byte_string 
The byte_string crate provides two types: ByteStr and ByteString.
Both types provide a Debug implementation
that outputs the slice using the Rust byte string syntax.
ByteStr wraps a byte slice ([u8]).
ByteString wraps a vector of bytes (Vec<u8>).
For example:
extern crate byte_string;
use ByteStr;
ByteStr is an unsized type, as [u8] is.
ByteStr::new() returns a &ByteStr
and ByteStr::new_mut() returns a &mut ByteStr.
ByteStr and ByteString are meant to be used as an implementation detail.
You should generally avoid exposing a ByteStr or a ByteString
as part of a struct or enum;
prefer exposing the underlying slice or vector instead.
However, ByteStr and ByteString implement many traits, including derivable traits,
which makes them suitable for use as a private member of a struct or enum.
License
byte_string is licensed under the terms of both the MIT license and the Apache License, version 2.0.