Another critical consideration of this is that if you make a mistake in unsafe rust code it could manifest itself as a 'bug' in the 'safe' rust code due to inva

Another critical consideration of this is that if you make a mistake in unsafe rust code it could manifest itself as a 'bug' in the 'safe' rust code due to invariants that the safe code depends on not being upheld. It is literally undefined behaviour, in the "rm -rf / and insult your mother" sense.