summaryrefslogtreecommitdiffstats
path: root/third_party/rust/pin-project/examples/unsafe_unpin-expanded.rs
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/rust/pin-project/examples/unsafe_unpin-expanded.rs
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/pin-project/examples/unsafe_unpin-expanded.rs')
-rw-r--r--third_party/rust/pin-project/examples/unsafe_unpin-expanded.rs107
1 files changed, 107 insertions, 0 deletions
diff --git a/third_party/rust/pin-project/examples/unsafe_unpin-expanded.rs b/third_party/rust/pin-project/examples/unsafe_unpin-expanded.rs
new file mode 100644
index 0000000000..e9c7abcedd
--- /dev/null
+++ b/third_party/rust/pin-project/examples/unsafe_unpin-expanded.rs
@@ -0,0 +1,107 @@
+// Original code (./unsafe_unpin.rs):
+//
+// ```rust
+// #![allow(dead_code)]
+//
+// use pin_project::{pin_project, UnsafeUnpin};
+//
+// #[pin_project(UnsafeUnpin)]
+// pub struct Struct<T, U> {
+// #[pin]
+// pinned: T,
+// unpinned: U,
+// }
+//
+// unsafe impl<T: Unpin, U> UnsafeUnpin for Struct<T, U> {}
+//
+// fn main() {}
+// ```
+
+#![allow(dead_code, unused_imports, unused_parens, unknown_lints, renamed_and_removed_lints)]
+#![allow(clippy::needless_lifetimes)]
+
+use pin_project::{pin_project, UnsafeUnpin};
+
+// #[pin_project(UnsafeUnpin)]
+pub struct Struct<T, U> {
+ // #[pin]
+ pinned: T,
+ unpinned: U,
+}
+
+const _: () = {
+ pub(crate) struct __StructProjection<'pin, T, U>
+ where
+ Struct<T, U>: 'pin,
+ {
+ pinned: ::pin_project::__private::Pin<&'pin mut (T)>,
+ unpinned: &'pin mut (U),
+ }
+ pub(crate) struct __StructProjectionRef<'pin, T, U>
+ where
+ Struct<T, U>: 'pin,
+ {
+ pinned: ::pin_project::__private::Pin<&'pin (T)>,
+ unpinned: &'pin (U),
+ }
+
+ impl<T, U> Struct<T, U> {
+ pub(crate) fn project<'pin>(
+ self: ::pin_project::__private::Pin<&'pin mut Self>,
+ ) -> __StructProjection<'pin, T, U> {
+ unsafe {
+ let Self { pinned, unpinned } = self.get_unchecked_mut();
+ __StructProjection {
+ pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
+ unpinned,
+ }
+ }
+ }
+ pub(crate) fn project_ref<'pin>(
+ self: ::pin_project::__private::Pin<&'pin Self>,
+ ) -> __StructProjectionRef<'pin, T, U> {
+ unsafe {
+ let Self { pinned, unpinned } = self.get_ref();
+ __StructProjectionRef {
+ pinned: ::pin_project::__private::Pin::new_unchecked(pinned),
+ unpinned,
+ }
+ }
+ }
+ }
+
+ // Ensure that it's impossible to use pin projections on a #[repr(packed)]
+ // struct.
+ //
+ // See ./struct-default-expanded.rs and https://github.com/taiki-e/pin-project/pull/34
+ // for details.
+ #[forbid(unaligned_references, safe_packed_borrows)]
+ fn __assert_not_repr_packed<T, U>(this: &Struct<T, U>) {
+ let _ = &this.pinned;
+ let _ = &this.unpinned;
+ }
+
+ // Implement `Unpin` via `UnsafeUnpin`.
+ impl<'pin, T, U> ::pin_project::__private::Unpin for Struct<T, U> where
+ ::pin_project::__private::Wrapper<'pin, Self>: ::pin_project::UnsafeUnpin
+ {
+ }
+
+ // Ensure that struct does not implement `Drop`.
+ //
+ // See ./struct-default-expanded.rs for details.
+ trait StructMustNotImplDrop {}
+ #[allow(clippy::drop_bounds, drop_bounds)]
+ impl<T: ::pin_project::__private::Drop> StructMustNotImplDrop for T {}
+ impl<T, U> StructMustNotImplDrop for Struct<T, U> {}
+ // A dummy impl of `PinnedDrop`, to ensure that users don't accidentally
+ // write a non-functional `PinnedDrop` impls.
+ #[doc(hidden)]
+ impl<T, U> ::pin_project::__private::PinnedDrop for Struct<T, U> {
+ unsafe fn drop(self: ::pin_project::__private::Pin<&mut Self>) {}
+ }
+};
+
+unsafe impl<T: Unpin, U> UnsafeUnpin for Struct<T, U> {}
+
+fn main() {}