[PATCH v4 2/6] rust: bitmap: add BitmapVec::new_inline()

[Alice Ryhl <aliceryhl@google.com>]

This constructor is useful when you just want to create a BitmapVec
without allocating but don't care how large it is.

Acked-by: Yury Norov (NVIDIA) <yury.norov@gmail.com>
Reviewed-by: Burak Emir <bqe@google.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
 rust/kernel/bitmap.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/rust/kernel/bitmap.rs b/rust/kernel/bitmap.rs
index 15fa23b45054b9272415fcc000e3e3b52c74d7c1..f385a539a90ba87a7b9f6d686e150e95e358bbef 100644
--- a/rust/kernel/bitmap.rs
+++ b/rust/kernel/bitmap.rs
@@ -232,6 +232,16 @@ impl BitmapVec {
     /// The maximum length that avoids allocating.
     pub const NO_ALLOC_MAX_LEN: usize = BITS_PER_LONG;
 
+    /// Construct a longest possible inline [`BitmapVec`].
+    #[inline]
+    pub fn new_inline() -> Self {
+        // INVARIANT: `nbits <= NO_ALLOC_MAX_LEN`, so an inline bitmap is the right repr.
+        BitmapVec {
+            repr: BitmapRepr { bitmap: 0 },
+            nbits: BitmapVec::NO_ALLOC_MAX_LEN,
+        }
+    }
+
     /// Constructs a new [`BitmapVec`].
     ///
     /// Fails with [`AllocError`] when the [`BitmapVec`] could not be allocated. This

-- 
2.51.2.1041.gc1ab5b90ca-goog