Function gsl_sys::gsl_multifit_nlinear_eval_f

pub unsafe extern "C" fn gsl_multifit_nlinear_eval_f(
    fdf: *mut gsl_multifit_nlinear_fdf, 
    x: *const gsl_vector, 
    swts: *const gsl_vector, 
    y: *mut gsl_vector
) -> c_int