int always 32 bits on all platforms?

[AJ]

"Walter Bright" <newshound1 at digitalmars.com> wrote in message 
news:hbo5il$2snd$5 at digitalmars.com...
> AJ wrote:
>> How can/does D guarantee that "int" will always be 32 bits on all 
>> platforms?
>
> The implementation on a platform must implement it that way.
>
>> Does this mean that D won't work on some platforms?
>
> You can make anything work on any platform

How do you make ABC below work on a platform that requires 32-bit integers 
to be aligned on 32-bit boundaries while keeping the layount and size of ABC 
the same as on a platform that has no such alignment requirement?

struct ABC
{
    byte a;
    int b; // may be improperly aligned on some platforms
    int64 c; // same issue
};