Stabilise feature(never_type). Introduce feature(exhaustive_patterns)
This stabilizes `!`, removing the feature gate as well as the old defaulting-to-`()` behavior. The pattern exhaustiveness checks which were covered by `feature(never_type)` have been moved behind a new `feature(exhaustive_patterns)` gate.
Replace feature(never_type) with feature(exhaustive_patterns).
feature(exhaustive_patterns) only covers the pattern-exhaustives checks
that used to be covered by feature(never_type)
Move ascii::escape_default to libcore
As requested in #46409, the `ascii::escape_default` method has been added to the core library. All I did was copy over the `std::ascii` module file, remove the (redundant) `AsciiExt` trait, and change some of the documentation to match. None of the tests were changed.
I wasn't sure how to handle the annotations. For `EscapeDefault` and `escape_default()`, I changed them to `#[unstable(feature = "core_ascii", issue = "46409")]`. Is that alright? Or should I leave them as they were?
Required moving all fulldeps tests depending on `rand` to different locations as
now there's multiple `rand` crates that can't be implicitly linked against.
Add a potential cause raising `ParseIntError`.
Initially, I wanted to add it directly to the documentation of `str. parse()` method, I finally found that it was more relevant (I hope so?) to directly document the structure in question. I've added a scenario, in which we could all get caught at least once, to make it easier to diagnose the problem when parsing integers.
Stabilize FusedIterator
FusedIterator is a marker trait that promises that the implementing
iterator continues to return `None` from `.next()` once it has returned
`None` once (and/or `.next_back()`, if implemented).
The effects of FusedIterator are already widely available through
`.fuse()`, but with stable `FusedIterator`, stable Rust users can
implement this trait for their iterators when appropriate.
Closes#35602
Add functions for reversing the bit pattern in an integer
I'm reviving PR #32798 now that the LLVM issues have been resolved.
> This adds the bitreverse intrinsic and adds a reverse_bits function to all integer types.
Slight modification to the as_ref example of std::option::Option
A user in a reddit thread was confused by the name of the variable
"num_as_int"; they thought the example was trying to convert the
string "10" as if it were binary 2 by calling str::len(). In reality,
the example is simply demonstrating how to take an immutable reference
to the value of an Option. The confusion comes from the coincidence
that the length of the string "10" is also its binary representation,
and the implication from the variable names that a conversion was
occuring ("num_as_str" to "num_as_int").
This PR changes the example number to 12 instead of 10, and changes
the variable name from "num_as_int" to "num_length" to better
communicate what the example is doing.
The reddit thread:
https://www.reddit.com/r/rust/comments/7zpvev/notyetawesome_rust_what_use_cases_would_you_like/dur39xw/
The error was:
```
[00:05:25] tidy error: /checkout/src/libcore/num/mod.rs:3848: trailing whitespace
[00:05:25] tidy error: /checkout/src/libcore/num/mod.rs:3851: line longer than 100 chars
[00:05:25] tidy error: /checkout/src/libcore/num/mod.rs:3851: trailing whitespace
[00:05:26] some tidy checks failed
```
The line was truncated to 92 characters.
Initially, I wanted to add it directly to the documentation of `str. parse()' method, I finally found that it was more relevant (I hope so?) to directly document the structure in question. I've added a scenario, in which we could all get caught at least once, to make it easier to diagnose the problem when parsing integers.
