Hi, I would like to make a formal request for inclusion of complex numbers in Foreign.C.Types. Which steps should I follow? Here is a start on what I would write in such request. ----- Motivation: As complex is available in C, libraries can pass then by value in function calls, making it difficult to directly wrap such functions in Haskell. GNU GSL, for instance, even if actually using C < 99, does that with a struct type that is supposed to be binary equivalent to C99 double complex. Syntax: My sugestion is to add these: CFComplex --> for 'float complex' CDComplex --> for 'double complex' CLDComplex --> for 'long double complex' I believe this is better than trying to use a kind *->* type, as that would bring little help when actually wrapping C functions. Also, I think it's not important to have field names for real and imaginary, as long as we have an easy convertion for Data.Complex. Also, if we want to take imaginary and real parts in "pure C" Haskell code, we can use available C functions like cimag, creal, cimagf, crealf etc. ----- Thanks for your attention, Maurício