alias using Complex!Double in module ... linker error??

[james.p.leblanc via Digitalmars-d-learn]

I am getting linker errors with this stripped-down example:
-------------------------------------------
**my_main.d:**

import std.stdio;
import std.complex;
import my_module;


    void main(){
          my_TYPE xxx;
          writeln(xxx);
    }

-------------------------------------------
**my_module.d:**

module my_module;

import std.complex;

alias my_TYPE = Complex!double;    *// this causes link error: 
"undefined reference"*

/* alias my_TYPE = double; */      *// this works fine*

------------------------------------------

Why does the linker fail when I alias to the Complex!double ...
but would work fine when alias to the double ??

Any help to understand what is greatly appreciated.
James