Add blanket TryFrom impl when From is implemented.
Adds `impl<T, U> TryFrom<T> for U where U: From<T>`.
Removes `impl<'a, T> TryFrom<&'a str> for T where T: FromStr` (originally added in #40281) due to overlapping impls caused by the new blanket impl. This removal is to be discussed further on the tracking issue for TryFrom.
Refs #33417.
/cc @sfackler, @scottmcm (thank you for the help!), and @aturon
This verifies that TrustedRandomAccess has no side effects when the
iterator item implements Copy. This also implements TrustedLen and
TrustedRandomAccess for str::Bytes.
Replace str's transmute() calls with pointer casts
After the following conversation in #rust-lang:
```
[14:43:50] <Ixrec> TIL the implementation of from_utf_unchecked is literally just "mem::transmute(x)"
[14:43:59] <Ixrec> no wonder people keep saying transmute is overpowered
[15:15:30] <eddyb> Ixrec: it should be a pointer cast lol
[15:15:46] <eddyb> unless it doesn't let you
[16:50:34] <Ixrec> https://play.rust-lang.org/?gist=d1e6b629ad9ec1baf64ce261c63845e6&version=stable seems like it does let me
[16:52:35] <eddyb> Ixrec: yeah that's the preferred impl
[16:52:46] <eddyb> Ixrec: it just wasn't in 1.0
[16:52:50] <eddyb> IIRC
[16:53:00] <eddyb> (something something fat pointers)
```
Since I already wrote half of the preferred impls in the playground, might as well make an actual PR.
After the following conversation in #rust-lang:
```
[14:43:50] <Ixrec> TIL the implementation of from_utf_unchecked is literally just "mem::transmute(x)"
[14:43:59] <Ixrec> no wonder people keep saying transmute is overpowered
[15:15:30] <eddyb> Ixrec: it should be a pointer cast lol
[15:15:46] <eddyb> unless it doesn't let you
[16:50:34] <Ixrec> https://play.rust-lang.org/?gist=d1e6b629ad9ec1baf64ce261c63845e6&version=stable seems like it does let me
[16:52:35] <eddyb> Ixrec: yeah that's the preferred impl
[16:52:46] <eddyb> Ixrec: it just wasn't in 1.0
[16:52:50] <eddyb> IIRC
[16:53:00] <eddyb> (something something fat pointers)
```
Since I already wrote half of the preferred impls in the playground, might as well make an actual PR.
Adds `impl<T, U> TryFrom<T> for U where U: From<T>`.
Removes `impl<'a, T> TryFrom<&'a str> for T where T: FromStr` due to
overlapping impls caused by the new blanket impl. This removal is to
be discussed further on the tracking issue for TryFrom.
Refs #33417.
This PR cuts down on a large number of `#[inline(always)]` and `#[inline]`
annotations in libcore for various core functions. The `#[inline(always)]`
annotation is almost never needed and is detrimental to debug build times as it
forces LLVM to perform inlining when it otherwise wouldn't need to in debug
builds. Additionally `#[inline]` is an unnecessary annoation on almost all
generic functions because the function will already be monomorphized into other
codegen units and otherwise rarely needs the extra "help" from us to tell LLVM
to inline something.
Overall this PR cut the compile time of a [microbenchmark][1] by 30% from 1s to
0.7s.
[1]: https://gist.github.com/alexcrichton/a7d70319a45aa60cf36a6a7bf540dd3a
This commit
* Refactors the collect_lib_features function to work in a
non-checking mode (no bad pointer needed, and list of
lang features).
* Introduces checking whether unstable/stable tags for a
given feature have inconsistent tracking issues.
* Fixes such inconsistencies throughout the codebase.
Make RangeInclusive just a two-field struct
Not being an enum improves ergonomics and consistency, especially since NonEmpty variant wasn't prevented from being empty. It can still be iterable without an extra "done" bit by making the range have !(start <= end), which is even possible without changing the Step trait.
Implements merged https://github.com/rust-lang/rfcs/pull/1980; tracking issue https://github.com/rust-lang/rust/issues/28237.
This is definitely a breaking change to anything consuming `RangeInclusive` directly (not as an Iterator) or constructing it without using the sugar. Is there some change that would make sense before this so compilation failures could be compatibly fixed ahead of time?
r? @aturon (as FCP proposer on the RFC)
Not being an enum improves ergonomics, especially since NonEmpty could be Empty. It can still be iterable without an extra "done" bit by making the range have !(start <= end), which is even possible without changing the Step trait.
Implements RFC 1980
Added links to types in from_utf8 description
References #29375. Link to types mentioned in the documentation for `from_utf8` (`str`, `&[u8`], etc). Paragraphs were reformatted to keep any one line from being excessively long, but are otherwise unchanged.
Added links to from_utf8 methods in Utf8Error
Referencing #29375. Linked the `from_utf8` methods for both `String` and `str` in the description. Also linked the `u8` to its documentation
