> is never more expensive than the cost of copying a pointer Well, if you're passing something that is pointer size, yes. But say, `chan.send([0u8, .. 1_000_00

> is never more expensive than the cost of copying a pointer Well, if you're passing something that is pointer size, yes. But say, `chan.send([0u8, .. 1_000_000])` will do at least one 1 MB memcpy to load that into the stream, and a 1 MB memcpy to load it out of it when `.recv()` is called.