHookInfo.html#method.payload_as_str) - [`core::iter::chain`](https://doc.rust-lang.org/stable/core/iter/fn.chain.html) - [`u{N}::checked_signed_diff`](https://doc.rust-lang.org/stable/std/primitive.u16.html#method.checked_signed_diff) - [`core::array::repeat`](https://doc.rust-lang.org/stable/core/array/fn.repeat.html) - [`PathBuf::add_extension`](https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#method.add_extension) - [`PathBuf::with_added_extension`](https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#method.with_added_extension) - [`Duration::from_mins`](https://doc.rust-lang.org/stable/std/time/struct.Duration.html#method.from_mins) - [`Duration::from_hours`](https://doc.rust-lang.org/stable/std/time/struct.Duration.html#method.from_hours) - [`impl PartialEq<str> for PathBuf`](https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#impl-PartialEq%3Cstr%3E-for-PathBuf) - [`impl PartialEq<String> for PathBuf`](https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#impl-PartialEq%3CString%3E-for-PathBuf) - [`impl PartialEq<str> for Path`](https://doc.rust-lang.org/stable/std/path/struct.Path.html#impl-PartialEq%3Cstr%3E-for-Path) - [`impl PartialEq<String> for Path`](https://doc.rust-lang.org/stable/std/path/struct.Path.html#impl-PartialEq%3CString%3E-for-Path) - [`impl PartialEq<PathBuf> for String`](https://doc.rust-lang.org/stable/std/string/struct.String.html#impl-PartialEq%3CPathBuf%3E-for-String) - [`impl PartialEq<Path> for String`](https://doc.rust-lang.org/stable/std/string/struct.String.html#impl-PartialEq%3CPath%3E-for-String) - [`impl PartialEq<PathBuf> for str`](https://doc.rust-lang.org/stable/std/primitive.str.html#impl-PartialEq%3CPathBuf%3E-for-str) - [`impl PartialEq<Path> for str`](https://doc.rust-lang.org/stable/std/primitive.str.html#impl-PartialEq%3CPath%3E-for-str) - [`Ipv4Addr::from_octets`](https://doc.rust-lang.org/stable/std/net/struct.Ipv4Addr.html#method.from_octets) - [`Ipv6Addr::from_octets`](https://doc.rust-lang.org/stable/std/net/struct.Ipv6Addr.html#method.from_octets) - [`Ipv6Addr::from_segments`](https://doc.rust-lang.org/stable/std/net/struct.Ipv6Addr.html#method.from_segments) - [`impl<T> Default for Pin<Box<T>> where Box<T>: Default, T: ?Sized`](https://doc.rust-lang.org/stable/std/default/trait.Default.html#impl-Default-for-Pin%3CBox%3CT%3E%3E) - [`impl<T> Default for Pin<Rc<T>> where Rc<T>: Default, T: ?Sized`](https://doc.rust-lang.org/stable/std/default/trait.Default.html#impl-Default-for-Pin%3CRc%3CT%3E%3E) - [`impl<T> Default for Pin<Arc<T>> where Arc<T>: Default, T: ?Sized`](https://doc.rust-lang.org/stable/std/default/trait.Default.html#impl-Default-for-Pin%3CArc%3CT%3E%3E) - [`Cell::as_array_of_cells`](https://doc.rust-lang.org/stable/std/cell/struct.Cell.html#method.as_array_of_cells) - [`u{N}::carrying_add`](https://doc.rust-lang.org/stable/std/primitive.u64.html#method.carrying_add) - [`u{N}::borrowing_sub`](https://doc.rust-lang.org/stable/std/primitive.u64.html#method.borrowing_sub) - [`u{N}::carrying_mul`](https://doc.rust-lang.org/stable/std/primitive.u64.html#method.carrying_mul) - [`u{N}::carrying_mul_add`](https://doc.rust-lang.org/stable/std/primitive.u64.html#method.carrying_mul_add) - [`BTreeMap::extract_if`](https://doc.rust-lang.org/stable/std/collections/struct.BTreeMap.html#method.extract_if) - [`BTreeSet::extract_if`](https://doc.rust-lang.org/stable/std/collections/struct.BTreeSet.html#method.extract_if) - [`impl Debug for windows::ffi::EncodeWide<'_>`](https://doc.rust-lang.org/stable/std/os/windows/ffi/struct.EncodeWide.html#impl-Debug-for-EncodeWide%3C'_%3E) - [`str::ceil_char_boundary`](https://doc.rust-lang.org/stable/std/primitive.str.html#method.ceil_char_boundary) - [`str::floor_char_boundary`](https://doc.rust-lang.org/stable/std/primitive.str.html#method.floor_char_boundary) - [`impl Sum for Saturating<u{N}>`](https://doc.rust-lang.org/stable/std/num/struct.Saturating.html#impl-Sum-for-Saturating%3Cu32%3E) - [`impl Sum<&Self> for Saturating<u{N}>`](https://doc.rust-lang.org/stable/std/num/struct.Saturating.html#impl-Sum%3C%26Saturating%3Cu32%3E%3E-for-Saturating%3Cu32%3E) - [`impl Product for Saturating<u{N}>`](https://doc.rust-lang.org/stable/std/num/struct.Saturating.html#impl-Product-for-Saturating%3Cu32%3E) - [`impl Product<&Self> for Saturating<u{N}>`](https://doc.rust-lang.org/stable/std/num/struct.Saturating.html#impl-Product%3C%26Saturating%3Cu32%3E%3E-for-Saturating%3Cu32%3E) These previously stable APIs are now stable in const contexts: - [`<[T; N]>::each_ref`](https://doc.rust-lang.org/stable/std/primitive.array.html#method.each_ref) - [`<[T; N]>::each_mut`](https://doc.rust-lang.org/stable/std/primitive.array.html#method.each_mut) - [`OsString::new`](https://doc.rust-lang.org/stable/std/ffi/struct.OsString.html#method.new) - [`PathBuf::new`](https://doc.rust-lang.org/stable/std/path/struct.PathBuf.html#method.new) - [`TypeId::of`](https://doc.rust-lang.org/stable/std/any/struct.TypeId.html#method.of) - [`ptr::with_exposed_provenance`](https://doc.rust-lang.org/stable/std/ptr/fn.with_exposed_provenance.html) - [`ptr::with_exposed_provenance_mut`](https://doc.rust-lang.org/stable/std/ptr/fn.with_exposed_provenance_mut.html) <a id="1.91.0-Cargo"></a> ## Cargo - 🎉 Stabilize `build.build-dir`. This config sets the directory where intermediate build artifacts are stored. These artifacts are produced by Cargo and rustc during the build process. End users usually won't need to interact with them, and the layout inside `build-dir` is an implementation detail that may change without notice. ([config doc](https://doc.rust-lang.org/stable/cargo/reference/config.html#buildbuild-dir)) ([build cache doc](https://doc.rust-lang.org/stable/cargo/reference/build-cache.html)) [#15833](rust-lang/cargo#15833) [#15840](rust-lang/cargo#15840) - The `--target` flag and the `build.target` configuration can now take literal `"host-tuple"` string, which will internally be substituted by the host machine's target triple. [#15838](rust-lang/cargo#15838) [#16003](rust-lang/cargo#16003) [#16032](rust-lang/cargo#16032) <a id="1.91.0-Rustdoc"></a> ## Rustdoc - [In search results, rank doc aliases lower than non-alias items with the same name](rust-lang/rust#145100) - [Raw pointers now work in type-based search like references](rust-lang/rust#145731). This means you can now search for things like `*const u8 ->`, and additionally functions that take or return raw pointers will now display their signature properly in search results. <a id="1.91.0-Compatibility-Notes"></a> ## Compatibility Notes - [Always require coroutine captures to be drop-live](rust-lang/rust#144156) - [Apple: Always pass SDK root when linking with `cc`, and pass it via `SDKROOT` env var](rust-lang/rust#131477). This should fix linking issues with `rustc` running inside Xcode. Libraries in `/usr/local/lib` may no longer be linked automatically, if you develop or use a crate that relies on this, you should explicitly set `cargo::rustc-link-search=/usr/local/lib` in a `build.rs` script. - [Relaxed bounds in associated type bound position like in `TraitRef<AssocTy: ?Sized>` are now correctly forbidden](rust-lang/rust#135331) - [Add unstable `#[sanitize(xyz = "on|off")]` built-in attribute that shadows procedural macros with the same name](rust-lang/rust#142681) - [Fix the drop checker being more permissive for bindings declared with let-else](rust-lang/rust#143028) - [Be more strict when parsing attributes, erroring on many invalid attributes](rust-lang/rust#144689) - [Error on invalid `#[should_panic]` attributes](rust-lang/rust#143808) - [Error on invalid `#[link]` attributes](rust-lang/rust#143193) - [Mark all deprecation lints in name resolution as deny-by-default and also report in dependencies](rust-lang/rust#143929) - The lint `semicolon_in_expressions_from_macros`, for `macro_rules!` macros in expression position that expand to end in a semicolon (`;`), is now deny-by-default. It was already warn-by-default, and a future compatibility warning (FCW) that warned even in dependencies. This lint will become a hard error in the future. - [Trait impl modifiers (e.g., `unsafe`, `!`, `default`) in inherent impls are no longer syntactically valid](rust-lang/rust#144386) - [Start reporting future breakage for `ill_formed_attribute_input` in dependencies](rust-lang/rust#144544) - [Restrict the scope of temporaries created by the macros `pin!`, `format_args!`, `write!`, and `writeln!` in `if let` scrutinees in Rust Edition 2024.](rust-lang/rust#145342) This applies [Rust Edition 2024's `if let` temporary scope rules](https://doc.rust-lang.org/edition-guide/rust-2024/temporary-if-let-scope.html) to these temporaries, which previously could live past the `if` expression regardless of Edition. - [Invalid numeric literal suffixes in tuple indexing, tuple struct indexing, and struct field name positions are now correctly rejected](rust-lang/rust#145463) - [Closures marked with the keyword `static` are now syntactically invalid](rust-lang/rust#145604) - [Shebangs inside `--cfg` and `--check-cfg` arguments are no longer allowed](rust-lang/rust#146211) - [Add future incompatibility lint for temporary lifetime shortening in Rust 1.92](rust-lang/rust#147056) Cargo compatibility notes: - `cargo publish` no longer keeps `.crate` tarballs as final build artifacts when `build.build-dir` is set. These tarballs were previously included due to an oversight and are now treated as intermediate artifacts. To get `.crate` tarballs as final artifacts, use `cargo package`. In a future version, this change will apply regardless of `build.build-dir`. [#15910](rust-lang/cargo#15910) - Adjust Cargo messages to match rustc diagnostic style. This changes some of the terminal colors used by Cargo messages. [#15928](rust-lang/cargo#15928) - Tools and projects relying on the [internal details of Cargo's `build-dir`](https://doc.rust-lang.org/cargo/reference/build-cache.html) may not work for users changing their `build-dir` layout. For those doing so, we'd recommend proactively testing these cases particularly as we are considering changing the default location of the `build-dir` in the future ([cargo#16147](rust-lang/cargo#16147)). If you can't migrate off of Cargo's internal details, we'd like to learn more about your use case as we prepare to change the layout of the `build-dir` ([cargo#15010](rust-lang/cargo#15010)). <a id="1.91.0-Internal-Changes"></a> ## Internal Changes These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools. - [Update to LLVM 21](rust-lang/rust#143684) </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever MR becomes conflicted, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this MR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this MR, check this box --- This MR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).

rustbot assigned thomcc Apr 4, 2025

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 4, 2025

miried changed the title ~~Fix parameter order for _by() variants of min / max/ minmax i…~~ Fix parameter order for _by() variants of min / max/ minmax in std::cmp Apr 4, 2025

thomcc added regression-from-stable-to-stable Performance or correctness regression from one stable version to another. I-libs-nominated Nominated for discussion during a libs team meeting. labels Apr 24, 2025

rustbot added the I-prioritize Issue: Indicates that prioritization has been requested for this issue. label Apr 24, 2025

miried force-pushed the master branch from 2d2486d to f5a4bb6 Compare April 29, 2025 09:02

rfcbot added proposed-final-comment-period Proposed to merge/close by relevant subteam, see T-<team> label. Will enter FCP once signed off. disposition-merge This issue / PR is in PFCP or FCP with a disposition to merge it. labels Apr 30, 2025

rfcbot added final-comment-period In the final comment period and will be merged soon unless new substantive objections are raised. and removed proposed-final-comment-period Proposed to merge/close by relevant subteam, see T-<team> label. Will enter FCP once signed off. labels May 3, 2025

Fix parameter order for _by() variants of min / max/ minmax i…

1ddb4d0

…n `std::cmp`

miried force-pushed the master branch from f5a4bb6 to 1ddb4d0 Compare May 5, 2025 11:20

teor2345 reviewed May 10, 2025

View reviewed changes

rustbot assigned Amanieu and unassigned thomcc Jul 16, 2025

rustbot 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 Aug 13, 2025

Remove hs_abs_cmp examples

41d8d85

Merge remote-tracking branch 'upstream/master'

36d309e

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Aug 19, 2025

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-review Status: Awaiting review from the assignee but also interested parties. labels Aug 19, 2025

jhpratt mentioned this pull request Aug 19, 2025

Rollup of 9 pull requests #145636

Closed

This was referenced Aug 19, 2025

Rollup of 8 pull requests #145638

Closed

Rollup of 13 pull requests #145644

Merged

bors merged commit a6d648f into rust-lang:master Aug 20, 2025
10 checks passed

rustbot added this to the 1.91.0 milestone Aug 20, 2025

Mark-Simulacrum mentioned this pull request Sep 25, 2025

Draft release notes for 1.91 #147010

Closed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Fix parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp` #139357

Fix parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp` #139357

Uh oh!

miried commented Apr 4, 2025 •

edited

Loading

rustbot commented Apr 4, 2025

miried commented Apr 22, 2025

thomcc commented Apr 24, 2025

thomcc commented Apr 24, 2025

miried commented Apr 29, 2025

Amanieu commented Apr 30, 2025

rfcbot commented Apr 30, 2025 •

edited by joshtriplett

Loading

scottmcm commented May 1, 2025

Amanieu commented May 3, 2025

hanna-kruppe commented May 3, 2025

rfcbot commented May 3, 2025

teor2345 May 10, 2025

miried May 12, 2025

teor2345 May 12, 2025

Amanieu Jul 16, 2025

Amanieu commented Aug 13, 2025

Amanieu commented Aug 13, 2025

rustbot commented Aug 13, 2025

rustbot commented Aug 19, 2025

miried commented Aug 19, 2025

Amanieu commented Aug 19, 2025

bors commented Aug 19, 2025

Uh oh!

Labels

10 participants

Fix parameter order for _by() variants of min / max/ minmax in std::cmp #139357

Fix parameter order for _by() variants of min / max/ minmax in std::cmp #139357

Uh oh!

Conversation

miried commented Apr 4, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

rustbot commented Apr 4, 2025

miried commented Apr 22, 2025

thomcc commented Apr 24, 2025

thomcc commented Apr 24, 2025

miried commented Apr 29, 2025

Amanieu commented Apr 30, 2025

rfcbot commented Apr 30, 2025 • edited by joshtriplett Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

scottmcm commented May 1, 2025

Amanieu commented May 3, 2025

hanna-kruppe commented May 3, 2025

rfcbot commented May 3, 2025

teor2345 May 10, 2025

Choose a reason for hiding this comment

miried May 12, 2025

Choose a reason for hiding this comment

teor2345 May 12, 2025

Choose a reason for hiding this comment

Amanieu Jul 16, 2025

Choose a reason for hiding this comment

Amanieu commented Aug 13, 2025

Amanieu commented Aug 13, 2025

rustbot commented Aug 13, 2025

rustbot commented Aug 19, 2025

miried commented Aug 19, 2025

Amanieu commented Aug 19, 2025

bors commented Aug 19, 2025

Uh oh!

Labels

10 participants

Fix parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp` #139357

Fix parameter order for `_by()` variants of `min` / `max`/ `minmax` in `std::cmp` #139357

miried commented Apr 4, 2025 •

edited

Loading

rfcbot commented Apr 30, 2025 •

edited by joshtriplett

Loading