core: Add support for heapless-bytes

Similar to the existing support for multiple heapless versions, this
patch also adds support for heapless-bytes 0.3 and 0.4.

.github/workflows/ci.yml

@@ -31,6 +31,8 @@ jobs:
       - name: Check
         run: |
           cargo check --package littlefs2-core
+          cargo check --package littlefs2-core --features heapless-bytes03
+          cargo check --package littlefs2-core --features heapless-bytes04
           cargo check --package littlefs2-core --features heapless07
           cargo check --package littlefs2-core --features heapless08
           cargo check --package littlefs2-core --features serde

core/Cargo.toml

@@ -10,11 +10,15 @@ repository.workspace = true
 
 [dependencies]
 bitflags = "2.6.0"
+heapless-bytes03 = { package = "heapless-bytes", version = "0.3", optional = true }
+heapless-bytes04 = { package = "heapless-bytes", version = "0.4", optional = true }
 heapless07 = { package = "heapless", version = "0.7", optional = true }
 heapless08 = { package = "heapless", version = "0.8", optional = true }
 serde = { version = "1", default-features = false, features = ["derive"], optional = true }
 
 [features]
+heapless-bytes03 = ["dep:heapless-bytes03"]
+heapless-bytes04 = ["dep:heapless-bytes04"]
 heapless07 = ["dep:heapless07"]
 heapless08 = ["dep:heapless08"]
 serde = ["dep:serde"]

core/src/object_safe.rs

@@ -18,6 +18,30 @@ pub trait Vec: Default + AsRef<[u8]> + AsMut<[u8]> {
     fn truncate(&mut self, n: usize);
 }
 
+#[cfg(feature = "heapless-bytes03")]
+impl<const N: usize> Vec for heapless_bytes03::Bytes<N> {
+    fn resize_to_capacity(&mut self) {
+        heapless_bytes03::Bytes::resize_to_capacity(self)
+    }
+
+    fn truncate(&mut self, n: usize) {
+        use core::ops::DerefMut as _;
+
+        self.deref_mut().truncate(n)
+    }
+}
+
+#[cfg(feature = "heapless-bytes04")]
+impl<const N: usize> Vec for heapless_bytes04::Bytes<N> {
+    fn resize_to_capacity(&mut self) {
+        heapless_bytes04::Bytes::resize_to_capacity(self)
+    }
+
+    fn truncate(&mut self, n: usize) {
+        heapless_bytes04::Bytes::truncate(self, n)
+    }
+}
+
 #[cfg(feature = "heapless07")]
 impl<const N: usize> Vec for heapless07::Vec<u8, N> {
     fn resize_to_capacity(&mut self) {