do not mix overloading with virtual functions

README.md

@@ -45,11 +45,13 @@ class Func
 {
 public:
     virtual double operator()(const double& x) const = 0;
-    virtual void   operator()(double* x, const int n) const
+    virtual void eval(double* x, const int n) const
     {
         for(int i = 0; i < n; i++)
             x[i] = this->operator()(x[i]);
     }
+
+    virtual ~Func() {}
 };
 ```
 
@@ -158,6 +160,8 @@ class MFunc
 {
 public:
     virtual double operator()(Constvec& x) = 0;
+
+    virtual ~MFunc() {}
 };
 ```
 
@@ -276,6 +280,8 @@ class MFuncGrad
 {
 public:
     virtual double f_grad(Constvec& x, Refvec grad) = 0;
+
+    virtual ~MFuncGrad() {}
 };
 ```
 

inst/include/Func.h

@@ -23,14 +23,14 @@ typedef const Eigen::Ref<const Eigen::VectorXd> Constvec;
 class Func
 {
 public:
-    virtual ~Func() {}
-
     virtual double operator()(const double& x) const = 0;
-    virtual void   operator()(double* x, const int n) const
+    virtual void eval(double* x, const int n) const
     {
         for(int i = 0; i < n; i++)
             x[i] = this->operator()(x[i]);
     }
+
+    virtual ~Func() {}
 };
 
 
@@ -39,19 +39,19 @@ class Func
 class MFunc
 {
 public:
-    virtual ~MFunc() {}
-
     virtual double operator()(Constvec& x) = 0;
+
+    virtual ~MFunc() {}
 };
 
 
 // For optimization that requires gradient
 class MFuncGrad
 {
 public:
-    virtual ~MFuncGrad() {}
-
     virtual double f_grad(Constvec& x, Refvec grad) = 0;
+
+    virtual ~MFuncGrad() {}
 };
 
 

inst/include/integration/Integrator.h

@@ -552,7 +552,7 @@ class Integrator
         }
 
         // Evaluate points.
-        f(points.data(), 2 * numKronrodRows - 1);
+        f.eval(points.data(), 2 * numKronrodRows - 1);
         Eigen::Array<Scalar, 2 * numKronrodRows - 1, 1>& fPoints = points;  // Alias of points
 
         const Scalar fCenter = fPoints[0];

vignettes/introduction.Rmd

@@ -58,11 +58,13 @@ class Func
 {
 public:
     virtual double operator()(const double& x) const = 0;
-    virtual void   operator()(double* x, const int n) const
+    virtual void eval(double* x, const int n) const
     {
         for(int i = 0; i < n; i++)
             x[i] = this->operator()(x[i]);
     }
+
+    virtual ~Func() {}
 };
 ```
 
@@ -205,6 +207,8 @@ class MFunc
 {
 public:
     virtual double operator()(Constvec& x) = 0;
+
+    virtual ~MFunc() {}
 };
 ```
 
@@ -364,6 +368,8 @@ class MFuncGrad
 {
 public:
     virtual double f_grad(Constvec& x, Refvec grad) = 0;
+
+    virtual ~MFuncGrad() {}
 };
 ```