Fix double import in wasm thread
The `unsupported` type is imported two times, as `super::unsupported` and as `crate::sys::unsupported`, throwing an error. Remove `super::unsupported` in favor of the other.
As reported in #86802.
Fix#86802
Remove & from Command::args calls in documentation
Now that arrays implement `IntoIterator`, using `&` is no longer necessary. This makes examples easier to understand.
Merge `sys_common::bytestring` back into `os_str_bytes`
`bytestring` contains code for correctly debug formatting a byte slice (`[u8]`). This functionality is and has historically only been used to provide the debug formatting of byte-based os-strings (on unix etc.).
Having this functionality in the separate `bytestring` module was useful in the past to reduce duplication, as [when it was added](https://github.com/rust-lang/rust/pull/46798) `os_str_bytes` was still split into `sys::{unix, redox, wasi, etc.}::os_str`. However, now that is no longer the case, there is not much reason for the `bytestring` functionality to be separate from `os_str_bytes`; I don't think it is very likely that another part of std will need to handle formatting byte strings that are not os-strings in the future (everything should be `utf8`). This is why this PR merges the functionality of `bytestring` directly into the debug implementation in `os_str_bytes`.
add `track_path::path` fn for usage in `proc_macro`s
Adds a way to declare a dependency on external files without including them, to either re-trigger the build of a file as well as covering the use case of including dependencies within the `rustc` invocation, such that tools like `sccache`/`cachepot` are able to handle references to external files which are not included.
Ref #73921
The `unsupported` type is imported two times, as `super::unsupported` and as `crate::sys::unsupported`, throwing an error. Remove `super::unsupported` in favor of the other.
Add linked list cursor end methods
I add several methods to `LinkedList::CursorMut` and `LinkedList::Cursor`. These methods allow you to access/manipulate the ends of a list via the cursor. This is especially helpful when scanning through a list and reordering. For example:
```rust
let mut c = ll.back_cursor_mut();
let mut moves = 10;
while c.current().map(|x| x > 5).unwrap_or(false) {
let n = c.remove_current();
c.push_front(n);
if moves > 0 { break; } else { moves -= 1; }
}
```
I encountered this problem working on my bachelors thesis doing graph index manipulation.
While this problem can be avoided by splicing, it is awkward. I asked about the problem [here](https://internals.rust-lang.org/t/linked-list-cursurmut-missing-methods/14921/4) and it was suggested I write a PR.
All methods added consist of
```rust
Cursor::front(&self) -> Option<&T>;
Cursor::back(&self) -> Option<&T>;
CursorMut::front(&self) -> Option<&T>;
CursorMut::back(&self) -> Option<&T>;
CursorMut::front_mut(&mut self) -> Option<&mut T>;
CursorMut::back_mut(&mut self) -> Option<&mut T>;
CursorMut::push_front(&mut self, elt: T);
CursorMut::push_back(&mut self, elt: T);
CursorMut::pop_front(&mut self) -> Option<T>;
CursorMut::pop_back(&mut self) -> Option<T>;
```
#### Design decisions:
I tried to remain as consistent as possible with what was already present for linked lists.
The methods `front`, `front_mut`, `back` and `back_mut` are identical to their `LinkedList` equivalents.
I tried to make the `pop_front` and `pop_back` methods work the same way (vis a vis the "ghost" node) as `remove_current`. I thought this was the closest analog.
`push_front` and `push_back` do not change the "current" node, even if it is the "ghost" node. I thought it was most intuitive to say that if you add to the list, current will never change.
Any feedback would be welcome 😄
Redefine `ErrorKind::Other` and stop using it in std.
This implements the idea I shared yesterday in the libs meeting when we were discussing how to handle adding new `ErrorKind`s to the standard library: This redefines `Other` to be for *user defined errors only*, and changes all uses of `Other` in the standard library to a `#[doc(hidden)]` and permanently `#[unstable]` `ErrorKind` that users can not match on. This ensures that adding `ErrorKind`s at a later point in time is not a breaking change, since the user couldn't match on these errors anyway. This way, we use the `#[non_exhaustive]` property of the enum in a more effective way.
Open questions:
- How do we check this change doesn't cause too much breakage? Will a crate run help and be enough?
- How do we ensure we don't accidentally start using `Other` again in the standard library? We don't have a `pub(not crate)` or `#[deprecated(in this crate only)]`.
cc https://github.com/rust-lang/rust/pull/79965
cc `@rust-lang/libs` `@ijackson`
r? `@dtolnay`
Use HTTPS links where possible
While looking at #86583, I wondered how many other (insecure) HTTP links were in `rustc`. This changes most other `http` links to `https`. While most of the links are in comments or documentation, there are a few other HTTP links that are used by CI that are changed to HTTPS.
Notes:
- I didn't change any to or in licences
- Some links don't support HTTPS :(
- Some `http` links were dead, in those cases I upgraded them to their new places (all of which used HTTPS)
Use `#[non_exhaustive]` where appropriate
Due to the std/alloc split, it is not possible to make `alloc::collections::TryReserveError::AllocError` non-exhaustive without having an unstable, doc-hidden method to construct (which negates the benefits from `#[non_exhaustive]`).
`@rustbot` label +C-cleanup +T-libs +S-waiting-on-review
Add `BuildHasher::hash_one` as unstable
Inspired by https://github.com/rust-lang/rust/pull/86140/files#diff-246941135168fbc44fce120385ee9c3156e08a1c3e2697985b56dcb8d728eedeR2416, where I wanted to write a quick test for a `Hash` implementation and it took more of a dance than I'd hoped.
It looks like this would be handy in hashtable implementations, too -- a quick look at hashbrown found two places where it needs to do the same dance:
6302512a8a/src/map.rs (L247-L270)
I wanted to get a "seems plausible" from a libs member before making a tracking issue, so random-sampling the intersection of highfive and governance gave me...
r? `@joshtriplett`
(As always, bikeshed away! And let me know if I missed something obvious again that I should have used instead.)
Due to the std/alloc split, it is not possible to make
`alloc::collections::TryReserveError::AllocError` non-exhaustive without
having an unstable, doc-hidden method to construct (which negates the
benefits from `#[non_exhaustive]`.
Document associativity of iterator folds.
Document the associativity of `Iterator::fold` and
`DoubleEndedIterator::rfold` and add examples demonstrating this.
Add links to direct users to the fold of the opposite associativity.
Better errors for Debug and Display traits
Currently, if someone tries to pass value that does not implement `Debug` or `Display` to a formatting macro, they get a very verbose and confusing error message. This PR changes the error messages for missing `Debug` and `Display` impls to be less overwhelming in this case, as suggested by #85844. I was a little less aggressive in changing the error message than that issue proposed. Still, this implementation would be enough to reduce the number of messages to be much more manageable.
After this PR, information on the cause of an error involving a `Debug` or `Display` implementation would suppressed if the requirement originated within a standard library macro. My reasoning was that errors originating from within a macro are confusing when they mention details that the programmer can't see, and this is particularly problematic for `Debug` and `Display`, which are most often used via macros. It is possible that either a broader or a narrower criterion would be better. I'm quite open to any feedback.
Fixes#85844.
Add comments around code where ordering is important due for panic-safety
Iterators contain arbitrary code which may panic. Unsafe code has to be
careful to do its state updates at the right point between calls that may panic.
As requested in https://github.com/rust-lang/rust/pull/86452#discussion_r655153948
r? `@RalfJung`
Iterators contain arbitrary code which may panic. Unsafe code has to be
careful to do its state updates at the right point between calls
that may panic.