Rust means never having to close a socket
"Rust achieves both of these features without runtime costs (garbage collection or reference counting), and without sacrificing safety."If it is freeing everything at the scope boundary it is incurring a huge runtime cost relative to garbage collected languages. GC scales with the number of live objects during GC while this scheme scales with the number of allocated objects. It is far more predictable than GC but I don't believe that it isn't more expensive.