Support generic-array as arrayvec backend

src/lib.rs

@@ -13,10 +13,18 @@
 //!   - Requires Rust nightly channel
 //!   - Use the unstable feature untagged unions for the internal implementation,
 //!     which has reduced space overhead
+//!
+//! - `use_generic_array`
+//!   - Optional
+//!   - Depend on generic-array and allow using it just like a fixed
+//!     size array for ArrayVec storage.
 #![cfg_attr(not(feature="std"), no_std)]
 extern crate odds;
 extern crate nodrop;
 
+#[cfg(feature = "use_generic_array")]
+extern crate generic_array;
+
 #[cfg(not(feature="std"))]
 extern crate core as std;