From f9367b235b17a08845c35ede9c21240df05d3db1 Mon Sep 17 00:00:00 2001
From: Yixuan Qiu <yixuan.qiu@cos.name>
Date: Thu, 8 Dec 2016 19:56:14 -0500
Subject: [PATCH] do not mix overloading with virtual functions

---
 README.md                             |  8 +++++++-
 inst/include/Func.h                   | 14 +++++++-------
 inst/include/integration/Integrator.h |  2 +-
 vignettes/introduction.Rmd            |  8 +++++++-
 4 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index a69668c..6fd4d09 100644
--- a/README.md
+++ b/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() {}
 };
 ```
 
diff --git a/inst/include/Func.h b/inst/include/Func.h
index 9f3adf1..021714d 100644
--- a/inst/include/Func.h
+++ b/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() {}
 };
 
 
@@ -39,9 +39,9 @@ class Func
 class MFunc
 {
 public:
-    virtual ~MFunc() {}
-
     virtual double operator()(Constvec& x) = 0;
+
+    virtual ~MFunc() {}
 };
 
 
@@ -49,9 +49,9 @@ class MFunc
 class MFuncGrad
 {
 public:
-    virtual ~MFuncGrad() {}
-
     virtual double f_grad(Constvec& x, Refvec grad) = 0;
+
+    virtual ~MFuncGrad() {}
 };
 
 
diff --git a/inst/include/integration/Integrator.h b/inst/include/integration/Integrator.h
index 1366d33..ab0280d 100644
--- a/inst/include/integration/Integrator.h
+++ b/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];
diff --git a/vignettes/introduction.Rmd b/vignettes/introduction.Rmd
index 0b2edbb..60040b5 100644
--- a/vignettes/introduction.Rmd
+++ b/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() {}
 };
 ```