Swift AnyClass

AnyClass：是所有类都隐式遵循的协议，当你用AnyClass作为实例的具体类型，所有已知的@objc类的方法和属性都作为隐式解包的可选方法或者属性。

class Student{
  @objc static let describe = "class description"
  @objc class func getDefaultValue() -> Int {
    return 100
  }
}

func getDefaultValue(_ c: AnyClass) -> Int? {
  return c.getDefaultValue?()
}
func getDescribeValue(_ c: AnyClass) -> String? {
  return c.describe
}

// ptional(100)
print(getDefaultValue(Student.self))
// Optional("class description")
print(getDescribeValue(Student.self))

还可以作为类型检测：

protocol SomeDelegate {
}

class SomeClass: SomeDelegate{
}

let instance = SomeClass.self
func isSomeDelegate(_ type: AnyClass) -> Bool{
  if type is SomeDelegate.Type{
    return true
  }
  return false
}

// true
print(isSomeDelegate(instance))