Clean up qualifiers

src/mynonlinearity.hh

@@ -46,17 +46,17 @@ template <int dimension> class MyNonlinearity {
     }
   }
 
-  void upperGradient(const VectorType x, VectorType &ret) const {
+  void upperGradient(VectorType const x, VectorType &ret) const {
     ret = x;
     ret *= func_.rightDifferential(x.two_norm()) / x.two_norm();
   }
 
-  void lowerGradient(const VectorType x, VectorType &ret) const {
+  void lowerGradient(VectorType const x, VectorType &ret) const {
     ret = x;
     ret *= func_.leftDifferential(x.two_norm()) / x.two_norm();
   }
 
-  void directionalDomain(const VectorType &, const VectorType &,
+  void directionalDomain(VectorType const &, VectorType const &,
                          Interval<double> &dom) const {
     dom[0] = -std::numeric_limits<double>::max();
     dom[1] = std::numeric_limits<double>::max();