[m-users.] foreign_type confusion on how to do it across modules...

[Julien Fischer]

On Sun, 14 Jul 2019, Zoltan Somogyi wrote:

> Julien, Peter: I see that the reference manual is silent on how foreign code should
> allocate memory whose address is passed to Mercury code. Since you have more
> experience with interfacing to foreign language code than I do, could one of you
> please take a crack at adding a paragraph about this to the sections dealing
> with the interfaces to C, C#, Java and Erlang?

I'll take a crack at this; for C grades that use GC, it would probably
be best to document the MR_GC_* macros and functions from
runtime/mercury_memory.h in the reference manual.

For C# and Java, nothing special is required (e.g you can just use
the new operator to allocate somthing on the heap).  I'll note
this as well.

Julien.