[caf]

The padding has unspecified values, which is distinct from being uninitialised.

If it were otherwise, you couldn't `memcpy()` structures around.

[loup-vaillant]

I believe there's an exception for the likes of `memcpy()`. Something along the lines of "type punning and reading indeterminate values is undefined except when we're reading through a `char*` or something.

I'll check the unbelievably thick book that tries to specify C11 (I've printed it, it's over 2 pounds).

[caf]

The only way to access the padding without otherwise falling into undefined behaviour is by using a char * anyway (including indirectly using a char *, through memcpy()).