How to call opCall as template?

[Meta]

On Thursday, 30 January 2014 at 15:59:28 UTC, Namespace wrote:
> Here: http://dlang.org/operatoroverloading.html#FunctionCall
> is this example:
> ----
> import std.stdio;
>
> struct F {
> 	int opCall() {
> 		return 0;
> 	}
> 	
> 	int opCall(int x, int y, int z) {
> 		return x * y * z;
> 	}
> }
>
> void main() {
> 	F f;
> 	int i;
>
> 	i = f();      // same as i = f.opCall();
> 	i = f(3,4,5); // same as i = f.opCall(3,4,5);
> }
> ----
>
> And it works of course. But what if I want to templatize 
> opCall? How can I call it?
>
> ----
> import std.stdio;
>
> struct F {
> 	T opCall(T = int)(int a, int b, int c) {
> 		return cast(T)(a * b * c);
> 	}
> }
>
> void main() {
> 	F f;
> 	int i = f(3,4,5);
> 	float f_ = f!float(6, 7, 8);
> }
> ----
>
> Does not work, it fails with:
> Error: template instance f!float f is not a template 
> declaration, it is a variable

This is probably a bug. You should file it in Bugzilla.