STRUCT padding q

[Raj Pashwar]

Hello Friends

In the case where a STRUCT receives padding bytes, either right at the
beginning, or right at the end, will it be GUARANTEED by ANSI C that
size_of(struct) will include those extremal padding bytes?

Regards
Raj

 

[Ike Naar]

In the case where a STRUCT receives padding bytes, either right at the
beginning, or right at the end, will it be GUARANTEED by ANSI C that
size_of(struct) will include those extremal padding bytes?

Yes.

From the C11 standard:

6.5.3.4 The sizeof and _Alignof operators
4 [...] When applied to an operand that has structure or union
type, the result is the total number of bytes in such an object,
including internal and trailing padding.

Note that there is no padding at the beginning of a struct.