void initialization vs alignment holes

[strtr]

This is probably going a bit above my head, but

"the existence of alignment holes in the objects is accounted for, usually by setting them all to 0 upon initialization"

I suspect this isn't the case for void initialization; if my struct has some alignment hole I better not void initialize it if ever I want to compare it with somthing.
Is this correct?
Would you ever have an alignment hole if all the struct contains are basic types(excluding bool)?