In reply to your edit, that section in the RFD includes a link to the full example in the Rust playground. You’ll note that it does not make any use of ‘select!

In reply to your edit, that section in the RFD includes a link to the full example in the Rust playground. You’ll note that it does not make any use of ‘select!`: https://play.rust-lang.org/?version=stable&mode=debug&edition=2024&gist=3b8505524169c79a6bd53c3aa9f5fbfa https://play.rust-lang.org/?version=stable&mode=debug&editio... Perhaps the full example should have been reproduced in the RFD for clarity…