On Thursday, 2 April 2015 at 12:15:31 UTC, Daniel Murphy wrote:
"017hnoor" wrote in message
news:vxieyipmafnyksque...@forum.dlang.org...
I'm mainly talking about a simple
code based solution but I'm also curious about how easily this
would be by compiler modification.
It would be easier to comment on if I knew what problem you
were trying to solve. Porting an application? D plugin for
C++ app? C++ library D app?
NOOOO!!!!
You are completely off your rocker!! I'm not trying to solve any
problems! I'm simply curious if the above is possible?
We know we can bind D to C but if we could write C++ code that is
compatible with D at the binary level then maybe it would be
easier to bind C to D?
IIRC the issue was that C++'s class layout doesn't have a
metadata pointer and it's vtable is just a list(can't contain
pointers to other vtables or whatever).
But suppose it was possible to "finagle" C++ so that we had the
metadata pointer in the right place.
e.g., suppose we could do something like this in C++:
class CWrapper
{
....
void* operator new(std::size_t sz)
{
// e.g.,
int size = sizeof(CWrapper) + 4;
void* p = malloc(size);
p[0] = CWrapperMetaDataPtr;
return p+2*4;
}
}
So, the idea with the above scratch-code is that we have CWrapper
laid out like
MetaData ptr
vtable ptr
CWrapper
Which, I think is now similar to D. In theory, if the metadata is
correct then D should be able to use CWrapper directly as it
would then look like a D Class?
We could even probably mimic the build in operators in D in C++?
E.g., opdispatch can be added. Obviously the C++ compiler has no
idea about that so we would have to call it explicitly and this
may be bug prone(confusing C++ with D) but we could call it
explicitly if we need it on the C++ side.
Anyways, Just an idea. I'm curious to how well it well and easy
it would work. There is no real point at it, no application, etc.
Just call it a "thought experiment".
