Stabilize slice::strip_prefix and slice::strip_suffix
These two methods are useful. The corresponding methods on `str` are already stable.
I believe that stablising these now would not get in the way of, in the future, extending these to take a richer pattern API a la `str`'s patterns.
Tracking PR: #73413. I also have an outstanding PR to improve the docs for these two functions and the corresponding ones on `str`: #75078
I have tried to follow the [instructions in the dev guide](https://rustc-dev-guide.rust-lang.org/stabilization_guide.html#stabilization-pr). The part to do with `compiler/rustc_feature` did not seem applicable. I assume that's because these are just library features, so there is no corresponding machinery in rustc.
The size assertion in the comment was inverted compared to the code. After fixing that the implication that `(new_size >= old_size) => new_size != 0` still doesn't hold so explain why `old_size != 0` at this point.
Change:
```
`parse` can parse any type that...
```
to:
```
`parse` can parse into any type that...
```
Word `into` added to be more precise and in coherence with other parts of the doc.
This also eliminates a use of a `Path` convenience function, in support
of #80741, refactoring `std::path` to focus on pure data structures and
algorithms.
This allows us to return borrows of the captured backtrace frames
that are tied to a borrow of the Backtrace itself, instead of to
some short-lived Mutex guard.
It also makes it semantically clearer what synchronization is needed
on the capture.
Add more code spans to docs in intrinsics.rs
I have added some more code spans in core/src/intrinsics.rs, changing some `=` to `==`, etc. I also changed the wording in some sections.
remove allow(incomplete_features) from std
cc https://github.com/rust-lang/rust/pull/80349#issuecomment-753357123
> Now I am somewhat concerned that the standard library uses some of these features...
I think it is theoretically ok to use incomplete features in the standard library or the compiler if we know that there is an already working subset and we explicitly document what we have to be careful about. Though at that point it is probably better to try and split the incomplete feature into two separate ones, similar to `min_specialization`.
Will be interesting once `feature(const_evaluatable_checked)` works well enough to imo be used in the compiler but not yet well enough to be removed from `INCOMPLETE_FEATURES`.
r? `@RalfJung`
Add docs note about `Any::type_id` on smart pointers
Fixes#79868.
There's an issue I've run into a couple times while using values of type `Box<dyn Any>` - essentially, calling `value.type_id()` doesn't dereference to the trait object, but uses the implementation of `Any` for `Box<dyn Any>`, giving us the `TypeId` of the container instead of the object inside it.
I couldn't find any notes about this in the documentation and - while it could be inferred from existing knowledge of Rust and the blanket implemenation of `Any` - I think it'd be nice to have a note about it in the documentation for the `any` module.
Anyways, here's a first draft of a section about it. I'm happy to revise wording :)
Remove many unnecessary manual link resolves from library
Now that #76934 has merged, we can remove a lot of these! E.g, this is
no longer necessary:
[`Vec<T>`]: Vec
cc `@jyn514`
The return of the GroupBy and GroupByMut iterators on slice
According to https://github.com/rust-lang/rfcs/pull/2477#issuecomment-742034372, I am opening this PR again, this time I implemented it in safe Rust only, it is therefore much easier to read and is completely safe.
This PR proposes to add two new methods to the slice, the `group_by` and `group_by_mut`. These two methods provide a way to iterate over non-overlapping sub-slices of a base slice that are separated by the predicate given by the user (e.g. `Partial::eq`, `|a, b| a.abs() < b.abs()`).
```rust
let slice = &[1, 1, 1, 3, 3, 2, 2, 2];
let mut iter = slice.group_by(|a, b| a == b);
assert_eq!(iter.next(), Some(&[1, 1, 1][..]));
assert_eq!(iter.next(), Some(&[3, 3][..]));
assert_eq!(iter.next(), Some(&[2, 2, 2][..]));
assert_eq!(iter.next(), None);
```
[An RFC](https://github.com/rust-lang/rfcs/pull/2477) was open 2 years ago but wasn't necessary.
Remove all doc_comment!{} hacks by using #[doc = expr] where needed.
This replaces about 200 cases of
`````rust
doc_comment! {
concat!("The smallest value that can be represented by this integer type.
# Examples
Basic usage:
```
", $Feature, "assert_eq!(", stringify!($SelfT), "::MIN, ", stringify!($Min), ");",
$EndFeature, "
```"),
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MIN: Self = !0 ^ ((!0 as $UnsignedT) >> 1) as Self;
}
`````
by
```rust
/// The smallest value that can be represented by this integer type.
///
/// # Examples
///
/// Basic usage:
///
/// ```
#[doc = concat!("assert_eq!(", stringify!($SelfT), "::MIN, ", stringify!($Min), ");")]
/// ```
#[stable(feature = "assoc_int_consts", since = "1.43.0")]
pub const MIN: Self = !0 ^ ((!0 as $UnsignedT) >> 1) as Self;
```
---
**Note:** For a usable diff, make sure to enable 'ignore whitspace': https://github.com/rust-lang/rust/pull/79150/files?diff=unified&w=1
