Getting EXC_BAD_ACCESS in forEach closure [duplica

问题:

This question already has an answer here:

• Swift protocol with “where Self” clause 1 answer
• Forced to cast, even if protocol requires given type 5 answers

Getting EXC_BAD_ACCESS (code=1, address=0x0) in forEach closure.

I simplified code structure to make in understandable:

func reproduceCrash() {
    let instanceArray: [Class1] = [Class1(), Class2()]
    let filteredInstanceArray = instanceArray.compactMap { $0 as? Protocol2 }

    filteredInstanceArray.forEach { (instance) in
        instance.method()
    }
}

protocol Protocol1 { }

class Class1: Protocol1 { }

protocol Protocol2 where Self: Class1 {
    func method()
}

class Class2: Class1, Protocol2 {
    func method() { }
}