You should know that the type is promoted to int first, which is also what makes your example work. This is what happens when you perform the computation using

You should know that the type is promoted to int first, which is also what makes your example work. This is what happens when you perform the computation using an non-promoting 8 bit unsigned type: https://godbolt.org/z/fxxva4nWq https://godbolt.org/z/fxxva4nWq