Video: https://www.youtube.com/watch?v=xe2_whJWBC0 <!-- TRIAGEBOT_START --> <!-- TRIAGEBOT_ASSIGN_START --> This issue has been assigned to @amanjeev via [this comment](https://github.com/rust-lang/rustc-guide/issues/352#issuecomment-506102710). <!-- TRIAGEBOT_ASSIGN_DATA_START$${"user":"amanjeev"}$$TRIAGEBOT_ASSIGN_DATA_END --> <!-- TRIAGEBOT_ASSIGN_END --> <!-- TRIAGEBOT_END -->