text: #pragma once
  
  #include <config.h>
  
  namespace nspace{
    template<typename Derived>
    class Derivable{
    private:
      Derived & _derived;
    public:
      Derivable():_derived(*static_cast<Derived*>(this)){}
      inline Derived & derived(){return _derived;}
      inline const Derived & derived()const{return _derived;}
    };
  }