16 #ifndef ECL_MATH_NORMS_HPP_    17 #define ECL_MATH_NORMS_HPP_    50                 return std::sqrt(x1*x1 + x2*x2);
    62         T 
operator()(
const T& x1, 
const T& x2, 
const T& x3) {
    63                 return std::sqrt(x1*x1 + x2*x2 + x3*x3);
    83         return std::sqrt(x1*x1 + x2*x2);
    96         return std::sqrt(x1*x1 + x2*x2 + x3*x3);
 
T euclidean_norm(const T &x1, const T &x2)
Function for euclidean norms of dimension 2. 
T operator()(const T &x1, const T &x2)