D:/Projekt/ECF_trunk/ECF/cartesian/Xnor.h

#ifndef Xnor_h
#define Xnor_h
#include "Function.h"

namespace cart
{
    template <class T>
    class Xnor : public Function
    {
    public:
        Xnor();
        Xnor(uint numArgs);
        ~Xnor();

        void evaluate(voidP inputs, void* result);
    };

    typedef Xnor<uint> XnorUint;

    template <class T>
    Xnor<T>::Xnor()
    {
        name_ = "XNOR";
        numOfArgs_ = 2;
    }

    template <class T>
    Xnor<T>::Xnor(uint numArgs)
    {
        name_ = "XNOR";
        numOfArgs_ = numArgs;
    }

    template <class T>
    Xnor<T>::~Xnor()
    {
    }

    template <class T>
    void Xnor<T>::evaluate(voidP inputs, void* result)
    {
        T& xnor = *(T*) result;
        stringstream ss;
        ss << *((string*) inputs.get());
        vector<T> readInputs;
        T input, maxSize = 0;
        uint i = 0;
        //received inputs are in format: input1 sizeOfInput1 input2 sizeOfInput2 ...
        while (ss >> input)
        {
            readInputs.push_back(input);
            ss >> input;
            if (input > maxSize)
            {
                maxSize = input;
            }
            i += 2;
            if (i == 2 * numOfArgs_)
            {
                break;
            }
        }
        T mask = (T)pow(2.0, maxSize + 1.0) - 1;

        xnor = readInputs.at(0);
        for (int i = 1; i < (int)numOfArgs_; i++)
        {
            xnor = ~(xnor ^ readInputs.at(i));
            //masking is important in XNOR operation because instead of leading 0's there would be 
            //leading 1's as most significant bits
            xnor &= mask;
        }
    }

}

#endif /* Xnor_h */