C++ Reactive Programming

Map and filter operations on the list

Map is a functional operator where a function will be applied to a list. Filter will apply a predicate to a list and return another list. They are the cornerstone of any functional processing pipeline. They are also called higher-order functions. We can write a generic Map function, using std::transform for std::list and the std::vector:

template <typename R, typename F> 
R Map(R r , F&& fn) { 
      std::transform(std::begin(r), std::end(r), std::begin(r), 
         std::forward<F>(fn)); 
      return r; 
} 

Let's also write a function to filter a std::list (we assume only a list will be passed). The same can work on std::vector. We can compose a higher-order function using the pipe operator. The composite function can also be ...