Method which I use now:

source D:
---------
extern (C) {
    int on_metFromD(CEditWin* uk, int aa, int bb) {
        return (*uk).metFromD(int aa, int bb);
    }
}

class CEditWin {
    . . .
    // Method for to call
    int metFromD(int a, int b) {
        return a + b;
    }
}

main() {
    CEditWin f = new CEditWin(); void* pf = &f;
    // save pf and &on_metFromD in DLL
    toTransferInDLL(pf, &on_metFromD);
}

source C++ DLL
--------------
extern "C" typedef int (*execDmet1)(void*, int, int);

extern "C" void toTransferInDLL(void* pf, void* on_metFromD) {
    int rez = ((execDmet1)on_metFromD)(pf, 2, 3);
}

---------------------
How to change a code that it was possible transferring two parameters in C++ ( toTransferInDLL(pf, &on_metFromD) ) directly to call a method D.

How to call delegate from C++

On Saturday, 27 August 2016 at 04:44:10 UTC, MGW wrote:
> Method which I use now:
>
> source D:
> ---------
> extern (C) {
>     int on_metFromD(CEditWin* uk, int aa, int bb) {
>         return (*uk).metFromD(int aa, int bb);
>     }
> }
>
> class CEditWin {
>     . . .
>     // Method for to call
>     int metFromD(int a, int b) {
>         return a + b;
>     }
> }
>
> main() {
>     CEditWin f = new CEditWin(); void* pf = &f;
>     // save pf and &on_metFromD in DLL
>     toTransferInDLL(pf, &on_metFromD);
> }
>
> source C++ DLL
> --------------
> extern "C" typedef int (*execDmet1)(void*, int, int);
>
> extern "C" void toTransferInDLL(void* pf, void* on_metFromD) {
>     int rez = ((execDmet1)on_metFromD)(pf, 2, 3);
> }
>
> ---------------------
> How to change a code that it was possible transferring two parameters in C++ ( toTransferInDLL(pf, &on_metFromD) ) directly to call a method D.
>
> How to call delegate from C++

easiest method would be to mark the D class extern(C++) noting that in C++ a D class reference becomes a pointer to the C++ class.
Also note that in D classes are reference types so
int on_metFromD(CEditWin* uk, int aa, int bb)
should probably be
int on_metFromD(CEditWin uk, int aa, int bb)
as the extra level of indirection is unnecessary.

On Saturday, 27 August 2016 at 07:13:01 UTC, Nicholas Wilson wrote:
> easiest method would be to mark the D class extern(C++) noting that in C++ a D class reference becomes a pointer to the C++ class.

In "the D class extern(C++)" do't work phobos.

On Sunday, 28 August 2016 at 08:20:52 UTC, MGW wrote:
> On Saturday, 27 August 2016 at 07:13:01 UTC, Nicholas Wilson wrote:
>> easiest method would be to mark the D class extern(C++) noting that in C++ a D class reference becomes a pointer to the C++ class.
>
> In "the D class extern(C++)" do't work phobos.

? What has this got to do with Phobos?

extern(C++) ImACPlusPlusClassDefinedInD class
{
    //...
}