Implement `strip_prefix` for `BStr` by deferring to `slice::strip_prefix`
on the underlying `&[u8]`.
Reviewed-by: Gary Guo <gary@xxxxxxxxxxx>
Reviewed-by: Alice Ryhl <aliceryhl@xxxxxxxxxx>
Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxx>
---
It is also possible to get this method by implementing
`core::slice::SlicePattern` for `BStr`. `SlicePattern` is unstable, so this
seems more reasonable.
---
rust/kernel/str.rs | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index 1eb945bed77d6592216cf30678fcca70d4c0b3b3..80601206961e5b2d682af5f7028434bba1604272 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -31,6 +31,22 @@ pub const fn from_bytes(bytes: &[u8]) -> &Self {
// SAFETY: `BStr` is transparent to `[u8]`.
unsafe { &*(bytes as *const [u8] as *const BStr) }
}
+
+ /// Strip a prefix from `self`. Delegates to [`slice::strip_prefix`].
+ ///
+ /// # Example
+ /// ```
+ /// use kernel::b_str;
+ /// assert_eq!(Some(b_str!("bar")), b_str!("foobar").strip_prefix(b_str!("foo")));
+ /// assert_eq!(None, b_str!("foobar").strip_prefix(b_str!("bar")));
+ /// assert_eq!(Some(b_str!("foobar")), b_str!("foobar").strip_prefix(b_str!("")));
+ /// assert_eq!(Some(b_str!("")), b_str!("foobar").strip_prefix(b_str!("foobar")));
+ /// ```
+ pub fn strip_prefix(&self, pattern: &Self) -> Option<&BStr> {
+ self.deref()
+ .strip_prefix(pattern.deref())
+ .map(Self::from_bytes)
+ }
}
impl fmt::Display for BStr {
--
2.47.0
