greg:

Hi all,

Can anyone explain what the overhead of using StablePtrs is? Specifically I am interested in knowing the time/space complexity of the various Foreign.StablePtr operations and how many memory indirections are involved when using deRefStablePtr.

There's a hashtable in the runtime that maps pointers to stable pointers. So you have that overhead. Create N StablePtrs, and get a correspondingly large hashtable.