Drop obsolete qualifier

src/nicefunction.hh

@@ -10,17 +10,17 @@
 namespace Dune {
 class NiceFunction : public VirtualFunction<double, double> {
 public:
-  virtual double leftDifferential(const double s) const = 0;
-  virtual double rightDifferential(const double s) const = 0;
+  virtual double leftDifferential(double s) const = 0;
+  virtual double rightDifferential(double s) const = 0;
 };
 
 class Identity : public NiceFunction {
 public:
   void virtual evaluate(const double& x, double& y) const { y = x; }
 
-  double virtual leftDifferential(const double s) const { return 1; }
+  double virtual leftDifferential(double s) const { return 1; }
 
-  double virtual rightDifferential(const double s) const { return 1; }
+  double virtual rightDifferential(double s) const { return 1; }
 };
 
 class SampleFunction : public NiceFunction {
@@ -29,13 +29,9 @@ class SampleFunction : public NiceFunction {
     y = (x < 1) ? x : (2 * x - 1);
   }
 
-  double virtual leftDifferential(const double s) const {
-    return (s <= 1) ? 1 : 2;
-  }
+  double virtual leftDifferential(double s) const { return (s <= 1) ? 1 : 2; }
 
-  double virtual rightDifferential(const double s) const {
-    return (s < 1) ? 1 : 2;
-  }
+  double virtual rightDifferential(double s) const { return (s < 1) ? 1 : 2; }
 };
 
 class TrivialFunction : public NiceFunction {
@@ -56,7 +52,7 @@ class HorribleFunction : public NiceFunction {
     y = sum + (fl + 1) * (x - fl);
   }
 
-  double virtual leftDifferential(const double x) const {
+  double virtual leftDifferential(double x) const {
     double const fl = floor(x);
     if (x - fl < 1e-14)
       return fl;
@@ -64,7 +60,7 @@ class HorribleFunction : public NiceFunction {
       return fl + 1;
   }
 
-  double virtual rightDifferential(const double x) const {
+  double virtual rightDifferential(double x) const {
     double const c = ceil(x);
     if (c - x < 1e-14)
       return c + 1;
@@ -85,7 +81,7 @@ class HorribleFunctionLogarithmic : public NiceFunction {
     y += log(fl + 2) * (x - fl);
   }
 
-  double virtual leftDifferential(const double x) const {
+  double virtual leftDifferential(double x) const {
     double const fl = floor(x);
     if (x - fl < 1e-14)
       return log(fl + 1);
@@ -93,7 +89,7 @@ class HorribleFunctionLogarithmic : public NiceFunction {
       return log(fl + 2);
   }
 
-  double virtual rightDifferential(const double x) const {
+  double virtual rightDifferential(double x) const {
     double const c = ceil(x);
     if (c - x < 1e-14)
       return log(c + 2);