return r;
}
+template<typename T, unsigned N>
+inline bool operator==(const Vector<T, N> &v, const Vector<T, N> &w)
+{
+ for(unsigned i=0; i<N; ++i)
+ if(v[i]!=w[i])
+ return false;
+ return true;
+}
+
template<typename T, unsigned N>
inline T inner_product(const Vector<T, N> &v1, const Vector<T, N> &v2)
{