pass test of #223 on compiler clang++:

Apple LLVM version 6.0 (clang-600.0.56) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin13.4.0
Thread model: posix

Author: wush978

inst/include/Rcpp/sugar/functions/var.h

@@ -3,6 +3,7 @@
 // var.h: Rcpp R/C++ interface class library -- var
 //
 // Copyright (C) 2011 Dirk Eddelbuettel and Romain Francois
+// Copyright (C) 2015 Wush Wu
 //
 // This file is part of Rcpp.
 //
@@ -26,18 +27,38 @@ namespace Rcpp{
 namespace sugar{
 
 template <int RTYPE, bool NA, typename T>
-class Var : public Lazy< typename Rcpp::traits::storage_type<RTYPE>::type , Var<RTYPE,NA,T> > {
+class Var : public Lazy< double , Var<RTYPE,NA,T> > {
 public:
 	typedef typename Rcpp::VectorBase<RTYPE,NA,T> VEC_TYPE ;
-	typedef typename Rcpp::traits::storage_type<RTYPE>::type STORAGE ;
 
 	Var( const VEC_TYPE& object_ ) : object(object_){}
 
-	STORAGE get() const{
-	    STORAGE m = mean(object).get() ;
-		Minus_Vector_Primitive<RTYPE,NA,T> mm( object, m) ;
-		STORAGE ssq  = sum( pow(mm,2.0) ).get() ;
-	    return ssq / (object.size() - 1 ) ;
+	double get() const{
+        double
+            m = mean(object).get(),
+            ssq = sum( pow(object, 2.0) ).get();
+	    return (ssq - m * m * object.size()) / (object.size() - 1);
+	}
+
+private:
+	const VEC_TYPE& object ;
+} ;
+
+template <bool NA, typename T>
+class Var<CPLXSXP,NA,T> : public Lazy< double , Var<CPLXSXP,NA,T> > {
+public:
+    typedef typename Rcpp::VectorBase<CPLXSXP,NA,T> VEC_TYPE ;
+
+	Var( const VEC_TYPE& object_ ) : object(object_){}
+
+	double get() const{
+        double sq = 0, ssq = 0;
+        for(int i = 0;i < object.size();i++) {
+            Rcomplex z = object[i];
+            sq += z.r;
+            ssq += z.r * z.r;
+        }
+	    return (ssq - sq * sq / object.size()) / (object.size() - 1);
 	}
 
 private:
@@ -51,6 +72,20 @@ inline sugar::Var<REALSXP,NA,T> var( const VectorBase<REALSXP,NA,T>& t){
 	return sugar::Var<REALSXP,NA,T>( t ) ;
 }
 
+template <bool NA, typename T>
+inline sugar::Var<INTSXP,NA,T> var( const VectorBase<INTSXP,NA,T>& t){
+    return sugar::Var<INTSXP,NA,T>( t ) ;
+}
+
+template <bool NA, typename T>
+inline sugar::Var<LGLSXP,NA,T> var( const VectorBase<LGLSXP,NA,T>& t){
+    return sugar::Var<LGLSXP,NA,T>( t ) ;
+}
+
+template <bool NA, typename T>
+inline sugar::Var<CPLXSXP,NA,T> var( const VectorBase<CPLXSXP,NA,T>& t){
+    return sugar::Var<CPLXSXP,NA,T>( t ) ;
+}
 
 } // Rcpp
 #endif