We need a way to make functions pure and/or nothrow based on the

["Jérôme M. Berger"]

bearophile wrote:
>> @optional_tag(isPure!F, pure) int[] map(F)(F f, int[] data) {
>>     int[] res;
>>     foreach (x; data)
>>         res ~= f(x);
>>     return res;
>> }
> 
> This may not suffice to correctly tell apart strong pure functions from weak pure ones...
> 
	Untested:

==============================8<------------------------------
template optionalTag (bool test, char[] tag) {
   static if (test)
      const char[] optionalTag = tag;
   else
      const char[] optionalTag = "";
}

template bool isPure(F)() {
   return functionAttributes!F & FunctionAttribute.PURE;
}

mixin(optionalTag!(isPure!F, "pure")) int[] map(F)(F f, int[] data) ...
------------------------------>8==============================

	Of course, this suffers from the ugly syntax for string mixins...

		Jerome
-- 
mailto:jeberger at free.fr
http://jeberger.free.fr
Jabber: jeberger at jabber.fr

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