fmt-extra

Extra formatters (impliment fmt::Display and fmt::Debug) as wrapper types.

• AsciiStr: print a [u8]-like as a string of ascii characters with non-visible characters escaped with the rust & c-style "\xFF"
• Hs: print a [u8]-like as the hex digits without any seperators: "AF13"...
• SingleQuotedStr: print a &str with posix shell style single quote escaping
• Seperated: print an Iterator<T: Display> with a single Display-able seperator between each item.