Realm Swift detects lazy properties as optional, crashes when attempting to interpret them as RLMOptionalBase

[bdash]

A user on Stack Overflow has reported seeing a crash when attempting to save an object using code that looks like so:

class MyObject: Object {
    dynamic var someProperty: String = ""
    dynamic lazy var compoundPrimaryKey: String = self.compoundPrimaryKeyValue()
    private func compoundPrimaryKeyValue() -> String { return "SomeValue" }
    override static func primaryKey() -> String? { return "compoundPrimaryKey" }
}

try! Realm().write {
    Realm().add(MyObject())
}

This results in either a crash or an exception being thrown:

2016-03-15 18:07:57.988 TestHost[12404:378454] -[__NSTaggedDate underlyingValue]: unrecognized selector sent to instance 0x103aa3add

The crash and exception originate from RLMAddObjectToRealm:

* thread #1: tid = 0x5dec6, 0x00000001046658d6 Realm`RLMAddObjectToRealm(object=0x00006080000e6300, realm=0x000060000067c940, createOrUpdate=false) + 1830 at RLMObjectStore.mm:203, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
  * frame #0: 0x00000001046658d6 Realm`RLMAddObjectToRealm(object=0x00006080000e6300, realm=0x000060000067c940, createOrUpdate=false) + 1830 at RLMObjectStore.mm:203
    frame #1: 0x0000000104526eaa RealmSwift`Realm.add(object=0x00006080000e6300, update=false, self=0x0000608000028e60) -> () + 714 at Realm.swift:217
    frame #2: 0x00000001041f1c06 RealmSwift Tests`ObjectTests.(storeRealm=0x0000608000028e60) -> ()).(closure #1) + 54 at ObjectTests.swift:346
    frame #3: 0x0000000104529337 RealmSwift`thunk + 39 at Realm.swift:0
    frame #4: 0x0000000104777946 Realm`-[RLMRealm transactionWithBlock:error:](self=0x000060000067c940, _cmd="transactionWithBlock:error:", block=0x000060800004e880, outError=domain: nil - code: 140735238246560) + 86 at RLMRealm.mm:506
    frame #5: 0x0000000104526957 RealmSwift`Realm.write(block=0x00000001041f1bd0 RealmSwift Tests`RealmSwift_Tests.ObjectTests.(testFoo () -> ()).(closure #1) at ObjectTests.swift:345, self=0x0000608000028e60, $error=ErrorType @ 0x00007fff5fbfcbf0) -> ()) throws -> () + 215 at Realm.swift:111
    frame #6: 0x00000001041e3c0e RealmSwift Tests`ObjectTests.testFoo(self=0x0000608000267fc0) -> () + 462 at ObjectTests.swift:347

The property in question appears to be the internal storage of the lazy property, named compoundPrimaryKey.storage.

[quangpc-zz]

I meet the same issue here if use:
dynamic lazy var compoundPrimaryKey

[austinzheng]

A fix should roll out in the next release. Swift lazy properties are explicitly forbidden, unless they are ignored. Ignored lazy properties should work properly now.