# machine dependent type

this is why dangerous use default C type

![image](../_images/ab2fe93379a3a12a1f8c1bbf3d825092e88a5890ad2dffc12826ef5953bf82b5c028c0539985a2eb08fb222e33fb46bf9c96fa3e014d498f77c976c1.png)

`unsigned long` is 8 byte wide (on x64), but 32 bit wide (on x86 arch).