• "Nick Sabalausky" <a a.a> Nov 28 2009
• Robert Clipsham <robert octarineparrot.com> Nov 28 2009
• "Lars T. Kyllingstad" <public kyllingen.NOSPAMnet> Nov 29 2009

"Nick Sabalausky" <a a.a> writes:

Is there an idiom, preferably D1, to detect whether or not the code is 
currently executing as a ctfe?

Ie:

void foo()
{
    (static?) if( ???? )
    {
        // Run-time code here
        // that does stuff the CTFE engine chokes on
    }
    else
    {
        // CTFE code here
        // that might not be ideal, but at least works as CTFE
    }
}

Robert Clipsham <robert octarineparrot.com> writes:

Nick Sabalausky wrote:
 Is there an idiom, preferably D1, to detect whether or not the code is 
 currently executing as a ctfe?
 
 Ie:
 
 void foo()
 {
     (static?) if( ???? )
     {
         // Run-time code here
         // that does stuff the CTFE engine chokes on
     }
     else
     {
         // CTFE code here
         // that might not be ideal, but at least works as CTFE
     }
 }
 
 


Not currently, but you can use the following hack, which exploits a bug 
with CTFE (if the bug gets fixed then the code below won't work):

----
import tango.io.Stdout;

bool isCtfe()
{
         void test( char[] str )
         {
                 str[0] = 'b';
         }
         char[] a = "foo".dup;
         test(a);
         if( a == "boo" )
                 return false;
         return true;
}

const ctfe = isCtfe();

void main()
{
         Stdout.formatln( "CTFE: {}; Runtime: {};", ctfe, isCtfe() );
}
----

"Lars T. Kyllingstad" <public kyllingen.NOSPAMnet> writes:

Nick Sabalausky wrote:
 Is there an idiom, preferably D1, to detect whether or not the code is 
 currently executing as a ctfe?
 
 Ie:
 
 void foo()
 {
     (static?) if( ???? )
     {
         // Run-time code here
         // that does stuff the CTFE engine chokes on
     }
     else
     {
         // CTFE code here
         // that might not be ideal, but at least works as CTFE
     }
 }


Don posted one to the NG once, but I'm not sure if it works with D1:

http://www.digitalmars.com/d/archives/digitalmars/D/Going_from_CTFE-land_to_Template-land_101395.html#N101414

-Lars