On Saturday, 26 June 2021 at 20:03:01 UTC, kinke wrote:
On Saturday, 26 June 2021 at 13:49:25 UTC, Ola Fosheim Grøstad
wrote:
Is it possible to inherit from a C++ class and get a D
subclass, and is it possible to inherit from a D class and get
a C++ class?
Sure thing, with `extern(C++) class` of course.
That is all good, but it will lead to `extern(C++) class`
replacing D classes. So why not unify right away? Why wait for
the inevitable?
With C++, you can today, an `extern(C++) class C` is equivalent
to and mangled as C++ `C*`. You can't pass it directly to some
`unique_ptr<C>` or `shared_ptr<T>` of course; an according D
wrapper reflecting the C++ implementation (library-dependent)
would be needed anyway for correct mangling. It'd be
implemented as a templated D struct
Yes, this is all good. But if you unify the layout of C++ and D
classes and use the same layout as C++ shared_ptr for reference
counted D classes then you can easily move back and forth between
the languages. I think the presumption that development only
happens in D and you only use other people's C++ code is ill
advised. One may use a framework in C++ that one also extend in
C++, but maybe want to use another language for the high level
stuff.
