lean4. it analyses code. if it finds raii/linearity/single-ownership, it does exactly like rust mem mgmt. but if it js not, it does rc. so it does what rust,

lean4. it analyses code. if it finds raii/linearity/single-ownership, it does exactly like rust mem mgmt. but if it js not, it does rc. so it does what rust, but automagically without polluting code. so cow or pbw or 2mem are not only options to improve rust.