pub const PIECE_TIME: Duration;Expand description
The time on one thread that each piece of a ranges call is given at least. A call whose pieces would be shorter splits into fewer of them, because waking a thread for a shorter piece costs more than the piece saves. On an M5 Max, v+w on a million items, about 200 µs on one thread, took 0.51 copies split across 4 threads and 0.81 across all 18.