• Zekereth (14/14) Feb 18 2016 I'm confused by the following:
• Adam D. Ruppe (6/8) Feb 18 2016 "seconds" is a literal value that the compiler knows about.
• Zekereth (4/12) Feb 18 2016 Thanks a lot Adam!
• Zekereth (4/18) Feb 18 2016 Never mind I found a better solution to my problem by storing a
• Steven Schveighoffer (7/24) Feb 19 2016 Because it might help with some future issue:

Zekereth <paul acheronsoft.com> writes:

I'm confused by the following:

import std.stdio;
import std.datetime;

void main()
{
	string unitType = "seconds";
	auto seconds = 1;
//	auto myDur = dur!(unitType)(seconds); // Error unitType can't 
be read at compile time.
	auto myDur = dur!("seconds")(seconds); // Compiles why?
}

How is seconds able to be read at compile time but unitType 
cannot?

Thanks!

Adam D. Ruppe <destructionator gmail.com> writes:

On Friday, 19 February 2016 at 04:08:02 UTC, Zekereth wrote:
 How is seconds able to be read at compile time but unitType 
 cannot?

"seconds" is a literal value that the compiler knows about. 
unitType is a variable that might change between its declaration 
and use (it doesn't here, but the compiler doesn't check if it 
actually does, just if it *can*), so the compiler doesn't allow 
it.

Zekereth <paul acheronsoft.com> writes:

On Friday, 19 February 2016 at 04:16:23 UTC, Adam D. Ruppe wrote:
 On Friday, 19 February 2016 at 04:08:02 UTC, Zekereth wrote:
 How is seconds able to be read at compile time but unitType 
 cannot?

 "seconds" is a literal value that the compiler knows about. 
 unitType is a variable that might change between its 
 declaration and use (it doesn't here, but the compiler doesn't 
 check if it actually does, just if it *can*), so the compiler 
 doesn't allow it.

Thanks a lot Adam!

So is there a way around this?. I want duration to be 
configurable at runtime.

Zekereth <paul acheronsoft.com> writes:

On Friday, 19 February 2016 at 04:21:43 UTC, Zekereth wrote:
 On Friday, 19 February 2016 at 04:16:23 UTC, Adam D. Ruppe 
 wrote:
 On Friday, 19 February 2016 at 04:08:02 UTC, Zekereth wrote:
 How is seconds able to be read at compile time but unitType 
 cannot?

 "seconds" is a literal value that the compiler knows about. 
 unitType is a variable that might change between its 
 declaration and use (it doesn't here, but the compiler doesn't 
 check if it actually does, just if it *can*), so the compiler 
 doesn't allow it.

 Thanks a lot Adam!

 So is there a way around this?. I want duration to be 
 configurable at runtime.

Never mind I found a better solution to my problem by storing a 
Duration instead of the unitType. Works just fine.

Thanks a lot I appreciate your help!

Steven Schveighoffer <schveiguy yahoo.com> writes:

On 2/18/16 11:36 PM, Zekereth wrote:
 On Friday, 19 February 2016 at 04:21:43 UTC, Zekereth wrote:
 On Friday, 19 February 2016 at 04:16:23 UTC, Adam D. Ruppe wrote:
 On Friday, 19 February 2016 at 04:08:02 UTC, Zekereth wrote:
 How is seconds able to be read at compile time but unitType cannot?

 "seconds" is a literal value that the compiler knows about. unitType
 is a variable that might change between its declaration and use (it
 doesn't here, but the compiler doesn't check if it actually does,
 just if it *can*), so the compiler doesn't allow it.

 Thanks a lot Adam!

 So is there a way around this?. I want duration to be configurable at
 runtime.

 Never mind I found a better solution to my problem by storing a Duration
 instead of the unitType. Works just fine.

 Thanks a lot I appreciate your help!

Because it might help with some future issue:

Instead of auto, declare the unitType as immutable or enum:

immutable unitType = "seconds";
enum unitType = "seconds";

Then the compiler knows it won't change.

-Steve