Re: How to pass a class by (const) reference to C++

[Jan via Digitalmars-d-learn]

On Wednesday, 15 December 2021 at 17:10:51 UTC, Tim wrote:
Do you have a test case for your problem?

C++
```cpp
class Test
{
public:
  __declspec(dllexport) static int var;
};

int Test::var = 42;
```

D
```cpp
extern(C++, class) struct Test
{
  extern (C++) export extern __gshared int var;
}
```

(also tried without the duplicate extern(C++) and without 
'export')

DLL compiled with Visual Studio 2019. D DLL compiled with a 3 day 
old nightly build of DMD.

DMD says:
`error LNK2019: unresolved external symbol "public: static int 
Test::var" (?var@Test@@2HA)`

I've checked the .exp file of the DLL where the symbol is defined 
in, and it has the exact same name there. And yes, I correctly 
link against that DLL in general, other symbols located in that 
DLL are linked just fine by DMD.