[theseoafs]

Rust actually started with a model like this. The idea was when starting out for the first time you can use garbage collected pointers for everything and then switch to the manual model when you needed it. Problem is then that unless your standard library and all the major open source libraries work perfectly for both the garbage collected objects and for the manually managed objects then you need to learn manual memory management early on anyway, so the garbage collector wasn't helping anyone. The language design element of this is really tough to do in a usable way.

D has optional GC but their standard library is kind of fucked up.