Minor changes to variable bindings chapter
* In "*... name as another binding, that's currently in scope, will ...*", *"
that's currently in scope"* is not a parenthetical element, and the commas
can be omitted.
* Other minor changes.
* In "... name as another binding, that's currently in scope, will ...", ",
that's currently in scope, " is not a parenthetical element, and the commas
can be omitted.
* Other minor changes.
Rename main thread from "<main>" to "main".
Fix issue #33789
We may need to discuss whether this counts as a breaking change since code may check the main thread name against "\<main\>". Discussion is in #33789
Fix a few links in the book
Links to directories and direct links to doc.rust-lang.org don't work properly
when viewing the docs offline so fix them.
r? @steveklabnik
Clarify the English translation of `?Sized`
* It wasn't clear whether `?Sized` meant "not `Sized`" or "`Sized` or not `Sized`". According to #rust IRC, it does indeed mean "`Sized` or not `Sized`".
* Use the same language as [Trait std::marker::Sized](https://doc.rust-lang.org/std/marker/trait.Sized.html) about how `Sized` is implicitly bound.
* Refer to the syntax as `?Sized`, since it's currently the only allowed trait that can follow `?`.
Book: small improvement to a table to make it clearer
This table is used as an example of four heap values where two of them got deallocated leaving a gap.
It also has stack variables.
Instead of four stack variables I propose three, that way there's no misleading connection between the number of stack variables and heap variables.
But more importantly: three of the four stack variables had the same name (**y**) which could be confusing to a beginner, I changed this as well.
* Use "special bound syntax" instead of "special syntax". `?Sized` is technically a "bound", but `?Sized` is specialized syntax that _only_ works with `Sized`, and no other Trait.
* Replace "constant size" with "sized".
* It wasn't clear whether `?Sized` meant "not `Sized`" or "`Sized` or not `Sized`". According to #rust IRC, it does indeed mean "`Sized` or not `Sized`".
* Use the same language as [Trait std::marker::Sized](https://doc.rust-lang.org/std/marker/trait.Sized.html) about how `Sized` is implicitly bound.
Rust syntax coloring for some ignore, should-panic and no-run snippets.
In the book, some code blocks were missing the `rust` specifier which is needed for them to highlight correctly.
Add a note about Higher-Ranked Trait Bounds in docs on Closures.
I hit a snag with lifetimes a few days ago and it wasn't until @birkenfeld pointed out Higher-Ranked Trait Bounds that I was able to solve the issue involving lifetimes on closure traits. This adds a small section in the book so that other users can find it.
r? @steveklabnik
When using closures that take references with explicit lifetimes sometimes
it's required to use where F: for<..> ... syntax to express the right
lifetimes. This adds a quick note to the docs so other users can discover
it as well.
trivial tweaks to documentation (book)
These are small things I found while reading through The Book. The `<hash>` and `panic!` lines are simply to improve readability, while I believe the proceeding/following distinction is a bug (but might be a English dialect distinction?).
I've read `rust/CONTRIBUTING`, i'm not sure if there is anything I need to do other than submit this PR.
r? @steveklabnik
rustdoc: remove artificial indentation of doctest code
The indentation makes the examples look nicer when printed (when is this done?), but breaks tests using multi-line string literals.
Fixes: #25944
book: fixup code in error handling tutorial
A few oversights happened while porting the example from docopt to getopts. I retraced all the steps, fixing code and description as necessary.
Fixes: #33422
Add armv7-linux-androideabi target
This PR adds `armv7-linux-androideabi` target that matches `armeabi-v7a` Android ABI, ~~downscales `arm-linux-androideabi` target to match `armeabi` Android ABI~~ (TBD later if needed).
This should allow us to get the best performance from every [Android ABI level](http://developer.android.com/ndk/guides/abis.html).
Currently existing target `arm-linux-androideabi` started gaining features out of the supported range of [android `armeabi`](http://developer.android.com/ndk/guides/abis.html). While android compiler does not use a different target for later supported `armv7` architecture, it has distinct ABI name `armeabi-v7a`. We decided to add rust target `armv7-linux-androideabi` to match it.
Note that `NEON`, `VFPv3-D32`, and `ThumbEE` instruction sets are not added, because not all android devices are guaranteed to support all or some of these, and [their availability should be checked at runtime](http://developer.android.com/ndk/guides/abis.html#v7a).
~~This reduces performance of existing `arm-linux-androideabi` and may make it _much_ slower (we are talking more than order of magnitude in some random ad-hoc fp benchmark that I did).~~
Part of #33278.
