Function arf_complex_mul_fallback 

pub unsafe extern "C" fn arf_complex_mul_fallback(
    e: *mut arf_struct,
    f: *mut arf_struct,
    a: *const arf_struct,
    b: *const arf_struct,
    c: *const arf_struct,
    d: *const arf_struct,
    prec: slong,
    rnd: arf_rnd_t,
) -> c_int