TickDuration deprecation

[sarn]

On Wednesday, 22 November 2017 at 22:17:05 UTC, Walter Bright 
wrote:
> On 11/22/2017 5:45 AM, Steven Schveighoffer wrote:
>> 1. All OS calls with timing requirements use non-floating 
>> point to represent how long to sleep. After all a CPU uses 
>> discrete math, and the timing implementation is no different.
>
> Microsoft has numerous COM APIs for time functions. One of them 
> I had to deal with used doubles to represent seconds. This had 
> to be interfaced with other time functions that used integers. 
> The trouble came from round trips - there were cases where 
> double=>integer=>double did not produce the same result. Even 
> worse,
>
>     double=>integer=>double=>integer=>double ...
>
> produced a creeping shift in the value! It took much time to 
> come up with a method of preventing such drift, and even that 
> was unreliable.

It's fixed point, not floating point, but this famous software 
disaster is a pretty dramatic example: 
http://www-users.math.umn.edu/~arnold/disasters/patriot.html

+1 to using integer arithmetic for the low-level time APIs.