hybrid-array: Impl Zeroize/ZeroizeOnDrop for Array (#984)

hybrid-array/CHANGELOG.md

@@ -5,5 +5,9 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Pending
+
+* Implement `Zeroize` for `Array<T: Zeroize, U>`, and `ZeroizeOnDrop` for `Array<T: ZeroizeOnDrop, U>`
+
 ## 0.1.0 (2022-05-07)
 - Initial release

hybrid-array/Cargo.toml

@@ -18,3 +18,7 @@ rust-version = "1.65"
 
 [dependencies]
 typenum = "1.17"
+zeroize = { version = "1.7", path = "../zeroize", optional = true }
+
+[features]
+default = []

hybrid-array/README.md

@@ -25,6 +25,12 @@ possible with the stable implementation of const generics:
 Internally the crate is built on const generics and provides traits which make
 it possible to convert between const generic types and `typenum` types.
 
+## Features
+
+This crate exposes the following feature flags. The default is NO features.
+
+* `zeroize` - Implements [`Zeroize`](https://docs.rs/zeroize/latest/zeroize/trait.Zeroize.html) for `Array<T: Zeroize, U>`
+
 ## License
 
 Licensed under either of:

hybrid-array/src/impls.rs

@@ -1,5 +1,27 @@
 use super::{Array, ArrayOps, ArraySize, IntoArray};
 
+#[cfg(feature = "zeroize")]
+use zeroize::{Zeroize, ZeroizeOnDrop};
+
+#[cfg(feature = "zeroize")]
+impl<T, U> Zeroize for Array<T, U>
+where
+    T: Zeroize,
+    U: ArraySize,
+{
+    fn zeroize(&mut self) {
+        self.0.as_mut().iter_mut().zeroize()
+    }
+}
+
+#[cfg(feature = "zeroize")]
+impl<T, U> ZeroizeOnDrop for Array<T, U>
+where
+    T: ZeroizeOnDrop,
+    U: ArraySize,
+{
+}
+
 macro_rules! impl_array_size {
     ($($len:expr => $ty:ident),+) => {
         $(