Binding to GSL library

[Radek via Digitalmars-d-learn]

Hi, I'm making a trying to bind a gsl library 
http://www.gnu.org/software/gsl/ so far it was working but when i 
started binding complex numbers some functions won't work, like 
trigonometric functions - called they return null.

in gsl code complex struct looks like:
typedef struct
  {
    double dat[2];
  }
gsl_complex;


my complex struct looks like that:

struct _gsl_complex {
  double dat[2];
}
alias gsl_complex = _gsl_complex*;

So, what im doing wrong?