IupSetCallback function passing

[James Wirth]

When trying to associate an Icallback function to a button in the 
IUP GUI
API using the IupSetCallback function, the D compiler seems to 
insist on evaluating that callback in order to pass its value 
rather than passing the function itself.

I get this dmd compiler error (the source is named hitmeiup.d) :

Error: function hitmeiup.hitMeAct (Ihandle_* dmy) is not callable 
using argument types ()
hitmeiup.d(41): Error: expected 1 function arguments, not 0

for this line calling the IupSetCallback:

	IupSetCallback(btn,"ACTION",hitMeAct);

The callback function was named hitMeAct as follows:

extern(C) {
	int hitMeAct(Ihandle *dmy) {
		sayHit();
		return 0;
	}
}

I have also tried it with hitMeAct being a D function instead of 
extern(C).

It is as if the	call to IupSetCallback is interpreting hitMeAct 
to be a property function and that the call was meant to be:

	IupSetCallback(btn,"ACTION",hitMeAct());

It there someway to force D to consider the hitMeAct parameter to 
be passing a function and NOT calling it?  I tried prefixing a & 
- no go.

Would welcome any hints.

Yes I have already looked at the .d files purporting to provide 
access to IUP.
And a more or less equivalent C program works fine.