Call delegate from C++

[Alex]

On Wednesday, 24 April 2019 at 16:20:17 UTC, Nicholas Wilson 
wrote:
> How do you pass a delegate to a c++ function to be called by it?
>
> The function to pass the delegate to is:
>
> extern (C++) int
> fakeEntrypoint(
>     extern(C++) void function(void* /*delegate's context*/) 
> func,
>     void* /*delegate's context*/ arg);
>
>
> What I want is:
>
> int entrypoint(scope void delegate() func)
> {
>     return fakeEntrypoint(
>                 // for some reason func.funcptr is void 
> function()
>                 cast(void function(void*))func.funcptr,
>                 func.ptr);
> }
>
> but that fails with
>
> cannot pass argument cast(void function(void*))func.funcptr of 
> type
> void function(void*) to parameter extern (C++) void 
> function(void*) func

It's clear that your delegate is not extern C++


int entrypoint(scope extern(C++) void delegate() func)