On Monday, 13 December 2021 at 07:48:34 UTC, evilrat wrote:
On Sunday, 12 December 2021 at 21:24:39 UTC, Jan wrote:
In D I have an extern(C++) class:
```cpp
extern(C++) class A
{
~this();
// other stuff
}
```
An a function that takes A by const reference:
```cpp
void CppFunc(const A& arg);
```
But how do I bind this in D ?
```cpp
extern(C++) void CppFunc(A arg); // tries to pass as 'A*'
extern(C++) void CppFunc(ref const(A) arg); // tries to pass
as 'A const * const &'
```
I have solved similar problems with other classes by declaring
them as struct in D, but that only works for classes that have
no virtual functions. I now have a class where I do need to
use a class on the D side, and now I have problems passing
these objects to C++.
You can tell compiler to mangle it as struct/class using
extern(C++, struct).
```d
extern (C++, struct) // will use struct mangling even though
it's a class
class SomeDClass
{
...
}
```
I tried this, but it doesn't work, because it seems D decides how
to pass the object by whether it is a class or struct in D, not
in C++. So even with the change as you suggested it, it still
tries to pass the object as a pointer to begin with.
