message: Delete Vector::operator- and operator+
diff: @@ -307,6 +307,12 @@ public:
  Vector &operator+=(const Vector &v);
  + /// operator- is not supported. Use @ref subtract or @ref Add.
  + Vector &operator-(const Vector &v) = delete;
  +
  + /// operator+ is not supported. Use @ref Add.
  + Vector &operator+(const Vector &v) = delete;
  +
  /// (*this) += a * Va
  Vector &Add(const double a, const Vector &Va);
  