Alignof takes an expression x of any type and returns the required alignment of a hypothetical variable v as if v was declared via var v = x.

Offsetof returns the offset within the struct of the field represented by x, which must be of the form structValue.field.

Sizeof takes an expression x of any type and returns the size in bytes of a hypothetical variable v as if v was declared via var v = x.

ArbitraryType is here for the purposes of documentation only and is not actually part of the unsafe package.