Calling D from C, C++, Python…

[Adam D. Ruppe via Digitalmars-d-learn]

On Saturday, 12 September 2015 at 09:47:55 UTC, Jacob Carlborg 
wrote:
> Well, if your D function doesn't use anything of the runtime I 
> guess it's not necessary.

Right. If you don't call into the threading system in the 
druntime, you should be ok. Keep in mind though that the GC uses 
the threads.... and the new expression, array literals, array 
append, and others use the GC.

Runtime.initialize is also what calls static and module 
constructors... and might have responsibility for fixing up 
dynamic casting of class objects in a shared lib too, I'm not 
sure about that.

But if you avoid the bulk of the runtime functions, indeed you 
can get away without initializing it. Just that null thread 
handle is likely to cause segfaults in places where you might not 
expect if you don't.

It is best to initialize it. Lots of C libraries need an init an 
teardown call, so surely the Python interop provides some 
solution for it. idk what it would be though.