H1 2015 - C++ integration

[Daniel Murphy via Digitalmars-d]

"Guillaume Chatelet"  wrote in message 
news:fzxoskcrswitmsdsztso at forum.dlang.org...

> I did a few tests. Using a class doesn't work because of the added vptr.

This is a bug, D currently adds a vptr even if there are no members.  It's 
just one that doesn't happen to affect ddmd so I never got around to fixing 
it.

> struct std_string {
>    void[8] _ = void; // to match sizeof(std::string) and pad the object 
> correctly.
> }
>
> The padding will be left untouched on the D side because of void 
> initializer and will be managed entirely on the C++ side.

Just remember to be careful that any C++ structs don't rely on interior 
pointers.

> - name mangling on linux (bug reported in my first message)

Is this in bugzilla?

> - name mangling on Windows at least (name would be mangled as a struct 
> instead of class)

We can probably use pragma(mangle) to fix this or add a new pragma for it. 
eg pragma(cpp_class/cpp_struct);

> - disabled default constructor.

Yeeeeah I've always felt like we're going to have to add default struct 
ctors to D eventually.