Update BufWriter example to include call to flush()
I was playing with a writing a Huffman encoder/decoder and was getting weird corruptions and truncations. I finally realized it was was because `BufWriter` was swallowing write errors 😬. I've found Rust to generally be explicit and err on the safe side, so I definitely found this unintuitive and not "rustic".
https://twitter.com/johnterickson/status/1159514988123312128
std: Remove the `wasm_syscall` feature
This commit removes the `wasm_syscall` feature from the
wasm32-unknown-unknown build of the standard library. This feature was
originally intended to allow an opt-in way to interact with the
operating system in a posix-like way but it was never stabilized.
Nowadays with the advent of the `wasm32-wasi` target that should
entirely replace the intentions of the `wasm_syscall` feature.
This commit removes the `wasm_syscall` feature from the
wasm32-unknown-unknown build of the standard library. This feature was
originally intended to allow an opt-in way to interact with the
operating system in a posix-like way but it was never stabilized.
Nowadays with the advent of the `wasm32-wasi` target that should
entirely replace the intentions of the `wasm_syscall` feature.
Fixed floating point issue with asinh function
This should fixes#63271 , in which `asinh(-0.0)` returns `0.0` instead of `-0.0`.
according to @nagisa
>
>
> IEEE-754 (2008), section 9.2.1:
>
> > For the functions expm1, exp2m1, exp10m1, logp1, log2p1, log10p1, sin, tan, sinPi, atanPi, asin, atan, sinh, tanh, asinh, and atanh, f(+0) is +0 and f(−0) is −0 with no exception.
>
> and
>
> > sinh(±∞) and asinh(±∞) are ±∞ with no exception.
After ensuring that the function `asinh` is the only function affected (functions like `sin`, `sinh` are all based on `cmath` library or `llvm` intrinsics), and that `atanh` always gives the correct result. The only function to modify is `asinh`.
VxWorks does not provide a way to set the task name except at creation time
Make set_name do thing as VxWorks does not provide a way to set the task name except at creation time.
r? @alexcrichton
cc @n-salim
Consolidate sigemptyset workarounds
In sys/unix/process, we work around the sigemptyset linking issues
on android in two different ways. This change consolidates these
workarounds, and avoids duplicating bindings from `libc`.
avoid unnecessary reservations in std::io::Take::read_to_end
Prevously the `read_to_end` implementation for `std::io::Take` used its
own `limit` as a cap on the `reservation_size`. However, that could
still result in an over-allocation like this:
1. Call `reader.take(5).read_to_end(&mut vec)`.
2. `read_to_end_with_reservation` reserves 5 bytes and calls `read`.
3. `read` writes 5 bytes.
4. `read_to_end_with_reservation` reserves 5 bytes and calls `read`.
5. `read` writes 0 bytes.
6. The read loop ends with `vec` having length 5 and capacity 10.
The reservation of 5 bytes was correct for the read at step 2 but
unnecessary for the read at step 4. By that second read, `Take::limit`
is 0, but the `read_to_end_with_reservation` loop is still using the
same `reservation_size` it started with.
Solve this by having `read_to_end_with_reservation` take a closure,
which lets it get a fresh `reservation_size` for each read. This is an
implementation detail which doesn't affect any public API.
In sys/unix/process, we work around the sigemptyset linking issues
on android in two different ways. This change consolidates these
workarounds, and avoids duplicating bindings from `libc`.
This commit updates the `backtrace` crate from 0.3.34 to 0.3.35. The
[included set of changes][changes] for this update mostly includes some
gimli-related improvements (not relevant for the standard library) but
critically includes a fix for rust-lang/backtrace-rs#230. The standard
library will not aqcuire a session-local lock whenever a backtrace is
generated on Windows to allow external synchronization with the
`backtrace` crate itself, allowing `backtrace` to be safely used while
other threads may be panicking.
[changes]: https://github.com/rust-lang/backtrace-rs/compare/0.3.34...0.3.35
… and add a separately-unstable field to force non-exhaustive matching
(`#[non_exhaustive]` is no implemented yet on enum variants)
so that we have the option to later expose the allocator’s error value.
CC https://github.com/rust-lang/wg-allocators/issues/23
Remove uses of `mem::uninitialized()` from cloudabi
This PR removes uses of `mem::uninitialized` from `cloudabi` module,
excluding the layout test in `src/libstd/sys/cloudabi/abi/cloudabi.rs`.
r? @RalfJung
cc @EdSchouten
cc #62397
