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| author | Dylan DPC <dylan.dpc@gmail.com> | 2020-01-19 17:22:09 +0530 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2020-01-19 17:22:09 +0530 |
| commit | d276e6942ea1af5c1ad79743e7f0ee797010023f (patch) | |
| tree | 7c54dabdc1a8a57a5da2d78f5c87b21971428cbf | |
| parent | a29ba0010765cb63de71a92df8c701e8e87878fc (diff) | |
| parent | d7a18f89864a4360230e3cbbdcbf22d9864a86e0 (diff) | |
| download | rust-d276e6942ea1af5c1ad79743e7f0ee797010023f.tar.gz rust-d276e6942ea1af5c1ad79743e7f0ee797010023f.zip | |
Rollup merge of #68348 - xfix:patch-14, r=nagisa
Make iter::Empty<T> Send and Sync for any T Continuing from #57682 It's quite funny, when I initially submitted this pull request, I said "Likely nobody will be using that property of `iter::empty`", but then a year later I got a compilation error because it wasn't `Send` and `Sync`. Unfortunately, `PhantomData<fn() -> T>` still errors out. Oh well. I proposed ` struct PhantomFnWorkaround<T>(fn() -> T);`, but dtolnay did not like it, so using explicit implementations.
| -rw-r--r-- | src/libcore/iter/sources.rs | 5 | ||||
| -rw-r--r-- | src/test/ui/threads-sendsync/sync-send-iterators-in-libcore.rs | 1 |
2 files changed, 6 insertions, 0 deletions
diff --git a/src/libcore/iter/sources.rs b/src/libcore/iter/sources.rs index a65d47cc2c1..25dfc573e41 100644 --- a/src/libcore/iter/sources.rs +++ b/src/libcore/iter/sources.rs @@ -208,6 +208,11 @@ pub fn repeat_with<A, F: FnMut() -> A>(repeater: F) -> RepeatWith<F> { #[stable(feature = "iter_empty", since = "1.2.0")] pub struct Empty<T>(marker::PhantomData<T>); +#[stable(feature = "iter_empty_send_sync", since = "1.42.0")] +unsafe impl<T> Send for Empty<T> {} +#[stable(feature = "iter_empty_send_sync", since = "1.42.0")] +unsafe impl<T> Sync for Empty<T> {} + #[stable(feature = "core_impl_debug", since = "1.9.0")] impl<T> fmt::Debug for Empty<T> { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { diff --git a/src/test/ui/threads-sendsync/sync-send-iterators-in-libcore.rs b/src/test/ui/threads-sendsync/sync-send-iterators-in-libcore.rs index 44beb9dc1e5..2f6d35f01be 100644 --- a/src/test/ui/threads-sendsync/sync-send-iterators-in-libcore.rs +++ b/src/test/ui/threads-sendsync/sync-send-iterators-in-libcore.rs @@ -88,6 +88,7 @@ fn main() { is_sync_send!((1..)); is_sync_send!(repeat(1)); is_sync_send!(empty::<usize>()); + is_sync_send!(empty::<*mut i32>()); is_sync_send!(once(1)); // for option.rs |