…d docs

…arithmetic

Fix rust-lang#83550 regression

When the problem for a method not being found in its receiver is due to
arbitrary self-types, we don't want to mention importing or implementing
the trait, instead we suggest wrapping.

update comment at MaybeUninit::uninit_array

rust-lang#49147 is closed; this now instead needs inline const expressions (rust-lang#76001).

…st, r=dtolnay

Constantify some slice methods

Tracking issue: rust-lang#83570

This PR constantifies the following functions under feature `const_slice_first_last`:
- `slice::first`
- `slice::split_first`
- `slice::last`
- `slice::split_last`

Blocking on `#![feature(const_mut_refs)]`:
- `slice::first_mut`
- `slice::split_first_mut`
- `slice::last_mut`
- `slice::split_last_mut`

Improve pointer arithmetic docs

* Add slightly more detailed definition of "allocated object" to the module docs, and link it from everywhere.
* Clarify the "remains attached" wording a bit (at least I hope this is clearer).
* Remove the sentence about using integer arithmetic; this seems to confuse people even if it is technically correct.

As usual, the edit needs to be done in a dozen places to remain consistent, I hope I got them all.

Wrap non-pre code blocks

Fix rust-lang#83550 regression

```
$ cargo new --lib whitespace && cd whitespace && echo '//! `"   foo   "`' > src/lib.rs && cargo doc --open
```

Before

![](https://user-images.githubusercontent.com/89623/112713498-c0dfc200-8ed5-11eb-8c57-efdf26372e74.png)

After

![](https://user-images.githubusercontent.com/89623/112713538-f08eca00-8ed5-11eb-8a98-675179f60ae2.png)

r? ``@GuillaumeGomez``
cc ``@mgeisler``

Add a regression test for issue-82865

Closes rust-lang#82865
r? `@petrochenkov`

Update books

## reference

4 commits in d10a0af8dca25d9d548ca6a369fd66ad06acb3c9..fd97729e2d82f8b08d68a31c9bfdf0c37a7fd542
2021-03-21 11:14:06 -0700 to 2021-03-28 14:29:19 -0700
- Editorial cleanup on expressions (part 1) (rust-lang/reference#967)
- Update type casts section (rust-lang/reference#961)
- Add missing "?" notion (rust-lang/reference#989)
- Fix typo (rust-lang/reference#988)

## book

8 commits in fc2f690fc16592abbead2360cfc0a42f5df78052..b54090a99ec7c4b46a5203a9c927fdbc311bb1f5
2021-03-05 14:03:22 -0500 to 2021-03-24 11:21:46 -0500
- correct the signature of the `deref` method (rust-lang/book#2658)
- Clarify the immutability of a reference (rust-lang/book#2646)
- Tweak wording around Windows representation of enter
- Ch. 02 note - Enter results in CRLF on Windows (rust-lang/book#2648)
- Added an example of slicing result (rust-lang/book#2649)
- Fix word wrapping, mention dictionary.txt is also in the ci dir
- README: note that spellcheck.sh is in ci directory (rust-lang/book#2652)
- Change someurl.com to example.org (rust-lang/book#2655)

## rust-by-example

12 commits in eead22c6c030fa4f3a167d1798658c341199e2ae..29d91f591c90dd18fdca6d23f1a9caf9c139d0d7
2021-03-04 16:26:43 -0300 to 2021-03-23 09:03:39 -0300
- Unwrap some drinks. (rust-lang/rust-by-example#1431)
- doc(testcase_linked_list): add a little extra note about pattern (rust-lang/rust-by-example#1408)
- Update function name in comment (rust-lang/rust-by-example#1413)
- Fixes minor typo in src/types/cast.md (rust-lang/rust-by-example#1414)
- Add destructuring example to generics new type (rust-lang/rust-by-example#1416)
- update struct.md (rust-lang/rust-by-example#1419)
- fix name from rectangle to Rectangle (rust-lang/rust-by-example#1420)
- Typo "incures" in code comment (rust-lang/rust-by-example#1422)
- Changed impl to use Self::Item (rust-lang/rust-by-example#1425)
- Fix code highlighting in some places (rust-lang/rust-by-example#1427)
- Update multi_bounds.md (rust-lang/rust-by-example#1428)
- Reformulated text for redability (rust-lang/rust-by-example#1429)

## rustc-dev-guide

3 commits in 67ebd4b..0687daa
2021-03-11 13:36:25 -0800 to 2021-03-28 13:33:56 -0400
- Add notes about nightly rustc version for the rustc-driver examples
- Update rustc-driver-*.rs examples (rust-lang/rustc-dev-guide#1095)
- Fix rust compiler meeting info (rust-lang/rustc-dev-guide#1087)

## embedded-book

1 commits in f61685755fad7d3b88b4645adfbf461d500563a2..d3f2ace94d51610cf3e3c265705bb8416d37f8e4
2021-03-08 01:06:44 +0000 to 2021-03-17 07:53:09 +0000
- Add binary attribute to .jpeg files, closes rust-embedded/book#287  (rust-embedded/book#288)

Suggest box/pin/arc ing receiver on method calls

_Extracted from https://fasterthanli.me/articles/pin-and-suffering_