Good share, thanks. My approach so far has been to define macros that generate the container type for a given underlying type, as well as all of the relevant ty

Good share, thanks. My approach so far has been to define macros that generate the container type for a given underlying type, as well as all of the relevant type-safe functions, which end up calling into functions that take void*. But the union trick plus the structural identity does seem to simplify things a bit.