Why is the function called in the template at the line of .stringof?

template t(alias fn) {
    static if(fn.stringof) // f(int i) isn't callable using ()
        enum t = true;
    else
        enum t = false;
}

void main() {
    void f(int i) {}
    t!f;
}

On Saturday, 16 March 2013 at 13:01:44 UTC, simendsjo wrote:
> Why is the function called in the template at the line of .stringof?
>
> template t(alias fn) {
>     static if(fn.stringof) // f(int i) isn't callable using ()
>         enum t = true;
>     else
>         enum t = false;
> }
>
> void main() {
>     void f(int i) {}
>     t!f;
> }

Seems pragma(msg, fn) also has the same behavior.
Guess this is because all functions can be called using property syntax. It really hurts my generic code though..

On 3/16/13, simendsjo <simendsjo@gmail.com> wrote:
> Why is the function called in the template at the line of .stringof?
>
> template t(alias fn) {
>      static if(fn.stringof) // f(int i) isn't callable using ()

Use __traits(identifier, fn).