How to add time to Clock.currTime

[JohnnyK]

On Friday, 4 October 2013 at 21:54:19 UTC, Brad Anderson wrote:
> On Friday, 4 October 2013 at 21:50:31 UTC, Brad Anderson wrote:
>> On Friday, 4 October 2013 at 21:46:43 UTC, JohnnyK wrote:
>>> Hi All,
>>> I did search but I cannot find it anywhere.  All I want to do 
>>> is add 300 seconds to the output of Clock.currTime.  So 
>>> basically if Clock.currTime equals 2013-Oct-04 
>>> 17:19:31.3338333 then I want to subtract 300 seconds from 
>>> that to get the time that it was 300 seconds ago.  In other 
>>> languages I would convert the time value to seconds and 
>>> subtract the 300 seconds then convert it back to what ever 
>>> time value it was before. I don't know how to convert 300 
>>> seconds to hnsecs and I have never actually heard of hnsecs 
>>> before.  Anyway if someone could help I would appreciate it.
>>
>> auto t = Clock.currTime;
>> t -= 300.seconds;
>> t += 300.seconds;
>
> And just a little bit more info, another way to write this is:
>
> auto t = Clock.currTime;
> t -= seconds(300);
> t += seconds(300);
>
> The first way I wrote is just the UFCS version of that.
>
> You could also do:
>
> auto t = Clock.currTime;
> t -= dur!"seconds"(300);
> t += dur!"seconds"(300);
>
> seconds() is just an alias for the dur template with the 
> "seconds" template argument.

Wow I appreciate the quick response.  Ok I have seen this before. 
  What is the dur?  Where is dur defined?  Also I am confused how 
300.seconds would work.  How can a literal number have properties?