Define "createXXX" functions for the constructors of class XXX

[Johan Engelen via Digitalmars-d-learn]

On Saturday, 23 January 2016 at 19:42:29 UTC, Johan Engelen wrote:
> Hi all,
>   While trying to interface C++ and D, I have to new a few D 
> objects in C++ code. I am doing this using a D function: "XXX 
> createXXX(...) { return new XXX(...); }".

An easier way for trivial constructors (note parents!), is to 
also define the constructor inline in C++ header.

in .d:
   extern (C++) class Klass {
     int b;
     this(int a) { b = a+1; }
   }
in .h:
   class Klass {
     int b;
     Klass(int a) { b = a+1; }
   };

It's what DDMD does in a few cases.