Safe code can invalidate invariants of unsafe code in block containing perfectly safe code. Famous example is: impl Vec { pub unsafe fn set_capacit

Safe code can invalidate invariants of unsafe code in block containing perfectly safe code. Famous example is: impl Vec { pub unsafe fn set_capacity(&mut self, capacity: usize) { self.capacity = capacity; // why is that unsafe? } } What OP possibly did was invalidate his invariants in safe code.