Add `std::error::Report` type
This is a continuation of https://github.com/rust-lang/rust/pull/90174, split into a separate PR since I cannot push to ```````@seanchen1991``````` 's fork
In commit 29403ee, documentation for the methods on `std::any::Any` was
modified so that they referred to the concrete value behind the trait
object as the "inner" value. This is a more accurate wording than
"boxed": while putting trait objects inside boxes is arguably the most
common use, they can also be placed behind other pointer types like
`&mut` or `std::sync::Arc`.
This commit does the same documentation changes for `std::error::Error`.
Previously suggested in https://github.com/rust-lang/rfcs/issues/2854.
It makes sense to have this since `char` implements `From<u8>`. Likewise
`u32`, `u64`, and `u128` (since #79502) implement `From<char>`.
Using it through the crate-local path in `std` means that it shouldn't make an "Implementations on Foreign Types" section in the `std::error::Error` docs.
Add functions `Duration::try_from_secs_{f32, f64}`
These functions allow constructing a Duration from a floating point value that could be out of range without panicking.
Tracking issue: #83400
Implement Error for &(impl Error)
Opening this up just to see what it breaks. It's unfortunate that `&(impl Error)` doesn't actually implement `Error`. If this direct approach doesn't work out then I'll try something different, like an `Error::by_ref` method.
**EDIT:** This is a super low-priority experiment so feel free to cancel it for more important crater runs! 🙂
-----
# Stabilization Report
## Why?
We've been working for the last few years to try "fix" the `Error` trait, which is probably one of the most fundamental in the whole standard library. One of its issues is that we commonly expect you to work with abstract errors through `dyn Trait`, but references and smart pointers over `dyn Trait` don't actually implement the `Error` trait. If you have a `&dyn Error` or a `Box<dyn Error>` you simply can't pass it to a method that wants a `impl Error`.
## What does this do?
This stabilizes the following trait impl:
```rust
impl<'a, T: Error + ?Sized + 'static> Error for &'a T;
```
This means that `&dyn Error` will now satisfy a `impl Error` bound.
It doesn't do anything with `Box<dyn Error>` directly. We discussed how we could do `Box<dyn Error>` in the thread here (and elsewhere in the past), but it seems like we need something like lattice-based specialization or a sprinkling of snowflake compiler magic to make that work. Having said that, with this new impl you _can_ now get a `impl Error` from a `Box<dyn Error>` by dereferencing it.
## What breaks?
A crater run revealed a few crates broke with something like the following:
```rust
// where e: &'short &'long dyn Error
err.source()
```
previously we'd auto-deref that `&'short &'long dyn Error` to return a `Option<&'long dyn Error>` from `source`, but now will call directly on `&'short impl Error`, so will return a `Option<&'short dyn Error>`. The fix is to manually deref:
```rust
// where e: &'short &'long dyn Error
(*err).source()
```
In the recent Libs meeting we considered this acceptable breakage.
This impl was effectively stable. #[unstable] had no effect here,
since both Error and LayoutErr were already stable.
This effectively became stable as soon as LayoutErr became stable, which
was in 1.28.0.
