asynchronous I/O with promises25 May 2015 My Rust implementation of the Cap’n Proto remote procedure call protocol was designed in a bygone era. Back then, Rust’s runtime library provided thread-like “tasks” that were backed by libgreen and were therefore “cheap to spawn.” These enabled CSP-style programming with beautifully simple blocking I/O operations that were, under the hood, dispatched through libuv. While the question
