diff options
| -rw-r--r-- | src/libcore/option.rs | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/src/libcore/option.rs b/src/libcore/option.rs index 3aab8b1b333..63a5277100f 100644 --- a/src/libcore/option.rs +++ b/src/libcore/option.rs @@ -133,8 +133,6 @@ //! [`Box<T>`]: ../../std/boxed/struct.Box.html //! [`i32`]: ../../std/primitive.i32.html -// ignore-tidy-undocumented-unsafe - #![stable(feature = "rust1", since = "1.0.0")] use crate::iter::{FromIterator, FusedIterator, TrustedLen}; @@ -301,6 +299,8 @@ impl<T> Option<T> { #[inline] #[stable(feature = "pin", since = "1.33.0")] pub fn as_pin_ref(self: Pin<&Self>) -> Option<Pin<&T>> { + // SAFETY: `x` is guaranteed to be pinned because it comes from `self` + // which is pinned. unsafe { Pin::get_ref(self).as_ref().map(|x| Pin::new_unchecked(x)) } } @@ -310,6 +310,8 @@ impl<T> Option<T> { #[inline] #[stable(feature = "pin", since = "1.33.0")] pub fn as_pin_mut(self: Pin<&mut Self>) -> Option<Pin<&mut T>> { + // SAFETY: `get_unchecked_mut` is never used to move the `Option` inside `self`. + // `x` is guaranteed to be pinned because it comes from `self` which is pinned. unsafe { Pin::get_unchecked_mut(self).as_mut().map(|x| Pin::new_unchecked(x)) } } @@ -858,6 +860,8 @@ impl<T> Option<T> { match *self { Some(ref mut v) => v, + // SAFETY: a `None` variant for `self` would have been replaced by a `Some` + // variant in the code above. None => unsafe { hint::unreachable_unchecked() }, } } |