[Redirect to gcc-help. The gcc list is for the development of GCC.] On 04/14/2014 10:11 AM, Yves Mocquard wrote: > long long fct() > { > return 0x123456789; > } > int main() > { > int a = fct(); > cerr << a << endl; > } `-Wconversion' is the warning you want. This warning is not enabled by default because it produces too many warnings on good code. Andrew.