Ada. Time-tested, safe and secure.

The title given to this book is incorrect due to technical limitations. The correct title is Ada Programming/Delimiters/<>.

The box <> is a placeholder for something not (yet) fully specified.

Contexts

• In array declaration

type Some_Array is (Integer range <>) of Some_Type;

Declare an array type with bounds known only at runtime.

• a type that has unknown discriminants

type T (<>) is private;

• Generic declaration of a discrete type

generic
  type T is (<>);

It means that T must be a discrete type: either an enumeration, a range, or a modular type.

• component association in Ada 2005

Some_Rec_Type'(others => <>);

• partial parameterization of generics in Ada 2005

generic
  with package P is new G
     (Param_1 => T,
      others => <>);

See also