kotlin reified关键字（备用机制）

/**
 * DESC   : reified关键字（具体化）备用机制
 */
const val KtBaseReifiedTest01_TAG = "KtBaseReifiedTest01"

data class ObjectClass01(val name: String, val age: Int)
data class ObjectClass02(val name: String, val age: Int)
data class ObjectClass03(val name: String, val age: Int)
data class ObjectClassDefault(val name: String, val age: Int)

class KtBaseReifiedTest01 {

    inline fun <reified T> testReified01(defaultLambdaAction : () -> T) : T? {
        val objectList : List<Any> = listOf(ObjectClass01("zhangsan", 10),
            ObjectClass02("lisi", 11), ObjectClass03("wangwu", 12))
        val randomObj : Any? = objectList.shuffled().first()

        //testReified01==>objClass=ObjectClass03(name=wangwu, age=12)
        //testReified01==>objClass=ObjectClass01(name=zhangsan, age=10)
        Log.d(KtBaseReifiedTest01_TAG, "testReified01==>randomObj="+randomObj)
        //如果objClass为空，备用返回defaultLambdaAction()方法返回的对象（因加入了reified关键字）
        //1.类型转换as T和as T?是不同的，
        //2.randomObj is T如果返回false，那么randomObj.takeIf也会返回null,
        //3.如果as T不加问号，接着判断null as T会奔溃（null 不能转换成 T 类型），所以防止崩溃，改成as T?
        //2.改成as T?后，接着2步骤，null as T?可为空，走defaultLambdaAction逻辑
        return randomObj.takeIf { randomObj is T } as T? ?: defaultLambdaAction()
    }

}