Unexpected result when non type template parameter is used in the program without assigning to local variable?

Question

Since direct floating point comparisons are risky, i am writing one wrapper class for checking relational operations for floating point numbers.

#include<iostream>
#include  <cmath>

template<unsigned int round_off_digits=10>
class FloatRelationalOperators
{
   private:
      inline static double calcEpsilonValue()
      {         

         int localVar=round_off_digits;

         double withLocalVar=pow(10, (localVar  * -1 ));
         double WithoutLocalVar=pow(10, (round_off_digits  * -1 ));

         std::cout<<"withLocalVar: "<<withLocalVar<<" "<<"WithoutLocalVar :"<<WithoutLocalVar;

         return WithoutLocalVar;
      }

   public:

      inline static bool notequal(double a,double b)
      {
         double res=fabs(a-b);

         if( res <= calcEpsilonValue())
         {
            return true;
         }
         else
         {
            return false;
         }
         return false;
      }
};


int main()
{
   FloatRelationalOperators<>::notequal(10.1,10.0);
}

I am trying to calculate the epsilon value from max round off digits.

When i run the program, i got the result as follows,

withLocalVar: 1e-10 WithoutLocalVar :inf

Why my answer is wrong when non-type template parameter is used directly in the function?

Am I doing anything wrong?

Answer 1

round_off_digits is an unsigned value and you multiply it with -1 which makes a pretty big unsigned int. If you change it to int it works

http://cpp.sh/8yflj