Add optional embedded_io::Write impl for Vec.

.github/workflows/build.yml

@@ -176,6 +176,7 @@ jobs:
           cargo check --target="${target}" --features="portable-atomic-critical-section"
           cargo check --target="${target}" --features="serde"
           cargo check --target="${target}" --features="ufmt"
+          cargo check --target="${target}" --features="embedded-io"
         env:
           target: ${{ matrix.target }}
 

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Added
+
+- Added optional `embedded_io::Write` impl for `Vec`.
+
 ### Changed
 
 - `bytes::BufMut` is now implemented on `VecInner`.

Cargo.toml

@@ -38,6 +38,9 @@ ufmt = ["dep:ufmt", "dep:ufmt-write"]
 # Implement `defmt::Format`.
 defmt = ["dep:defmt"]
 
+# Implement `embedded_io::Write`
+embedded-io = ["dep:embedded-io"]
+
 # Enable larger MPMC sizes.
 mpmc_large = []
 
@@ -54,6 +57,7 @@ serde = { version = "1", optional = true, default-features = false }
 ufmt = { version = "0.2", optional = true }
 ufmt-write = { version = "0.1", optional = true }
 defmt = { version = "1.0.1", optional = true }
+embedded-io = { version = "0.6", optional = true }
 
 # for the pool module
 [target.'cfg(any(target_arch = "arm", target_pointer_width = "32", target_pointer_width = "64"))'.dependencies]

src/embedded_io.rs

@@ -0,0 +1,55 @@
+use embedded_io::{Error, ErrorKind, ErrorType, Write};
+
+use crate::{
+    len_type::LenType,
+    vec::{VecInner, VecStorage},
+    CapacityError,
+};
+
+impl Error for CapacityError {
+    fn kind(&self) -> ErrorKind {
+        ErrorKind::OutOfMemory
+    }
+}
+
+impl<LenT: LenType, S: VecStorage<u8> + ?Sized> ErrorType for VecInner<u8, LenT, S> {
+    type Error = CapacityError;
+}
+
+impl<LenT: LenType, S: VecStorage<u8> + ?Sized> Write for VecInner<u8, LenT, S> {
+    #[inline]
+    fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
+        self.extend_from_slice(buf)?;
+        Ok(buf.len())
+    }
+
+    #[inline]
+    fn flush(&mut self) -> Result<(), Self::Error> {
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::Vec;
+    use embedded_io::{Error, ErrorKind, Write};
+
+    fn write(w: &mut impl Write, data: &[u8]) -> Result<(), ErrorKind> {
+        w.write_all(data).map_err(|e| e.kind())
+    }
+
+    #[test]
+    fn test_write() {
+        let mut v: Vec<u8, 4> = Vec::new();
+        assert_eq!(v.len(), 0);
+        write(&mut v, &[1, 2]).unwrap();
+        assert_eq!(v.len(), 2);
+        assert_eq!(v.as_slice(), &[1, 2]);
+        write(&mut v, &[3]).unwrap();
+        assert_eq!(v.len(), 3);
+        assert_eq!(v.as_slice(), &[1, 2, 3]);
+        assert!(write(&mut v, &[4, 5]).is_err());
+        assert_eq!(v.len(), 3);
+        assert_eq!(v.as_slice(), &[1, 2, 3]);
+    }
+}

src/lib.rs

@@ -237,6 +237,9 @@ pub mod spsc;
 #[cfg(feature = "ufmt")]
 mod ufmt;
 
+#[cfg(feature = "embedded-io")]
+mod embedded_io;
+
 /// Implementation details for macros.
 /// Do not use. Used for macros only. Not covered by semver guarantees.
 #[doc(hidden)]