docs/test: add UI test and long-form error docs for `E0461`
Might take a couple of tries to pass CI. The UI test is x86-linux only; I'm not sure how to generalize it to other architectures.
r? ``@GuillaumeGomez``
Some `compare_method` tweaks
1. Make some of the comparison functions' names more regular
2. Reduce pub scope of some of the things in `compare_method`
~3. Remove some unnecessary opaque type handling code -- `InferCtxt` already is in a mode that doesn't define opaque types~
* moved to a different PR
4. Bubble up `ErrorGuaranteed` for region constraint errors in `compare_method` - Improves a redundant error message in one unit test.
5. Move the `compare_method` module to have a more general name, since it's more like `compare_impl_item` :)
6. Rename `collect_trait_impl_trait_tys`
Remove some totally duplicated files in `rustc_infer`
I have no idea why or how I duplicated these files from `compiler/rustc_infer/src/infer/error_reporting/note.rs`, but I did by accident, and nothing caught it 🤦
Implement allow-by-default `multiple_supertrait_upcastable` lint
The lint detects when an object-safe trait has multiple supertraits.
Enabled in libcore and liballoc as they are low-level enough that many embedded programs will use them.
r? `@nikomatsakis`
Account for `match` expr in single line
When encountering `match Some(42) { Some(x) => x, None => "" };`, output
```
error[E0308]: `match` arms have incompatible types
--> f53.rs:2:52
|
2 | let _ = match Some(42) { Some(x) => x, None => "" };
| -------------- - ^^ expected integer, found `&str`
| | |
| | this is found to be of type `{integer}`
| `match` arms have incompatible types
```
Fix backoff doc to match implementation
The commit 8dddb2294310ad3e8ce0b2af735a702ad72a9a99 in the crossbeam-channel PR (#93563) changed the backoff strategy to be quadratic instead of exponential. This updates the doc to prevent confusion.
Test leaking of BinaryHeap Drain iterators
Add test cases about forgetting the `BinaryHeap::Drain` iterator, and slightly fortifies some other test cases.
Consists of separate commits that I don't think are relevant on their own (but I'll happily turn these into more PRs if desired).
Clarify docs of `RefCell`
Comparison operators only panic if the `RefCell` is mutably borrowed, and `RefCell::swap()` can also panic if swapping a `RefCell` with itself.
Use correct clock in `park_timeout` on Horizon
Horizon does not support using `CLOCK_MONOTONIC` with condition variables, so use the system time instead.
Fix UnsafeCell Documentation Spelling Error
This fixes the spelling of "deallocated" (instead of the original "deallocted") In the `cell.rs` source file. Honestly probably not worth the time to evaluate, but since it doesn't involve any code change, I figure why not?
Update the documentation of `Vec` to use `extend(array)` instead of `extend(array.iter().copied())`
Another option is to use `extend_from_slice()` (that may be faster), but I find this approach cleaner.
Fix doc comment parsing description in book
This can actually make a difference for the user if they rely on unicode formating.
Prompted by https://github.com/dtolnay/syn/issues/771
Fix a formatting error in Iterator::for_each docs
There is a formatting error (extra space in an assignment) in the documentation of `core::iter::Iterator::for_each`, which I have fixed in this pull request.
More inference-friendly API for lazy
The signature for new was
```
fn new<F>(f: F) -> Lazy<T, F>
```
Notably, with `F` unconstrained, `T` can be literally anything, and just `let _ = Lazy::new(|| 92)` would not typecheck.
This historiacally was a necessity -- `new` is a `const` function, it couldn't have any bounds. Today though, we can move `new` under the `F: FnOnce() -> T` bound, which gives the compiler enough data to infer the type of T from closure.
