Encapsulated Random number generator in C++-11 using boost

I am trying to generate random numbers in C++-11 using boost. I have seen some nice posts about this and I was able to generate random numbers putting all my code in the main function, like suggested in this webpage (http://ift.tt/1Obf3yA).

However, I was not able to encapsulate a random number generator (RNG) that can be called by different functions. I would like this encapsulated RNG to receive as parameters the range of numbers and a random seed. I tried to do it by following the suggestions of this post (Boost random number generator).

I implemented the code below. But it fails in both: the change of random seed and the definition of the range of values.

    #include <boost/random/variate_generator.hpp>
    #include <boost/generator_iterator.hpp>
    #include <boost/random/mersenne_twister.hpp>
    #include <boost/random/normal_distribution.hpp>

    typedef boost::mt19937                     ENG;    // Mersenne Twister
    typedef boost::normal_distribution<double> DIST;   // Normal Distribution
    typedef boost::variate_generator<ENG,DIST> GEN;    // Variate generator

    class RNG {

      private:
         ENG eng;
         DIST dist;

      public:
         GEN gen;
         RNG(double min,double max,int seed)
         : dist(min,max), gen(eng,dist)
         {eng.seed(seed); }
    };

And this is my main function.

    int main(int argc, char **argv){
        if(argc == 2){
            int myseed = atoi(argv[1]);
            double minimum = 1.;
            double maximum = 10.;
            int N = 20;

            RNG myrn(minimum,maximum,myseed);

            for (int i = 0; i < N; i++){
                std::cout << myrn.gen() << std::endl;
            }
                return 0;
        }
        exit(1);
    }

This implementation generates the same sequence of random numbers independently of the seed I use. Also, the random numbers are not in the range between minimum and maximum. Does any of you know how to fix these two issues?

Many thanks for any help!