Special suggestion for illegal unicode curly quote pairs
Fixes#58436
Did not end up expanding the error message span to include the full string literal since I figured the start of the token was the issue, while the help suggestion span would include up to the closing quotation mark.
The look ahead logic does not affect the reader position, not sure if that is an issue (if eg it should still continue to parse after the closing quote without erroring out).
AFAICT, we do not have the same const-eval issues that we used to when
rust-lang/rust#23926 was filed. (Probably because of the switch to
miri for const-evaluation.)
Add a note about 2018e if someone uses `try {` in 2015e
Inspired by https://github.com/rust-lang/rust/issues/58491, where a `try_blocks` example was accidentally run in 2015, which of course produces a bunch of errors.
What's the philosophy about gating for this? The keyword is stably a keyword in 2018, so I haven't gated it for now but am not mentioning what the keyword _does_. Let me know if I should do differently.
Resolves#53672
make generalization code create new variables in correct universe
In our type inference system, when we "generalize" a type T to become
a suitable value for a type variable V, we sometimes wind up creating
new inference variables. So, for example, if we are making V be some
subtype of `&'X u32`, then we might instantiate V with `&'Y u32`.
This generalized type is then related `&'Y u32 <: &'X u32`, resulting
in a region constriant `'Y: 'X`. Previously, however, we were making
these fresh variables like `'Y` in the "current universe", but they
should be created in the universe of V. Moreover, we sometimes cheat
in an invariant context and avoid creating fresh variables if we know
the result must be equal -- we can only do that when the universes
work out.
Fixes#57843
r? @pnkfelix
Make overflowing and wrapping negation const
Remember that the signed and unsigned versions are slightly different here, so there's four functions made const instead of just two.
Modify doctest's auto-`fn main()` to allow `Result`s
This lets the default `fn main()` ~~return `impl Termination`~~ unwrap Results, which allows the use of `?` in most tests without adding it manually. This fixes#56260
~~Blocked on `std::process::Termination` stabilization.~~
Using `Termination` would have been cleaner, but this should work OK.
rustdoc: Don't modify library path for doctests
It shouldn't be needed anymore because doctests are no longer compiled with `prefer-dynamic` (since #54939).
r? @QuietMisdreavus
Rustdoc remove old style files
Reopening of #56577 (which I can't seem to reopen...).
I made the flag unstable so with this change, what was blocking the PR is now gone I assume.
Add specific feature gate error for const-unstable features
Before:
```
error: `impl Trait` in const fn is unstable
--> src/lib.rs:7:19
|
7 | const fn foo() -> impl T {
| ^^^^^^
error: aborting due to previous error
```
After:
```
error[E0723]: `impl Trait` in const fn is unstable (see issue #57563)
--> src/lib.rs:7:19
|
7 | const fn foo() -> impl T {
| ^^^^^^
= help: add #![feature(const_fn)] to the crate attributes to enable
error: aborting due to previous error
```
This improves the situation with https://github.com/rust-lang/rust/issues/57563. Fixes https://github.com/rust-lang/rust/issues/57544. Fixes https://github.com/rust-lang/rust/issues/54469.
r? @oli-obk
