Function gsl_sys::gsl_integration_qng

pub unsafe extern "C" fn gsl_integration_qng(
    f: *const gsl_function, 
    a: f64, 
    b: f64, 
    epsabs: f64, 
    epsrel: f64, 
    result: *mut f64, 
    abserr: *mut f64, 
    neval: *mut usize
) -> c_int