$ dmd
Digital Mars D Compiler v1
...


$ make
+ /home/dpc/stg/d/bin/dsss_build -I/home/dpc/stg/d/include/d -LIBPATH=/home/dpc/stg/d/lib/ -LIBPATH=./  -od.
server.d -Tserver
/home/dpc/stg/d/include/d/std/c/time.d(40): Error: non-constant expression
(sysconf)(2)

else version (linux)
{
    extern (C) int sysconf(int);
    const clock_t CLK_TCK = cast(clock_t) sysconf(2); // <---------- THIS
}


How can THIS be a const, hmm?

Dawid Ci??arkiewicz schrieb am 2007-01-07:
> $ dmd
> Digital Mars D Compiler v1
> ...
>
>
> $ make
> + /home/dpc/stg/d/bin/dsss_build -I/home/dpc/stg/d/include/d -LIBPATH=/home/dpc/stg/d/lib/ -LIBPATH=./  -od.
> server.d -Tserver
> /home/dpc/stg/d/include/d/std/c/time.d(40): Error: non-constant expression
> (sysconf)(2)
>
> else version (linux)
> {
>     extern (C) int sysconf(int);
>     const clock_t CLK_TCK = cast(clock_t) sysconf(2); // <---------- THIS
> }

Please replace the line with:
clock_t CLK_TCK(){ return cast(clock_t) sysconf(2); }

Using "static this" would work for common use-cases but not if running applications are beeing migrated between different systems.

> How can THIS be a const, hmm?

D's const isn't exactly Java's const ...

http://www.digitalmars.com/d/attribute.html#const
#
# The const attribute declares constants that can be evaluated at
# compile time.
#

sounds good, but

#
# A const declaration without an initializer must be initialized in a
# constructor (for class fields) or in a static constructor (for static
# class members, or module variable declarations).
#

Thomas

Thomas Kuehne wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Dawid Ci??arkiewicz schrieb am 2007-01-07:
>> $ dmd
>> Digital Mars D Compiler v1
>> ...
>>
>>
>> $ make
>> + /home/dpc/stg/d/bin/dsss_build -I/home/dpc/stg/d/include/d -LIBPATH=/home/dpc/stg/d/lib/ -LIBPATH=./  -od. server.d -Tserver
>> /home/dpc/stg/d/include/d/std/c/time.d(40): Error: non-constant expression
>> (sysconf)(2)
>>
>> else version (linux)
>> {
>>     extern (C) int sysconf(int);
>>     const clock_t CLK_TCK = cast(clock_t) sysconf(2); // <---------- THIS
>> }
> 
> Please replace the line with:
> clock_t CLK_TCK(){ return cast(clock_t) sysconf(2); }
> 
> Using "static this" would work for common use-cases but not if
> running applications are beeing migrated between different systems.

My first instinct when I read that message was to post just such a reply, but then I noticed he wasn't talking about his own code. This is in Phobos's std.c.time module...

Frits van Bommel wrote:
>> Please replace the line with:
>> clock_t CLK_TCK(){ return cast(clock_t) sysconf(2); }
>> 
>> Using "static this" would work for common use-cases but not if running applications are beeing migrated between different systems.
> 
> My first instinct when I read that message was to post just such a reply, but then I noticed he wasn't talking about his own code. This is in Phobos's std.c.time module...

Yes indeed. This is D.bug, not D.learn, right? :)