Polymorphism in the IccResource class

Three virtual methods are defined in the base class IccResource, as shown in Figure 1.

Figure 1. Code example: Defining virtual clear, get, and put methods in the IccResource class

// clear function
    virtual void clear();
// get function
    virtual const IccBuf& get();
// put function 
    virtual void put(const IccBuf& buffer);

These methods are implemented differently in the classes that are derived from the IccResource class. Table 1 shows where the get, clear, and put methods have been implemented in the subclasses of IccResource. Each implemented method is marked with an × in the table.

Table 1. Implementation of get, clear, and put methods in IccResource subclasses
Class name	clear method	get method	put method
IccConsole			×
IccDataQueue	×	×	×
IccJournal			×
IccSession		×	×
IccTempStore	×	×	×
IccTerminal	×	×	×

These virtual methods are not supported by any subclasses of IccResource except those that are shown in Table 1.

Note: The default implementations of the clear, get, and put methods in the base class IccResource throw an exception to prevent the user from calling an unsupported method.