Function libffi_sys::ffi_prep_closure

pub unsafe extern fn ffi_prep_closure(arg1: *mut ffi_closure,
                                      arg2: *mut ffi_cif,
                                      fun: Option<unsafe extern fn(_: *mut ffi_cif, _: *mut c_void, _: *mut *mut c_void, _: *mut c_void)>,
                                      user_data: *mut c_void)
                                      -> ffi_status