Dedupe::Dataholding::Variant Namespace Reference

Data Structures
class	Data
class	DataVariant
Enumerations
enum	CastResults {   CastOK, DifferentDatatypes, CouldNotCast, BadCastException,   NULLPointerGiven }
Functions
template<class T >
CastResults	CastDataVariant (Data *incoming, T &returning)

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Detailed Description

Namespace Variant includes two classes to handle various datatypes which come out of an SQLite Database (alternative to BOOST::Variant)

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Enumeration Type Documentation

enum Dedupe::Dataholding::Variant::CastResults

CastResults contains the possible results from CastDataVariant

Enumerator:

DifferentDatatypes	No problems in the dynamic_cast.
CouldNotCast	Data and given variable are different types.
BadCastException	Cast is not possible.
NULLPointerGiven	Cast throws a BadCast Exception. The incoming pointer is NULL

Definition at line 98 of file datavariant.h.

      {
        CastOK,             
        DifferentDatatypes, 
        CouldNotCast,       
        BadCastException,   
        NULLPointerGiven    
      };

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Function Documentation

template<class T >

CastResults Dedupe::Dataholding::Variant::CastDataVariant	(	Data *	incoming,
		T &	returning
	)

A free function to get the data from GetData while using only the baseclasspointer. First argument is the baseclasspointer, second argument is the variable where the data is written, if there were no cast errors.

Returns:

one type from CastResults

Definition at line 114 of file datavariant.h.

References Dedupe::Dataholding::Variant::DataVariant< T >::GetData().

      {
        //Make sure, the incoming pointer is not NULL
        if( incoming == NULL ) return NULLPointerGiven;

        /*Make sure, holded data and the
          returning variable are frome the same type
        */
        if( incoming->GetType() != typeid( T ) ) return DifferentDatatypes;

        //Define the pointer here, cause the cast is in a different scope
        DataVariant<T> *ptr = NULL;

        //catch bad_cast exceptions and return an BadCastExecption error
        try
        {
          ptr = dynamic_cast
          <Dedupe::Dataholding::Variant::DataVariant<T> *>(incoming);
        }
        catch (std::bad_cast& bc)
        {
          return BadCastException;
        }

        if( ptr == NULL ) return CouldNotCast;
        //write the data to the returning varible
        returning = ptr->GetData();

        return CastOK;
      }