I think the answer from ninefingers sums up my feelings on the issue. You can't ever make a really safe memcpy(), you just need to use it properly and test your code.

Using APIs like GLib and APR that do some memory management of data structures for you can be helpful, but ultimately, you're still free to memcpy() yourself into oblivion even when you use them exclusively, and the solution isn't to try to make memcpy safer, it's to use it properly, or not at all if you aren't disciplined enough for it (at which point, hopefully Clippy will pop up and recommend that you use Java or Ruby or something that keeps you from hanging yourself.)