make is_power_of_two a const function
This makes `is_power_of_two` a const function by using `&` instead of short-circuiting `&&`; Rust supports bitwise `&` for `bool` and short-circuiting is not required in the existing expression.
I don't think this needs a const-hack label as I don't find the changed code less readable, if anything I prefer that it is clearer that short circuiting is not used.
@oli-obk
Remove leading :: from paths in doc examples
Noted some pre-2018 path syntax in the doc examples, for example:
https://doc.rust-lang.org/std/process/fn.exit.html
```rust
fn main() {
::std::process::exit(match run_app() {
Ok(_) => 0,
...
```
Couldn't find an existing issue on this (then again, "::" makes for an annoying thing to search for) so if there is already something fixing this and/or there's a reason to not fix it, just close this PR.
(Also fixed indentation in the `process::exit()` docs)
Remove unneeded `ref` from docs
Will reduce confusion like in https://users.rust-lang.org/t/help-understanding-the-ref-t-syntax/33779 since match ergonomics means you (almost) never have to say `ref` anymore!
There might be more like this, but I don't have a checkout on my computer right this second and I'm on slow wifi and GitHub search isn't powerful enough and that's my story.
Inline `ptr::null(_mut)` even in debug builds
I think we should treat `ptr::null(_mut)` as a constant. As It may help reduce code size
in debug build.
See godbolt link: https://godbolt.org/z/b9YMtD
properly document panics in div_euclid and rem_euclid
For signed numbers, document that `div_euclid` and `rem_euclid` panic not just when `rhs` is 0, but also when the division overflows.
For unsigned numbers, document that `div_euclid` and `rem_euclid` panic when `rhs` is 0.
Always inline `mem::{size_of,align_of}` in debug builds
Those two are const fn and do not have any arguments. Inlining
helps reducing generated code size in debug builds.
See also #64996.
Move debug_map assertions after check for err
Fixes#65231
We have some assertions in `DebugMap` to catch broken implementations of `Debug` that produce malformed entries. These checks don't make sense if formatting fails partway through. This PR moves those assertions to within the `and_then` closures along with the other formatting logic, so they're only checked if the map hasn't failed to format an entry already.
- Compatible with Emscripten 1.38.46-upstream or later upstream.
- Refactors the Emscripten target spec to share code with other wasm
targets.
- Replaces the old incorrect wasm32 C call ABI with the correct one,
preserving the old one as wasm32_bindgen_compat for wasm-bindgen
compatibility.
- Updates the varargs ABI used by Emscripten and deletes the old one.
- Removes the obsolete wasm32-experimental-emscripten target.
- Uses EMCC_CFLAGS on CI to avoid the timeout problems with #63649.
Add `dyn` to `Any` documentation
I noticed that in documentation to `Any` trait the old trait object syntax is used, which could be confusing for newcomers, since we generally recommend using `dyn Trait` instead of just `Trait`. This PR changes the documentation comment, so that it uses `&dyn Any`, `&mut dyn Any` and `Box<dyn Any>`, correspondingly.
Split non-CAS atomic support off into target_has_atomic_load_store
This PR implements my proposed changes in https://github.com/rust-lang/rust/issues/32976#issuecomment-518542029 by removing `target_has_atomic = "cas"` and splitting `target_has_atomic` into two separate `cfg`s:
* `target_has_atomic = 8/16/32/64/128`: This indicates the largest width that the target can atomically CAS (which implies support for all atomic operations).
* ` target_has_atomic_load_store = 8/16/32/64/128`: This indicates the largest width that the target can support loading or storing atomically (but may not support CAS).
cc #32976
r? @alexcrichton
I noticed that in documentation to `Any` trait the old trait object syntax is used, which could be confusing for newcomers, since we generally recommend using `dyn Trait` instead of just `Trait`. This PR changes the documentation comment, so that it uses `&dyn Any`, `&mut dyn Any` and `Box<dyn Any>`, correspondingly.
Improve docs on some char boolean methods
simple revival of #61794
(also rustfmt on rest of file :)
Documentation for `is_xid_start()` and `is_xid_continue()` couldn't be improved since both methods got remove from this repository
r? @dtolnay
cc @JohnCSimon
Make `Cell::new` method come first in documentation
Methods to create a thing usually comes first in `std` documentation, and `Cell` has been an exception. Also, `T: Copy` specialized methods should not be on top of the page. (This had led me to miss that most of its methods are not bounded by `Copy`...)
rewrite documentation for unimplemented! to clarify use
The current docs for `unimplemented!` seem to miss the point of this macro.
> This can be useful if you are prototyping and are just looking to have your code type-check, or if you're implementing a trait that requires multiple methods, and you're only planning on using one of them.
You could also return a `()` if you just want your code to type-check.
I think `unimplemented!` is useful for when you want your program to exit when it reaches an unimplemented area.
I rewrote the explanation and gave examples of both forms of this macro that I think clarify its use a little better.
Revert #63649 - "Upgrade Emscripten targets to use upstream LLVM backend"
This change caused the runtime of the linux-asmjs builder to nearly double from 2+ hours to about 4 hours, which happens to be the bors timeout. (It made it in barely under 4 hours when it was merged.) This is causing timeouts on all new changes.
This reverts commit 7870050796, reversing
changes made to 2e7244807a.
Stabilize `Option::as_deref` and `Option::as_deref_mut`
The tracking issue https://github.com/rust-lang/rust/issues/50264 still has unresolved question for the corresponding `Result` methods.
