impl From<Infallible> for TryFromSliceError
I believe this was missed when TryFrom was stabilized. I think `TryFromSliceError` and `TryFromIntError` are the only two `TryFrom` error types that appear in `std`. I think trait implementations have to be insta-stable, but I'm not sure.
Rollup of 6 pull requests
Successful merges:
- #60529 (RFC 2008: Uninhabitedness fixes for enum variants and tests)
- #60620 (Fix a couple of FIXMEs in ext::tt::transcribe)
- #60659 (Tweak `Symbol` and `InternedString`)
- #60692 (Extend #60676 test for nested mut patterns.)
- #60697 (add regression test for #60629)
- #60701 (Update mailmap for mati865)
Failed merges:
r? @ghost
add regression test for #60629
This bug was fixed, but I don't know which one. (I think it even doesn't matter at all).
Added a regression test.
```
op@OP ~/m/r/s/t/incremental> rustc --version
rustc 1.35.0-nightly (acd8dd6a5 2019-04-05)
op@OP ~/m/r/s/t/incremental> rustc -C incremental= --cfg rpass1 issue-60629.rs
warning: struct is never constructed: `A`
--> issue-60629.rs:3:1
|
3 | struct A;
| ^^^^^^^^^
|
= note: #[warn(dead_code)] on by default
op@OP ~/m/r/s/t/incremental> rustc -C incremental= --cfg rpass2 issue-60629.rs
error: internal compiler error: src/librustc/ty/query/plumbing.rs:1195: Cannot force dep node: coherent_trait(core[c27c]::ops[0]::drop[0]::Drop[0])
thread 'rustc' panicked at 'Box<Any>', src/librustc_errors/lib.rs:635:9
note: Run with `RUST_BACKTRACE=1` environment variable to display a backtrace.
error: aborting due to previous error
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports
note: rustc 1.35.0-nightly (acd8dd6a5 2019-04-05) running on x86_64-unknown-linux-gnu
note: compiler flags: -C incremental
```
with latest nightly it does not crash anymore, so nothing more to do.
Fixes#60629
(accidentally removed the remote branch on github, therefore GH closed the other PR.)
r? @nikomatsakis
Extend #60676 test for nested mut patterns.
At request of @centril, this commit extends the existing test added by #60676 to include nested `mut` patterns.
cc @Centril
Fix a couple of FIXMEs in ext::tt::transcribe
_Blocked on #60618_
A crater run would be nice to make sure my understanding is correct. A quick google search seems to indicate these are extremely rare errors if they are possible (which I don't believe they are).
r? @petrochenkov
cc #2887 (there is only one FIXME left and it is hygiene-related)
RFC 2008: Uninhabitedness fixes for enum variants and tests
Part of #44109.
At the request of @Centril, this PR adds tests asserting that uninhabited non-exhaustive types are considered inhabited in extern crates. In adding these tests, I fixed an oversight in the implementation of RFC 2008 on enum variants that resulted in non-exhaustive enum variants being considered uninhabited in extern crates.
Before this PR, these lines would error:
```rust
// extern crate
pub enum UninhabitedVariants {
#[non_exhaustive] Tuple(!),
#[non_exhaustive] Struct { x: ! }
}
pub enum PartiallyInhabitedVariants {
Tuple(u8),
#[non_exhaustive] Struct { x: ! }
}
// current crate
match uninhabited_variant() /* fn() -> Option<UninhabitedVariants> */ {
Some(_x) => (), //~ ERROR unreachable pattern
None => (),
}
while let PartiallyInhabitedVariants::Struct { x, .. } = partially_inhabited_variant() /* fn() -> PartiallyInhabitedVariants */ {
//~^ ERROR unreachable pattern
}
```
cc @Centril
r? @petrochenkov
