ParameterIdentifierTuple returns empty strings

[Andre Pany]

Hi,

I need to retrieve the parameter identifier but only empty 
strings are returned:
tuple("", "")

``` d
alias fpt = extern(C) nothrow void function(int a, int b);

void main()
{
     import std.traits : ParameterIdentifierTuple;
     pragma(msg, ParameterIdentifierTuple!(fpt));
}
```

Where is here the error?

Kind regards
André