On Wednesday, 15 December 2021 at 19:28:44 UTC, Jan wrote:
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.
I can reproduce your problem. It seems to work if var is
additionally static:
extern(C++, class) struct Test
{
extern (C++) export extern static __gshared int var;
}
It's probably a bug, that it does not work without static. The
documentation says "__gshared may also be applied to member
variables and local variables. In these cases, __gshared is
equivalent to static, except that the variable is shared by all
threads rather than being thread local."
(https://dlang.org/spec/attribute.html#gshared)
