Re: D string to C struct fixed-size array

[bdh via Digitalmars-d-learn]

On Monday, 4 January 2021 at 17:24:27 UTC, Steven Schveighoffer 
wrote:
On 1/3/21 9:17 PM, bdh wrote:
On Sunday, 3 January 2021 at 11:16:25 UTC, rikki cattermole 
wrote:
Your definition of Image is probably wrong.
You may have missed a pointer (8 bytes).

[...]


How to test:

in D-land:

import magickd.core.c.image : Image;

pragma(msg, Image.filename.offsetof);

In C-land

#include <stdio.h>
#include <magick/image.h>

int main()
{
   Image *ptr = NULL;
   printf("%ld", &(ptr->filename)); // may need a different 
specifier
}

If those are not the same, then your struct is off.

-Steve

Thanks for this, I wasn't aware of the .offsetof property (I see 
it's mentioned in the Struct and Unions section of the language 
reference).

As rikki guessed, I had missed something (offset was 480 instead 
of 488).  The issue wasn't with the Image struct itself, but with 
the TimerInfo struct (used for the `timer` member of Image) 
missing a "private" unsigned long.

Thanks again.