add comment to VC6 hack

stepmania/src/EnumHelper.h

@@ -94,6 +94,7 @@ static const RString EMPTY_STRING;
 		return (X)(i+1); /*invalid*/	\
 	} \
 	template<> void StringTo<X>( const RString& s, X &out ) { out = StringTo##X( s ); }
+// VC6 hack: even templated functions can't differ by only return value.  Move return value to a reference parameter.
 template<class T> void StringTo( const RString& s, T &out );
 
 #define LuaXToString(X)	\

stepmania/src/ThemeMetric.h

@@ -219,6 +219,7 @@ public:
 	}
 };
 
+// VC 6 hack: even templated functions can't differ by only return value.  Move return value to a reference parameter.
 template<class T> void StringTo( const RString& s, T &out );
 template<class T>
 class ThemeMetricEnum : public ThemeMetric<RString>