text: #ifndef VECTOR_2D_HPP
  #define VECTOR_2D_HPP
  
  namespace STool {
  
  struct Vector2D {
  public:
      double x, y;
  
      Vector2D(): x(0), y(0) {}
      Vector2D(double x, double y): x(x), y(y) {}
  
      bool operator== (const Vector2D& v) const {
          return 
              this->x == v.x ||
              this->y == v.y;
      } 
  };
  
  }
  
  #endif