Are padding bits always zero?

[Steven Schveighoffer via Digitalmars-d-learn]

On 6/24/17 4:44 AM, Honey wrote:
> Hi everyone!
> 
> Are there any guarantees about the values of padding bits in structs?
> 
> Thanks,
> Honey

Any padding bits between fields should be 0 as long as the struct is 
initialized (i.e. as long as you don't do Struct s = void).

Padding bits after the fields I assume would be 0, but I don't know if 
this is defined. It's possible the compiler doesn't consider those bits 
to be part of the struct, and just there for alignment.

There is no spec for this, but I know that when the compiler has to fill 
gaps with something it chooses 0.

-Steve