> But I have never seen anyone actually do this (which is why it didn't occur to me). I wrote about this in my two earlier comments. This is very old technolog

> But I have never seen anyone actually do this (which is why it didn't occur to me). I wrote about this in my two earlier comments. This is very old technology. And very commonly used. I think most plugin systems wrap dynamically linked libraries. This is also an easy way to redefine functions without needing GC. Under the hood, it is implemented in the loader's way: virtual memory pages mapped as read-only and executable (see mmap() or mprotect() for example).