A Slice class definition is similar to a structure definition, but uses the
class keyword. For example:
Apart from the keyword
class, this definition is identical to the structure example. You can use a Slice class wherever you can use a Slice structure (but, as we will see shortly, for performance reasons, you should not use a class where a structure is sufficient). Unlike structures, classes can be empty:
Much the same design considerations as for empty interfaces apply to empty classes: you should at least stop and rethink your approach before committing yourself to an empty class.
A class can define any number of data members, including optional data members. You can also specify a default value for a data member if its type is one of the following:
The legal syntax for literal values is the same as for Slice constants, and you may also use a constant as a default value. The language mapping guarantees that data members are initialized to their declared default values using a language-specific mechanism.