summaryrefslogtreecommitdiff
path: root/rust/kernel/num
diff options
context:
space:
mode:
Diffstat (limited to 'rust/kernel/num')
-rw-r--r--rust/kernel/num/bounded.rs70
1 files changed, 68 insertions, 2 deletions
diff --git a/rust/kernel/num/bounded.rs b/rust/kernel/num/bounded.rs
index fa81acbdc8c2..bbab6bbcb315 100644
--- a/rust/kernel/num/bounded.rs
+++ b/rust/kernel/num/bounded.rs
@@ -379,6 +379,9 @@ where
/// Returns the wrapped value as the backing type.
///
+ /// This is similar to the [`Deref`] implementation, but doesn't enforce the size invariant of
+ /// the [`Bounded`], which might produce slightly less optimal code.
+ ///
/// # Examples
///
/// ```
@@ -387,8 +390,8 @@ where
/// let v = Bounded::<u32, 4>::new::<7>();
/// assert_eq!(v.get(), 7u32);
/// ```
- pub fn get(self) -> T {
- *self.deref()
+ pub const fn get(self) -> T {
+ self.0
}
/// Increases the number of bits usable for `self`.
@@ -473,6 +476,48 @@ where
// `N` bits, and with the same signedness.
unsafe { Bounded::__new(value) }
}
+
+ /// Right-shifts `self` by `SHIFT` and returns the result as a `Bounded<_, RES>`, where `RES >=
+ /// N - SHIFT`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use kernel::num::Bounded;
+ ///
+ /// let v = Bounded::<u32, 16>::new::<0xff00>();
+ /// let v_shifted: Bounded::<u32, 8> = v.shr::<8, _>();
+ ///
+ /// assert_eq!(v_shifted.get(), 0xff);
+ /// ```
+ pub fn shr<const SHIFT: u32, const RES: u32>(self) -> Bounded<T, RES> {
+ const { assert!(RES + SHIFT >= N) }
+
+ // SAFETY: We shift the value right by `SHIFT`, reducing the number of bits needed to
+ // represent the shifted value by as much, and just asserted that `RES >= N - SHIFT`.
+ unsafe { Bounded::__new(self.0 >> SHIFT) }
+ }
+
+ /// Left-shifts `self` by `SHIFT` and returns the result as a `Bounded<_, RES>`, where `RES >=
+ /// N + SHIFT`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use kernel::num::Bounded;
+ ///
+ /// let v = Bounded::<u32, 8>::new::<0xff>();
+ /// let v_shifted: Bounded::<u32, 16> = v.shl::<8, _>();
+ ///
+ /// assert_eq!(v_shifted.get(), 0xff00);
+ /// ```
+ pub fn shl<const SHIFT: u32, const RES: u32>(self) -> Bounded<T, RES> {
+ const { assert!(RES >= N + SHIFT) }
+
+ // SAFETY: We shift the value left by `SHIFT`, augmenting the number of bits needed to
+ // represent the shifted value by as much, and just asserted that `RES >= N + SHIFT`.
+ unsafe { Bounded::__new(self.0 << SHIFT) }
+ }
}
impl<T, const N: u32> Deref for Bounded<T, N>
@@ -1059,3 +1104,24 @@ where
unsafe { Self::__new(T::from(value)) }
}
}
+
+impl<T> Bounded<T, 1>
+where
+ T: Integer + Zeroable,
+{
+ /// Converts this [`Bounded`] into a [`bool`].
+ ///
+ /// This is a shorter way of writing `bool::from(self)`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use kernel::num::Bounded;
+ ///
+ /// assert_eq!(Bounded::<u8, 1>::new::<0>().into_bool(), false);
+ /// assert_eq!(Bounded::<u8, 1>::new::<1>().into_bool(), true);
+ /// ```
+ pub fn into_bool(self) -> bool {
+ self.into()
+ }
+}