e019: Let's `Clone` a `Cow`

The final pieces of the story for (single-threaded) memory management in Rust. Notes ----- Sometimes, we actually do need to copy types. Wouldn't it be nice if Rust gave us a convenient way to do that when it's convenient, or when the cost is low enough that the ergonomic tradeoffs are worth it? Well, perhaps unsurprisingly, it does! The Copy and Clone traits, plus the Cow type, give us everything we need! Sponsors -------- - Aleksey Pirogov - Andreas Fischer - Andrew Thompson - Austin LeSure - Ben Whitley - Charlie Egan - Chris Palmer - Christopher Giffard - Daniel Collin - Derek Morr - Jakub "Limeth" Hlusička - Jordan Henderson - Jupp Müller - Keith Gray - Lachlan Collins - Luca Schmid - Matt Rudder - Matthew Piziak - [Max Jacobson] - Micael Bergeron - Ovidiu Curcan - Pascal Hertleif - Peter Tillemans - Philipp Keller - Ralph Giles ("rillian") - Raph Levien - reddraggone9 - Steven Murawski - Stuart Hinson - Tyler Harper - Vesa Kaihlavirta - Vlad Bezden - William Roe - Zaki (Thanks to the couple people donating who opted out of the reward tier, as well. You know who you are!) ### Become a sponsor - Patreon.com/newrustacean - Venmo.com/chriskrycho - Dwolla](https://www.dwolla.com/hub/chriskrycho - Cash.me/$chriskrycho - Flattr.com/profile/chriskrycho - PayPal.me/chriskrycho Contact ------- - New Rustacean: + Twitter: @newrustacean + Email: [email protected] - Chris Krycho + GitHub: chriskrycho + Twitter: @chriskrycho