add missing refs in string compare helper methods

acompare2/src/StringCompare.cpp

@@ -20,7 +20,7 @@ bool StringCompare::testCompare ( const string::CyclicString < > &, const string
 }
 template < class T >
-void StringCompare::setCompare ( const ext::set < T > a, const ext::set < T > b ) {
+void StringCompare::setCompare ( const ext::set < T > & a, const ext::set < T > & b ) {
 	ext::set < T > aMinusB;
 	std::set_difference ( a.begin ( ), a.end ( ), b.begin ( ), b.end ( ), std::inserter ( aMinusB, aMinusB.begin ( ) ) );
@@ -37,7 +37,7 @@ void StringCompare::setCompare ( const ext::set < T > a, const ext::set < T > b
 }
 template < class T >
-void StringCompare::vectorCompare ( const ext::vector < T > a, const ext::vector < T > b ) {
+void StringCompare::vectorCompare ( const ext::vector < T > & a, const ext::vector < T > & b ) {
 	ext::vector < T > aMinusB;
 	std::set_difference ( a.begin ( ), a.end ( ), b.begin ( ), b.end ( ), std::inserter ( aMinusB, aMinusB.begin ( ) ) );

acompare2/src/StringCompare.h

@@ -26,9 +26,9 @@ private:
 	static void printCompare ( const string::CyclicString < > & a, const string::CyclicString < > & b );
 	template < class T >
-	static void setCompare ( const ext::set < T > a, const ext::set < T > b );
+	static void setCompare ( const ext::set < T > & a, const ext::set < T > & b );
 	template < class T >
-	static void vectorCompare ( const ext::vector < T > a, const ext::vector < T > b );
+	static void vectorCompare ( const ext::vector < T > & a, const ext::vector < T > & b );
 public:
 	template < class T >