Class Declaration

Quite as in C++

class MyArrayOfInt {
  Int* numbers = NullPtr
  Int size = 0
  func clear()
}

In member functions this is a reference to the instance/object (not a pointer).

class String {
  func toLower() -> String& {
    // ...
    return this
  }
}

Default member access specifier is public.

Default inheritance access specifier is also public:

class MySubClass : ThePublicBaseClass {
  ...
}

class MySubClass : protected ABaseClass {
  ...
}

No struct

Not using struct, as it would be just too similar to class (especially in Cilia) with no real benefit. Keep as a reserved keyword for future use.
Cilia’s roots are more in C++ and OOP than in plain C. Not using record either (Pascal, Ada).