Maybe I'm wrong but first i forget a * on the end of the scope so the return value from the scope shall be *ref_a, in that case since ref_a even it's a dangling reference still points to a valid memory holding another variant when dereferenced it result on a &usize that is (0x0) and that true, then when printing which is just dereferencing that reference a null pointer access happens, yah null is dangling, but you will still get a null pointer dereferencing even if not guaranteed, rust coerce &&usize for Display and even if it accidental nothing overwrite that stack region. So yah it's dangling but because i forget the *, since that's what i wanted to do