C++ interface problem

[Laeeth Isharc via Digitalmars-d-learn]

On Sunday, 26 April 2015 at 15:49:46 UTC, extrawurst wrote:
> I hope someone can tell me where my bug is.
> I am linking to a dynamic library with C++ interfaces:
>
> ```
> //alias S = ulong;
> struct S
> {
>   ulong data;
> }
>
> extern(C) I getI();
>
> extern(C++) interface I
> {
>   void foo();
>   S bar();
> }
> ```
>
> now the question is why does it crash to access bar() in both 
> cases? (using alias aswell as the struct)
> The C++ class S is a POD class (it contains only 64bits of data 
> and is compiled byte aligned)
> The call to bar() from D just crashes on win32, the interface 
> works fine on osx 64bit.
> Any help would be welcome! Is this even possible to solve ? I 
> have no access to the library code so I am not able to build 
> the C++ lib with like DMC or something...

Long always 64 bit in D but varies with architecture in C.  See 
here:
http://wiki.dlang.org/Converting_C_.h_Files_to_D_Modules

Core.stdc.config has alias for the C type that you can use in 
place of long.