D string to C struct fixed-size array

[bdh]

On Monday, 4 January 2021 at 18:05:40 UTC, tsbockman wrote:
>> /* XXX: haven't done private members yet, wonder if they're 
>> needed to
>>  * complete this */
>
> Leaving out the private members of a struct changes its size, 
> and sometimes its alignment. This will definitely break things 
> if you ever allocate an instance yourself (including via the 
> stack).
>
> If you only EVER access that type via pointers to instances 
> allocated by an API which internally uses the complete, correct 
> definition, and ALL of the private members are at the end of 
> the struct, it should work - but those are two big "if"s, and 
> too easy to unthinkingly violate later by accident. So, it is 
> best to ensure that the struct definition matches precisely on 
> both the D and C sides of the API, or at least enough to ensure 
> that the size and alignment are the same.

While the struct that comment is from (ImageInfo) had been fixed 
before your message[0], I do appreciate the information here 
since I wasn't aware of it before and it helped solve the issue 
(see my reply to Steve). Thanks.

[0]: https://repo.or.cz/magickd.git/commit/27ac82b110