Memento::NoData Class Reference

Trivial class for when no memento data is needed or when memento construction fails. More...

#include <Workspace/Application/LanguageUtils/memento.h>

Inheritance diagram for Memento::NoData:

Public Member Functions
bool	isValid () const override
Public Member Functions inherited from Memento::Data
virtual	~Data ()=default
virtual bool	isValid () const

Additional Inherited Members
Protected Member Functions inherited from Memento::Data
	Data ()=default

Detailed Description

This class returns false from its isValid() function so that clients can detect when a Memento is not valid. What "not valid" means is partly context-dependent. Normally, it means either that no memento data is needed and the caller should know this, or it means that the creation of a memento failed so the memento creator returned a NoData memento instead. In the latter case, the memento creator needs to be able to detect a NoData memento being passed to it, almost always by checking the value returned by isValid().

Member Function Documentation

isValid()

bool isValid ( ) const

inlineoverridevirtual

Returns

False unconditionally. This is the whole reason for this class.

Reimplemented from Memento::Data.