Problem calling extern(C) function

[Adam D. Ruppe via Digitalmars-d-learn]

On Monday, 15 December 2014 at 17:48:32 UTC, AuoroP via 
Digitalmars-d-learn wrote:
>     ulong jpegSize,

Without looking too closely, this sets off an alarm to me: C's 
long and D's long are not really compatible because C's long has 
variable size and D's long is 64 bit.

I'd say try "import core.stdc.config;" and replace all instances 
of ulong with c_ulong and all instances of long with c_long when 
interfacing with C.


> DLLEXPORT int DLLCALL tjDecompressHeader2(tjhandle handle,
> unsigned char *jpegBuf, unsigned long jpegSize, int *width, int 
> *height,


yeah the D long is 32 bits longer than the C function expects, so 
every argument after it is offset by that amount.