This way we can call `cmp` instead of `partial_cmp` in the loop,
removing some burden of optimizing `Option`s away from the compiler.
PR #39538 introduced a regression where sorting slices suddenly became
slower, since `slice1.lt(slice2)` was much slower than
`slice1.cmp(slice2) == Less`. This problem is now fixed.
To verify, I benchmarked this simple program:
```rust
fn main() {
let mut v = (0..2_000_000).map(|x| x * x * x * 18913515181).map(|x| vec![x, x ^ 3137831591]).collect::<Vec<_>>();
v.sort();
}
```
Before this PR, it would take 0.95 sec, and now it takes 0.58 sec.
I also tried changing the `is_less` lambda to use `cmp` and
`partial_cmp`. Now all three versions (`lt`, `cmp`, `partial_cmp`) are
equally performant for sorting slices - all of them take 0.58 sec on the
benchmark.
Previously, `assert_eq!(left, right,)` (respectively, `assert_ne!(left,
right,)`; note the trailing comma) would result in a confusing "requires
at least a format string argument" error. In reality, a format string is
optional, but the trailing comma puts us into the "match a token tree of
zero or more tokens" branch of the macro (in order to support the
optional format string), and passing the empty token tree into
`format_args!` results in the confusing error. If instead we match a
token tree of one or more tokens, we get a much more sensible
"unexpected end of macro invocation" error.
While we're here, fix up a stray space before a comma in the match
guards.
Resolves#39369.
Fix TryFrom for i128/u128
Another case of `as` cast silent truncation being error prone.
This also adds a few missing TryFrom tests to libcoretest.
cc #33417
cc #35118
Add a name for the parameter to `TryFrom::try_from`.
Although signatures with anonymous parameters may not be deprecated or removed at this point, the team seems to agree that the ability to have an anonymous parameter is unfortunate historical baggage, and that we shouldn't create new code that uses it.
Context: https://github.com/rust-lang/rust/issues/33417#issuecomment-276933861
Provide Entry-like API for Option
This implements #39288.
I am wondering whether to use std::intrinsics::unreachable!() here. Both seems fine to me (the second match optimizes away in release mode).
branchless .filter(_).count()
I found that the branchless version is only slower if we have little to no branch misses, which usually isn't the case. I notice speedups between -5% (perfect prediction) and 60% (real world data).
Add 128-bit atomics
This is currently only supported on AArch64 since that is the only target which unconditionally supports 128-bit atomic operations.
cc #35118
Bump version, upgrade bootstrap
This commit updates the version number to 1.17.0 as we're not on that version of
the nightly compiler, and at the same time this updates src/stage0.txt to
bootstrap from freshly minted beta compiler and beta Cargo.
This commit updates the version number to 1.17.0 as we're not on that version of
the nightly compiler, and at the same time this updates src/stage0.txt to
bootstrap from freshly minted beta compiler and beta Cargo.
Extend Cell to work with non-Copy types
I'm not sure that I did this right but all of the tests pass.
I also had to move the `new()` function so that `Cell`s with non-`Copy` `T`s could be created. That wasn't in the RFC but I assume it needed to be done?
Although signatures with anonymous parameters may not be deprecated or
removed at this point, the team seems to agree that the ability to have
an anonymous parameter is unfortunate historical baggage, and that we
shouldn't create new code that uses it.
Context: https://github.com/rust-lang/rust/issues/33417#issuecomment-276933861
std: Stabilize APIs for the 1.16.0 release
This commit applies the stabilization/deprecations of the 1.16.0 release, as
tracked by the rust-lang/rust issue tracker and the final-comment-period tag.
The following APIs were stabilized:
* `VecDeque::truncate`
* `VecDeque::resize`
* `String::insert_str`
* `Duration::checked_{add,sub,div,mul}`
* `str::replacen`
* `SocketAddr::is_ipv{4,6}`
* `IpAddr::is_ipv{4,6}`
* `str::repeat`
* `Vec::dedup_by`
* `Vec::dedup_by_key`
* `Result::unwrap_or_default`
* `<*const T>::wrapping_offset`
* `<*mut T>::wrapping_offset`
* `CommandExt::creation_flags` (on Windows)
* `File::set_permissions`
* `String::split_off`
The following APIs were deprecated
* `EnumSet` - replaced with other ecosystem abstractions, long since unstable
Closes#27788Closes#35553Closes#35774Closes#36436Closes#36949Closes#37079Closes#37087Closes#37516Closes#37827Closes#37916Closes#37966Closes#38080
This commit applies the stabilization/deprecations of the 1.16.0 release, as
tracked by the rust-lang/rust issue tracker and the final-comment-period tag.
The following APIs were stabilized:
* `VecDeque::truncate`
* `VecDeque::resize`
* `String::insert_str`
* `Duration::checked_{add,sub,div,mul}`
* `str::replacen`
* `SocketAddr::is_ipv{4,6}`
* `IpAddr::is_ipv{4,6}`
* `str::repeat`
* `Vec::dedup_by`
* `Vec::dedup_by_key`
* `Result::unwrap_or_default`
* `<*const T>::wrapping_offset`
* `<*mut T>::wrapping_offset`
* `CommandExt::creation_flags` (on Windows)
* `File::set_permissions`
* `String::split_off`
The following APIs were deprecated
* `EnumSet` - replaced with other ecosystem abstractions, long since unstable
Closes#27788Closes#35553Closes#35774Closes#36436Closes#36949Closes#37079Closes#37087Closes#37516Closes#37827Closes#37916Closes#37966Closes#38080
