Is it safe to force unwrap variables that have been optionally accessed in the same line of code?

Question

someFunction(completion: { [weak self] in
    self?.variable = self!.otherVariable
})

Is this always safe? I access the optional <

Answer 1

Is this always safe

No. You are not doing the "weak-strong dance". Do it! Whenever you use weak self, you should unwrap the Optional safely, and then refer only to the result of that unwrapping — like this:

someFunction(completion: { [weak self] in
    if let sself = self { // safe unwrap
        // now refer only to `sself` here
        sself.variable = sself.otherVariable
        // ... and so on ...
    }
})