The problem here isn't a mismatch between double and float, it's that Python's float object is immutable, and hence there's no way to translate it into a C++ lvalue. You simply can't wrap a C++ function with a "double &" (or "int &" or "string &") argument to Python with the same signature, regardless of whether you're using Boost.Python or something else, because Python won't allow the argument you pass to be changed.
You have two options: - Add an extra struct (similar to your NativeDouble idea) that is a wrapped class that only contains a double. But you'll need explicit get/set methods, not just a public data member, though you can add a Python property to make the get/set look like a data member. - Transform the function signature, by wrapping a new function that takes a non-reference double and returns the new one, delegating it's work to the original function. Jim _______________________________________________ Cplusplus-sig mailing list Cplusplus-sig@python.org https://mail.python.org/mailman/listinfo/cplusplus-sig
