io-async: add std/alloc features, add Box/Vec impls.

Author: Dirbaio

embedded-io-async/Cargo.toml

@@ -11,5 +11,13 @@ categories = [
     "no-std",
 ]
 
+[features]
+std = ["alloc", "embedded-io/std"]
+alloc = ["embedded-io/alloc"]
+
 [dependencies]
 embedded-io = { version = "0.5", path = "../embedded-io" }
+
+[package.metadata.docs.rs]
+features = ["std"]
+rustdoc-args = ["--cfg", "docsrs"]

embedded-io-async/src/impls/boxx.rs

@@ -0,0 +1,44 @@
+use crate::{BufRead, Read, Seek, SeekFrom, Write};
+use alloc::boxed::Box;
+
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+impl<T: ?Sized + Read> Read for Box<T> {
+    #[inline]
+    async fn read(&mut self, buf: &mut [u8]) -> Result<usize, Self::Error> {
+        T::read(self, buf).await
+    }
+}
+
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+impl<T: ?Sized + BufRead> BufRead for Box<T> {
+    #[inline]
+    async fn fill_buf(&mut self) -> Result<&[u8], Self::Error> {
+        T::fill_buf(self).await
+    }
+
+    #[inline]
+    fn consume(&mut self, amt: usize) {
+        T::consume(self, amt)
+    }
+}
+
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+impl<T: ?Sized + Write> Write for Box<T> {
+    #[inline]
+    async fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
+        T::write(self, buf).await
+    }
+
+    #[inline]
+    async fn flush(&mut self) -> Result<(), Self::Error> {
+        T::flush(self).await
+    }
+}
+
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+impl<T: ?Sized + Seek> Seek for Box<T> {
+    #[inline]
+    async fn seek(&mut self, pos: SeekFrom) -> Result<u64, Self::Error> {
+        T::seek(self, pos).await
+    }
+}

embedded-io-async/src/impls/mod.rs

@@ -1,2 +1,7 @@
 mod slice_mut;
 mod slice_ref;
+
+#[cfg(feature = "alloc")]
+mod boxx;
+#[cfg(feature = "alloc")]
+mod vec;

embedded-io-async/src/impls/vec.rs

@@ -0,0 +1,12 @@
+use alloc::vec::Vec;
+
+use crate::Write;
+
+#[cfg_attr(docsrs, doc(cfg(any(feature = "std", feature = "alloc"))))]
+impl Write for Vec<u8> {
+    #[inline]
+    async fn write(&mut self, buf: &[u8]) -> Result<usize, Self::Error> {
+        self.extend_from_slice(buf);
+        Ok(buf.len())
+    }
+}

embedded-io-async/src/lib.rs

@@ -1,9 +1,12 @@
-#![no_std]
 #![feature(async_fn_in_trait, impl_trait_projections)]
+#![cfg_attr(not(feature = "std"), no_std)]
 #![cfg_attr(docsrs, feature(doc_cfg))]
 #![warn(missing_docs)]
 #![doc = include_str!("../README.md")]
 
+#[cfg(feature = "alloc")]
+extern crate alloc;
+
 mod impls;
 
 pub use embedded_io::{Error, ErrorKind, Io, ReadExactError, SeekFrom, WriteAllError};