Explicitly avoid GC of objects?

[Robert M. Münch]

The D docs for interfacing with C state:

If pointers to D garbage collector allocated memory are passed to C 
functions, it's critical to ensure that that memory will not be 
collected by the garbage collector before the C function is done with 
it. This is accomplished by:

1. Making a copy of the data using core.stdc.stdlib.malloc() and 
passing the copy instead.
2. Leaving a pointer to it on the stack (as a parameter or automatic 
variable), as the garbage collector will scan the stack.
3. Leaving a pointer to it in the static data segment, as the garbage 
collector will scan the static data segment.
4. Registering the pointer with the garbage collector with the 
std.gc.addRoot() or std.gc.addRange() calls.

1 and 4 are pretty clear.

Is there a trick to accomplish 2 when objects are created from 
different scopes which need to be kept? So, I have one function 
creating the objects and one using them. How can I keep things on the 
stack between these two functions?

How is 3 done? Is this only useful for static variables?

-- 
Robert M. Münch
http://www.saphirion.com
smarter | better | faster