什么时候转换为 int 会导致问题?

When does casting to `int` cause problems?

最近(从 Xcode 6 开始?)我在没有转换的情况下收到数百条警告:

如果我要添加演员:

This page 同意你的第一点- "This is not a problem if your value is anywhere between 0 and 4,294,967,295 (or between −2,147,483,648 and 2,147,483,647 respectively)."