[kzrdude]

My go-to example of "UB is everywhere" is this one:

    int increment(int x) {
        return x + 1;
    }

Which is UB for certain values of x.

[CodeArtisan]

C23 removed the whole stuff about indeterminate value and trap representation. Underflow/overflow being silent or not is implementation defined.

[saagarjha]

Signed overflow is just undefined.

[jstimpfle]

TBF that is the same as saying "signed overflow is UB".

[kzrdude]

yes but it is a 'picture' that makes you think about it in a different way.