Mtime.SpanSourceMonotonic time spans
abs_diff s0 s1 is the absolute difference between s0 and s1.
n * dur is n times duration n. Does not check for overflow or that n is positive.
to_uint64_ns s is s as an unsigned 64-bit integer nanosecond span.
of_uint64_ns u is the unsigned 64-bit integer nanosecond span u as a span.
of_float_ns f is the positive floating point nanosecond span f as a span. This is None if f is negative, non finite, or larger or equal than 253 (~104 days, the largest exact floating point integer).
to_float_ns s is span as a nanosecond floating point span. Note that if s is larger than 253 (~104 days, the largest exact floating point integer) the result is an approximation and will not round trip with of_float_ns.
pp formats with Fmt.uint64_ns_span.