You have several options, at least if you are willing to stick with GCC/Clang. Passing -fwrapv will give you well-defined (wrapping) signed overflow, which is o

You have several options, at least if you are willing to stick with GCC/Clang. Passing -fwrapv will give you well-defined (wrapping) signed overflow, which is often the native machine behaviour anyway. If you are interested in catching overflow when it happens, you can use intrinsics like __builtin_add_overflow. These look at the overflow flags present on many machines to let you know if the operation overflowed so you can handle it any way you like. If you are of the opinion that overflow should never happen in your program, you can pass -ftrapv which asks the compiler to crash your program if overflow ever occurs.