Complex numbers are harder to use than in C

[Marduk via Digitalmars-d-learn]

On Saturday, 19 November 2016 at 11:11:36 UTC, Nordlöw wrote:
> On Saturday, 19 November 2016 at 09:38:38 UTC, Marduk wrote:
>> The difference is that D is more verbose. Am I missing 
>> something? Can we have C's behaviour in D?
>
> Something like
>
> auto I(T)(T im)
>     if (isNumeric!T)
> {
>     return complex(0, im);
> }
>
> unittest
> {
>     auto x = 1 + 2.I;
> }

Nice. But I am unsure of how to use this. I just pasted the 
definition of I inside the main function of my program followed 
by auto x = 1 + 2.I; and the compiler complained with Error: no 
property 'I' for type 'int'.