Below is a simplified example, with question marks where I'm not sure what to do. I've tried accepting a pointer to A, playing with using XPtrs, and a bunch of things which made far less sense, but so far no luck.
As an addendum to others' comments... I've been working on a kinda-sorta similar problem: passing user-supplied C++ worker functions to a module's method. Not sure if it helps, but it's a full example of passing XPtrs from C++ to R back to a module's method, where it's called in C++: https://code.google.com/p/unm-r-programming/source/browse/#git%2FRaggedArray * In ./src/helpers.cpp, sapply_master(infun, cppfun=true) takes an R function infun that returns an XPtr to a function that does something. sapply_master pulls the XPtr, dereferences it to the C++ function, and calls that function on a class member. * In ./inst/tests/userFun.cpp are the user-specified worker functions, and the associated XPtr-exporting wrapper functions that are passed to sapply_master(). Incidentally, my plan is for this to be a gallery post in the not too distant future. -Christian
A man, a plan, a cat, a ham, a yak, a yam, a hat, a canal ? Panama!