Generic type.
It is a placeholder used in cases where no specific type requirements are needed, such as defining polymorphic parameters in functions and operators.
Abstract base scalar type.
All scalar types are derived from this type.
Abstract base enumerated type.
All enum types are derived from this type.
Generic tuple.
Similarly to anytype it denotes a generic tuple without going
into details of what the components are. Just as with
anytype, this is useful when defining polymorphic parameters
in functions and operators.
