RealCmp.h

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#ifndef REAL_CMP_H
#define REAL_CMP_H

#include <sstream>
#include <string>
#include <iomanip>

/*adtmag.com*/
template <class T>
class RealCmp
{
    enum FloatCmp {
        FC_LT,
        FC_GT,
        FC_EQ
    };

public:
    static FloatCmp comparator(T a, T b) {
        std::string s, n;
        int exp1, exp2;

        s = toString(a);
        n = s.substr(s.rfind("e")+1);
        exp1 = atof(n.c_str());

        s = toString(b);
        n = s.substr(s.rfind("e")+1); 
        exp2 = atof(n.c_str());

        FloatCmp result;
        if ((exp1 + 6) < exp2){
            result = FC_LT;
        }
        else if (exp1 > (exp2 + 6)) {
            result = FC_GT;
        }
        else if ((abs(a-b) / (b==0.0 ? 1.0 : abs(b))) < 0.00001/*std::numeric_limits<float>::epsilon()*/) {
            result = FC_EQ;
        }
        else if (a < b) {
            result = FC_LT;
        }
        else if (a > b) {
            result = FC_GT;
        }

        return result;
    }

    static inline bool compareLT(T a, T b) { return (comparator(a, b) == FC_LT); }

    static inline bool compareGT(T a, T b) { return (comparator(a, b) == FC_GT); }

    static inline bool compareEQ(T a, T b) { return (comparator(a, b) == FC_EQ); }

    static inline bool compareLTEQ(T a, T b) { return ((comparator(a, b) == FC_LT) || (comparator(a, b) == FC_EQ)); }

    static inline bool compareGTEQ(T a, T b) { return ((comparator(a, b) == FC_GT) || (comparator(a, b) == FC_EQ)); }

private:
    static std::string toString(T number) {
        std::stringstream sstr;
        sstr << std::scientific << number;
        return sstr.str();
    }

};

#endif