On Thu, 31 May 2012 11:36:47 +0200, Sandeep Datta wrote:
> Hi,
>
> I was going through some sample code online and came across the
> following code fragment...
>
> listenHttp(settings, &handleRequest); //Where handleRequest is a
> function
>
> My question to you is (as the title says) is the address-of operator (&)
> really needed here? Wouldn't it be better to consider handleRequest to
> be a reference to the actual function? I think this will make the system
> consistent with the way variables work in D. IMO this will bring
> functions/delegates closer to being first class objects in D.
>
> What do you think?
>
> Regards,
> Sandeep Datta.
It is needed.
Consider this example:
import std.stdio;
/*
float handleRequest() {
return 1.0f;
}
*/
int handleRequest() {
return 200;
} // handleRequest() function
int main() {
int function() fptr;
//fptr = handleRequest; // will not work, because it is "understdood"
as:
// fptr = handleRequest();
fptr = &handleRequest; // This will work if we have only one
handleRequest();
// If you uncomment the first one, you are in
trouble
int val = handleRequest; // calls handleRequest() actualy
//listenHttp(settings, fptr); // no need for & because fptr is an
object of "int function()" type
writeln(val); // OUTPUT: 200
return 0;
} // main function
--
Dejan Lekic
mailto:dejan.lekic(a)gmail.com
http://dejan.lekic.org
