How to get current time as long or ulong?

[John via Digitalmars-d-learn]

On Tuesday, 5 July 2016 at 18:16:31 UTC, Charles Hixson wrote:
> I've been reading std.datetime documentation backwards and 
> forwards, but if the information is there, I've been missing it.
>
> How do I get the current time as a long?
>
> Clock.currTime() returns a SysTime, and while currently I can 
> convert that to a long, this is because I looked into the code. 
> What's the supported way?  All the documentation seems to be 
> based around auto, which is great if you don't need to store it 
> in memory with a defined number of bits allocated...but lousy 
> if you do.   (E.g., I don't want to store a time zone, just the 
> UTC time.
>
> What I'm looking for is the opposite of the "FromUnixTime" 
> function.

Clock.currTime.stdTime