xorp

ElemNull Class Reference

An element representing nothing. More...

#include <elem_null.hh>

Inheritance diagram for ElemNull:
Element

List of all members.

Public Member Functions

 ElemNull (const char *)
string str () const
 Every element must be representable by a string.
const char * type () const

Static Public Attributes

static const char * id = "null"
static Hash _hash = HASH_ELEM_NULL

Detailed Description

An element representing nothing.

Null.

This is used by VarRW when an element being read is not available. For example, if the route is IPv4, but the IPv6 representation is being asked for.

The dispatcher also treats Null arguments as a special case by returning a Null.


Member Function Documentation

string ElemNull::str ( ) const [inline, virtual]

Every element must be representable by a string.

This is a requirement to enable the policy manager to send elements to the backend filters via XRL calls for example.

Returns:
string representation of the element.

Implements Element.

const char* ElemNull::type ( ) const [inline, virtual]
Returns:
string representation of element type.

Implements Element.


The documentation for this class was generated from the following files:
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