Revert #85176 addition of `clone_from` for `ManuallyDrop`
Forwarding `clone_from` to the inner value changes the observable behavior, as previously the inner value would *not* be dropped by the default implementation.
Frankly, this is a super-niche case, so #85176 is welcome to argue the behavior should be otherwise! But if we overrride it, IMO documenting the behavior would be good.
Example: https://play.rust-lang.org/?version=nightly&mode=debug&edition=2018&gist=c5d0856686fa850c1d7ee16891014efb
This is a fairly common attribute on methods, but is not something you
need to know when reading the method docs - the purpose of the attribute
is for the compiler to tell you about it if you forget to use a value.
Removing reclaims some valuable space in the summary of methods.
Fix font weight
Fixes#86256.
I realized that the only cases where we actually needed to have bold text was inside `impl-items`.
cc `@camelid`
r? `@jsha`
Fix ICEs on invalid vtable size/alignment const UB errors
The invalid vtable size/alignment errors from `InterpCx::read_size_and_align_from_vtable` were "freeform const UB errors", causing ICEs when reaching validation. This PR turns them into const UB hard errors to catch them during validation and avoid that.
Fixes#86193
r? `@RalfJung`
(It seemed cleaner to have 2 variants but they can be merged into one variant with a message payload if you prefer that ?)
Update cargo
11 commits in aa8b09297bb3156b849e73db48af4cd050492fe6..44456677b5d1d82fe981c955dc5c67734b31f340
2021-06-09 00:28:53 +0000 to 2021-06-12 18:00:01 +0000
- Fix package_default_run test. (rust-lang/cargo#9577)
- Change how the fix_deny_warnings_but_not_others test works (rust-lang/cargo#9571)
- Add mising documentation regarding `cargo doc` (rust-lang/cargo#9565)
- Implement warning for ignored trailing arguments (rust-lang/cargo#9561)
- Make clippy happy (rust-lang/cargo#9569)
- Fix rustc/rustdoc config values to be config-relative. (rust-lang/cargo#9566)
- Update rustfix. (rust-lang/cargo#9567)
- Warn if an "all" target is specified, but we don't match anything (rust-lang/cargo#9549)
- add default_run to SerializedPackage (rust-lang/cargo#9550)
- respect user choice of lib/bin over heuristics (rust-lang/cargo#9522)
- Add a mean to mutably access the members of a workspace (rust-lang/cargo#9547)
Pretty print generator witness only in `-Zverbose` mode
In release build of deeply-nested-async benchmark the size of
`no-opt.bc` file is reduced from 46MB to 62kB.
Helps with #84873, where in one of reported test cases the size of `no-opt.bc`
file is reduced from 2.3GB to 799kB.
Implement nonzero arithmetics for NonZero types.
Hello'all, this is my first PR to this repo.
Non-zero natural numbers are stable by addition/multiplication/exponentiation, so it makes sense to make this arithmetic possible with `NonZeroU*`.
The major pitfall is that overflowing underlying `u*` types possibly lead to underlying `0` values, which break the major invariant of `NonZeroU*`. To accommodate it, only `checked_` and `saturating_` operations are implemented.
Other variants allowing wrapped results like `wrapping_` or `overflowing_` are ruled out *de facto*.
`impl Add<u*> for NonZeroU* { .. }` was considered, as it panics on overflow which enforces the invariant, but it does not so in release mode. I considered forcing `NonZeroU*::add` to panic in release mode by deferring the check to `u*::checked_add`, but this is less explicit for the user than directly using `NonZeroU*::checked_add`.
Following `@Lokathor's` advice on zulip, I have dropped the idea.
`@poliorcetics` on Discord also suggested implementing `_sub` operations, but I'd postpone this to another PR if there is a need for it. My opinion is that it could be useful in some cases, but that it makes less sense because non-null natural numbers are not stable by subtraction even in theory, while the overflowing problem is just about technical implementation.
One thing I don't like is that the type of the `other` arg differs in every implementation: `_add` methods accept any raw positive integer, `_mul` methods only accept non-zero values otherwise the invariant is also broken, and `_pow` only seems to accept `u32` for a reason I ignore but that seems consistent throughout `std`. Maybe there is a better way to harmonize this?
This is it, Iope I haven't forgotten anything and I'll be happy to read your feedback.
Do not suggest to add type annotations for unnameable types
Consider this example:
```rust
const A = || 42;
struct S<T> { t: T }
const B: _ = S { t: || 42 };
```
This currently produces the following output:
```
error: missing type for `const` item
--> src/lib.rs:1:7
|
1 | const A = || 42;
| ^ help: provide a type for the item: `A: [closure@src/lib.rs:1:11: 1:16]`
error[E0121]: the type placeholder `_` is not allowed within types on item signatures
--> src/lib.rs:4:10
|
4 | const B: _ = S { t: || 42 };
| ^
| |
| not allowed in type signatures
| help: replace `_` with the correct type: `S<[closure@src/lib.rs:4:21: 4:26]>`
error: aborting due to 2 previous errors
```
However, these suggestions are obviously useless, because the suggested types cannot be written down. With my changes, the suggestion is replaced with a note, because there is no simple fix:
```
error: missing type for `const` item
--> test.rs:1:7
|
1 | const A = || 42;
| ^
|
note: however, the inferred type `[closure@test.rs:1:11: 1:16]` cannot be named
--> test.rs:1:11
|
1 | const A = || 42;
| ^^^^^
error[E0121]: the type placeholder `_` is not allowed within types on item signatures
--> test.rs:4:10
|
4 | const B: _ = S { t: || 42 };
| ^ not allowed in type signatures
|
note: however, the inferred type `S<[closure@test.rs:4:21: 4:26]>` cannot be named
--> test.rs:4:14
|
4 | const B: _ = S { t: || 42 };
| ^^^^^^^^^^^^^^
error: aborting due to 2 previous errors
```
Original senders that are still hanging around could cause
Receiver::recv to not block since this is a potential footgun
for beginners, clarify more on this in the docs for readers to
be aware about it.
Fix minor tidbits in sender recv doc
Co-authored-by: Dylan DPC <dylan.dpc@gmail.com>
Add example for unbounded receive loops in doc
Show the drop(tx) pattern, based on tokio docs
https://tokio-rs.github.io/tokio/doc/tokio/sync/index.html
Fix example code for drop sender recv
Fix wording in sender docs
Co-authored-by: Josh Triplett <josh@joshtriplett.org>
Hash DefId in rustc_span.
This is mostly just moving code around. Changes are simplifications of unneeded callbacks from rustc_span to rustc_middle.
r? `@petrochenkov`
