现在我想在用户个人资料页面上创建一个feed,告诉每个人他们在做什么,有点像facebook,但简单得多。Bob SmithBob Smith joined John Doe's group
要做这样的事情,我应该从适当的表中提取所有信息,还是每次执行希望包含在提要中的任务时都将一行插入到“提要”表中。
根据swift/stdlib/public/SwiftShims/RefCount.h - The strong RC is stored as an extra count: when the physical field is 0 the logical value is 1.- The weak RC also has an extra +1 on behalf of the unowned references 我想知道为什么一个对象以+