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digitalmars.D.bugs - [Issue 6740] New: Can't call variadic type argument as a template function

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=6740

           Summary: Can't call variadic type argument as a template
                    function
           Product: D
           Version: D2
          Platform: Other
        OS/Version: Windows
            Status: NEW
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: nobody puremagic.com
        ReportedBy: andrej.mitrovich gmail.com


--- Comment #0 from Andrej Mitrovic <andrej.mitrovich gmail.com> 2011-09-28
11:25:03 PDT ---
template test(T, Preds...)
{
    enum bool test = Preds[0]!T;  // error: semicolon expected, not '!'
}

Example use-case:

import std.traits;
template anyPredicateSatisfy(T, Preds...) 
{
   static if (Preds.length)
       enum bool anyPredicateSatisfy = (Preds[0]!T) || anyPredicateSatisfy!(T,
Preds[1 .. $]);
   else
       enum bool anyPredicateSatisfy = false;
}

void main()
{
    assert(anyPredicateSatisfy!(int, isFloatingPoint, isIntegral));
}

A workaround (by Bearophile) is:

template satisfies(T, alias P) { enum satisfies = P!T; }

template anyPredicateSatisfy(T, Preds...) 
{
   static if (Preds.length)
       enum bool anyPredicateSatisfy = satisfies!(T, Preds[0]) ||
anyPredicateSatisfy!(T, Preds[1 .. $]);
   else
       enum bool anyPredicateSatisfy = false;
}

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parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=6740


Andrej Mitrovic <andrej.mitrovich gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |DUPLICATE


--- Comment #1 from Andrej Mitrovic <andrej.mitrovich gmail.com> 2013-02-10
09:10:37 PST ---
*** This issue has been marked as a duplicate of issue 6474 ***

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