Function copy_ns_per_element 

pub fn copy_ns_per_element() -> f64

Serial throughput of a copy in nanoseconds per element on this host (copy_ns_per_element_of of HostClass::detect).

The Copy class of the strided stack (strided_basic::execution::KernelClass holds the class table; this crate sits below it and owns the one rate it needs). copy_into* multiply it by the element count and ask the token whether one section pays.