text: #include "rxcpp/rx.hpp"
  
  #include <iostream>
  
  #include <array>
  
  int main() {
  
    auto values = rxcpp::observable<>::range(1, 12).
  
                  filter([](int v){
   return v % 2 == 0;
  }).map([](int x) {return x*x;}); 
    values.
  subscribe(
   [](int v){printf("OnNext: %d\n", v);},
    
                  [](){printf("OnCompleted\n");});
  
  
  }
  